The authors of a new study published in the journal Radiotherapy & Oncology have cautioned against a rapid transition to using post-prostatectomy intensity-modulated (IMRT) over 3D-conformal (3D-CRT) radiotherapy.
Although there is a lack of high-quality evidence demonstrating superior functional and oncological outcomes compared to 3D-CRT, IMRT is being rapidly adopted in the postprostatectomy setting. The current study used real-world data to compare genitourinary (GU) and gastrointestinal (GI) toxicity after post-prostatectomy IMRT or 3D-CRT.
This population-based study included all men diagnosed with prostate cancer and treated with post-prostatectomy 3D-CRT (n=2422) and IMRT (n=603) in NHS England between 1 January 2010 and 31 December 2013.
In the IMRT group, the rate of GI events was 5.5/100 person-years of follow-up compared to 5.8/100 person-years in the 3D-CRT group (unadjusted HR 0.89; 95% CI 0.70-1.13; P=0.32). The rate of GU events was 3.8/100 person-years in the IMRT group compared to 5.4 in the 3D-CRT group (unadjusted HR 0.67; 95% CI 0.51-0.88; P<.01 however following adjustment there was no statistically significant difference in either gi hr ci p="0.26)" or gu toxicity between the groups.>
There was a trend toward reduced cumulative GU toxicity with time with IMRT. Patients who started radiotherapy more than six months after radical prostatectomy (RP) were less likely to experience GU toxicity than those who started treatment within six months (adjusted HR 0.72; 95% CI 0.59-0.89; p <.01 men who received a hypofractionated regimen were less likely to experience gi toxicity ci p than those conventional fractionated regimen.>
Based on the findings, the authors “caution against a rapid transition to IMRT in the postprostatectomy setting until further studies provide data that would demonstrate that IMRT has superior functional and oncological outcomes”.