The Effects of Dose Escalation on Pelvic Lymph Node Control in Patients with Node Positive Cervical Cancer

Abstract

To review our institutional experience treating patients with node positive cervical cancer to assess whether RT dose was associated with pelvic lymph node control or GI toxicity. We retrospectively reviewed 390 patients with carcinoma of the uterine cervix treated with RT between October 1997 and October 2017. We included node positive patients and excluded those with <1 follow-up visit and those treated for palliative intent. Acute and late GI toxicity was recorded for all patients. A total of 77 patients with 206 lymph nodes were identified. Median stage at presentation was FIGO IIB. 13 patients were treated with definitive surgical resection followed by adjuvant radiation, of which 12 were treated to doses ≤50.4Gy. 64 patients were treated with definitive chemo-RT (CRT) of which 37 patients (57.8%) received ≤50.4Gy and 27 (42%) >50.4Gy. Patients treated definitively with pre-CRT LN ≥2cm had inferior pelvic LN control compared to patients with pre-CRT LN <2 cm (12 months, 88% vs 53%; p=0.05). While increased RT dose was not associated with pelvic LN control in patients with pre-RT lymph nodes measuring <2 cm (12 months, 88% vs 80%; p=0.53), RT dose was associated with pelvic lymph node control in patients with pre-RT pelvic LN ≥2 cm (12 months, 88% vs 31%; p=0.04). Acute grade 2 GI toxicity was not associated with RT dose (16% (n=46) vs 11% (n=4); p=0.88). 1 patient developed grade ≥2 late GI toxicity, treated to ≤50.4 Gy. Our experience treating patients with node positive cervical cancer supports the role of dose escalation for patients with regional LN ≥2cm. Higher pelvic LN dose is associated with improved regional control and does not seem to be associated with greater GI toxicity.