Impact of Boost Irradiation on Pelvic Lymph Node Control in Patients with Cervical Cancer

Abstract

Radiation therapy (RT) for metastatic pelvic lymph nodes (PLNs) is not well established in cervical cancer. In this study the correlation between size of lymph nodes and control doses of RT was analyzed. Between January 2002 and December 2007, 245 patients with squamous cell carcinoma of the cervix treated with a combination of external beam irradiation with or without boost irradiation and high-dose rate brachytherapy were investigated. Size of lymph node was measured by computed tomography before RT and just after 50 Gy RT. Of the 245 patients, 78 had PLN metastases, and a total of 129 had enlarged PLNs diagnosed as metastases; 22 patients had PLN failure. The PLN control rate at 5 years was 79.5% for positive cases and 95.8% for negative cases. In cases with positive PLNs, 12 of 129 nodes (9.3%) developed recurrences. There was significant correlation between PLN control rate and size of PLN after 50 Gy (<10 mm: 96.7%, 10 mm: 75.7 % (P<0.001)). In addition, the recurrence in these poor-response nodes was significantly correlated with dose of RT. Nine of 16 nodes receiving ≤ 58 Gy had recurrence, but none of 21 nodes receiving > 58 Gy had recurrence (P = 0.0003). These results suggested that the response of lymph nodes after RT was a more significant predictive factor for recurrence than size of lymph node before RT, and poor-response lymph nodes might require boost irradiation at a total dose of > 58 Gy.

The Prognosis and Risk Stratification Based on Pelvic Lymph Node Characteristics in Patients With Locally Advanced Cervical Squamous Cell Carcinoma Treated With Concurrent Chemoradiotherapy

“…These results are consistent with previous studies. 20,21 In addition, we focused our attention on the question of how positive PLNs impact the prognosis of advanced cervical cancer. We further analyzed the effects of different PLN characteristics including LN-diameter, LN-volume, LN-number, and the presence of matted/necrotic LN on the outcomes in cervical cancer patients.…”

“…This explained that the prognosis of patients with low-risk PLN characteristics is very good, so there is no need to give excessive treatment for them. On the contrary, for patients with high-risk PLN characteristics, it is necessary to take more intensive therapy with increasing radiation doses of the involved LN 21,38 to improve the rate of pelvic control or with adjuvant chemotherapy 40 for further improvement of survival outcomes. But multicenter randomized trials are necessary to confirm the value of adjuvant chemotherapy.…”