Rebalancing treatment outcomes in rectal cancer

Abstract

Risks and benefits of short course radiotherapy with prolonged interval to surgery In order to counsel intermediate risk rectal cancer patients on the choice between short course radiotherapy with immediate surgery versus short course radiotherapy with prolonged interval to surgery, information on risks and benefits of both treatment strategies is needed. Chapter 2 provides detailed information on the toxicity during short course radiotherapy with prolonged interval to surgery. Chapter 3 aims to confirm the advantage in the postoperative complication and pathological complete response rate following SCRT with a prolonged interval compared to direct surgery, that was demonstrated by the Stockholm III trial, in a Dutch nationwide database. Radiotherapy dose-escalation for improving organ preservation rates The majority of patients would prefer organ preservation over surgical management, but only a small proportion of patients reaches a cCR after standard neoadjuvant treatments. The randomised RECTAL-BOOST trial aimed to increase the proportion of pCR by administering dose-escalated CRT for locally advanced rectal cancer. In chapter 4 the 2-year follow-up data on quality of life and oncological outcomes of participants to the RECTAL-BOOST trial are analysed. The RECTAL-BOOST trial followed the trials within cohorts (TwiCs) design. The experience of control patients with this trial design is evaluated in chapter 5. Chapter 6 describes the protocol of the preRADAR trial, wherein SCRT will be dose-escalated for intermediate risk rectal cancer using the new technique of magnetic resonance-guided radiotherapy.