ABSTRACT
Objective@#To evaluate gastrointestinal (GI) patient reported outcomes (PROs) in cervical cancer patients treated with definitive radiotherapy (RT), comparing 3D conformal RT (3DCRT) vs. intensity modulated/volumetric modulated arc therapy (IMRT/VMAT). @*Methods@#An analysis of patients treated with definitive RT between 2015–2018 was performed. GI PROs were prospectively collected at baseline, during RT (acute), ≤12 weeks after RT (subacute), and >12 weeks after RT (late). GI PROs evaluated three symptom domains: bowel problems (BPs), bowel bother (BB), and abdominal problems (APs). Multiple linear regression analysis was performed to investigate associations between mean changes of symptom scores with clinical and dosimetric variables. @*Results@#The cohort included 167 patients. A total of 100 (60%) patients were treated with IMRT/VMAT and 67 (40%) with 3DCRT. In the subacute phase, the mean change of symptom scores from baseline in 3DCRT vs. IMRT/VMAT were +0.9 vs. −1.15 (p=0.004) for BP, +2.18 vs. −0.10 (p=0.019) for BB, and +1.41 vs. −0.38 (p=0.021) for AP. Likewise, in the late phase, mean changes were +0.72 vs. −0.82 (p=0.014) for BP, +1.98 vs. −0.03 (p=0.008) for BB, and +1.29 vs. −0.31 (p<0.001) for AP. On multiple linear regression, use of 3DCRT vs. IMRT/VMAT was associated with greater mean changes in subacute BP (p=0.023) and late phase AP (p=0.019). A higher small bowel V50Gy was associated increased symptom scores in late AP (p=0.012). @*Conclusion@#3DCRT was associated with significantly greater worsening of GI PRO symptom scores in the subacute and late phase. These data support the ongoing use of IMRT/VMAT in routine practice.