Background
post-prostatectomy, toxicity, non-cutaneous cancer, cancer death, Prostate cancer, prostate cancer
DISEASE, PROSTATE CANCER, PROSTATE CANCER
Prostate cancer is the most common non-cutaneous cancer and the second leading cause of cancer death in men [Post-operative radiotherapy is the current standard of care for men who develop BCR or are at risk of BCR after radical prostatectomy. Post-operative radiotherapy is a potentially curative treatment after prostatectomy for men with BCR and may avoid or delay the need for chronic, non-curative treatment, such as long-term androgen suppression. Given the increase in both prostate cancer diagnosis and the proportion of men with high-risk disease undergoing radical prostatectomy, the number of men requiring post-operative radiotherapy is likely to increase [Adjuvant radiotherapy, the administration of immediate post-operative radiotherapy based on adverse pathological features, has been demonstrated to improve biochemical progression free survival (PFS) across multiple prospective randomized trials [Increasingly, there has been a trend toward delivering higher doses of radiation over fewer treatment sessions, termed hypofractionation, as opposed to longer courses of treatment with conventional fractionation (1.8–2 Gy/fraction) [The advent of magnetic resonance imaging (MRI)-guided radiotherapy (MRgRT) – enabled through the integration of MRI and linear accelerator (MR-LINAC) technology may facilitate safe delivery of hypofractionated and ultra-hypofractionated regimens. Multi-parametric MR imaging on the MR-LINAC improves target delineation and this feature combined with real-time MR image-guidance and tracking, allows for reduction in planning margins and accounts for inter-fractional changes in anatomy during treatment thereby decreasing dose to adjacent structures, including the bladder and rectum [The SHORTER trial (NCT04422132) is designed to evaluate if MR-guided ultra-hypofractionated post-operative radiotherapy (5 fractions in two weeks) has a non-inferior GU and GI toxicity profile as compared with MR-guided moderately-hypofractionated post-operative radiotherapy (20 fractions in four weeks) among prostate cancer patients undergoing salvage radiotherapy. This randomized phase II study lays the foundation to potentially redefine the standard of care for post-prostatectomy patients with BCR to include MRgRT and decrease treatment burden.