Patients with locally advanced cervical cancer (LACC) are at risk of para-aortic lymph node (PALN) metastasis. Pelvic concurrent chemoradiotherapy, the current standard treatment for LACC, has a PALN failure rate of 9% according to the Radiation Therapy Oncology Group Trial 90–01, suggesting that it may not completely eliminate all microscopic tumors in the PALNs. To minimize the toxicities associated with conventional prophylactic extended-field radiotherapy, our institute use prophylactic semiextended field radiotherapy that includes only the PALNs below the level of the renal vessels. Use of intensity-modulated radiotherapy (IMRT) is another means of reducing the incidence of toxicity. This study evaluated the safety and efficacy of prophylactic semiextended field IMRT (SEF-IMRT) and concurrent cisplatin chemotherapy in patients with LACC.
We retrospectively assessed survival and toxicity in 76 patients with stage IB2–IVA cervical cancer and negative PALNs who received prophylactic SEF-IMRT and concurrent weekly cisplatin (40 mg/m2) between 2004 and 2013. The region targeted by SEF-IMRT included the PALNs below the level of the renal vessels, and the prescribed dose was 50.4 Gy in 28 fractions. Brachytherapy was administered at a dose of 30 Gy in 6 fractions. Survival outcomes were calculated by using the Kaplan–Meier method, and acute and late toxicities were scored according to the Common Terminology Criteria for Adverse Events, version 3.0.
All patients completed the planned SEF-IMRT, as well as brachytherapy. Acute grade ≥3 gastrointestinal, genitourinary, and hematologic toxicities were observed in 2, 0, and 41 patients, respectively. The median follow-up time after SEF-IMRT was 55 (range, 11–124) months. Eight patients developed out-field distant recurrences without PALN failure, and 1 patient experienced out-field PALN failure with simultaneous distant metastasis. No patients had late genitourinary toxicities, and 3 patients had late grade 3 gastrointestinal toxicities. The 5-year overall survival, disease-free survival, local failure-free survival, regional failure-free survival, PALN failure-free survival, and distant metastasis-free survival rates were 85.0%, 84.4%, 96.0%, 97.3%, 98.6%, and 88.4%, respectively.
For patients with LACC, prophylactic PALN irradiation up to the level of the renal vessels reduced PALN recurrence and resulted in favorable outcomes with few severe toxicities.