Expanded pelvic radiotherapy fields for treatment of local-regionally advanced carcinoma of the cervix: Outcome and complications

OBJECTIVE: Recent anatomic and radiographic studies have indicated that standard external beam radiation portals may not adequately treat the volume at risk in patients with local-regionally advanced cervical cancer. A feasibility study was undertaken to evaluate toxicity, outcome, and patterns of failure in patients with advanced cervical cancer treated by expanded pelvic radiation fields. STUDY DESIGN: Thirty-eight women with stages IIB and III cancers of the cervix confined to the pelvis were irradiated with curative intent with expanded pelvic radiation portals. Anteriorly and posteriorly, the median field length and width were 20 and 17.5 cm, respectively. Lateral fields had a median width of 16.5 cm, and the posterior border encompassed the entire sacral silhouette. The median external beam whole-pelvis dose was 4140 cGy, with overall point A dose boosted by brachytherapy to 8315 cGy. RESULTS: Stage IIB patients (n = 22) had a 4-year actuarial local control rate of 70%, freedom from distant metastases rate of 62%, and disease-specific survival rate of 76%. In stage III disease (n = 16), the 4-year actuarial local control, freedom from distant metastases, and disease-specific survival rates were 80%, 48%, and 53%, respectively. Radiographically determined nodal status was an important predictor of disease-specific survival and distant metastases but not local control. The 4-year disease-specific survival rate was 40% in 11 patients with nodal disease compared with 71% in 27 node-negative patients (p < 0.01). The rate of freedom from distant metastases was 36% in node-positive patients versus 67% in node-negative cases (p < 0.01). The actuarial overall 4-year severe late complication rate was 14.8%. CONCLUSION: This study has demonstrated that expanded fields for pelvic radiotherapy is feasible, well tolerated, and therapeutic. The pelvic field design concepts presented should be integrated into radiation oncology practice.