Lymph node–directed simultaneous integrated boost in patients with clinically lymph node–positive cervical cancer treated with definitive chemoradiotherapy: clinical outcomes and toxicity

Objective Lymph node (LN)–positive cervical cancer is associated with a poor prognosis. We report outcomes for women with LN-positive cervical cancer treated with intensity-modulated radiation therapy (IMRT) with dose-escalated simultaneous integrated boost (SIB) to involved LNs. Materials/methods Between 2005 and 2017, 59 women with LN-positive, non-metastatic, cervical cancer underwent definitive chemoradiotherapy (CRT) with an image-guided LN boost to a median dose of 56.25 Gy in 25 fractions. Acute and late adverse events (AEs) were recorded per common terminology criteria for adverse events. The Kaplan-Meier method was used to estimate the overall survival (OS), progression-free survival (PFS), and locoregional control (LRC). Results Median age was 49 years (IQR 37–56). Women had involved LNs in the pelvis (56%) or pelvis and para-aortic (PA) LNs (44%), with a median of 3 (IQR 2–6) grossly involved LNs per patient. Median follow-up was 30 months (IQR 11–45). Estimated 3-year OS, PFS, and LRC were 67% (95% CI, 51%–84%), 60% (95% CI, 45%–76%), and 89% (95% CI, 76%–99%), respectively. PA LN involvement (HR 2.51; 95% CI, 1.05–5.99; p = 0.04) and the presence of ≥ 4 grossly involved LNs (HR 2.79; 95% CI, 1.16–6.71; p = 0.02) were associated with a higher risk of disease progression on univariate analysis. The incidence of treatment-related acute grade 3+ acute GI or GU AEs was 3%, while late GI or GU treatment-related AEs occurred in 12%. Conclusion Chemoradiation with a LN-directed SIB for women with LN-positive cervical cancer is well tolerated and is associated with excellent oncologic outcomes. Summary In this report, we evaluated the oncologic efficacy and adverse events associated with definitive chemoradiotherapy with a simultaneous integrated boost to grossly involved lymph nodes for women with lymph node–positive cervical cancer. We have identified acceptable rates of adverse events and excellent oncologic outcomes, even in a very high risk cohort of women with cervical cancer.