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Copyright of Journal of Medical Imaging & Radiation Sciences is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: We aimed to examine whether elective inclusion of the posterolateral supraclavicular node (SCL) region to the standard medial SCL target volume improves SCL control and survival outcomes in patients with high-risk node-positive breast cancer undergoing regional nodal irradiation (RNI).Methods and Materials: We retrospectively reviewed 544 consecutive women with high-risk breast cancer treated with postoperative chest wall/breast and RNI in our center from January 2015 to December 2016. High-risk features were defined as clinical or pathologic stage N2-3b disease. Patients were classified into the medial SCL irradiation (M-SCLI) group and the entire SCL irradiation (E-SCLI) group, which included both the medial and the posterolateral SCL region. SCL recurrence (SCLR), disease-free survival (DFS), and overall survival (OS) were estimated and compared. Propensity-score matching (PSM) and multivariate cox regression were used for analysis.Results: The median follow-up time was 64.2 months. Before PSM, there was no significant difference in the cumulative incidence of SCLR between the 2 groups, with 5-year rates of 2.0% in the M-SCLI group and 0.6% in the E-SCLI group (P = .1). After PSM, there was also no significant difference in the cumulative incidence of SCLR (2.1% vs 0.5%; P = .2). Only 2 patients had recurrence in the posterolateral SCL region, with 1 patient in each group. Similarly, there was no significant difference in DFS and OS between the M-SCLI and E-SCLI group both before PSM (5-year rates of 78.5% vs 78.8%, P = .8; 92.2% vs 90.0%, P = .2) and after PSM (76.7% vs 77.2%, P = .8; 91.5% vs 88.4%, P = .1). Multivariate analysis demonstrated that E-SCLI was not independently prognostic for DFS and OS.Conclusions: E-SCLI does not appear to be associated with improved SCL control and survival outcomes in high-risk node-positive breast cancer. These data do not support the routine use of E-SCLI in N2-3b disease. We initiated a multicenter randomized controlled phase 3 study comparing M-SCLI and E-SCLI to further validate these results. [ABSTRACT FROM AUTHOR]

We present the update of the recommendations of the French society of radiotherapy and oncology on the indications and the technical methods of carrying out radiotherapy of sinonasal cancers. Sinonasal cancers (nasal fossae and sinus) account for 3 to 5% of all cancers of the head and neck. They include carcinomas, mucosal melanomas, sarcomas and lymphomas. The management of sinonasal cancers is multidisciplinary but less standardized than that of squamous cell carcinomas of the upper aerodigestive tract. As such, patients with sinonasal tumors can benefit from the expertise of the French expertise network for rare ENT cancers (Refcor). Knowledge of sinonasal tumour characteristics (histology, grade, risk of lymph node involvement, molecular characterization, type of surgery) is critical to the determination of target volumes. An update of multidisciplinary indications and recommendations for radiotherapy in terms of techniques, target volumes and radiotherapy fractionation of the French society of radiotherapy and oncology (SFRO) was reported in this manuscript. [ABSTRACT FROM AUTHOR]

The RadioTransNet programme launched under the auspices of French societies for radiation oncology (SFRO) and medical physics (SFPM) was approved by the French national cancer institute (INCa) in December 2018 and is dedicated to proposing a relevant national and transversal structure for preclinical research including translational research in radiation oncology with well-defined priority areas of research. Its activities, coordinated by a scientific committee that includes radiation oncologists, medical physicists, academic biologists, are structured around several main areas, i.e.: target volume definition, interaction of radiation with normal tissues, combined treatments and modern dose calculation approaches. Four work packages have been created in these areas and are associated with other objectives pertaining to fundamental radiobiology, early implementation of new drugs in a preclinical setting, contribution of imaging in this task, research in medical physics including transversal components such as medical oncology, radiology, nuclear medicine and also cost/efficiency evaluation. All these tasks will be included in a national network that uses the complementary expertise provided by partners involved in the scheme. Calls for proposals will be selected by the scientific council to be submitted to INCa and the various academic associations to obtain funding for the human and technical resources required to conduct under optimal conditions projects in preclinical and translational research in radiation-oncology. [ABSTRACT FROM AUTHOR]

• The 1- and 5-year local recurrence rates were 13.6% and 44.3, respectively. • The 2-and 5-year overall survival rates were 76.1% and 35.9%, respectively. • A biological equivalent dose of ≥120 Gy led to an improvement in local recurrence. • The presence of lung metastases was associated with improved local recurrence. • A larger total PTV size (≥17.5 cc) was associated with worse OS, PFS, and WSP. In recent years, stereotactic body radiotherapy (SBRT) has emerged as an effective treatment for oligometastatic cancers. Here, we report radiation treatment parameters and clinical outcomes for patients with oligometastatic colorectal cancer (CRC) treated with SBRT using a large multi-institutional database. Patients with extra-cranial oligometastatic CRC (≤5 lesions) treated with SBRT at six large academic cancer centers were included. The primary outcome was local recurrence while secondary outcomes included overall survival (OS) progression free survival, oligo-progression, and widespread progression. Survival outcomes were estimated using the Kaplan-Meier method. Univariable and multivariable analyses were performed to determine the relationship between patient and treatment characteristics and clinical outcomes. We identified 235 patients with a total of 381 oligometastatic CRC lesions. The 1- and 5-year local recurrence rate was 13.6% and 44.3% respectively. The median OS was 49 months with a 2-and 5-year OS of 76.1% and 35.9%, respectively. On multivariable analysis, a BED 10 of ≥120 Gy, and lung versus liver metastases were associated with a reduction in local recurrence. Larger total PTV size (≥17.5 cc) was associated with worse overall survival, progression free survival, and widespread progression. This large multi-institutional analysis found that the use of SBRT for oligometastatic colorectal cancer resulted in favorable overall survival. However, local recurrence is higher than expected for ablative radiation treatment. An increase in BED 10 should be considered if feasible and safe. [ABSTRACT FROM AUTHOR]

Les progrès de la chirurgie reconstructrice des cancers des voies aérodigestives supérieures de la chirurgie mini-invasive par voie endoscopique endonasale, pour les tumeurs nasosinusiennes, sont peu évalués du point de vue de leur impact sur la pratique de radiothérapie. Ces progrès ont permis de réduire la morbidité chirurgicale. Il n'existe pas de recommandation de délinéation des volumes cibles en situation de lambeau ni de prise en compte des marges en situation de chirurgie endonasale. En l'absence de recommandation, les pratiques sont hétérogènes. Des efforts sont nécessaires pour augmenter l'index thérapeutique de la radiothérapie postopératoire dans ces situations. Nous avons analysé la rare littérature existante aux regards des pratiques actuelles et ébauché des bases préliminaires à une recommandation. Le renforcement de la multidisciplinarité sur des aspects de définitions précises des volumes cibles est nécessaire entre radiologues, chirurgiens et oncologues radiothérapeutes dans ces situations complexes et relativement nouvelles, et des « réunions de concertation de délinéation » pourraient probablement y contribuer. Advances in the reconstructive surgery and minimally invasive endonasal endoscopic surgery of head and neck is poorly evaluated in terms of their impact on radiotherapy planning and outcomes. These surgical advances have resulted in reduced morbidity with equivalent or better tumor control. In the absence of a recommendation on how to delineate target volumes in patients with flaps or to consider margins after endoscopic endonasal surgery, radiotherapy practices are inevitably heterogeneous. Efforts are needed to increase the therapeutic index of postoperative radiotherapy in these situations. We analysed the rare existing literature and outlined a preliminary basis for a recommendation. Strengthening of multidisciplinarity to accurately define target volumes in these complex and relatively new situations, and "delineation concertation meetings" between radiologists, surgeons and radiation oncologists could probably contribute to improved outcomes. [ABSTRACT FROM AUTHOR]

Despite representing a 1% of diagnosed cancer cases in the USA and up to 5% in eastern Asia and Africa, oesophageal cancer still holds numerous questions concerning the best therapeutic management. For squamous cell carcinoma, while radiochemotherapy has proven itself to be the gold standard as part of the trimodality or alone as a definitive treatment, radiotherapy modalities are still debated especially regarding lymph node irradiation. Involved nodes irradiation was developed with the aim of maintaining clinical outcomes and enhancing quality of life but lacks grade 1 evidence. In this article, we aim to summarize the state of art regarding lymph node irradiation, discuss the impact of target definition, delivery techniques, concomitant treatment and the perspectives. Being highly connected to the lymph vessels, lymphatic metastases are frequent and can locate from the neck to the coeliac area with each node having a different prognostic significance. Regarding the comparison between elective nodal irradiation and involved nodes irradiation, evidence-based medicine mostly relies on retrospective studies. Pooled, it suggests similar clinical outcomes with lower acute toxicities in favour of involved nodes irradiation. However, delivery techniques, doses and concomitant treatment were not consensual. Studies are ongoing evaluating the impact of radiation delivery techniques and the choice of concomitant treatment, i.e. immunotherapy. Modern techniques of imaging, radiation therapy progressing each day and alternative treatment modalities being tested, the need of randomized controlled trials has never been so high. Elective nodal irradiation should remain the standard of care while phase 3 trials explore the safety of involved nodal irradiation. [ABSTRACT FROM AUTHOR]

• Difference in elective nodal neck delineation. • Difference in elective nodal neck level selection. • Half of participants think an update or clarification of elective nodal delineation guidelines is needed. • Heterogeneous primary tumour clinical target volume delineation. In the last decade precision of radiotherapy treatment execution increased, demanding more accurate delineations to fully exploit these developments. The aim of this study was to identify the extent of interobserver variability in delineation of head and neck cancer (HNC). In February 2017 all Belgian radiotherapy departments were invited to complete an online survey and submit clinical target volumes for five HNC reference cases. Clinical target volume of the primary tumour (CTVp) and elective nodal neck (CTVe) were submitted and compared between centres for CTVp and to the CTVe 'gold standard' (CTVeGS). Volume, DICE similarity coefficient (DSC) and median Hausdorff Distance (HD) were measured and calculated. Fourteen of 22 centres (64%) completed both survey and delineations. They all used delineation guidelines for CTVe and twelve confirmed the use of guidelines of Grégoire et al. Nine centres used CTVp guidelines, although none used the same ones. Median DSC for CTVe comparing centres with CTVeGS ranged between 0.67 and 0.82 and HD50 between 1.7 mm and 2.8 mm. Good agreement was shown for neck level II, III and IV, whilst worst consensus was observed for level Ib, V, VI, VIIa and VIIb. Improvement of DSC and HD50 was observed when the same levels as CTVeGS were selected. Median DSC and HD50 for CTVp ranged between 0.51 and 0.79 and 2.8 mm and 4.1 mm respectively, which both slightly improved when calculating it for only the centres using a 10 mm margin. Although nearly all participants used identical guidelines for CTVe there were large discrepancies in neck levels selected and volumes delineated. CTVp delineations were also heterogeneous although we expect improvement with implementation of recently published guidelines. Additional teaching in target volume delineation is necessary as this paper demonstrates that availability and implementation of guidelines alone is not enough to guarantee uniform delineation. [ABSTRACT FROM AUTHOR]

Functional and molecular imaging, including positron emission tomography with computed tomography imaging (PET/CT) is increasing for radiotherapy (RT) definition of the target volume. This expert review summarizes existing data of functional imaging modalities and RT management, in terms of target volume delineation, for the following anatomical districts: brain (for primary and secondary tumors), head/neck and lung. A collection of available published data was made, by PubMed a search. Only original articles were carefully and critically revised. For primary and secondary brain tumors, amino acid PET radiotracers could be useful to identify microscopic residual areas and to differ between recurrence and treatment-related alterations in case of re-irradiation. As for head and neck neoplasms may benefit from precise PET/CT-based target delineation, due to the major capability to identify high-risk RT areas. In primary and secondary lung cancer, PET/CT could be useful both to delimit a tumor and collapsed lungs and as a predictive parameter of treatment response. Taken together, molecular and functional imaging approaches offer a major step to individualize radiotherapeutic care going forward. Nevertheless, several uncertainties remain on the standard method to properly assess the target volume definition including PET information for primary and secondary brain tumors. [ABSTRACT FROM AUTHOR]

• FDG-PET has an important and promising role for the definition of RT target volume, including Stereotactic body RT for pancreatic cancer. • Choline PET/CT could be useful for identifying high-risk RT volumes, including nodes, for prostate cancer; while PSMA PET/CT is still under evaluation for the RT target definition. • FDG-PET has an important and promising role for the definition of RT target volume, including Stereotactic body RT for pancreatic cancer. • FDG PET-CT is the most sensitive imaging modality for detecting nodes metastases in gynecological cancer and has been shown to impact external-beam radiotherapy planning by modifying the treatment field. • FDG-PET/CT can be used to evaluate features at presentation, therapy response and it could be useful for assessing the oncological outcomes of anal and rectal cancer Positron Emission Tomography with Computed Tomography (PET/CT) has been proven to be useful in the definition of Radiotherapy (RT) target volume. In this regard, the present expert review summarizes existing data for pancreas, prostate, gynecological and rectum/anal cancer. A comprehensive search of published original article was made, based on SCOPUS and PubMed database, selecting the paper that evaluated the role of PET/CT in the definition of RT volume. FDG-PET has an important and promising role for pancreatic cancer. Choline PET/CT could be useful for identifying high-risk volumes for prostate cancer; while PSMA PET/CT is still under evaluation. FDG PET/CT in gynecological cancers has been shown to impact external-beam RT planning. The role of FDG-PET for Gross Tumor volume identification is crucial, representing a useful and powerful tool for anal and rectal cancer. Taken together, molecular and functional imaging approaches offer a major step to individualize radiotherapeutic approach. [ABSTRACT FROM AUTHOR]

Advances in diagnostic imaging create opportunities for improved therapeutic targeting of cancer but conceptual thinking about radiotherapy target volume definition and dose-prescription is not keeping up. In this opinion paper we discuss how modern imaging can contribute to new concepts for radiotherapy dose-prescription and target volume definition illustrated by the example of head and neck cancer. These new insights have the potential to significantly reduce radiation associated toxicity and may have important impact on the combination of radiotherapy with systemic cancer therapies. [ABSTRACT FROM AUTHOR]

• The present ESTRO-EANO guideline reports the novel standard for target delineation of glioblastoma and refines the ESTRO-ACROP/EORTC standard. • GTV is defined on MRI as T1 contrast-enhancing tumour (for biopsy only patients) and/or resection cavity plus residual contrast-enhancing tumour, if present. • A 15 mm margin around the GTV should be applied to generate the CTV, edited to take account of anatomical barriers to tumour spread. • Inclusion of oedema within CTV is not advised, whereas T2/FLAIR signal abnormalities may represent non-enhancing tumour and should be considered for inclusion within the CTV. Target delineation in glioblastoma is still a matter of extensive research and debate. This guideline aims to update the existing joint European consensus on delineation of the clinical target volume (CTV) in adult glioblastoma patients. The ESTRO Guidelines Committee identified 14 European experts in close interaction with the ESTRO clinical committee and EANO who discussed and analysed the body of evidence concerning contemporary glioblastoma target delineation, then took part in a two-step modified Delphi process to address open questions. Several key issues were identified and are discussed including i) pre-treatment steps and immobilisation, ii) target delineation and the use of standard and novel imaging techniques, and iii) technical aspects of treatment including planning techniques and fractionation. Based on the EORTC recommendation focusing on the resection cavity and residual enhancing regions on T1-sequences with the addition of a reduced 15 mm margin, special situations are presented with corresponding potential adaptations depending on the specific clinical situation. The EORTC consensus recommends a single clinical target volume definition based on postoperative contrast-enhanced T1 abnormalities, using isotropic margins without the need to cone down. A PTV margin based on the individual mask system and IGRT procedures available is advised; this should usually be no greater than 3 mm when using IGRT. [ABSTRACT FROM AUTHOR]

Technological advances in radiation therapy permit steep dose gradients from the target to spare normal tissue, but increase the risk of geographic miss. Suboptimal target delineation adversely affects clinical outcomes. Prospective peer review is a method for quality assurance of oncologists' radiotherapy plans. Published surveys suggest it is widely implemented. However, it may not be feasible to review every case before commencement of radiation therapy in all departments. The rate of plan changes following peer review of cases without a specific subsite or modality is typically around 10%. Stereotactic body radiation therapy, head and neck, gynaecological, gastrointestinal, haematological and lung cases are associated with higher rates of change of around 25%. These cases could thus be prioritised for peer review. Other factors may limit peer review efficacy including organisational culture, time constraints and the physical environment in which sessions are held. Recommendations for peer review endorsed by the American Society for Radiation Oncology were made available in 2013, but a number of relevant studies have been published since. Here we review and update the literature, and provide an updated suggestion for the implementation of peer review to serve as an adjunct to published guidelines. This may help practitioners evaluate their current processes and maximise the utility and effectiveness of peer review sessions. [ABSTRACT FROM AUTHOR]

Aims The increasing use of highly conformal radiation techniques to treat meningioma confers a greater need for accurate targeting. Several groups have shown that positron emission tomography/computed tomography (PET/CT) information alters meningioma targets contoured by single observers, but whether this translates into improved accuracy has not been defined. As magnetic resonance imaging (MRI) is the cornerstone of meningioma target contouring, simultaneous PET/MRI may be superior to PET/CT. We assessed whether 68 Ga DOTATATE PET imaging (from PET/CT and PET/MRI) reduced interobserver variability (IOV) in meningioma target volume contouring. Materials and methods Ten patients with meningioma underwent simultaneous 68 Ga DOTATATE PET/MRI followed by PET/CT. They were selected as it was anticipated that target volume definition in their cases would be particularly challenging. Three radiation oncologists contoured target volumes according to an agreed protocol: gross tumour volume (GTV) and clinical target volume (CTV) on CT/MRI alone, CT/MRI+PET(CT) and CT/MRI+PET(MRI). GTV/CTV Kouwenhoven conformity levels (KCL), regions of contour variation and qualitative differences between PET(CT) and PET(MRI) were evaluated. Results There was substantial IOV in contouring. GTV mean KCL: CT/MRI 0.34, CT/MRI+PET(CT) 0.38, CT/MRI+PET(MRI) 0.39 ( P = 0.06). CTV mean KCL: CT/MRI 0.31, CT/MRI+PET(CT) 0.35, CT/MRI+PET(MRI) 0.35 ( P = 0.04 for all groups; P > 0.05 for individual pairs). One observer consistently contoured largest and one smallest. Observers rarely decreased volumes in relation to PET. Most IOV occurred in bone followed by dural tail, postoperative bed and venous sinuses. Tumour edges were qualitatively clearer on PET(MRI) versus PET(CT), but this did not affect contouring. Conclusion IOV in contouring challenging meningioma cases was large and only slightly improved with the addition of 68 Ga DOTATATE PET. Simultaneous PET/MRI for meningioma contouring is feasible, but did not improve IOV versus PET/CT. Whether volumes can be safely reduced according to PET requires evaluation. [ABSTRACT FROM AUTHOR]

• First recurrence analysis taking the actual distance of recurrences into account. • Most of the recurrences appeared within the GTV or very close to its boundary. • Relatively larger irradiated volumes didn't show any benefit in survival. • Smaller GTV had a higher rate of distant recurrences. Radiation therapy for glioblastoma (GBM) typically involves large target volumes. The aim of this study was to examine the recurrence pattern of GBM following modern radiochemotherapy according to EORTC guidelines and provide dose and distance information for the choice of optimal target volume margins. In this study, the recurrences of 97 GBM patients, treated with radiochemotherapy from 2013 to 2017 at the Medical Center- University of Freiburg, Germany were analysed. Dose and distance based metrices were used to derive recurrence patterns. The majority of recurrences (75%) occurred locally within the primary tumor area. Smaller GTVs had a higher rate of distant recurrences. Larger treated volumes did not show a clinical benefit regarding progression free and overall survival. The identified recurrence pattern suggests that adjustments or reductions in target volume margins are feasible and could result in similar survival rates, potentially combined with a lower risk of side effects. [ABSTRACT FROM AUTHOR]

Background and purpose Volume delineation is a well-recognised potential source of error in radiotherapy. Whilst it is important to quantify the degree of interobserver variability (IOV) in volume delineation, the resulting impact on dosimetry and clinical outcomes is a more relevant endpoint. We performed a literature review of studies evaluating IOV in target volume and organ-at-risk (OAR) delineation in order to analyse these with respect to the metrics used, reporting of dosimetric consequences, and use of statistical tests. Methods and materials Medline and Pubmed databases were queried for relevant articles using keywords. We included studies published in English between 2000 and 2014 with more than two observers. Results 119 studies were identified covering all major tumour sites. CTV ( n = 47) and GTV ( n = 38) were most commonly contoured. Median number of participants and data sets were 7 (3–50) and 9 (1–132) respectively. There was considerable heterogeneity in the use of metrics and methods of analysis. Statistical analysis of results was reported in 68% ( n = 81) and dosimetric consequences in 21% ( n = 25) of studies. Conclusion There is a lack of consistency in conducting and reporting analyses from IOV studies. We suggest a framework to use for future studies evaluating IOV. [ABSTRACT FROM AUTHOR]

Résumé Les cancers bronchiques non à petites cellules de stade IIIA-N2 exposent à un risque de récidive locale de 20 à 40 %, même après chirurgie et chimiothérapie adjuvante. La radiothérapie postopératoire médiastinale a démontré son intérêt en termes de contrôle local, mais jusqu’alors sans bénéfice prouvé de survie. Considérée depuis plusieurs années comme une option comme traitement adjuvant des cancers de stade pN2, elle reste néanmoins jugée trop toxique. Qu’en est-il actuellement de sa place ? L’essai contrôlé randomisé de phase III Lung Adjuvant Radiotherapy Trial (Lung ART) doit permettre d’apporter une réponse objective. Cependant, cette étude rencontre des difficultés d’inclusion. Nous abordons dans cet article pourquoi la radiothérapie postopératoire n’est pas encore admise, quels sont ses résultats en termes d’efficacité et de tolérance, quels sont les volumes à traiter et les doses à délivrer. The rate of local failure of stage IIIA-N2 non-small cell lung cancer is 20 to 40%, even if they are managed with surgery and adjuvant chemotherapy. Postoperative radiotherapy improves local control, but its benefit on global survival remains to be demonstrated. Considered for many years as an adjuvant treatment option for pN2 cancers, it continues nevertheless to be deemed too toxic. What is the current status of postoperative radiotherapy? The Lung Adjuvant Radiotherapy Trial (Lung ART) phase III trial should give us a definitive, objective response on global survival, but inclusion of patients is difficult. The results are consequently delayed. The aim of this review is to show all the results about efficacy and tolerance of postoperative radiotherapy and to define the target volume and dose to prescribe. [ABSTRACT FROM AUTHOR]

Background and purpose Target delineation in glioblastoma (GBM) varies substantially between different institutions and several consensus statements are available. This guideline aims to develop a joint European consensus on the delineation of the clinical target volume in patients with a glioblastoma (GBM). Material and methods A literature search was conducted in PubMed that evaluated adults with GBM. Both MeSH terms and text words were used and the following search strategy was applied: (“Glioblastoma/radiotherapy” [MeSH] OR “glioblastoma” OR “malignant glioma” OR high-grade glioma) AND ((delineation) OR (target volume) OR (CTV) OR (PTV) OR (margin) OR (recurrence pattern) OR (contouring) OR (organs at risk)). In parallel, abstracts from ESTRO and ASTRO 2010–2015 were analysed and separately reviewed. The ACROP committee identified 14 European experts in close interaction with the ESTRO clinical committee who discussed and analysed the body of evidence concerning GBM target delineation. Results Several key issues were identified and are discussed including (i) pre-treatment steps and immobilization, (ii) target delineation and the use of standard and novel imaging techniques, and (iii) technical aspects of treatment including planning techniques, and fractionation. Based on the EORTC recommendation focusing on the resection cavity and residual enhancing regions on T1-sequences with the addition of a 20 mm margin, special situations are presented with corresponding potential adaptations depending on the specific clinical situation. Conclusions Currently, based on the EORTC consensus, a single clinical target volume definition based on postoperative T1/T2 FLAIR abnormalities is recommended, using isotropic margins without the need to cone down. A PTV margin based on the individual mask system and IGRT procedures available is advised, usually of the order of 3–5 mm. [ABSTRACT FROM AUTHOR]

Rotational setup errors are usually neglected in most clinical centers. An analytical formula is developed to determine the extra margin between clinical target volume (CTV) and planning target volume (PTV) to account for setup errors. The proposed formula corrects for both translational and rotational setup errors and then incorporated into margin determination for PTV. [ABSTRACT FROM AUTHOR]

Résumé: Les sarcomes des tissus mous sont des tumeurs assez rares (1 % des tumeurs de l’adulte), de localisation ubiquitaire et de grande diversité morphologique (plus de 50 types et sous-types), dont le diagnostic et la prise en charge thérapeutique initiale qui en dépendent sont très importants pour le devenir des patients. Ainsi, la prise en charge doit être pluridisciplinaire au sein d’une équipe expérimentée. Les sarcomes des membres représentent plus de la moitié de l’ensemble des sarcomes. Le standard thérapeutique consiste en une chirurgie élargie conservatrice planifiée selon les résultats de la biopsie, souvent associée à une radiothérapie postopératoire mais qui peut aussi être préopératoire. Les indications de la radiothérapie préopératoire sont discutées en réunion de concertation pluridisciplinaire pour des tumeurs localement évoluées. La définition des volumes cibles en vue d’une radiothérapie conformationnelle nécessite la connaissance du dossier du patient (imagerie, aspects de la cicatrice et du lit opératoire, maladies associées éventuelles), mais également une lecture attentive des compte-rendus chirurgicaux et histologiques. Les définitions des volumes cibles allient une approche anatomique et géométrique. Le volume tumoral macroscopique correspond à la masse tumorale visible sur l’IRM préopératoire. Le volume cible anatomoclinique correspondant est défini par une extension automatique longitudinale plus importante que l’extension radiaire. Il est corrigé manuellement en tenant compte des barrières anatomiques à l’extension tumorale. Le volume cible prévisionnel correspond à une marge automatique concentrique pouvant varier d’une institution à une autre, selon les moyens de contention et les modes de vérification du repositionnement. Les techniques innovantes de radiothérapie permettent de diminuer en partie la taille des marges des volumes cibles et de mieux protéger les organes à risque. [ABSTRACT FROM AUTHOR]

Abstract: Background and purpose: A previous prospective trial reported that three-dimensional conformal postoperative radiotherapy (PORT) for pN2 NSCLC patients using a limited clinical target volume (CTV) had a late morbidity rate and pulmonary function that did not differ from those observed in pN1 patients treated with surgery without PORT. The aim of this study was to assess locoregional control and localization of failure in patients treated with PORT. Materials and methods: The pattern of locoregional failure was evaluated retrospectively in 151 of 171 patients included in the PORT arm. The CTV included the involved lymph node stations and those with a risk of invasion >10%. Competing risk analysis was used to assess the incidence of locoregional failure and its location outside the CTV. Results: Overall survival at 5years was 27.1% with a median follow-up of 67months for 40 living patients. The 5-year cumulative incidence of locoregional failure was 19.4% (95% CI: 18.2–20.5%) including a failure rate of 2% (95% CI: 0–17%) in locations outside or at the border of the CTV. Conclusions: The use of limited CTV was associated with acceptable risk of geographic miss. Overall locoregional control was similar to that reported by other studies using PORT for pN2 patients. [Copyright &y& Elsevier]

Abstract: Objective: Overall survival (OS) and pattern of failure in R1-resected non-small cell lung cancer (NSCLC) patients treated with 3D-planned postoperative radiotherapy (PORT) was retrospectively evaluated. The outcomes and patterns of failure in patients with (+) and without (−) extracapsular nodal extension (ECE) were compared and analyzed with respect to the radiation target volume design. Materials and methods: Eighty R1-resected (37 ECE+ and 43 ECE−) patients received PORT (60Gy, 2Gy daily) between 2002 and 2011. Patients with N2 disease received limited elective nodal irradiation (ENI); for pN0-1 disease the use of ENI was optional. Among ECE− (extranodal-R1) patients there were 35 pN0-1 and eight pN2 cases; in pN0-1 patients, patterns of failure and outcomes were analyzed with respect to the use of ENI. Loco-regional failure (LRF) was defined as in-field relapse; isolated nodal failure (INF) was defined as out-of-field regional nodal recurrence occurring without LRF, irrespective of distant metastases. Results: The actuarial 3-year OS rate was 36.3% (median: 30 months). Three-year OS rates in the ECE− and ECE+ group were 40.4% and 31.4%, with median OS of 31 and 24 months, respectively (p =0.43). In multivariate analysis, the presence of ECE was correlated with OS (HR=3.02; 95% CI: 1.00–9.16; p =0.05). Three-year cumulative incidence of LRF (CILRF) was 14.5% and 15.5% in the ECE− and ECE+ groups, respectively (p =0.98). Three-year cumulative incidence of INF (CIINF) was 14.1% in the ECE− group and 11.1% in the ECE+ group (p =0.76). For pN0-1 patients treated with and without ENI (13 and 22 patients) 3-year CILRF rates were 7.7% and 20.8%, respectively (p =0.20); 3-year CIINF rates were 9.1% and 16.3%, respectively (p =0.65). Conclusion: PORT resulted in a relatively good survival of R1-resected NSCLC patients. Relatively high incidence of INF was found in both ECE+ and ECE− patients. For ECE+ patients, treated with limited ENI, distant failure remains a major concern, so the design of ENI fields seems of lesser importance. Omission of ENI in pN0-1 (extranodal-R1) patients resulted in an unacceptably high incidence of INF. We postulate the use of some form of ENI in this setting. [Copyright &y& Elsevier]

Purpose: The use of four-dimensional computed tomography (4D-CT) to determine the tumor internal target volume (ITV) is usually characterized by high patient radiation exposure. The objective of this study was to propose and evaluate an approach that relies on a single static positron emission tomography (PET)/CT scan to determine the ITV, thereby eliminating the need for 4D-CT and thus reduce patient radiation dose. Methods and Materials: The proposed approach is based on the concept that the observed PET image is the result of a joint convolution of an ideal PET image (free from motion and partial volume effect) with a motion-blurring kernel (MBK) and partial volume effect. In this regard, the MBK and tumor ITV are then estimated from the deconvolution of this joint model. To test this technique, phantom and patient studies were performed using different sphere/tumor sizes and motion trajectories. In all studies, a 4D-CT and a PET/CT image of the sphere/tumor were acquired. The ITV from the proposed technique was then compared to the maximum intensity projection (MIP) volume of the 4D-CT images. A Dice coefficient of the two volumes was calculated to represent the similarity between the two ITVs. Results: The average ITVs of the proposed technique were 97.2% ± 0.3% and 81.0% ± 16.7% similar to the MIP volume in the phantom and patient studies, respectively. The average dice coefficients were 0.87 ± 0.05 and 0.73 ± 0.16, respectively, for the two studies. Conclusion: Using the proposed approach, a single static PET/CT scan has the potential to replace a 4D-CT to determine the tumor ITV. This approach has the added advantage of reducing patient radiation exposure and determining the tumor MBK compared to 4D-CT/MIP-CT. [Copyright &y& Elsevier]

Purpose: Historically, the appropriate target volume to be irradiated for spinal metastases is 1–2 vertebral bodies above and below the level of involvement for three reasons: (1) to avoid missing the correct level in the absence of simulation or (2) to account for the possibility of spread of disease to the adjacent level, and (3) to account for beam penumbra. In this study, we hypothesized that isolated failures occurring in the level adjacent to level treated with stereotactic body radiosurgery (SBRS) were infrequent and that with improved localization techniques with image-guided radiation therapy, treatment of only the involved level of spinal metastases may be more appropriate. Methods and Materials: Patients who had received SBRS treatments to only the involved level of the spine as part of a prospective trial for spinal metastases comprised the study population. Follow-up imaging with spine MRI was performed at 3-month intervals following initial treatment. Failures in the adjacent (V±1, V±2) and distant spine were identified and classified accordingly. Results: Fifty-eight patients met inclusion criteria for this study and harbored 65 distinct spinal metastases. At 18-month median follow-up, seven (10.7%) patients failed simultaneously at adjacent levels V±1 and at multiple sites throughout the spine. Only two (3%) patients experienced isolated, solitary adjacent failures at 9 and 11 months, respectively. Conclusion: Isolated local failures of the unirradiated adjacent vertebral bodies may occur in <5% of patients with isolated spinal metastasis. On the basis of the data, the current practice of irradiating one vertebral body above and below seems unnecessary and could be revised to irradiate only the involved level(s) of the spine metastasis. [Copyright &y& Elsevier]

Abstract: This article describes the determination and the delineation of the target volumes for head-and-neck cancers treated with intensity-modulated radiotherapy (IMRT). The delineation of the clinical target volumes (CTV) on the computerized tomography scanner (CT scan) requires a rigorous methodology due to the complexity of head-and-neck anatomy. The clinical examination with a sketch of pretreatment tumour extension, the surgical and pathological reports and the adequate images (CT scan, magnetic resonance imaging and fluorodeoxyglucose positron emission tomography) are necessary for the delineation. The target volumes depend on the overall strategy: sequential IMRT or simultaneous integrated boost-IMRT (SIB-IMRT). The concept of selectivity of the potential subclinical disease near the primary tumor and the selection of neck nodal targets are described according to the recommendations and the litterature. The planing target volume (PTV), mainly reflecting setup errors (random and systematic), results from a uniform 4–5mm expansion around the CTV. We propose the successive delineation of: (1) the gross volume tumour (GTV); (2) the “high risk” CTV1 around the GTV or including the postoperative tumour bed in case of positive margins or nodal extracapsular spread (65–70Gy in 30–35 fractions); (3) the CTV2 “intermediate risk” around the CTV1 for SIB-IMRT (59–63Gy in 30–35 fractions); (4) the “low-risk” CTV3 (54–56Gy in 30–35 fractions); (5) the PTVs. [Copyright &y& Elsevier]

Purpose: To study various standardized uptake value (SUV)-based approaches to ascertain the best strategy for delineating metabolic tumor volumes (MTV). Methods and Materials: Twenty-two consecutive previously treated esophageal cancer patients with positron emission tomography (PET) imaging and computed tomography (CT)-based radiotherapy plans were studied. At the level of the tumor epicenter, MTVs were delineated at 11 different thresholds: SUV ≥2, ≥2.5, ≥3, ≥3.5 (SUVn); ≥40%, ≥45%, and ≥50% of the maximum (SUVn%); and mean liver SUV + 1, 2, 3, and 4 standard deviations (SUVLnσ). The volume ratio and conformality index were determined between MTVs, and the corresponding CT/endoscopic ultrasound-based gross tumor volume (GTV) at the epicenter. Means were analyzed by one-way analysis of variance for repeated measures and further compared using a paired t test for repeated measures. Results: The mean conformality indices ranged from 0.33 to 0.48, being significantly (p < 0.05) closest to 1 at SUV2.5 (0.47 ± 0.03) and SUVL4σ (0.48 ± 0.03). The mean volume ratios ranged from 0.39 to 2.82, being significantly closest to 1 at SUV2.5 (1.18 ± 0.36) and SUVL4σ (1.09 ± 0.15). The mean value of the SUVs calculated using the SUVL4σ approach was 2.4. Conclusions: Regardless of the SUV thresholding method used (i.e., absolute or relative to liver mean), a threshold of approximately 2.5 yields the highest conformality index and best approximates the CT-based GTV at the epicenter. These findings may ultimately aid radiation oncologists in the delineation of the entire GTV in esophageal cancer patients. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: This study investigated two fixed threshold methods to delineate the target volume using 18FDG PET/CT before and during a course of radical radiotherapy in locally advanced squamous cell carcinoma of the head and neck. Materials and methods: Patients were enrolled into the study between March 2006 and May 2008. 18FDG PET/CT scans were carried out 72h prior to the start of radiotherapy and then at 10, 44 and 66Gy. Functional volumes were delineated according to the SUV Cut Off (SUVCO) (2.5, 3.0, 3.5, and 4.0bwg/ml) and percentage of the SUVmax (30%, 35%, 40%, 45%, and 50%) thresholds. The background 18FDG uptake and the SUVmax within the volumes were also assessed. Results: Primary and lymph node volumes for the eight patients significantly reduced with each increase in the delineation threshold (for example 2.5–3.0bwg/ml SUVCO) compared to the baseline threshold at each imaging point. There was a significant reduction in the volume (p ⩽0.0001–0.01) after 36Gy compared to the 0Gy by the SUVCO method. There was a negative correlation between the SUVmax within the primary and lymph node volumes and delivered radiation dose (p ⩽0.0001–0.011) but no difference in the SUV within the background reference region. The volumes delineated by the PTSUVmax method increased with the increase in the delivered radiation dose after 36Gy because the SUVmax within the region of interest used to define the edge of the volume was equal or less than the background 18FDG uptake and the software was unable to effectively differentiate between tumour and background uptake. Conclusions: The changes in the target volumes delineated by the SUVCO method were less susceptible to background 18FDG uptake compared to those delineated by the PTSUVmax and may be more helpful in radiotherapy planning. The best method and threshold have still to be determined within institutions, both nationally and internationally. [Copyright &y& Elsevier]

Abstract: A large number of histological and anatomically distinct malignancies originate from the gastro-intestinal (GI) tract. Radiotherapy (RT) plays an increasing role in the multimodal treatment of most of these malignancies. The proximity of different organs at risk such as the kidneys, the spinal cord and the small bowel and the potential toxicity associated with combined treatment modalities make accurate target volume delineation imperative. The ability of positron emission tomography (PET) imaging to visualize a so-called ‘biological target volume’ (BTV) may be helpful in this respect. Currently the most widely used tracer for diagnosis, staging, restaging and response assessment is [18F]Fluoro-deoxyglucose (FDG). Promising preliminary results in esophageal, pancreatic and anorectal cancers and colorectal liver metastasis suggest that FDG-PET might provide us with additional information useful in target volume delineation. Poor image resolution and a low sensitivity for lymph node detection currently obstructs its widespread implementation. Moreover, validation in large prospective trials and the pathological validation of the correct tumor volume is still lacking. In hepatocellular carcinoma (HCC) and gastric adenocarcinoma there is currently little evidence for the use of FDG-PET in target delineation. However more extensive research is warranted before the true value of FDG-PET in these sites can be assessed. Also other tracers are constantly being developed and investigated. Up to now however none of these tracers has found its way into the daily practice of target volume delineation. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To provide a reference for determination of the postoperative radiotherapy target volume for thoracic esophageal squamous cell carcinoma. Background data: The irradiation target volume is important for effective postoperative treatment of thoracic esophageal squamous cell carcinoma. Methods: One hundred forty patients with recurrent or metastatic thoracic esophageal squamous cell carcinoma who had been treated with radical surgery but not with postoperative radiotherapy were enrolled in this study. The information of locoregional recurrence and distant metastasis for these patients was analyzed. Results: The median time to progression in the 140 patients with recurrence or metastasis was 18.3months (range 15.4–21.1months). Anastomotic recurrence accounted for 13.6% of treatment failures. The supraclavicular and station 1–5 and 7 lymph nodes had high metastasis rates for esophageal squamous cell carcinomas in all locations. The order from highest to lowest metastasis rate for the station 3 and 4 lymph nodes was middle, upper and lower thoracic esophageal regions and the order for upper abdominal lymph nodes was lower, middle, and upper thoracic esophageal regions. Locoregional recurrence was the most common type of recurrence. Conclusions: For upper and middle thoracic esophageal squamous cell carcinomas, the anastomosis, supraclavicular, and station 1–5 and 7 lymph nodes should be delineated as the postoperative prophylactic irradiation target volume with upper abdominal lymph nodes excluded; for lower thoracic esophageal squamous cell carcinomas, anastomosis, supraclavicular, station 1–5 and 7 lymph nodes and upper abdominal lymph nodes should be delineated as the postoperative prophylactic irradiation target volume. [Copyright &y& Elsevier]

Abstract: Purpose: To study the pattern of lymph node metastases after esophagectomy and clarify the clinical target volume (CTV) delineation of thoracic esophageal squamous cell carcinoma (ESCC). Methods and materials: Total 1077 thoracic ESCC patients who had undergone esophagectomy and lymphadenectomy were retrospectively examined. The clinicopathologic factors related to lymph node metastasis were analyzed using logistic regression analysis. Results: The rates of lymph node metastases in patients with upper thoracic tumors were 16.7% (9/54) cervical, 38.9% (18/54) upper mediastinal, 11.1% (6/54) middle mediastinal, 5.6% (3/54) lower mediastinal, and 5.6% (3/54) abdominal, respectively. The rates of lymph node metastases in patients with middle thoracic tumors were 4.0% (27/680), 3.8% (26/680), 32.9% (224/680), 7.1% (48/680), and 17.1% (116/680), respectively. The rates of lymph node metastases in patients with lower thoracic tumors were 1.0% (5/343), 3.0% (10/343), 22.7% (78/343), 37.0% (127/343), and 33.2% (114/343), respectively. T stage, the length of tumor and the histological differentiation emerged as statistically significant risk factors of lymph node metastases of thoracic ESCC (P <0.001). Conclusions: T stage, the length of tumor and the histologic differentiation influence the pattern of lymph node metastases in thoracic ESCC. These factors should be considered comprehensively to design the CTV for radiotherapy (RT) of thoracic ESCC. Selective regional irradiation including the correlated lymphatic drainage regions should be performed as well. [Copyright &y& Elsevier]

Purpose: To evaluate the margins currently used to generate the planning target volume for lung tumors and to determine whether image-guided patient setup or respiratory gating is more effective in reducing uncertainties in tumor position. Methods and Materials: Lung tumors in 7 patients were contoured on serial four-dimensional computed tomography (4DCT) data sets (4–8 4DCTs/patient; 50 total) obtained throughout the course of treatment. Simulations were performed to determine the tumor position when the patient was aligned using skin marks, image-guided setup based on vertebral bodies, fiducials implanted near the tumor, and the actual tumor volume under various scenarios of respiratory gating. Results: Because of the presence of setup uncertainties, the reduction in overall margin needed to completely encompass the tumor was observed to be larger for imaged-guided patient setup than for a simple respiratory-gated treatment. Without respiratory gating and image-guided patient setup, margins ranged from 0.9 cm to 3.1 cm to completely encompass the tumor. These were reduced to 0.7–1.7 cm when image-guided patient setup was simulated and further reduced with respiratory gating. Conclusions: Our results indicate that if respiratory motion management is used, it should be used in conjunction with image-guided patient setup in order to reduce the overall treatment margin effectively. [Copyright &y& Elsevier]

Purpose: To assess day-to-day differences between planned and delivered target volume (TV) and organ-at-risk (OAR) dose distributions in liver stereotactic body radiation therapy (SBRT), and to investigate the dosimetric impact of setup corrections. Methods and Materials: For 14 patients previously treated with SBRT, the planning CT scan and three treatment scans (one for each fraction) were included in this study. For each treatment scan, two dose distributions were calculated: one using the planned setup for the body frame (no correction), and one using the clinically applied (corrected) setup derived from measured tumor displacements. Per scan, the two dose distributions were mutually compared, and the clinically delivered distribution was compared with planning. Doses were recalculated in equivalent 2-Gy fraction doses. Statistical analysis was performed with the linear mixed model. Results: With setup corrections, the mean loss in TV coverage relative to planning was 1.7%, compared with 6.8% without corrections. For calculated equivalent uniform doses, these figures were 2.3% and 15.5%, respectively. As for the TV, mean deviations of delivered OAR doses from planning were small (between −0.4 and +0.3 Gy), but the spread was much larger for the OARs. In contrast to the TV, the mean impact of setup corrections on realized OAR doses was close to zero, with large positive and negative exceptions. Conclusions: Daily correction of the treatment setup is required to obtain adequate TV coverage. Because of day-to-day patient anatomy changes, large deviations in OAR doses from planning did occur. On average, setup corrections had no impact on these doses. Development of new procedures for image guidance and adaptive protocols is warranted. [Copyright &y& Elsevier]

Abstract: The development of three-dimensional conformal radiotherapy (3DCRT) and intensity modulated therapy (IMRT) has enabled high dose radiation to be directed to tumors, this however subject to a perfect demarcation of the tumoral volume and the anatomical structures to be saved. At the same time, imaging modalities have improved their ability to demonstrate the location and the extension of tumors. The precise location of the target volume and the prediction of the dose absorbed by the tumor thus become an essential stage of the planning of the treatment. This planning is mostly determined on CT pictures. The technique usually used is a non enhanced CT allowing a location of the tumor by its mass effect mass or by its spontaneous difference of density from the adjacent structures. However, the clear visualization of the tumoral volume remains sometimes difficult for small-sized tumors or those with limited contrast with regard to surrounding tissues. This lack of contrast represents a source of variability for the demarcation of the target volume which has been highlighted in numerous papers. Tumors must be then localized by correlation with pictures made at the diagnosis time by other imaging modalities, essentially the MRI and the PET. This approach answers the concept of multimodality diagnosis which resumes the principle of complementarity of the various techniques. Every technique indeed brings, according to its physical principle, one or several specific information. It is advisable from then to clarify the contribution of every used imaging modality, this according to the pathologies and their localizations. [Copyright &y& Elsevier]

Abstract: Purpose: The Gastro-Intestinal Working Party of the EORTC Radiation Oncology Group (GIWP-ROG) developed guidelines for target volume definition in neoadjuvant radiation of adenocarcinomas of the gastroesophageal junction (GEJ) and the stomach. Methods and materials: Guidelines about the definition of the clinical target volume (CTV) are based on a systematic literature review of the location and frequency of local recurrences and lymph node involvement in adenocarcinomas of the GEJ and the stomach. Therefore, MEDLINE was searched up to August 2008. Guidelines concerning prescription, planning and treatment delivery are based on a consensus between the members of the GIWP-ROG. Results: In order to support a curative resection of GEJ and gastric cancer, an individualized preoperative treatment volume based on tumour location has to include the primary tumour and the draining regional lymph nodes area. Therefore we recommend to use the 2nd English Edition of the Japanese Classification of Gastric Carcinoma of the Japanese Gastric Cancer Association which developed the concept of assigning tumours of the GEJ and the stomach to anatomically defined sub-sites corresponding respectively to a distinct lymphatic spread pattern. Conclusion: The GIWP-ROG defined guidelines for preoperative irradiation of adenocarcinomas of the GEJ and the stomach to reduce variability in the framework of future clinical trials. [Copyright &y& Elsevier]

Purpose: Radiation therapy to the pelvic lymph nodes in high-risk prostate cancer is required on several Radiation Therapy Oncology Group (RTOG) clinical trials. Based on a prior lymph node contouring project, we have shown significant disagreement in the definition of pelvic lymph node volumes among genitourinary radiation oncology specialists involved in developing and executing current RTOG trials. Materials and Methods: A consensus meeting was held on October 3, 2007, to reach agreement on pelvic lymph node volumes. Data were presented to address the lymph node drainage of the prostate. Extensive discussion ensued to develop clinical target volume (CTV) pelvic lymph node consensus. Results: Consensus was obtained resulting in computed tomography image-based pelvic lymph node CTVs. Based on this consensus, the pelvic lymph node volumes to be irradiated include: distal common iliac, presacral lymph nodes (S1-S3), external iliac lymph nodes, internal iliac lymph nodes, and obturator lymph nodes. Lymph node CTVs include the vessels (artery and vein) and a 7-mm radial margin being careful to “carve out” bowel, bladder, bone, and muscle. Volumes begin at the L5/S1 interspace and end at the superior aspect of the pubic bone. Consensus on dose–volume histogram constraints for OARs was also attained. Conclusions: Consensus on pelvic lymph node CTVs for radiation therapy to address high-risk prostate cancer was attained and is available as web-based computed tomography images as well as a descriptive format through the RTOG. This will allow for uniformity in evaluating the benefit and risk of such treatment. [Copyright &y& Elsevier]

Purpose: We conducted a comparative study of clinical target volume (CTV) definition of pelvic lymph nodes by multiple genitourinary (GU) radiation oncologists looking at the levels of discrepancies amongst this group. Methods and Materials: Pelvic computed tomography (CT) scans from 2 men were distributed to 14 Radiation Therapy Oncology Group GU radiation oncologists with instructions to define CTVs for the iliac and presacral lymph nodes. The CT data with contours were then returned for analysis. In addition, a questionnaire was completed that described the physicians'' method for target volume definition. Results: Significant variation in the definition of the iliac and presacral CTVs was seen among the physicians. The minimum, maximum, mean (SD) iliac volumes (mL) were 81.8, 876.6, 337.6 ± 203 for case 1 and 60.3, 627.7, 251.8 ± 159.3 for case 2. The volume of 100% agreement was 30.6 and 17.4 for case 1 and 2 and the volume of the union of all contours was 1,012.0 and 807.4 for case 1 and 2, respectively. The overall agreement was judged to be moderate in both cases (kappa = 0.53 (p < 0.0001) and kappa = 0.48 (p < 0.0001). There was no volume of 100% agreement for either of the two presacral volumes. These variations were confirmed in the responses to the associated questionnaire. Conclusions: Significant disagreement exists in the definition of the CTV for pelvic nodal radiation therapy among GU radiation oncology specialists. A consensus needs to be developed so as to accurately assess the merit and safety of such treatment. [Copyright &y& Elsevier]

Abstract: Purpose: Differences in the delineation of the gross target volume (GTV) and planning target volume (PTV) in patients with non-small-cell lung cancer are considerable. The focus of this work is on the analysis of observer-related reasons while controlling for other variables. Methods: In three consecutive patients, eighteen physicians from fourteen different departments delineated the GTV and PTV in CT-slices using a detailed instruction for target delineation. Differences in the volumes, the delineated anatomic lymph node compartments and differences in every delineated pixel of the contoured volumes in the CT-slices (pixel-by-pixel-analysis) were evaluated for different groups: ten radiation oncologists from ten departments (ROs), four haematologic oncologists and chest physicians from four departments (HOs) and five radiation oncologists from one department (RO1D). Results: Agreement (overlap⩾70% of the contoured pixels) for the GTV and PTV delineation was found in 16.3% and 23.7% (ROs), 30.4% and 38.6% (HOs) and 32.8% and 35.9% (RO1D), respectively. Conclusion: A large interobserver variability in the PTV and much more in the GTV delineation were observed in spite of a detailed instruction for delineation. The variability was smallest for group ROID where due to repeated discussions and uniform teaching a better agreement was achieved. [Copyright &y& Elsevier]

Purpose: The role of three-dimensional breast ultrasound (3D US) in planning partial breast radiotherapy (PBRT) is unknown. This study evaluated the accuracy of coregistration of 3D US to planning computerized tomography (CT) images, the seroma contouring consistency of radiation oncologists using the two imaging modalities and the clinical situations in which US was associated with improved contouring consistency compared to CT. Materials and Methods: Twenty consecutive women with early-stage breast cancer were enrolled prospectively after breast-conserving surgery. Subjects underwent 3D US at CT simulation for adjuvant RT. Three radiation oncologists independently contoured the seroma on separate CT and 3D US image sets. Seroma clarity, seroma volumes, and interobserver contouring consistency were compared between the imaging modalities. Associations between clinical characteristics and seroma clarity were examined using Pearson correlation statistics. Results: 3D US and CT coregistration was accurate to within 2 mm or less in 19/20 (95%) cases. CT seroma clarity was reduced with dense breast parenchyma (p = 0.035), small seroma volume (p < 0.001), and small volume of excised breast tissue (p = 0.01). US seroma clarity was not affected by these factors (p = NS). US was associated with improved interobserver consistency compared with CT in 8/20 (40%) cases. Of these 8 cases, 7 had low CT seroma clarity scores and 4 had heterogeneously to extremely dense breast parenchyma. Conclusion: 3D US can be a useful adjunct to CT in planning PBRT. Radiation oncologists were able to use US images to contour the seroma target, with improved interobserver consistency compared with CT in cases with dense breast parenchyma and poor CT seroma clarity. [Copyright &y& Elsevier]

Purpose: To evaluate the effect of the time from surgery and other clinical factors on seroma volume and clarity and establish the optimal time to use the computed tomography (CT)-based seroma to plan partial breast irradiation (PBI). Methods and Materials: A total of 205 women with early-stage breast cancer underwent planning CT after breast-conserving surgery. One radiation oncologist contoured the seroma volume and scored the seroma clarity, using a standardized Seroma Clarity Score scale, from 0 (not detectable) to 5 (clearest). Univariate and multivariate analyses were performed to evaluate the associations between the seroma characteristics and the interval from surgery and other clinical factors. Results: The mean interval from surgery to CT was 84 days (standard deviation 59). During postoperative Weeks 3–8, the mean seroma volume decreased from 47 to 30 cm3, stabilized during Weeks 9–14 (mean 21) and was involuted beyond 14 weeks (mean 9 cm3). The mean seroma clarity score was 3.4 at Weeks 3–8, 2.5 at Weeks 9–14, and 1.6 after 14 weeks. The seroma clarity was greater in patients aged ≥70 years. The seroma volume and clarity correlated significantly with the volume of excised breast tissue but not with the maximal tumor diameter, surgical re-excision, or chemotherapy use. Conclusion: The optimal time to obtain the planning CT scan for PBI is within 8 weeks after surgery. During Weeks 9–14, the seroma might remain adequately defined in some patients; however, after 14 weeks, alternate strategies are needed to identify the PBI target. The lack of correlation between the seroma volume and tumor size suggests that the CT-based seroma should not be the sole guide for PBI target volume definition. [Copyright &y& Elsevier]

Abstract: Introduction: Post-operative residual disease in differentiated thyroid cancer is an indication for external beam radiotherapy (EBRT) especially if there is poor radioiodine uptake by the residual disease. There are no standardized guidelines or consensus in target delineation for radiotherapy in thyroid cancer. Aims: To determine the pattern of recurrence in patients with well differentiated thyroid cancer who received adjuvant or definitive radiotherapy as well as radioiodine ablation following surgery or biopsy with a view to better defining future target volume delineation for radiotherapy. Materials and methods: Forty-nine patients with differentiated thyroid cancer received radical external beam radiotherapy and radioiodine ablation (3.5GBq) following thyroidectomy or biopsy between 1990 and 2000. Nineteen patients had macroscopic residual (11) or inoperable disease (8), whilst 30 patients had clear (5) or microscopic positive resection margin (24), and 1 patient the resection margin status was unknown. All the patients were deemed high risk for local recurrence or progressive disease. The thyroid bed and regional nodes were irradiated using two radiotherapy techniques: (1) non co-planar lateral fields (NCLF) in coronal plane using 6MV photons to a dose of 45–50Gy in 16 fractions over 22 days and (2) anterior–posterior parallel pair of 6MV photons to a dose of 40–42.5Gy in 16 fractions over 22 days. There was no attempt to irradiate the lymph nodes in that part of the anterior and posterior mediastinum extending from the brachiocephalic veins to the carina. Results: The median follow-up was 5.4 years (range 0.9–12.4 years). The actuarial 5-year cause-specific survival and local control for the whole group was 75.7% and 81.4%, respectively. Of the 4 patients with mediastinal recurrence, all had neck recurrences and two had distant metastases. All the medisastinal recurrences occurred in superior mediastinum (level VII) and all were treated with NCLF in coronal plane radiotherapy technique. Furthermore, mediastinal recurrences did not occur in isolation. The 5-years loco-regional control rate was 89.1% for those with clear or microscopic positive margins and 69.2% for those with macroscopic residual or inoperable disease. Five-year cause specific survival was 58.3% for patients with macroscopic residual or inoperable disease and 91.4% for those with clear or microscopic positive margins. Conclusion: The status of postoperative margin relating to bulk of disease influences local control and cause specific survival. Surgical resection in locally advanced thyroid cancer should be performed by an experienced surgeon to achieve macroscopic clearance where possible. The majority of recurrences were loco-regional. The few superior mediastinal recurrences did not occur in isolation. All the mediastinal recurrences occurred in the superior mediastinum (level VII). We recommend the target volume should encompass the thyroid bed and regional neck nodes and the superior mediastinum level VII excluding the lymph nodes on both sides of the trachea within the anterior and posterior mediastinum extending from the brachiocephalic veins to the carina (compartment 4). Thus, this should facilitate dose escalation to improve loco-regional control and avoiding radiation induced mediastinal toxicity. [Copyright &y& Elsevier]

Abstract: Three-dimensional radiotherapy planning techniques, including conformal radiotherapy and intensity-modulated radiotherapy, have potential for improving outcomes in cervical cancer. Accurate target volume definition is essential in order to maximise normal tissue sparing while minimising the risk of a geographical miss. This reduction in toxicity provides the option of dose escalation, particularly with simultaneous integrated boost intensity-modulated radiotherapy. The evidence for the current use and potential applications of these techniques in the treatment of cervical cancer are discussed. [Copyright &y& Elsevier]

Purpose: To assess the variation in carbon beam dose distribution due to residual motion in lung cancer patients undergoing respiratory-gated radiotherapy. Methods and Materials: A total of 11 lung cancer patients underwent four-dimensional computed tomography with a 256-multislice computed tomography scanner under free-breathing conditions. A compensating bolus was designed to cover the treatment beam for all planning target volumes during a 30% duty cycle centered on exhalation (gating window). This bolus was applied to the four-dimensional computed tomography data for one respiratory cycle, and then the carbon beam dose distribution was calculated. Results: A water equivalent pathlength variation of <5 mm was observed in the gating window, but this increased to ≤20 mm on inhalation. As a result, beam overshoot/undershoot occurred around inhalation, which increased the excessive dosing to normal tissues and the organs at risk. The dose for >95% volume irradiation is dependent on the respiratory phase but not the gating window. However, the dose for >95% volume irradiation correlated well with the tumor displacement distance. More than 90% of the dose for >95% volume irradiation could be delivered in the gating window with <4-mm tumor displacement resulting from exhalation. Conclusion: The results of our study have shown that even when the treatment beam delivery occurs outside the gating window, the prescribed dose to the target is not affected in patients with a tumor displacement of <4 mm. Thus, respiratory gating is not required in radiotherapy for patients with <4-mm tumor displacement in a respiratory cycle. [Copyright &y& Elsevier]

Purpose: Regional nodal metastasis after neoadjuvant chemoradiation of adenocarcinoma of the esophagogastric junction (AEG) predicts survival. We aimed to clarify the lymph node (LN) distribution of AEG according to location of the tumor mass and invasion of neighboring areas for the selection of radiotherapy planning target volume (PTV) margins. Methods and Materials: Patterns of regional spread were analyzed in pathology reports of 326 patients patients with AEG who had undergone primary resection, with ≥15 lymph nodes examined. Tumors were classified into AEG types based on endoscopy and pathology reports. Fisher''s exact test was used to compare nodal disease and tumor characteristics. Pulmonary dose–volume histograms were tested in 8 patients. Results: Nodes were positive in 81% of T2 to T4 tumors. Type of AEG, tumor size, lymphovascular invasion, and grading significantly influenced nodal distribution. We found that marked esophageal invasion of AEG II/III significantly correlated with paraesophageal nodal disease, and T3 to T4 AEG II/III had a significant rate of splenic hilum/artery nodes. Middle and lower paraesophageal nodes should be treated in T2 to T4 AEG I and AEG II with ≥15 mm involvement above the Z-line, and T3 to T4 AEG II. The splenic hilum and artery nodes can be spared in T2 AEG tumors, especially Type I tumors. The influence of paraesophageal nodal treatment on the risk of postoperative pulmonary complications can be estimated from dose–volume histograms. Conclusions: Accurate pretherapeutic staging predicts the risk of subclinical nodal disease and should be used to select the appropriate radiotherapeutic PTV. Careful selection of the PTV can be used to maximize the therapeutic window in multimodal therapy for AEG. [Copyright &y& Elsevier]

Purpose: To examine variability in target volume delineation for partial breast radiotherapy planning and evaluate characteristics associated with low interobserver concordance. Methods and Materials: Thirty patients who underwent planning CT for adjuvant breast radiotherapy formed the study cohort. Using a standardized scale to score seroma clarity and consensus contouring guidelines, three radiation oncologists independently graded seroma clarity and delineated seroma volumes for each case. Seroma geometric center coordinates, maximum diameters in three axes, and volumes were recorded. Conformity index (CI), the ratio of overlapping volume and encompassing delineated volume, was calculated for each case. Cases with CI ≤0.50 were analyzed to identify features associated with low concordance. Results: The median time from surgery to CT was 42.5 days. For geometric center coordinates, variations from the mean were 0.5–1.1 mm and standard deviations (SDs) were 0.5–1.8 mm. For maximum seroma dimensions, variations from the mean and SDs were predominantly <5 mm, with the largest SDs observed in the medial–lateral axis. The mean CI was 0.61 (range, 0.27–0.84). Five cases had CI ≤0.50. Conformity index was significantly associated with seroma clarity (p < 0.001) and seroma volume (p < 0.002). Features associated with reduced concordance included tissue stranding from the surgical cavity, proximity to muscle, dense breast parenchyma, and benign calcifications that may be mistaken for surgical clips. Conclusion: Variability in seroma contouring occurred in three dimensions, with the largest variations in the medial–lateral axis. Awareness of clinical features associated with reduced concordance may be applied toward training staff and refining contouring guidelines for partial breast radiotherapy trials. [Copyright &y& Elsevier]

Abstract: External beam radiotherapy to the prostate and seminal vesicles as a radical treatment for prostate cancer can result in a significant dose being delivered to the rectum. This can be reduced if the target volume includes the prostate only. Using a Medline search, published studies are reviewed to show that the risk of seminal vesicle involvement can be accurately predicted using readily available pre-treatment parameters. We recommend when to exclude the seminal vesicles from a target volume, and the proportion of seminal vesicles that should be included in a target volume in higher risk patients. [Copyright &y& Elsevier]

Summary: The concept of internal target volume is of marked importance for radiotherapy to lung tumors as respiration-induced motion is important. Individualized assessment of motion is required as tumor site may not predict the extent or pattern of tumor motion. We performed volumetric cine scanning using the 256-multi-slice CT (256MSCT) to study tumor motion during free breathing in 14 inpatients who were treated with carbon-ion radiotherapy. Motion assessment in 16 respiratory phases of the cine CT revealed most tumors to show hysteresis-like behavior. Isocenter displacement between peak exhalation and inhalation for the average of the right and left lungs were 7mm, 7mm and 15mm for the upper, middle and lower lobes, respectively. Cine CT with the 256MSCT improved the evaluation of tumor displacement and overcomes some of the limitations associated with current CT methods. Volumetric cine CT data provides useful data on motion for planning in all radiation approaches for lung tumors. [Copyright &y& Elsevier]

Purpose: To compare the planning target volume (PTV) definitions for computed tomography (CT) vs. positron emission tomography (PET) in non-small-cell lung cancer (NSCLC). Methods and Materials: A total of 21 patients with NSCLC underwent three-dimensional conformal radiotherapy planning. All underwent a staging F-18 fluorodeoxyglucose-position emission tomography (18FDG-PET) scan and underwent treatment simulation using CT plus a separate planning 18FDG-PET scan. Three sets of target volumes were defined: Set 1, CT volumes (CT tumor + staging PET nodal disease); Set 2, PET volumes (planning PET tumor {gross tumor volume (GTV) = [(0.3069 x mean standardized uptake value) + 0.5853])}; Set 3, composite CT-PET volumes (fused CT-PET tumor). Sets 1 and 2 were compared using a matching index. Three-dimensional conformal radiotherapy plans were created using the Set 1 (CT) volumes; and coverage of the Set 3 (composite) volumes was evaluated. Separate three-dimensional conformal radiotherapy plans were designed for the Set 3 volumes. Results: For the primary tumor GTV, the Set 1 (CT) volume was larger than the Set 2 (PET) volume in 48%, smaller in 33%, and equal in 19%. The mean matching index was 0.65 (35% CT-PET mismatch). Although quantitatively similar, the volumes differed qualitatively. The Set 3 (composite) volume was larger than either CT or PET alone in 62%, smaller in 24%, and equal in 14%. The dose-volume histogram parameters did not differ among the plans for Set 1 (CT) vs. Set 3 (composite) volumes. Small portions of the Set 3 PTV were significantly underdosed in 40% of cases using the CT-only plan. Conclusion: Computed tomography and PET are complementary and should be obtained in the treatment position and fused to define the GTV for NSCLC. Although the quantitative absolute target volume is sometimes similar, the qualitative target locations can be substantially different, leading to underdosage of the target when planning is done using CT alone without PET fusion. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to review retrospectively the results of low-dose radiotherapy for Stage I seminoma using four different fractionation schedules and target volume definitions. Methods and Materials: A total of 191 patients underwent irradiation for histologically proven Stage I seminoma after undergoing an inguinal orchiectomy. Fractionation schedules were used one after another as follows: Total dose 30 Gy (dose/fraction 1.5 Gy, 16 patients), total dose 25.5 Gy (dose/fraction 1.5 Gy, 62 patients), total dose 20 Gy (dose/fraction 2 Gy, 69 patients), total dose 26 Gy (dose/fraction 2 Gy, 29 patients). The remaining 12 patients were excluded from this study. In the same period the target volume was gradually reduced. In 1983 the paraaortic, pelvic and inguinal regions were irradiated; later the target volume was reduced to the paraaortic region exclusively. Results: Overall survival and event-free survival were identical in all groups ranging from 95% to 100% /5 years. Three patients experienced a lymph node metastasis during follow-up, 3 patients a distant metastasis to the lung and the bones. Mild acute side effects were noted in 8% to 15% of the patients, and very mild long-term side effects in 1% to 5% of patients. Multivariate analysis showed no prognostic significance of total dose, dose per fraction, or target volume. In univariate analysis, a higher frequency of acute side effects to the skin and the bowel was related to a higher total dose, and an elevated frequency of nausea was related to a higher daily dose per fraction. Conclusion: Using lower doses and limiting the target volume to the paraaortic region exclusively did not result in a worse prognosis in our patient series. [Copyright &y& Elsevier]

The use of positron-emission tomography (PET) in the treatment planning process has become more and more popular over the years, although important questions such as how, when, and for which clinical benefit have never been answered. In this framework, the objective of this article is to review the evidence supporting the use of PET in radiotherapy treatment planning, with special emphasis on its application for head and neck tumors. The use of positron-labeled fluorodeoxyglucose for target volume selection should be discussed in terms of sensitivity and specificity in comparison with typical anatomic imaging modalities. It will not be of similar utility across all tumor sites. The use of PET for target volume delineation requires specific tuning of parameters such as image acquisition, processing, and segmentation, and this may vary from one tumor site to another. Molecular imaging with other tracers and “theragnostic” are in the pipeline, but how much the patient will gain from it and how these advances should be implemented in routine clinical practice are unresolved questions. Therefore, although integration of PET images into the radiotherapy process seems promising, for the moment it should remain in the research arena. [Copyright &y& Elsevier]