Analysis of data to Advance Personalised Therapy with MR-Linac (ADAPT-MRL).

BACKGROUND: Analysis of Data to Advance Personalised Therapy with MR-Linac (ADAPT-MRL) is a multi-site, multinational, observational cohort registry designed to collect data on the use of the magnetic resonance linear accelerator (MR-Linac) for radiation therapy and patient outcomes. The registry will provide a linked repository of technical and clinical data that will form a platform for prospective studies and technology assessment. METHODS: Design: This registry aims to include an estimated 10,000 eligible participants across Australia and other countries over a 7- to 10-year period. Participants will undergo treatment and assessments in accordance with standard practice. Toxicity and survival outcomes will be assessed at baseline, during treatment, and with 3 monthly follow-up until 24 months, patient reported outcome measures will also be collected. Participants with a variety of cancers will be included. DISCUSSION: Data obtained from the ADAPT-MRL registry is expected to provide evidence on the safety and efficacy of the MR-Linac, a new technical innovation in radiation oncology. We expect this registry will generate data that will be used to optimise treatment techniques, MR-Linac software algorithms, evaluate participants' outcomes and toxicities and to create a repository of adapted plans, anatomical and functional MR sequences linked to participants' outcomes.

MRI-Based Upper Abdominal Organs-at-Risk Atlas for Radiation Oncology.

PURPOSE: The purpose of our study was to provide a guide for identification and contouring of upper abdominal organs-at-risk (OARs) in the setting of online magnetic resonance imaging (MRI)-guided radiation treatment planning and delivery. METHODS AND MATERIALS: After a needs assessment survey, it was determined that an upper abdominal MRI-based atlas of normal OARs would be of benefit to radiation oncologists and radiation therapists. An anonymized diagnostic 1.5T MRI from a patient with typical upper abdominal anatomy was used for atlas development. Two MRI sequences were selected for contouring, a T1-weighted gadoxetic acid contrast-enhanced MRI acquired in the hepatobiliary phase and axial fast imaging with balanced steady-state precession. Two additional clinical MRI sequences from commercial online MRI-guided radiation therapy systems were selected for contouring and were included in the final atlas. Contours from each data set were completed and reviewed by radiation oncologists, along with a radiologist who specializes in upper abdominal imaging, to generate a consensus upper abdominal MRI-based OAR atlas. RESULTS: A normal OAR atlas was developed, including recommendations for contouring. The atlas and contouring guidance are described, and high-resolution MRI images and contours are displayed. OARs, such as the bile duct and biliary tree, which may be better seen on MRI than on computed tomography, are highlighted. The full DICOM/DICOM-RT MRI images from both the diagnostic and clinical online MRI-guided radiation therapy systems data sets have been made freely available, for educational purposes, at econtour.org. CONCLUSIONS: This MRI contouring atlas for upper abdominal OARs should provide a useful reference for contouring and education. Its routine use may help to improve uniformity in contouring in radiation oncology planning and OAR dose calculation. Full DICOM/DICOM-RT images are available online and provide a valuable educational resource for upper abdominal MRI-based radiation therapy planning and delivery.

Treatment Outcomes from 68Ga-PSMA PET/CT-Informed Salvage Radiation Treatment in Men with Rising PSA After Radical Prostatectomy: Prognostic Value of a Negative PSMA PET.

68Ga-PSMA (prostate-specific membrane antigen) PET/CT is increasingly used in men with prostate-specific antigen (PSA) failure after radical prostatectomy (RP) to triage those who will benefit from salvage radiation treatment (SRT). This study examines the value of PSMA-informed SRT in improving treatment outcomes in the context of biochemical failure after RP. Methods: We analyzed men with rising PSA after RP with PSA readings between 0.05 and 1.0 ng/mL, considered eligible for SRT at the time of PSMA. For each patient, clinical and pathologic features as well as scan results, including site of PSMA-positive disease, number of lesions, and a certainty score, were documented. Subsequent management, including SRT, and most recent PSA were recorded using medical records. Treatment response was defined as both PSA ≤ 0.1 ng/mL and >50% reduction in PSA. Multivariate logistic regression analysis was performed for association of clinical variables and treatment response to SRT. Results: One hundred sixty-four men were included. PSMA was positive in 62% (n = 102/164): 38 of 102 in the prostatic fossa, 41 of 102 in pelvic nodes, and 23 of 102 distantly. Twenty-four patients received androgen-deprivation therapy (ADT) and were excluded for outcomes analysis. In total, 99 of 146 received SRT with a median follow-up after radiation treatment of 10.5 mo (interquartile range, 6-14 mo). Overall treatment response after SRT was 72% (n = 71/99). Forty-five percent (n = 27/60) of patients with a negative PSMA underwent SRT whereas 55% (33/60) did not. In men with a negative PSMA who received SRT, 85% (n = 23/27) demonstrated a treatment response, compared with a further PSA increase in 65% (22/34) in those not treated. In 36 of 99 patients with disease confined to the prostate fossa on PSMA, 81% (n = 29/36) responded to SRT. In total, 26 of 99 men had nodal disease on PSMA, of whom 61% (n = 16/26) had treatment response after SRT. On multivariate logistic regression analysis, PSMA and serum PSA significantly correlated with treatment response, whereas pT stage, Gleason score, and surgical margin status did not. Conclusion: PSMA PET is independently predictive of treatment response to SRT and stratifies men into a high treatment response to SRT (negative or fossa-confined PSMA) versus men with poor response to SRT (nodes or distant-disease PSMA). In particular, a negative PSMA PET result predicts a high response to salvage fossa radiotherapy.

Prospective Comparison of 18F-Fluoromethylcholine Versus 68Ga-PSMA PET/CT in Prostate Cancer Patients Who Have Rising PSA After Curative Treatment and Are Being Considered for Targeted Therapy.

UNLABELLED: In prostate cancer with biochemical failure after therapy, current imaging techniques have a low detection rate at the prostate-specific antigen (PSA) levels at which targeted salvage therapy is effective. (11)C-choline and (18)F-fluoromethylcholine, though widely used, have poor sensitivity at low PSA levels. (68)Ga-PSMA (Glu-NH-CO-NH-Lys-(Ahx)-[(68)Ga-N,N'-bis[2-hydroxy-5-(carboxyethyl)benzyl]ethylenediamine-N,N'-diacetic acid]) has shown promising results in retrospective trials. Our aim was to prospectively compare the detection rates of (68)Ga-PSMA versus (18)F-fluoromethylcholine PET/CT in men who were initially managed with radical prostatectomy, radiation treatment, or both and were being considered for targeted therapy. METHODS: A sample of men with a rising PSA level after treatment, eligible for targeted treatment, was prospectively included. Patients on systemic treatment were excluded. (68)Ga-PSMA, (18)F-fluoromethylcholine PET/CT, and diagnostic CT were performed sequentially on all patients between January and April 2015, and the images were assessed by masked, experienced interpreters. The findings and their impact on management were documented, together with the results of histologic follow-up when feasible. RESULTS: In total, 38 patients were enrolled. Of these, 34 (89%) had undergone radical prostatectomy and 4 (11%) had undergone radiation treatment. Twelve (32%) had undergone salvage radiation treatment after primary radical prostatectomy. The mean PSA level was 1.74 ± 2.54 ng/mL. The scan results were positive in 26 patients (68%) and negative with both tracers in 12 patients (32%). Of the 26 positive scans, 14 (54%) were positive with (68)Ga-PSMA alone, 11 (42%) with both (18)F-fluoromethylcholine and (68)Ga-PSMA, and only 1 (4%) with (18)F-fluoromethylcholine alone. When PSA was below 0.5 ng/mL, the detection rate was 50% for (68)Ga-PSMA versus 12.5% for (18)F-fluoromethylcholine. When PSA was 0.5-2.0 ng/mL, the detection rate was 69% for (68)Ga-PSMA versus 31% for (18)F-fluoromethylcholine, and when PSA was above 2.0, the detection rate was 86% for (68)Ga-PSMA versus 57% for (18)F-fluoromethylcholine. On lesion-based analysis, (68)Ga-PSMA detected more lesions than (18)F-fluoromethylcholine (59 vs. 29, P < 0.001). The tumor-to-background ratio in positive scans was higher for (68)Ga-PSMA than for (18)F-fluoromethylcholine (28.6 for (68)Ga-PSMA vs. 9.4 for (18)F-fluoromethylcholine, P < 0.001). There was a 63% (24/38 patients) management impact, with 54% (13/24 patients) being due to (68)Ga-PSMA imaging alone. Histologic follow-up was available for 9 of 38 patients (24%), and 9 of 9 (68)Ga-PSMA-positive lesions were consistent with prostate cancer ((68)Ga-PSMA was true-positive). The lesion positive on (18)F-fluoromethylcholine imaging and negative on (68)Ga-PSMA imaging was shown at biopsy to be a false-positive (18)F-fluoromethylcholine finding ((68)Ga-PSMA was true-negative). CONCLUSION: In patients with biochemical failure and a low PSA level, (68)Ga-PSMA demonstrated a significantly higher detection rate than (18)F-fluoromethylcholine and a high overall impact on management.

Prostate brachytherapy in New South Wales: patterns of care study and impact of caseload on treatment quality.

PURPOSE: We performed the first comprehensive, population-based brachytherapy (BT) Patterns of Care Study in the Australian setting. Herein we report on prostate BT and assess the technical quality of BT practice, focusing on whether a caseload effect could be identified in New South Wales (NSW). MATERIAL AND METHODS: Site visits were made to all radiation oncology departments in NSW that delivered prostate BT, collecting relevant data on NSW residents treated with prostate BT in 2003. Overall quality of NSW prostate BT treatment was assessed using benchmarks including treatment of appropriate prostate cancer disease risk category, absence of (relative) physical contraindications, optimal planned and treated dosimetry, and pre-/post-implant planning/CT. Quality was compared between higher and lower caseload departments. RESULTS: One hundred and fifty-seven (67%) patients underwent temporary BT and 79 (33%) permanent seed BT. Prostate BT was concentrated in five departments, with three of four departments with active programmes treating greater than the recommended 25 cases. Rates of concordance with quality benchmarks were high (85-99%) with no consistent caseload effect identified. CONCLUSIONS: Prostate BT in NSW in 2003 was generally of high quality and a caseload effect on quality could not be identified. This may be because the number of departments was insufficient to determine a caseload effect, or because the prostate BT was largely concentrated in a small number of high caseload departments.

High-dose rate brachytherapy compared with open radical prostatectomy for the treatment of high-risk prostate cancer: 10 year biochemical freedom from relapse.

OBJECTIVE: • To compare long-term biochemical control of high-risk prostate cancer in those men receiving high-dose rate brachytherapy (HDRB) and radical prostatectomy (RP). PATIENTS AND METHODS: • The 10-year biochemical freedom from relapse (BFR) was calculated for 243 patients who underwent either RP or combined therapy with HDRB + external beam radiotherapy + androgen deprivation between 1998 and 2000. • INCLUSION CRITERIA: clinical stage ≥ T2b, or Gleason sum ≥ 8, or PSA level of > 20 ng/mL. Groups were appraised using the Kattan nomogram for surgery to calculate progression-free probability (PFP). RESULTS: • For the RP group (153 patients) the median PSA level was 8.1 ng/mL and the median age was 62.2 years. The median 5- and 10-year predicted PFP for RP was 64% and 56 %, respectively. The 5- and 10-year BFR was 65.5% and 55.4%. There was no significant difference between the predicted and the actual PFP for the RP group (P= 0.525). • For HDRB group (90 patients). The median PSA level was 14.2 ng/mL and the median age was 67.6 years. The median 5- and 10-year predicted PFP for HDRB was 46% and 35%, respectively. The 5- and 10-year BFR was 79.6% and 53.6%. There was a significant improvement between the actual and the predicted PFP for the HDRB group (P= 0.002). CONCLUSIONS: • Amongst a high-risk cohort, patients undergoing RP performed as predicted by the pre-treatment surgical nomogram, whereas the patients undergoing HDRB performed significantly better than was predicted by the surgical nomogram at 10 years.