2. Histological confirmation of prostate adenocarcinoma requiring radical radiotherapy
3. Gleason score 3+3, 3+4 or 4+3 (ISUP Grade groups (GG) 1, 2 or 3)
4. MRI-visible tumour(s) of PIRADS v2 grade 3 or higher and able to be delineated on T2 and diffusion-weighted imaging +/- dynamic contrast-enhanced imaging. Tumour nodule visible on MRI should be considered able to be boosted by treating clinician and \<2.5cm in maximal dimension. MRI must be performed within 3 months of trial entry
5. The MRI-defined lesion must be confirmed as malignant on biopsies (any Gleason grade is sufficient as long as Gleason score is reported).
6. MRI stages mT1 and T2 or mT3a with ≤ 1mm tumour outside gland AND otherwise favourable intermediate risk characteristics (Gleason 3+3, 3+4)(as staged by AJCC TNM 2018)
9. Ability of the participant to understand and the willingness to sign a written informed consent (IC) form.
10. Ability/willingness to comply with the patient reported outcome questionnaires schedule throughout the study.
You may not be if
1. Contraindications to MRI (e.g. pacemaker, potentially mobile metal implant, claustrophobia)
2. IPSS Score \> 19
3. High grade disease (GG3) occult to MRI-defined lesion. As a guide, any pathology for which you would consider surveillance is allowed outside of the MRI-defined area.
4. Prostate volume \>90cc
5. Comorbidities which predispose to significant toxicity (e.g. inflammatory bowel disease) or preclude long term follow up
6. Hip replacement, or other pelvic metalwork which causes artefact on diffusion-weighted imaging
7. Previous pelvic radiotherapy
8. Patients needing \>6 months of ADT due to disease parameters.
9. Previous invasive malignancy within the last 2 years excluding basal or squamous cell carcinomas of the skin, low risk non-muscle invasive bladder cancer (assuming cystoscopic follow up now negative) or small renal masses on surveillance.
Clareo Health | Dose De-escalation in Prostate Radiotherapy Using an MR-Linac in Two Fractions
