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PURPOSE To evaluate the PSA outcomes and the late patient's reported health related quality of life (HRQOL) and toxicity after single-fraction High-Dose-Rate brachytherapy (HDRB) and Low-Dose-Rate brachytherapy (LDRB) for prostate cancer. METHODS Men with low and favorable intermediate-risk prostate cancer across 3 centres were randomized between monotherapy brachytherapy with either Iodine-125 LDRB or 19 Gy single-fraction HDRB. Biochemical outcomes were evaluated using the Phoenix definition, PSA nadir and absolute PSA value

Purpose This study aimed to evaluate if the F18-fluorodeoxyglucose positron emission tomography (F18-FDG PET) response after two weeks of chemoradiation for locoregionally advanced esophageal cancer (staged Tumor (T) 3 and/or Nodes (N)+ Metastases (M) 0) was linked to the pathologic response for patients undergoing surgery, to disease-free survival (DFS) or overall survival (OS). Materials and Methods Between March 2006 and September 2017, 40 patients were prospectively enrolled in our study, gave written consent, and had PET scans performed before treatment and after two weeks of chemoradiation. One patient did not undergo his two-week PET without informing study coordinators and was excluded from analyses. Results The median age at diagnosis was 62 years. Seventy-two percent of patients had N+ disease. Median OS for the entire group was 24 months. Five-year overall survival was 17%. Survival curves for patients with no PET response, minor PET response, or good PET response overlapped and were not statistically different. For the 25 patients who underwent surgery, the positive predictive value (PPV) of the PET response relative to the pathologic response was 75% and the negative predictive value (NPV) was 62%. In study patients, the crude recurrence rate was 68% and there was no correlation between PET response and DFS. Conclusion In our study, interim PET response after two weeks of chemoradiation for locoregionally advanced esophageal cancer was not predictive of outcome or pathologic response. Based on our data and current literature, interim PET should not be used to alter treatment (whether to escalate neo-adjuvant treatment or omit surgery).

The diagnosis and treatment of prostate cancer (PCa) are limited by a lack of intraoperative information to accurately target tumors with needles for biopsy and brachytherapy. An innovative image-guidance technique using optical devices could improve the diagnostic yield of biopsy and efficacy of radiotherapy.To evaluate the performance of multimodal PCa detection using biomolecular features from in-situ Raman spectroscopy (RS) combined with image-based (radiomics) features from multiparametric magnetic resonance images (mpMRI).In a prospective pilot clinical study, 18 patients were recruited and underwent high-dose-rate brachytherapy. Multimodality image fusion (preoperative mpMRI with intraoperative transrectal ultrasound) combined with electromagnetic tracking was used to navigate an RS needle in the prostate prior to brachytherapy. This resulting dataset consisted of Raman spectra and co-located radiomics features from mpMRI. Feature selection was performed with the constraint that no more than 10 features were retained overall from a combination of inelastic scattering spectra and radiomics. These features were used to train support vector machine classifiers for PCa detection based on leave-one-patient-out cross-validation.RS along with biopsy samples were acquired from 47 sites along the insertion trajectory of the fiber-optics needle: 26 were confirmed as benign or grade group = 1, and 21 as grade groupgt;1, according to histopathological reports. The combination of the fingerprint region of the RS and radiomics showed an accuracy of 83% (sensitivity = 81 % and a specificity = 85 % ), outperforming by more than 9% models trained with either spectroscopic or mpMRI data alone. An optimal number of features was identified between 6 and 8 features, which have good potential for discriminating grade group ≥1 / grade grouplt;1 (accuracy = 87 % ) or grade groupgt;1 / grade group ≤1 (accuracy = 91 % ).In-situ Raman spectroscopy combined with mpMRI radiomics features can lead to highly accurate PCa detection for improved in-vivo targeting of biopsy sample collection and radiotherapy seed placement.

QTc prolongation is linked to Torsade de Pointes, sudden cardiac death, and overall cardiovascular mortality. 754 prostate cancer patients undergoing brachytherapy were analyzed, prolonged QTc was defined as ���450ms. A prolonged QTc was more frequent (10.1 vs. 5.1%, p = 0.040) in patients with high-risk cancer than in low to intermediate risk patients. The absolute QTc-time was correlated with age (r = 0.125), neutrophil count (r = 0.130) and negatively correlated with the testosterone level (r=���0.205). Treating physicians should be aware of this and monitor the QTc during ADT to possibly decrease cardiac morbidity/mortality in these patients who are more likely to require ADT.

BACKGROUND AND PURPOSE Advances in high-dose-rate brachytherapy to treat prostate cancer hinge on improved accuracy in navigation and targeting while optimizing a streamlined workflow. Multimodal image registration and electromagnetic (EM) tracking are two technologies integrated into a prototype system in the early phase of clinical evaluation. We aim to report on the system's accuracy and workflow performance in support of tumor-targeted procedures. MATERIALS AND METHODS In a prospective study, we evaluated the system in 43 consecutive procedures after clinical deployment. We measured workflow efficiency and EM catheter reconstruction accuracy. We also evaluated the system's MRI-TRUS registration accuracy with/without deformation, and with/without y-axis rotation for urethral alignment at initialization. RESULTS The cohort included 32 focal brachytherapy and 11 integrated boost whole-gland implants. Mean procedure time excluding dose delivery was 38 min (range: 21-83) for focal, and 56 min (range: 38-89) for whole-gland implants; stable over time. EM catheter reconstructions achieved a mean difference between computed and measured free-length of 0.8mm (SD 0.8, no corrections performed), and mean axial manual corrections 1.3mm (SD 0.7). EM also enabled the clinical use of a non or partially visible catheter in 21% of procedures. Registration accuracy improved with y-axis rotation for urethral alignment at initialization and with the elastic registration (mTRE 3.42mm, SD 1.49). CONCLUSION The system supported tumor-targeting and was implemented with no demonstrable learning curve. EM reconstruction errors were small, correctable, and improved with calibration and control of external distortion sources; increasing confidence in the use of partially visible catheters. Image registration errors remained despite rotational alignment and deformation, and should be carefully considered.

Purpose To compare health-related quality of life (HRQOL) of high-dose-rate brachytherapy (HDRB) versus low dose-rate brachytherapy (LDRB) for localized prostate cancer in a multi-institutional phase 2 randomized trial. Methods and Materials Men with favorable-risk prostate cancer were randomized between monotherapy brachytherapy with either Iodine-125 LDRB to 144 Gy or single-fraction Iridium-192 HDRB to 19 Gy. HRQOL and urinary toxicity were recorded at baseline and at 1, 3, 6, and 12 months using the Expanded Prostate Cancer Index Composite (EPIC)-26 scoring and the International Prostate Symptom Score (IPSS). Independent samples t test and mixed effects modeling were performed for continuous variables. Time to IPSS resolution, defined as return to its baseline score ±5 points, was calculated using Kaplan-Meier estimator curves with the log-rank test. A multiple-comparison adjusted P value of ≤.05 was considered significant. Results LDRB and HDRB were performed in 15 and 16 patients, respectively, for a total of 31 patients. At 3 months, patients treated with LDRB had a higher IPSS score (mean, 15.5 vs 6.0, respectively; P = .003) and lower EPIC urinary irritative score (mean, 69.2 vs 85.3, respectively; P = .037) compared with those who received HDRB. On repeated measures at 1, 3, 6, and 12 months, the IPSS (P = .003) and EPIC urinary irritative scores (P = .019) were significantly better in the HDR arm, translating into a lower urinary toxicity profile. There were no significant differences in the EPIC urinary incontinence, sexual, or bowel habit scores between the 2 groups at any measured time point. Time to IPSS resolution was significantly shorter in the HDRB group (mean, 2.0 months) compared with the LDRB group (mean, 6.0 months; P = .028). Conclusions HDRB monotherapy is a promising modality associated with a lower urinary toxicity profile and higher HRQOL in the first 12 months compared with LDRB.

Purpose Interstitial brachytherapy (ISBT) can be effective for vaginal tumors due to its ability to deliver conformal treatment with 3D planning. As there is no consensus for 3D vaginal brachytherapy (BT) contouring, the goals of this study are to evaluate the variability in practices and contouring, and to develop consensus concepts on target definitions. Methods A survey/contouring study was conducted with 16 radiation oncologists from 10 Canadian academic centers. The study included three vaginal ISBT cases. Participants were provided staging, prebrachytherapy (pre-BT), and BT MRIs. Participants responded to a questionnaire and contoured on the provided images. Agreement between contours was analyzed. A meeting was held to develop consensus definitions of targets. Results Median ISBT experience was 3.5 years. All 16 participants regularly contour with MRI, whereas three also plan on MRI. For the three cases, there was variation into how CTV HR and CTV IR was defined. Kappa statistics showed higher agreement with bulky tumors (mean 0.59) as compared with small residual tumors (mean 0.29). For all cases, kappa was highest in pre-BT GTV res as compared with BT GTV res (mean 0.58, 0.46). Consensus concepts to define targets were developed. Conclusions Variations exist in how ISBT targets are defined for vaginal tumors. Highest contouring variability was seen with small residual at BT. Contouring is more consistent on pre-BT MRI as compared with BT MRI suggesting a needle distortion effect. Consensus CTV HR and CTV IR definitions have been developed and further work is warranted to establish international standards.

Aims We aimed to characterise a large cohort of non-invasive, human papillomavirus (HPV) and p53-independent verruciform lesions, such as 'vulvar acanthosis with altered differentiation' (VAAD), 'differentiated exophytic vulvar intra-epithelial lesion' (DEVIL) and 'verruciform lichen simplex chronicus' (vLSC). Methods and results From January 2008 to December 2020 we retrospectively identified 36 eligible patients with verruciform non-invasive lesions (n = 36) and collected clinical, histological and follow-up parameters. Verruciform non-invasive lesions occurred at a median age of 71 years, with a median follow-up of 33.5 months. Clinically, pruritus was only reported in patients with VAAD (n = 3, 21%). Lesion colour was significantly different across categories (P = 0.028). Apart from the histopathological criteria already known to distinguish these entities (hypogranulosis, epithelial pallor and low-magnification architecture), no other significant criteria were discovered and significant overlap was observed, particularly between VAAD and DEVIL. Patients with vLSC trended towards longer survival without recurrence compared to VAAD and DEVIL (P = 0.082), but showed comparable invasion-free survival interval (P = 0.782). Squamous cell carcinomas (SCC) associated with either VAAD, DEVIL or vLSC displayed similar clinical, histopathological and biological parameters. In non-invasive precursor lesions, stromal oedema was associated with invasion (P = 0.015) and remained so upon Cox regression analysis (P = 0.009). Conclusion Our study of HPV and p53 independent non-invasive verruciform lesions of the vulva highlights significant clinical, histopathological and biological overlap between VAAD, DEVIL and vLSC, suggesting that these pre-invasive lesions should be viewed as a spectrum. We also show that stromal features such as oedema might play an import role in progression to invasion.

Purpose/Objective(s) To determine if hypofractionated post-operative prostate bed radiotherapy (HYPORT) does not increase patient-reported genitourinary (GU) or gastrointestinal (GI) toxicity over conventionally fractionated post-operative radiotherapy (COPORT). Materials/Methods Eligibility criteria were: 1) an undetectable PSA ( Results Between July 2017 and July 2018, 298 patients were screened and 296 were randomized: 144 to HYPORT and 152 to COPORT. Compliance with the EPIC was 100% at baseline, 83% at the end of RT, 77% at 6 months, 78% at 12 months, and 73% at 24 months. At the end of RT, the HYPORT and COPORT mean GU change scores were neither clinically significant nor significantly different and remained so at 6 and 12 months. The mean GI change scores for HYPORT and COPORT were both clinically significant and significantly different at the end of RT (HYPORT mean GI = -15.0 vs COPORT mean GI = -6.8 P ≤ 0.01). However, both the HYPORT and COPORT mean GI change scores clinically and statistically significant differences were resolved at 6 and 12 months. The 24-month mean GU and GI change scores for HYPORT and COPORT remained neither clinically nor statistically significant (HYPORT mean GU = -5.2 vs COPORT mean GU = -3.0, P = 0.81; HYPORT mean GI = -2.2 vs COPORT mean GI = -1.5, P = 0.12). With a median follow-up for censored patients of 2.1 years, there was no difference between HYPORT versus COPORT for biochemical failure defined as a PSA ≥ 0.4 ng/mL followed by a value higher than the first by any amount (2-yr actuarial, 12% vs 8%, P = 0.29) or local failure (2-yr actuarial, 0.7% vs 0.8%, P = 0.35). Conclusion HYPORT is non-inferior to COPORT in terms of late patient-reported GU or GI toxicity. More follow-up is needed to appropriately assess disease control endpoints. In some clinic scenarios, HYPORT may be considered an acceptable practice standard.

Objectives: The first ASTRO guidelines on cervical cancer has recently been published recommending the use of modern radiation therapy. Furthermore, imaging has been incorporated in the new FIGO 2018 cervical cancer staging, which now re-categorizes nodal disease (IIIC). We sought to evaluate the outcomes and patterns of recurrence using FIGO 2018 staging in a cohort of patients treated in an era of high precision image-guided radiotherapy. Methods: A retrospective database review of 196 non-metastatic patients treated at a single institution from 2011 to 2018 was performed. All had pre-treatment MRI and PET scans and were treated with definitive concurrent chemoradiation using both intensity-modulated radiotherapy and 3D-image guided brachytherapy. Previously assigned 2009 FIGO staging and all imaging were reviewed for FIGO 2018 re-classification. Descriptive analyses and Kaplan-Meier survival curves were performed. Log-rank test was used to compare outcome between groups. Results: Five-year locoregional control rate, OS and DFS and were 82%, 79.6% and 70.1% respectively, with a median follow-up time of 51 months. Forty-eight patients experienced a recurrence, 80% of which included distant disease. In-field recurrence rate was 11.7%. Using the new FIGO staging, 48% of patients were upstaged to IIIC. Compared to FIGO 2009, OS and DFS were higher for all early 2018 FIGO stages, while stage III and IVA disease had poorer outcomes. Five-year OS was 91.6%, 72.8% and 61.7% for node-negative disease, IIIC1 and IIIC2 stages, respectively (p Conclusions: Integration of state-of-the-art imaging in cervical cancer staging as well as in radiotherapy and brachytherapy planning leads to excellent oncologic outcomes, however distant recurrence remains an important issue. FIGO 2018 staging better reflects patient prognosis, highlighting the need for new treatment strategies in stage IIIC cervical cancer.

Long-term androgen deprivation therapy has been associated with decreased bone mineral density in men with prostate cancer. Some evidence suggests that there is no impact on fracture risk despite this bone mineral density loss. Our study aimed to quantify changes in bone mineral density in men with high risk prostate cancer on long-term androgen deprivation therapy and calcium and vitamin D supplementation.Bone mineral density analysis was conducted for localized high risk prostate cancer patients enrolled in the phase III randomized trial PCS-V (Prostate Cancer Study 5), comparing conventional and hypofractionated radiation therapy. Patients received 28 months of luteinizing hormone-releasing hormone agonist and calcium and vitamin D supplementation (500 mg calcium BID+400 IU vitamin D3 BID). The areal density and T-scores (spine, femoral neck and total femur) at baseline and 30 months of followup were extracted, and the absolute change was calculated. Clinical bone density status (normal, osteopenia, osteoporosis) was monitored.The lumbar spine, femoral neck and total femoral bone mineral density were measured for 226, 231, and 173 patients, respectively. The mean percent change in bone mineral density was -2.65%, -2.76% and -4.27% for these respective sites (p0.001 for all). The average decrease in bone mineral density across all sites was -3.2%, with no decline in bone mineral density category in most patients (83%). Eight patients (4%) became osteoporotic.Despite a mild decline in bone mineral density, the change in clinical bone mineral density category remained low with long-term androgen deprivation therapy. Consequently, calcium and vitamin D supplementation alone may suffice for most localized prostate cancer patients on long-term androgen deprivation therapy.

Purpose Volumetric arc therapy (VMAT) is a radiation therapy (RT) technique that spares normal tissues from high and intermediate RT doses but increases the volume of tissues receiving low doses of RT compared with 3-dimensional conformal RT (3DCRT). We hypothesized that palliative VMAT would reduce the detriment to patient quality of life (QOL) compared with palliative 3DCRT. Methods and Materials This phase 2 trial randomized patients to palliative RT using VMAT or 3DCRT to 1 painful site of metastatic disease in the trunk. Treating physicians could choose 8 Gy in 1 fraction or 20 Gy in 5 fractions to stratify randomization. The primary endpoint was the change in European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Version 3.0 (EORTC QLQ-C30) global health status QOL subscale at 1 week after RT. Repeated measures analysis of variance was used to assess the relationship of patient QOL over time with other factors. Results From July 2014 to November 2017, 37 patients who underwent 3DCRT and 32 patients who underwent VMAT were randomized into the study. Median overall survival was 9 months. Overall pain responses to RT were equivalent (P = .53) between the techniques. Patient compliance in returning QOL questionnaires was 94%, 81%, and 69% at baseline, 1 week after RT, and 1 month after RT, respectively. At 1 week after RT, change in global QOL was not significantly (P = .31) different between VMAT versus 3DCRT. At 4 weeks after RT, VMAT induced significantly (P = .049) less global QOL deterioration than 3DCRT did. Patients who underwent VMAT maintained better physical (P = .012), role (P = .041), and social (P = .025) functioning, but they reported more diarrhea symptoms (P = .017) than in the 3DCRT group. Conclusions Palliative VMAT and 3DCRT did not differ in their ability to control pain; however, palliative VMAT induced fewer QOL detriments than 3DCRT did at 4 weeks after RT.

BackgroundHistorically, radical hysterectomy followed by adjuvant radiotherapy has been offered to patients with endometrial cancer who have gross cervical involvement; however, this approach is known to carry considerable morbidity. Neoadjuvant radiotherapy followed by extra-fascial hysterectomy has been proposed as an alternative treatment but has been poorly studied to date.ObjectiveTo evaluate the locoregional control rate associated with neoadjuvant radiotherapy followed by extra-fascial hysterectomy.MethodsA retrospective cohort study of 30 patients with endometrial cancer with gross cervical involvement treated between May 2006 and January 2016 was performed. Eligible patients were those aged >18 years with non-metastatic endometrial adenocarcinoma and gross cervical disease treated with curative intent at the Centre hospitalier de l’Université de Montréal. Treatment protocol consisted of pelvic neoadjuvant radiotherapy and high-dose rate brachytherapy followed by extra-fascial hysterectomy. Kaplan-Meier curves were used for survival analysis.ResultsThe median age was 60 (range 37–82) and median body mass index was 32 kg/m2 (range 16–55). Twenty-four (80%) patients were diagnosed with a positive cervical/endocervical biopsy. Clinical staging confirmed 36.7% (n=11) as stage II, 20% (n=6) stage IIIB, 30% (n=9) stage IIIC1, and 13.3% (n=4) stage IIIC2. Seventy-seven per cent (n=23) of patients had an endometrioid histology. Locally advanced disease was identified by imaging alone in six patients. Rates of parametrial, adnexal, vaginal, and nodal invasion were 10% (n=3), 6.7% (n=2), 13.3% (n=4), and 43.3% (n=13) at diagnosis, respectively. All patients completed pelvic radiotherapy (13.3% extended field) and 90% received brachytherapy. Twenty per cent (n=6) of surgeries were performed using minimal invasive technique. On surgical specimen, 63.3% (n=19) had complete cervical response, 90% (n=27) had negative margins, and 10% (n=3) had residual nodal involvement. Median follow-up time was 62 months (range 1–120). Six recurrences were identified; all except one involved distant failure, and two with locoregional failure. Five-year locoregional control rate, disease-free, overall, and disease-specific survival were 90.5%, 78.5%, 92.6%, and 96.2%, respectively. Two patients (6.7%) had grade 3+ acute radiation-related complications (all grade 3). Grade 3+ post-operative morbidity was noted in 2 (6.7%) patients.ConclusionsNeoadjuvant radiotherapy followed by extra-fascial hysterectomy offers good locoregional control with low treatment-related morbidity in patients with endometrial cancer with overt cervical involvement.

Purpose The aim of this study was to compare early prostate-specific antigen (PSA) decline patterns and PSA nadirs between low-dose-rate seed prostate brachytherapy (LDR-PB) and different fractionations of external beam radiotherapy (EBRT) and their predictive importance for biochemical failure (bF). Methods and Materials Patients with D'Amico low- or intermediate-risk prostate cancer who underwent a single-modality treatment without androgen deprivation were included in this study. Three different treatment groups were compared: (1) normofractionation EBRT up to 70.2–79.2 Gy/1.8–2.0 Gy, (2) LDR-PB, and (3) EBRT with hypofractionation 60 Gy/3 Gy daily or 5–7.25 Gy once a week over 9–5 weeks, to a total dose of 45–36.25 Gy, respectively. The log-rank test, Cox regression analysis, and nonparametric tests were used. Results We analyzed 892 patients: the median followup for patients without bF was 84 months (interquartile range 60–102 months), with 12% of patients experiencing bF. The PSA decline within the first 15 months was generally exponential. LDR-PB showed a faster early exponential decline compared with EBRT treatments, but whether decline was fast or slow had no influence on recurrence. The only factors that were positive predictive factors in univariate and multivariate analyses were the time to nadir >48 months (median), PSA nadir Conclusions Although there are significant differences in early exponential PSA decline between different treatments, only the PSA nadir and longer time to nadir were predictive factors for bF.

PURPOSE/OBJECTIVE(S) TRUS-guided biopsies still yield a notable rate of sampling error for prostate cancer (PCa) and do not allow in situ characterization. Raman spectroscopy (RS) is a minimally invasive optical imaging modality allowing to measure tissue properties within seconds. In this study, we present the first in man results from a navigated RS optical probe used to confirm sites of tumor burden during HDR brachytherapy. MATERIALS/METHODS The study included 8 prospectively recruited subjects with PCa prior to HDR brachytherapy. An electromagnetic (EM) guidance system was used to navigate in vivo RS acquisition using MRI-TRUS image fusion, and integrated within the HDR brachytherapy procedure workflow. The optical device includes a dual wavelength laser source (680 and 785 nm), a spectrometer, a custom design probe, and an acquisition/processing software. For each case, deformable registration of mpMRI (with prostate, urethra and GTV segmentations) to interventional 3D TRUS reconstructed images (with prostate and urethra segmentations), enabled visualization of GTV with the navigation system. The EM tracked RS probe was inserted through a co-axial needle. Once in place, high wavenumber (HW) and fingerprint (FP) spectra were measured, a biopsy was taken at the corresponding site, and the location was recorded; then, the HDR brachytherapy procedure resumed. Biopsy samples were evaluated histologically to confirm presence of cancer. For the radiomics analysis, 8 first order and 8 GLCM image features were calculated on the MRI (T2W and ADC), extracted from the corresponding optically scanned sites, using open-source software. RESULTS In total, 26 sites were inspected with the RS probe and biopsied (range 2-5 per case). The pathology results identified 14 samples as cancer (Gleason score ≥ 7) and 12 samples as benign. On average the optical measurements took 45 seconds per site (range 23-90) and added 20 minutes (range 15-24) to the intervention. The spectra were pre-processed and labeled according to the pathology results. Neighborhood component analysis was applied to select the features that optimize the prediction performance, extracting 15 features from FP, 1 from HW and 11 from MRI radiomics. Classification models using a support vector machine were trained with a leave one out scheme for evaluation, using different feature combinations. Table 1 presents the average results over all folds. CONCLUSION We presented an image-guided system allowing the first in situ characterization of prostate lesions with RS during brachytherapy, in a manner integrated with the procedural workflow. The acquired spectra from benign and malignant regions show promising preliminary data, demonstrating the potential of the technique for real-time PCa confirmation. Finally, the combination of optical and MRI features yields an improvement in classification accuracy.

MRI has been adopted as part of the standard planning workflow of multiple tumor sites in radiotherapy. While computed tomography remains the standard of care for dose calculation, the use of MRI in radiotherapy planning allows for higher-quality delineation of target volumes and organs at risk. Increased accuracy of delineation, combined with the possibilities of functional imaging, has the potential to improve therapeutic ratios and enhance individualized approaches in radiotherapy planning. In this chapter, we review the applications and evidence for the use of MRI in radiotherapy planning in head and neck, central nervous system, prostate, gynecological, gastrointestinal, breast, and lung cancer sites.

Introduction We assessed the inter- and intra-observer variability in contouring the prostate bed for radiation therapy planning using MRI compared with computed tomography (CT). Methods We selected 15 patients with prior radical prostatectomy. All had CT and MRI simulation for planning purposes. Image fusions were done between CT and MRI. Three radiation oncologists with several years of experience in treating prostate cancer contoured the prostate bed first on CT and then on MRI. Before contouring, each radiation oncologist had to review the Radiation Therapy Oncology Group guidelines for postoperative external beam radiotherapy. The agreement between volumes was calculated using the Dice similarity coefficient (DSC). Analysis was done using the Matlab software. The DSC was compared using non-parametric statistical tests. Results Contouring on CT alone showed a statistically significant (P = 0.001) higher similarity between observers with a mean DSC of 0.76 (standard deviation ± 0.05) compared with contouring on MRI with a mean of 0.66 (standard deviation ± 0.05). Mean intra-observer variability between CT and MRI was 0.68, 0.75 and 0.78 for the three observers. The clinical target volume was 19–74% larger on CT than on MRI. The intra-observer difference in clinical target volume between CT and MRI was statistically significant in two observers and non-significant in the third one (P = 0.09). Conclusions We found less inter-observer variability when contouring on CT than on MRI. Radiation Therapy Oncology Group contouring guidelines are based on anatomical landmarks readily visible on CT. These landmarks are more inter-observer dependent on MRI. Therefore, present contouring guidelines might not be applicable to MRI planning.

We tested different classification systems in order to separate intermediate-risk prostate cancers into prognostic groups. We then examined which groups were most suited for either prostate seed brachytherapy (PB) or external beam radiotherapy (EBRT).We selected patients with D'Amico intermediate-risk prostate cancer who were treated exclusively with either PB or EBRT. Patients were excluded if they had received androgen deprivation therapy in combination with EBRT or a follow up of30 months without recurrence. The Kaplan-Meier method was used to compare groups.Our sample consisted of 475 patients treated from July 2002-September 2013. Median follow up for patients without biochemical failure (BF) was 56 months (interquartile range 44-78); 222 patients (47%) were treated with PB exclusively (D90 interquartile range 145-176 Gy) and 253 (53%) with EBRT exclusively (dose interquartile range 76-80 Gy). The rate of BF was significantly lower in patients treated with PB (5.4%) than in patients treated with EBRT (14.2%) (p = 0.036, log-rank test). Upon univariate analysis, significant predictors of BF included the number of unfavorable intermediate-risk factors (0, 1, 2, 3) (p = 0.024) as well as the Cancer of the Prostate Risk Assessment (CAPRA) score (p = 0.002). After adjusting for the type of treatment, only the CAPRA score remained predictive (p = 0.025). For patients with a CAPRA score of 0-2, those with PB fared better than those treated with EBRT (p = 0.042). This difference disappeared in patients with a CAPRA score of 3-5 (p = 0.5).Using our current selection criteria for monotherapy, we found that PB or EBRT as monotherapy are equally effective treatment options for intermediate-risk prostate cancer.