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To evaluate the educational impact on radiation oncology residents in training when introducing an automatic segmentation software in head and neck cancer patients regarding organs at risk (OARs) and prophylactic cervical lymph node level (LNL) volumes. Two cases treated by exclusive intensity-modulated radiotherapy were delineated by an expert radiation oncologist and were considered as reference. Then, these cases were delineated by residents divided into two groups: group 1 (control group), experienced residents delineating manually, group 2 (experimental group), young residents on their first rotation trained with automatic delineation, delineating manually first (M -) and then after using the automatic system (M +). The delineation accuracy was assessed using the Overlap Volume (OV). Regarding the OARs, mean OV was 0.62 (SD = 0.05) for group 1, 0.56 (SD = 0.04) for group 2 M - , and 0.61 (SD = 0.03) for group 2 M + . Mean OV was higher in group 1 compared to group 2 M - (p = 0.01). There was no OV difference between group 1 and group 2 M + (p = 0.67). Mean OV was higher in the group 2 M + compared to group 2 M - (p 0.003). Regarding LNL, mean OV was 0.53 (SD = 0.06) in group 1, 0.54 (SD = 0.03) in group 2 M - , and 0.58 (SD = 0.04) in group 2 M + . Mean OV was higher in group 2 M + for 11 of the 12 analysed structures compared to group 2 M - (p = 0.016). Prior use of the automatic delineation software reduced the average contouring time per case by 34 to 40%. Prior use of atlas-based automatic segmentation reduces the delineation duration, and provides reliable OARs and LNL delineations.

We present the update of the recommendations of the French society of oncological radiotherapy on radiotherapy of pancreatic tumors. Currently, the use of radiation therapy for patients with pancreatic cancer is subject to discussion. In the adjuvant setting, the standard treatment is six months of chemotherapy with 5-fluorouracile, irinotecan and oxaliplatin. Chemoradiation may improve the survival of patients with incompletely resected tumours (R1). This remains to be confirmed by a prospective trial. Neoadjuvant chemoradiation is a promising treatment especially for patients with borderline resectable tumours. For patients with locally advanced tumours, there is no standard. An induction chemotherapy followed by chemoradiation for non progressive patients reduces the rate of local relapse. Whereas in the first trials of chemoradiation large fields were used, the treated volumes have been reduced to improve tolerance. Tumour movements induced by breathing should be taken in account. Intensity modulated radiation therapy allows a reduction of doses to the organs at risk. Whereas widely used, this technique has poor evidence-based recommendation. Stereotactic body radiation therapy is also being studied, as a neoadjuvant or exclusive treatment.

Purpose The aim of this study is to correlate locoregional relapse with radiation therapy volumes in patients with rectal cancer treated with neoadjuvant chemoradiation in the ACCORD 12/0405-PRODIGE 02 trial. Patients and methods We identified patients who had a locoregional relapse included in ACCORD 12's database. We studied their clinical, radiological, and dosimetric data to analyze the dose received by the area of relapse. Results 39 patients (6.5%) presented 54 locoregional relapses. Most of the relapses were in-field (n = 21, 39%) or marginal (n = 13, 24%) with only six out-of-field (11%), 14 could not be evaluated. Most of them happened in the anastomosis, the perirectal space, and the usual lymphatic drainage areas (presacral and posterior lateral lymph nodes). Only patients treated for a lower rectum adenocarcinoma had a relapse outside of the treated volume. 2 patients with T4 tumors extending into anterior pelvic organs had relapses in anterior lateral and external iliac lymph nodes. Conclusions Lowering the upper limit of the treatment field for low rectal tumors increased the risk of out of the field recurrence. For very low tumors, including the inguinal lymph nodes in the treated volume should be considered. Recording locoregional involvement, treated volumes, and relapse areas in future prospective trials would be of paramount interest to refine delineation guidelines.

Introduction: Adjuvant whole-pelvic radiation therapy (WPRT) improves locoregional control for high-intermediate stages I–III endometrial cancer patients. Intensity modulated radiation therapy (IMRT) tends to replace the standard 3D conformal radiation therapy (3DCRT) technique used in trials. Material and methods: Consecutive patients with stages I–IIIc endometrial cancer treated between 2008 and 2014 in our department with post-operative 3DCRT or IMRT WPRT were studied retrospectively. Patients with cervical involvement underwent additional low-dose rate vaginal brachytherapy. The impact of the WPRT technique on local control, tolerance, disease-free survival (DFS) and overall survival (OS) was assessed. Clinicians evaluated routinely acute radiation toxicity each week during radiation therapy and late toxicity during standard follow-up consultations. Results: Median follow-up was 50 months (range: 6–158). Among the 83 patients included, 47 were treated with 3DCRT and 36 with IMRT. There was no difference in patient characteristics between groups. The 5-year locoregional control and DFS rates were 94.5% and 68%, respectively. No significant difference was found between the 3DCRT and IMRT groups in terms of survival, with 5-year OS rates of 74.6% and 78%, respectively. In multivariate analysis, age over 68, stage > T1 and grade 3 were independently associated with shorter DFS and OS. Seven patients (8.4%) had grades 3–4 acute gastrointestinal (GI) toxicity with five patients (10.6%) and two (5.4%) in the 3DCRT and IMRT groups, respectively (p = .69). One case (1.2%) of late grade 3 GI toxicity was observed treated in 3DCRT. Conclusions: IMRT seems to be a safe technique for the treatment of endometrial cancer with a trend towards decreased acute GI toxicities. Results of the phase 3 RTOG 1203 trial are needed to confirm these results.

International audience; Introduction: Adjuvant whole-pelvic radiation therapy (WPRT) improves locoregional control for high-intermediate stages I-III endometrial cancer patients. Intensity modulated radiation therapy (IMRT) tends to replace the standard 3D conformal radiation therapy (3DCRT) technique used in trials.Material and methods: Consecutive patients with stages I-IIIc endometrial cancer treated between 2008 and 2014 in our department with post-operative 3DCRT or IMRT WPRT were studied retrospectively. Patients with cervical involvement underwent additional low-dose rate vaginal brachytherapy. The impact of the WPRT technique on local control, tolerance, disease-free survival (DFS) and overall survival (OS) was assessed. Clinicians evaluated routinely acute radiation toxicity each week during radiation therapy and late toxicity during standard follow-up consultations.Results: Median follow-up was 50 months (range: 6-158). Among the 83 patients included, 47 were treated with 3DCRT and 36 with IMRT. There was no difference in patient characteristics between groups. The 5-year locoregional control and DFS rates were 94.5% and 68%, respectively. No significant difference was found between the 3DCRT and IMRT groups in terms of survival, with 5-year OS rates of 74.6% and 78%, respectively. In multivariate analysis, age over 68, stage > T1 and grade 3 were independently associated with shorter DFS and OS. Seven patients (8.4%) had grades 3-4 acute gastrointestinal (GI) toxicity with five patients (10.6%) and two (5.4%) in the 3DCRT and IMRT groups, respectively (p = .69). One case (1.2%) of late grade 3 GI toxicity was observed treated in 3DCRT.Conclusions: IMRT seems to be a safe technique for the treatment of endometrial cancer with a trend towards decreased acute GI toxicities. Results of the phase 3 RTOG 1203 trial are needed to confirm these results.

Currently, the use of radiation therapy for patients with pancreatic cancer is subject to discussion. In adjuvant setting, the standard treatment is 6 months of chemotherapy with gemcitabine and capecitabine. Chemoradiation (CRT) may improve the survival of patients with incompletely resected tumors (R1). This should be confirmed by a prospective trial. Neoadjuvant CRT is a promising treatment especially for patients with borderline resectable tumors. For patients with locally advanced tumors, there is no a standard. An induction chemotherapy followed by CRT for non-progressive patients reduces the rate of local relapse. Whereas in the first trials of CRT large fields were used, the treated volumes have been reduced to improve tolerance. Tumor movements induced by breathing should be taken in account. Intensity modulated radiation therapy allows a reduction of doses to the organs at risk. Whereas widely used, this technique is not recommended.

Introduction et but de l’etude L’essai Accord 12/0405-Prodige 02 a compare les protocoles CAP45 (capecitabine 45 Gy) et Capox50 (capecitabine-oxaliplatine 50 Gy) dans la prise en charge neoadjuvante des adenocarcinomes rectaux localement evolues. Cette etude s’est interessee aux rechutes locoregionales et a leur rapport avec la dose delivree. Materiel et methodes Grâce a Unicancer nous avons identifie les patients inclus dans l’essai Accord 12 ayant eu une rechute locoregionale. Nous avons ensuite etudie leurs donnees cliniques, radiologiques et de planification de traitement pour creer des donnees digital imaging and communications in medicine (Dicom) et evaluer la dose recue au niveau du site de rechute. Les rechutes ont ete classees en trois categories : – dans le volume traite (couvertes a 95 % par l’isodose 95 %), – marginales (couvertes entre 20 et 95 % par l’isodose 95 %), – hors du volume traite (couvertes a moins de 20 % par l’isodose 95 %). Resultats et analyse statistique Les sites de rechutes selon les caracteristiques tumorales sont presentes dans le Tableau 1 La majorite des rechutes etait dans le volume traite ou marginales (anastomose, espace perirectal et aires de drainage habituelles (presacrees et lateropelviennes posterieures). Seuls les patients recevant un traitement pour une tumeur du bas rectum ont ete atteints de rechutes hors du volume traite (notamment en inguinal). Des tumeurs de stade T4 envahissant les organes pelviens anterieurs ont rechute dans les aires ganglionnaires (obturatrices et iliaques externes). Conclusion Cette etude remet en question le fait d’abaisser la limite superieure du volume irradie en S2-S3, notamment pour les tumeurs du bas rectum. Elle fait se poser la question d’irradier pour les tumeurs du bas rectum les aires inguinales. Des donnees prospectives de qualite issues des prochains essais permettront de confirmer ces donnees.

Introduction et but de l’etude Il s’agissait d’evaluer l’impact educatif sur les internes en formation en oncologie radiotherapie de l’introduction d’un logiciel de delineation automatique. La precision, la coherence et la vitesse de delineation concernant les organes a risque et les aires ganglionnaires cervicales des patients atteints de cancers de la tete et du cou ont ete evaluees. Materiel et methodes Deux dossiers de cancers de la tete et du cou traites par irradiation exclusive avec modulation d’intensite ont ete delinees par un oncologue radiotherapeute expert et ont ete consideres comme reference. Ensuite, ces deux cas ont ete delinees par des internes divises en trois groupes : le groupe 1 (groupe temoin) compose d’internes experimentes qui n’avaient jamais ete exposes a un systeme de delineation automatique delineant manuellement, le groupe 2 (groupe experimental) compose de jeunes internes lors de leur premier semestre formes avec un systeme de delineation automatique au cours de leur periode d’apprentissage delineant d’abord manuellement (M-) puis avec le systeme automatique (M +). La precision de la delineation a ete evaluee a l’aide de l’indice overlap volume (OV) pour les organes a risque et les aires ganglionnaires cervicales. Le temps necessaire pour completer la delineation des deux cas a ete mesure. Resultats et analyse statistique En ce qui concerne les organes a risque, l’OV moyen etait de 0,62 (ecart type [ET] = 0,05) pour le groupe 1, 0,56 (ET = 0,04) pour le groupe 2 M-, et de 0,61 (ET = 0,03) pour le groupe 2 M+. L’OV moyen etait plus eleve dans le groupe 1 que dans le groupe 2 M- (p = 0,01). Il n’y avait pas de difference d’OV entre le groupe 1 et le groupe 2 M+ (p = 0,67). L’OV moyen etait plus eleve dans le groupe 2 M + que dans le groupe 2 M- apres analyse appariee (p Conclusion Dans cette etude de delineation du cancer de la tete et du cou, l’utilisation anterieure d’un outil de segmentation automatique basee sur atlas par les internes a reduit la duree de delineation et a ameliore la fiabilite des delineations des organes a risque et des aires ganglionnaires cervicales.

Introduction The aim of this study was to compare dosimetric gain using dynamic conformal arc (DCA) with flattened filter (FF) and flattening filter free (FFF) beam for lung stereotactic body radiation therapy (SBRT). Methods and materials In our institution, SBRT lung cancer patients were treated with prescribed dose 60 Gy in 4 or 8 fractions. In Pinnacle 9.10 were planned two partial DCA’s for peripheral tumors and three to four partial DCA’s for central region tumors to help pull dose of the OARs (heart, esophagus, spinal cord and ribs). Treatments were delivered with 6 MV beams and dose rate 600 MU, for TrueBeam STx accelerator. Fifty patients who underwent lung SBRT treatment with DCA with FF were retrospectively analyzed using 6 MV FFF beams with dose rate of 1400 MU. We were observing the planning target volume (PTV) coverage, sparing of organ at risks (OARs) and time of treatment delivery. Results The PTV coverage (D98% > 95%) were similar, 98.3% vs 98% for FF and FFF, with 1887 MU’s vs 1860 MU’s, respectively. Dosimetric gain between FF and FFF for max dose to the heart was 1 Gy vs 0.87 Gy (p 0.0001). Max dose for spinal cord was 8.84 Gy vs 8.38 Gy (p 0.0001). Max dose for esophagus was 9.76 Gy vs 8.94 Gy (p 0.0001). Max dose for ribs was 34.16 Gy vs 31.89 Gy (p 0.0001). Time of treatment delivery was 4.50 min vs 2.43 min (p = 0.0006), for FF and FFF, respectively. Conclusion Treatment delivery with FFF DCA allows better sparing of OARs for SBRT of lung cancer patients. Shorter treatment time with FFF DCA for SBRT of lung cancer patients can reduce potentially discomfort or patient motion.

Currently, the use of radiation therapy for patients with pancreatic cancer is subject to discussion. In adjuvant setting, the standard treatment is 6 months of chemotherapy with gemcitabine and capecitabine. Chemoradiation (CRT) may improve the survival of patients with incompletely resected tumors (R1). This should be confirmed by a prospective trial. Neoadjuvant CRT is a promising treatment especially for patients with borderline resectable tumors. For patients with locally advanced tumors, there is no a standard. An induction chemotherapy followed by CRT for non-progressive patients reduces the rate of local relapse. Whereas in the first trials of CRT large fields were used, the treated volumes have been reduced to improve tolerance. Tumor movements induced by breathing should be taken in account. Intensity modulated radiation therapy allows a reduction of doses to the organs at risk. Whereas widely used, this technique is not recommended.

Objectif de l’etude L’objectif de cette etude etait de comparer le gain dosimetrique sur les organes a risque chez les patients atteints d’un cancer pulmonaire traite en conditions stereotaxiques en utilisant l’arc conformationnel dynamique (DCA) avec des faisceaux filtres (FF) et sans filtre (FFF). Materiel et methode Les cancers pulmonaires de petite taille (moins de 5 cm) sont traites par la technique stereotaxique dans notre institution. Une dose de 60 Gy est administree au volume cible previsionnel en quatre a huit fractions, selon la proximite des organes a risque (cœur, gros vaisseaux, moelle epiniere, œsophage, cotes). Les traitements sont prepares avec le systeme de planification Pinnacle 9.10 selon la technique DCA (deux a quatre arcs partiels). L’irradiation est effectuee sur l’accelerateur TrueBeam STx™, (6 MV, indice de qualite [IQ] = 0,669, 600 UM/min [unites moniteur]). Nous avons analyse retrospectivement les dossiers de 75 patients traites par irradiation stereotaxique avec l’arc conformationnel dynamique filtre, en utilisant des faisceaux de 6 MV sans filtre, IQ = 0,630, 1400 UM/min. La couverture mediane du volume cible previsionnel et la reduction mediane de dose maximale dans les organes a risque, ont ete analysees selon la localisation centrale (a une distance d’au plus 2 cm du mediastin) ou peripherique (a plus de 2 cm du mediastin) des lesions. Resultats La couverture du volume cible previsionnel (dose dans 98 % du volume [D98 %] > 95 %) etait respectivement de 98,90 % contre 98,40 % pour les faisceaux filtres et sans filtre. Le gain entre les faisceaux filtres et sans filtre sur la dose maximale pour le cœur etait de 18,90 Gy contre 17,71 Gy (localisation centrale) et de 0,96 Gy contre 0,83 Gy (localisation peripherique). La dose maximale dans la moelle etait de 10,70 Gy contre 10,20 Gy (localisation centrale) et de 5,22 Gy contre 4,64 Gy (LP). La dose maximale a l’œsophage etait de 13,19 Gy contre 12,81 Gy (localisation centrale) et 7,70 Gy contre 7,02 Gy (localisation peripherique). La dose maximale costale a une distance d’au plus 1 cm de la tumeur etait de 66,85 Gy contre 62,49 Gy et plus de 1 cm, de 33,95 Gy contre 30,12 Gy, pour les faisceaux respectivement filtres et sans filtre. Conclusion En traitant avec des faisceaux sans filtre, la couverture du volume cible previsionnel reste identique (indice de conformite median de 1,46), tandis que la dose maximale administree aux organes a risque diminue selon la localisation lesionnelle. Les faisceaux sans filtre permettent une reduction de la dose dans les organes a risque de 3 a 14 %, selon les organes. Ces resultats suggerent que l’emploi de la technique sans filtre pourrait apporter un benefice dosimetrique independamment de la localisation tumorale.

Resume Objectif de l’etude Rechercher dans la litterature des arguments permettant de guider dans le choix entre radiochirurgie et radiotherapie stereotaxique hypofractionnee dans le traitement des metastases cerebrales. Patients et methodes Quatre cent quarante-huit patients ont ete traites dans huit series par irradiation stereotaxique hypofractionnee avec une contention non invasive, une marge de securite de 2 a 10 mm (mediane 3 mm) a une dose de 24 a 40 Gy delivree en trois a cinq seances sur cinq a huit jours dans six series et 15–16 jours dans deux autres series, completant une irradiation encephalique totale de modalites variables dans 30 % des cas. Deux mille cent cinquante-sept patients ont ete traites dans 12 series recentes par radiochirurgie avec une contention invasive, sans marge perilesionnelle, a une dose de 10 a 25 Gy en une seule seance, completant une irradiation encephalique totale, le plus souvent de 30 Gy en dix fractions et 12 jours, dans des 58 % des cas. Les comparaisons ont porte sur les volumes tumoraux macroscopiques medians, la duree mediane de survie, les taux de survie a un an, de controle local et de toxicite. Resultats Pour les series de radiotherapie stereotaxique hypofractionnee, le volume tumoral macroscopique median etait de 0,52–4,47 cm 3 (mediane : 2,8 cm 3 ), la duree mediane de survie de cinq a 16 mois (mediane : 8,7 mois), le taux de survie a un an de 68,2 a 93 % (mediane : 82,5 %) et le taux de necrose de 3,1 %. Pour les series de radiochirurgie, le volume tumoral macroscopique median etait de 1,3 a 5,5 cm 3 (mediane : 2 cm 3 ), la duree mediane de survie de 5,5–22 mois (mediane : 11 mois), le taux de survie a un an de 71 a 95 % (mediane : 85 %) et la taux de necrose de 0,5 a 6 % (mediane : 2,4 %). La toxicite de la radiochirurgie est documentee dans les metastases volumineuses mais elle n’est pas connue pour la radiotherapie stereotaxique hypofractionnee. La marge de tissus sains incluse dans le volume cible previsionnel majore les risques de toxicite. L’association variable a une radiotherapie stereotaxique fractionnee rend l’interpretation des resultats difficile. Il s’agit d’une premiere etude exploratoire dont la methodologie est discutable. Conclusion Les volumes tumoraux macroscopiques ≤ 500 mm 3 (diametre de moins de 10 mm) necessitent une contention invasive et donc la radiochirurgie. Pour ceux de plus de 4200 mm 3 (diametre de 20 mm), la radiotherapie stereotaxique hypofractionnee parait preferable. La radiochirurgie ou la radiotherapie stereotaxique hypofractionnee sont utilisables pour les metastases cerebrales dont le volume tumoral macroscopique est compris entre 500 et 4200 mm 3 . Le fractionnement et l’etalement optimaux restent cependant a determiner.

Resume Objectif de l’etude Le travail presente est base sur l’etude de l’imageur portal aS500-II (Varian) et le systeme d’acquisition IAS3. Nous avons etudie les performances, la stabilite et la reproductibilite de cet imageur dans les mesures des facteurs de transmission et des profils des champs avec filtres dynamiques. Materiels et methodes Les proprietes dosimetriques de ce detecteur ont ete evaluees en utilisant le mode d’acquisition integre non synchronise dans les traitements avec filtres dynamiques pour des faisceaux de photons de six et 15 MV. La stabilite, la reproductibilite dans les mesures de profils et des facteurs de transmissions ont ete evaluees en analysant la dependance de la reponse de l’imageur portal en fonction de la direction du filtre, les dimensions du champ et la distance source – imageur portal. Les profils obtenus ont ete compares a ceux acquis avec la barrette de diodes « Profiler Sun Nuclear » et la chambre d’ionisation. Nous avons developpe des fonctions analytiques qui corrigent le profil des images portales et qui permettent le controle des profils des faisceaux filtres avec ce type de detecteur. Resultats La non uniformite des rayonnements retrodiffuses dus au bras de l’imageur portal a ete evaluee : les profils obtenus des champs avec filtres dynamiques dependaient de la direction du filtre et de la distance source – imageur portal. La transmission des differents filtres dynamiques a ete determinee a l’aide de ce detecteur, la difference entre les mesures acquises avec l’imageur portal et par chambre d’ionisation etait inferieure a 1 %. Deux fonctions analytiques ont ete developpees, ces fonctions sont valables pour toute energie et pour tout angle de filtre et dependent de la direction du filtre (inplane, crossplane). Conclusion De part sa reproductibilite, l’imageur portal peut assurer le controle de qualite regulier des faisceaux filtres et faciliter les controles qui sont effectues avec beaucoup moins de temps que par des methodes classiques.

Introduction This paper evaluates the role of an acquisition parameter, the frame cycle time “FCT”, in the performance of an aS500-II EPID. Materials and methods The work presented rests on the study of the Varian EPID aS500-II and the image acquisition system 3 (IAS3). We are interested in integrated acquisition using asynchronous mode. For better understanding the image acquisition operation, we investigated the influence of the “frame cycle time” on the speed of acquisition, the pixel value of the averaged gray-scale frame and the noise, using 6 and 15 MV X-ray beams and dose rates of 1–6 Gy/min on 2100 C/D Linacs. Results In the integrated mode not synchronized to beam pulses, only one parameter the frame cycle time “FCT” influences the pixel value. The pixel value of the averaged gray-scale frame is proportional to this parameter. When the FCT V f/s > 18 frames/s), the speed of acquisition becomes unstable and leads to a fluctuation of the portal dose response. A timing instability and saturation are detected when the dose per frame exceeds 1.53 MU/frame. Rules were deduced to avoid saturation and to optimize this dosimetric mode. Conclusion The choice of the acquisition parameter is essential for the accurate portal dose imaging.

Resume Objectif de l’etude Lors des traitements des cancers du sein par irradiation externe, les balistiques habituellement utilisees correspondent a deux faisceaux tangentiels filtres de maniere a obtenir la distribution de dose la plus homogene possible. En fonction des dimensions et forme du volume mammaire, cette technique entraine generalement des heterogeneites de dose superieures a 20 % aux recommandations de l’International Commission on Radiation Unit and Measurements (ICRU) (95–107 %). Nous nous proposons d’etudier la realisation de planifications de traitement de cancer du sein en compensant les epaisseurs des tissus traverses pour reduire les heterogeneites observees dans les distributions de dose. Materiel et methodes Nous avons decompose les faisceaux tangentiels initiaux utilises classiquement pour ce type de localisation en plusieurs segments dont la forme a ete adaptee a la repartition des niveaux de gris dans l’image numeriques reconstruite (DRR) editee pour les traitements conventionnels. Nous avons ainsi compense dosimetriquement les gradients d’epaisseurs rencontres en delivrant la dose appropriee a chaque groupe d’epaisseur. Resultats L’analyse des dosimetries realisees a partir de cette methode montre une amelioration de l’homogeneite des distributions de dose dans les trois dimensions ainsi qu’une diminution des doses maximales d’entre 5 et 10 % au-dela des recommandations de l’ICRU. Conclusion Cette methode nous permet de traiter, avec un accelerateur lineaire monoenergetique, des seins presentant de par leur forme d’importants gradients d’epaisseur. Toutefois, pour les seins volumineux, cette methode ne permet pas de diminuer les surdosages a l’entree dus aux epaisseurs importantes des volumes a traiter.

Purpose: Retrospective comparison of Linac radiosurgery (RS) in 93 single brain metastases with or without a 2-mm margin. Patients and Methods: A total of 153 patients had Linac RS (between April 1992 and June 2004), with 139 patients (90.8%) evaluable in June 2005. Sixty-one patients (44%) had extracranial lesions and 65 patients had neurologic symptoms (47%). RS alone: 105 patients (66%); RS +whole brain radiotherapy: 34 patients (24%). Single metastasis: 93/139 patients; classic RS: 42/93 patients; 2-mm margin: 51/93 patients; 30 multiple lesions patients were excluded. Treatment: 15 Mv X-ray Linac, circular minibeams, 8-30 mm, four to six noncoplanar coronal arcs. Isodose was 60-80%; doses were 10-20 Gy. Follow-up: 12 months-13 years; median, 14 months. Results: Local control (LC) was not improved in 51 margin patients vs. 42 classic RS patients: 1 year: 69.1% and 72.4%. Two-year LC rate: 64% and 54.7%, respectively. Survival: median classic RS: 11.3 months; margin RS, 19 months (p = 0.34) and 1 year, 41.6% and 60.2%, respectively. Margin RS patients had a significantly higher rate of severe parenchymal complications: 19.6% vs. 7.1% (p = 0.02); surgery was necessary in 4 of 51 cases vs. 1 of 42 classic RS cases. Conclusion: No increase ofmore » 1- and 2-year LC rate in margin RS or survival and median survival: 11.3 vs. 19 months (NS) 2-mm margin associated with more severe parenchymal complications (p = 0.02).This procedure is therefore not recommended. Late CT images and 1-mm margin as recommended by pathologists, use of three-dimensional magnetic resonance imaging and fuzzy method to calculate volumes may yield better results. Stereotactic hypofractionation requires further studies.« less

Objectif de l’etude Evaluer l’interet et la faisabilite d’une radiotherapie conformationnelle avec modulation d’intensite (RCMI) avec boost integre dans la prise en charge des carcinomes epidermoides du canal anal. Patients et methode Etude retrospective monocentrique incluant tous les patients pris en charge pour un carcinome epidermoide du canal anal de stade T2 ou plus, avec ou sans atteinte ganglionnaire, M0, par chimioradiotherapie entre 2011 et 2015. Les patients ont tous recu une RCMI de la dose totale de 60 Gy en 30 seances avec deux ou trois niveaux de dose, selon une technique de boost integre, sans intervalle libre. Une chimiotherapie concomitante par 5-fluoro-uracile et mitomycine-C y etait associee. Resultats Soixante-quatorze patients ont ete inclus. Il s’agissait principalement de femmes (81 %). L’âge median etait de 62 ans, six patients (8 %) etaient seropositifs. L’etalement median etait de 43 jours. Six patients (8 %) ont eu une neutropenie de grade 3 ou plus. Le volume cible previsionnel prophylactique superieur ou egal a 1 L (p = 0,011) et un tabagisme actif (p = 0,032) etaient predictifs de la survenue d’une hematotoxicite severe ; 17 patients (23 %) ont souffert d’une anite de grade 3 ou plus. Onze patients (15 %) ont ete atteints d’une rechute, pour six (8 %) locale. Avec un suivi median de 22 mois, les taux de survie sans recidive a 2 et 3 ans etaient de 91 % et 81 %, ceux de survie globale a 2 et 3 ans de 91 % et 83 %. Un envahissement ganglionnaire et une concentration de squamous cell carcinoma (SCC) de plus de 2 UI/mL au moment du diagnostic etaient les principaux facteurs predictifs de survie sans rechute et de survie globale. Conclusion La RCMI avec boost integre est bien toleree pour des cancers du canal anal, en concomitance d’une chimiotherapie. Cette technique permet d’eviter une pause therapeutique. Son benefice en termes de taux de controle local et de survie reste a evaluer dans une etude prospective.

About 7200 new cases of pancreatic adenocarcinomas are diagnosed each year in France. At the time of diagnosis, an efficient carcinologic surgery will not be possible for nearly 80% of patients, in relation to loco-regional extension or metastatic dissemination. After surgical resection, the median survival of resected patients ranges from 12 to 20 months, with a high rate of relapses. Currently, the use of radiotherapy for patients with pancreatic cancer is controversial. In adjuvant setting, the standard treatment is six months of chemotherapy with FUFOL or gemcitabine. Chemoradiation (CRT) may improve the survival of patients with incompletely resected tumors (R1). This must be validated in a prospective trial. Neoadjuvant CRT is a promising treatment but always under evaluation. For the treatment of patients with locally advanced tumors, there is not a standart treatment. A strategy of initial chemotherapy followed by CRT for non progressive patients is under evaluation. Whereas in the first trials of CRT large fields were used, the current trend is to reduce the treated volumes to improve tolerance. The delineation of target volumes has been improved by the use of simulation CT. The aims of this work are to precise the radio-anatomical particularities, the pattern of spread of pancreatic cancer and the principles of 3D conformal radiotherapy illustrated with a clinical case.

A survey of the literature has been performed to find arguments in order to help the choice between radiosurgery and hypofractionated stereotactic radiotherapy in the treatment of brain metastases.A comparison of two groups of brain metastases treated with hypofractionated stereotactic radiotherapy or radiosurgery, with or without WBRT was performed. Hypofractionated stereotactic radiotherapy: there were eight series including 448 patients published from 2000 to 2009; treated with 5-6 MV X-Rays, non invasive head immobilization, a margin 2 to 10mm; 24 to 40Gy in three to five fractions; a 5 to 8 days duration in six series and 15-16 days in two other series. WBRT (30%) ; radiosurgery: there were 12 series (1994 to 2005) including 2157 patients; an invasive head immobilization, no margin; doses from 10 to 25 Gy; six series over 12 had Gamma Knife radiosurgery and six had Linacs X-Rays. WBRT (30 Gy/10 F/12 days) associated to radiosurgery in several series. The following parameters were compared: median GTV, median survival, 1-year survival rate, local control rate, necrosis and WBRT rates.Hypofractionated stereotactic radiotherapy series: the parameters were respectively: 0,52-4,47 cm(3) (median 2,8 cm(3)); 5-16 months (median 8,7 months); 68,2-93% (median 82,5%); necrosis rate 3,1%; associated WBRT 30%. Radiosurgery series: the parameters were respectively: 1,3 to 5,5 cm(3) (median 2 cm(3)); 5,5 to 22 months (median 11 months); 71 to 95% (median 85%); 0,5 to 6% (median 2,4%); associated WBRT 58%. Results seem similar in the two groups: Hypofractionated stereotactic radiotherapy with non invasive immobilization could theoretically treat all brain metastases sizes except lesions10 mm (500 mm(3)). In large volumes,4200 mm(3) GTV, the toxicity of hypofractionated stereotactic radiotherapy was not reported, thus it was difficult to compare its results with the published reports of radiosurgery toxicity. WBRT was a confusing parameter. Obviously, this initial survey has important limitations, specifically its methodology.Radiosurgery and hypofractionated stereotactic radiotherapy could be used to treat brain metastases with GTV500 mm(3) andor = 4200 mm(3) (Ø 20mm); for GTV500 mm(3) (Ø 10mm) an invasive procedure with radiosurgery is necessary. For GTV4200 mm(3) (Ø 20mm), hypofractionated stereotactic radiotherapy could be proposed, provided further studies, using 4 to 6 Gy fractions, a duration less or equal to 10-12 days and a margin of 2mm will be performed.

The work presented herein rests on the study of the Varian EPID aS500-II and the Image Acquisition system IAS3. We assessed the dosimetric performance of this EPID for measurements and quality assurance of enhanced dynamic wedge profiles and wedge factors.We evaluated the dosimeter properties using the integrated asynchronous mode of acquisition in treatments with enhanced dynamic wedges (EDW). We studied the performance, stability and the reproducibility in measurements of the transmission factors and profiles of the fields with dynamic wedges. EPID profiles were compared to the "Profiler Sun Nuclear" diode array and PTW ion chamber. Analytical functions were developed in order to correct EDW profiles. The dependence of EPID measurements on wedge direction, beam dimensions and source to EPID distance was assessed.The backscatter produced by the "exact arm" was evaluated; EPID profiles depended on the EDW direction and on the detector source distance. Wedge factors were determined using this detector and compared to the ion chamber response, differences were all within 1 %. Two empirical correction functions were developed to produce EPID wedge profiles that correspond to diode for all wedge angles and energies depending on the wedge direction.The EPID is highly suited to regular measurement of EDW due to the reproducibility of the EPID-measured wedge factors and profiles.

In case of external breast radiotherapy, the usual treatment consists of two tangential beams homogeneously attenuated by a dynamic or physics wedge in order to obtain the most homogeneous dose distribution as possible. Depending of the shape and size of the breast volume, we may observe with this technique dose heterogeneity over 20% from the recommendation of the International Committee on Radiation Units and Measurements (95-107%). We propose to study breast treatment planning by compensating tissues thickness in order to decrease dose heterogeneity observed on the dose distribution for conventional treatment.We have segmented the initial tangential beams used for this kind of treatment into several smaller beams. Their shape was adapted to the distribution of the greys level on the DRR image. Therefore, we have compensated the thickness gradient and we have given the right dose to the right thickness group.Dose distribution performed with this method shows an improvement of the dose homogeneity in the three space dimensions and a decrease of the maximal dose between 5 and 10% over the ICRU recommendation.This technique allows us to perform breast irradiation on a single photon energy linac even if the treated volume presents important thickness gradient. However, in case of large breast, this method is not able to reduce the overdosage at the entry of the volume due to inappropriate photon energy relative to the breast thickness.

Objectif Etude retrospective evaluant les resultats de la radiotherapie externe apres chirurgie conservatrice pour un carcinome epidermoide larynge ou hypopharynge. Patients et methodes Entre 1999 et 2010, 79 patients atteints d’un carcinome epidermoide du larynx ou de l’hypopharynx ont eu une chirurgie partielle dans notre centre. Quarante patients avaient recu au prealable une chimiotherapie d’induction. Apres la chirurgie, 27 patients (34 %) ont eu une radiotherapie externe, principalement en raison d’un envahissement ganglionnaire (Groupe 1). Cinquante-deux patients n’en n’ont pas recu (Groupe 2). Le suivi median etait de 51 mois. Resultats Dix-huit patients (23 %) ont ete atteints d’une rechute (18,5 % dans le groupe 1 contre 25 % dans le groupe 2, p = 0,5). Les taux de survie sans rechute a 5 ans etaient de 81 % dans le groupe 1 et de 73 % dans le groupe 2 (p = 0,4). Les taux de survie globale a 5 ans etaient de 66 % dans le groupe 1 et 87 % dans le groupe 2 (p = 0,05). Le seul facteur predictif de la survie globale etait la localisation tumorale. Le taux de preservation laryngee etait de 91 % pour l’ensemble des patients. Sept pharyngolaryngectomies totales ont ete realisees, deux dans le groupe 1 et cinq dans le groupe 2. Le taux de tracheotomie etait de 6 % pour l’ensemble des patients, 15 % dans le groupe 1 et 2 % dans le groupe 2 (p = 0,04). Conclusion Apres chirurgie laryngee partielle, la radiotherapie externe postoperatoire permet d’obtenir une survie sans rechute prolongee et un taux eleve de preservation laryngee. Le taux de tracheotomie secondaire etait plus eleve dans le groupe 1, soulignant l’attention qui doit etre portee a la dose recue par le larynx restant.