Rebalancing treatment outcomes in rectal cancer

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.