Cervical

Late Toxicity After Adjuvant Conventional Radiation Versus Image-Guided Intensity-Modulated Radiotherapy for Cervical Cancer (PARCER): A Randomised Controlled Trial - PDF Version

Chopra S, Gupta S, Kannan S, Dora T, Engineer R, Mangaj A, Maheshwari A, Shylasree TS, Ghosh J, Paul SN, Phurailatpam R, Charnalia M, Alone M, Swamidas J, Mahantshetty U, Deodhar K, Kerkar R, Shrivastava SK.

J Clin Oncol. 2021 Nov 20;39(33):3682-3692. doi: 10.1200/JCO.20.02530.

PURPOSE

Postoperative Adjuvant Radiation in Cervical Cancer (PARCER), a phase III randomised trial, compared late toxicity after image-guided intensity-modulated radiotherapy (IG-IMRT) with three-dimensional conformal radiation therapy (3D-CRT) in women with cervical cancer undergoing postoperative radiation.

METHODS

Patients were randomly assigned to receive either IG-IMRT or 3D-CRT after stratification for the type of hysterectomy and use of concurrent chemotherapy. The primary end point was 3.0-year grade ≥ 2 late GI toxicity assessed using Common Toxicity Criteria for Adverse Events v 3.0 and estimated using time-to-event, intention-to-treat analysis, with a study level type I error of 0.05 and a nominal α of .047 after accounting for one interim analysis. Secondary end points included acute toxicity, health-related quality of life, and pelvic relapse-free, disease-free, and overall survival.

RESULTS

Between 2011 and 2019, 300 patients were randomly assigned (IG-IMRT 151 and 3D-CRT 149). At a median follow-up of 46 (interquartile range, 20-72) months, the 3.0-year cumulative incidence of grade ≥ 2.0 late GI toxicity in the IG-IMRT and 3D-CRT arms were 21.1% versus 42.4% (hazard ratio [HR] 0.46; 95% CI, 0.29 to 0.73; P < .001). The cumulative incidence of grade ≥ 2.0 any late toxicity was 28.1% versus 48.9% (HR 0.50; 95% CI, 0.33 to 0.76; P < .001), respectively. Patients reported reduced diarrhea (P = .04), improved appetite (P = .008), and lesser bowel symptoms (P = .002) with IG-IMRT. However, no difference was observed in the time by treatment interaction. The 3.0-year pelvic relapse-free survival and disease-free survival in the IG-IMRT versus the 3D-CRT arm were 81.8% versus 84% (HR 1.17; 95% CI, 0.68 to 1.99; P = .55) and 76.9% versus 81.2% (HR 1.03; 95% CI, 0.62 to 1.71; P = .89), respectively.

CONCLUSION

IG-IMRT results in reduced toxicity with no difference in disease outcomes.