Search

• The ongoing technical development challenges to define a clear value proposition. • Results offer insight into key elements for investment choices and future studies. • MR-Linac is found to be cost-effective compared to EBRT 20 and 39 fractions. • Comparisons with EBRT 5 fractions and LDR brachytherapy are most challenging. 1.5 Tesla magnetic resonance imaging radiotherapy linear accelerator (MR-Linac) is gaining interest for treatment of localized prostate cancer. Clinical evidence is lacking and it therefore remains uncertain whether MR-Linac is cost-effective. An early health economic analysis was performed to calculate the necessary relative reduction in complications and the maximum price of MR-Linac (5 fractions) to be cost-effective compared to 5, 20 and 39 fractionation schedules of external beam radiotherapy (EBRT) and low-dose-rate (LDR) brachytherapy. A state transition model was developed for men with localized prostate cancer. Complication rates such as grade ≥2 urinary, grade ≥2 bowel and sexual complications, and utilities were based on systematic literature searches. Costs were estimated from a Dutch healthcare perspective. Threshold analyses were performed to identify the thresholds of complications and costs for MR-Linac to be cost-effective, while holding other outcomes such as biochemical progression and mortality constant. One-way sensitivity analyses were performed to outline uncertainty outcomes. At €6460 per patient, no reductions in complications were needed to consider MR-Linac cost-effective compared to EBRT 20 and 39 fractions. Compared to EBRT 5 fractions and LDR brachytherapy, MR-Linac was found to be cost-effective when complications are relatively reduced by 54% and 66% respectively. Results are highly sensitive to the utilities of urinary, bowel and sexual complications and the probability of biochemical progression. MR-Linac is found to be cost-effective compared to 20 and 39 fractions EBRT at baseline. For MR-Linac to become cost-effective over 5 fractions EBRT and LDR brachytherapy, it has to reduce complications substantially or be offered at lower costs. [ABSTRACT FROM AUTHOR]

This systematic review provides an overview of literature on the impact of magnetic resonance–guided radiation therapy (MRgRT) on patient-reported outcomes (PROs) in patients with prostate cancer (PC). A systematic search was performed in October 2023 in PubMed, EMBASE, and Cochrane Library. The Patient, Intervention, Comparison, Outcomes, and Study design (PICOS) framework was used to determine eligibility criteria. Included were studies assessing PROs following MRgRT for PC with a sample size >10. Methodological quality was assessed using the Cochrane's Risk of Bias in Nonrandomized Studies - of Interventions and Cochrane's risk of bias tool for randomized trials. Relevant mean differences (MDs) compared with pre-RT were interpreted using minimal important differences. Meta-analyses were performed using random-effects models. Between-study heterogeneity was assessed using the I2 statistic. Eleven observational studies and 1 randomized controlled trial (n = 897) were included. Nine studies included patients with primary PC with MRgRT as first-line treatment (n = 813) and 3 with MRgRT as second-line treatment (n = 84). Substantial risk of bias was found in 5 studies. European Organization for Research and Treatment Quality of Life Questionnaire (EORTC QLQ) core 30 (C30) and EORTC QLQ prostate cancer module (PR25) scores were pooled from 3 studies, and Expanded Prostate Cancer Index Composite (EPIC)-26 scores were pooled from 4 studies. Relevant MDs for the urinary domain were found with the EPIC-26 (MD, −10.0; 95% CI, −12.0 to −8.1; I2 = 0%) and the EORTC QLQ-PR25 (MD, 8.6; 95% CI, −4.7 to 22.0; I2 = 97%), both at end-RT to 1-month follow-up. Relevant MDs for the bowel domain were found with the EPIC-26 (MD, −4.7; 95% CI, −9.2 to −0.2; I2 = 82%) at end-RT or 1-month follow-up, but not with the EORTC QLQ-PR25. For both domains, no relevant MDs were found after 3 months of follow-up. No relevant MDs were found in the general quality of life domains of the EORTC QLQ C30. MRgRT for PC results in a temporary worsening of patient-reported urinary and bowel symptoms during the first month after treatment compared with pre-RT, resolving at 3 months. No clinically relevant changes were found for general quality of life domains. These results provide important information for patient counseling and can serve as a benchmark for future studies. [ABSTRACT FROM AUTHOR]

Purpose: Most patients with local prostate cancer recurrence after radiation therapy undergo palliative androgen deprivation therapy because whole-gland salvage treatments have a high risk of severe toxicity. Focal treatment reduces this risk while offering a second opportunity for cure. We report updated outcomes of ultrafocal salvage high-dose-rate brachytherapy (HDR-BT).Methods and Materials: Prospectively collected data from the first 50 treated patients were analyzed. Disease status was assessed by 3T multiparametric magnetic resonance imaging (MRI), 18F-Choline or 68Ga-prostate-specific membrane antigen positron emission tomography/computed tomography, and systematic or tumor-targeted biopsies. Ultrafocal salvage HDR-BT (1 × 19 Gy) was performed by implanting the clinical target volume (CTV: gross tumor volume + 5 mm margin) under fused transrectal ultrasound/MRI guidance. Follow-up included toxicity grading (using Common Terminology Criteria for Adverse Events 4.0), quality of life assessment, and prostate-specific antigen (PSA) testing.Results: Median follow-up was 31 months. Median CTV D95% was 18.8 Gy. We observed 2% grade 3 genitourinary toxicity, no grade 3 gastrointestinal toxicity, and 22% newly developed grade 3 erectile dysfunction. Five of 13 patients (38%) with self-reported pretreatment potency (International Index of Erectile Function >17) remained potent. Clinically relevant quality of life deterioration was reported for only 6 of 31 items and was not statistically significant. Biochemical failure (nadir + 2) occurred in 26 patients. Among intraprostatic recurrences, 73% were in field. After 2.5 years, biochemical disease-free survival was 51% (95% confidence interval, 37%-69%), metastases-free survival was 75% (64%-89%), androgen deprivation therapy-free survival was 90% (82%-99%), and overall survival was 98% (94%-100%). Presalvage PSA, CTV size, and stage ≥T3 were significantly associated with biochemical failure. Higher-risk patients (stage ≥T3, PSA ≥10, or PSA double time ≤9 months) had 25% biochemical disease-free survival at 2.5 years versus 71% for lower-risk patients.Conclusions: At this early stage, MRI-guided ultrafocal HDR-BT seems to be a safe salvage treatment option, with acceptable biochemical control in a well-selected group of patients and potential for effectively postponing androgen deprivation therapy. [ABSTRACT FROM AUTHOR]

Background and purpose Boosting the dose to the largest (dominant) lesion in radiotherapy of prostate cancer may improve treatment outcome. The success of this approach relies on the detection and delineation of tumors. The agreement among teams of radiation oncologists and radiologists delineating lesions on multiparametric magnetic resonance imaging (mp-MRI) was assessed by measuring the distances between observer contours. The accuracy of detection and delineation was determined using whole-mount histopathology specimens as reference. Material and methods Six observer teams delineated tumors on mp-MRI of 20 prostate cancer patients who underwent a prostatectomy. To assess the inter-observer agreement, the inter-observer standard deviation (SD) of the contours was calculated for tumor sites which were identified by all teams. Results Eighteen of 89 lesions were identified by all teams, all were dominant lesions. The median histological volume of these was 2.4 cm 3 . The median inter-observer SD of the delineations was 0.23 cm. Sixty-six of 69 satellites were missed by all teams. Conclusion Since all teams identify most dominant lesions, dose escalation to the dominant lesion is feasible. Sufficient dose to the whole prostate may need to be maintained to prevent under treatment of smaller lesions and undetected parts of larger lesions. [ABSTRACT FROM AUTHOR]