Pelvis Adaptive Radiotherapy (ART)

Pelvis Adaptive radiotherapy (ART) is a two phase study looking at using adaptive radiotherapy to help reduce toxicity for cancer patients having radiotherapy in the pelvic region. Adaptive radiotherapy is a new technology that provides the ability to account for daily changes in anatomy. Adaptive radiotherapy also provides a foundation for which radiotherapy margins might be safely reduced. Phase 1 of this study is looking to see if a radiation therapist centred adaptive workflow can be implemented. If phase 1 of this study is safe and feasible, the study will proceed to phase 2. Phase 2 of the study looks at using adaptive technology to reduce radiation treatment margins. The primary aim of this study is to see whether margin reduced treatment using adaptive radiotherapy can reduce side effects for patients with cancer in the pelvic area.

Despite major technological advancements in the delivery of pelvic radiation therapy including the use of dynamic therapy, image guidance, integrated boosting and stereotactic techniques, toxicity from pelvic radiation remains a significant issue impacting on patient's quality of life and preventing the delivery of higher (and more curative) doses of radiation. Although evidence showed that adaptive radiotherapy demonstrating promising reduction of acute toxicity, the uptake of adaptive radiotherapy remains poor as adaptive radiation therapy is very labour intensive, time consuming and usually requires a radiation oncologist (RO) and Medical Physicist in attendance to review/modify target contours. These practices of daily multi-disciplinary team (MDT) in person attendance is not sustainable in the long term. Since 2021, Royal North Shore Hospital has been treating patients with cancer in the pelvic with Adaptive Radiation Therapy (ART) and Radiation Therapists (RT) at the site have undergone a rigorous University based Advanced Practitioner training programme. This study aims to evaluate RT-led ART in a randomised trial to assess the safety and feasibility of ART in a two stage phase 3 randomised controlled trial. If this study can prove safety and feasibility in the first phase, it will proceed to the second phase of the study which will look at using adaptive radiotherapy to safely reduce CTV and PTV margins. The primary aim of the study will be to measure the difference in combined acute patient reported gastrointestinal (GI) and genitourinary (GU) toxicity between ART with margin reduction versus standard radiotherapy. Secondary aims will be to look at differences in clinician and patient reported acute and late GI and GU toxicity, disease free survival locoregional control, location of recurrence, the efficiency of ART including time taken per treatment, radiation dosimetric differences between the treatment arms and patients' perception of ART.

Inclusion Criteria: 1. Age \> 18 2. ECOG performance status 0-2 3. Patients receiving curative or adjuvant pelvic radiation including: 1. Prostate cancer where nodal treatment is required 2. Prostate cancer post prostatectomy 3. Bladder cancer 4. Rectal cancer 5. Anal cancer 6. Adjuvant radiotherapy for gynaecological cancers 7. Pelvic Lymph nodes only 4. Ability to understand and the willingness to sign an informed consent Exclusion Criteria: * Hip prosthesis * Patient separation from approximate radiation centre to skin edge \> 24cm, measured on diagnostic scan