A Feasibility Study of Dose De-escalation in Prostate Radiotherapy Using the Magnetic Resonance Linear Accelerator (MRL)
The goal of this feasibility study is to learn about dose de-escalation in the treatment of men with intermediate risk prostate cancer. The main question it aims to answer is the technical feasibility of treating prostate cancer with toxicity-minimising radiotherapy on an Magnetic Resonance Linear Accelerator (MR-linac). It will also examine gastrointestinal and genitourinary toxicity in the acute and late setting post radiotherapy as well as Prostate-Specific antigen (PSA) control up until 2 years post treatment. Participants will be treated with radiotherapy to the prostate with which will be given in 30Gy in 5 fractions to the whole prostate and 45Gy in 5 fractions to the dominant lesion.
• Men aged ≥18 years
• Histological confirmation of prostate adenocarcinoma requiring radical radiotherapy
• Gleason score 3+3, 3+4 or 4+3 (Grade groups 1, 2 or 3)
• MRI stage T2 or less (as staged by AJCC TNM 2018)
• MRI-visible tumour(s) of Prostate Imaging-Reporting and Data System (PIRADS) v2 grade 3 or higher on T2 and diffusion-weighted imaging and/or dynamic contrast-enhanced imaging with concordant pathology
• Tumour nodule visible on MRI occupying \<50% of prostate on any axial slice and \<50% total prostate volume
• PSA \<20 ng/ml prior to starting androgen deprivation therapy (ADT)
• Patients can be concurrently treated with androgen deprivation therapy if this would be standard of care. Luteinizing hormone-releasing hormone (LHRH) analogues or Bicalutamide are permitted. ADT is not mandatory where this would usually be omitted.
• World Health Organisation (WHO) Performance status 0-2
• Ability of the participant understand and the willingness to sign a written informed consent form.
• Ability/willingness to comply with the patient reported outcome questionnaires schedule throughout the study.