Preliminary Results of a Phase 1/2 Study of Computed Tomography-Guided Interstitial High-Dose-Rate Brachytherapy in Combination With Regional Positive Lymph Node Intensity-Modulated Radiation Therapy in Locally Advanced Peripheral Non–small Cell Lung Canc

Abstract

The purpose of this article is to present preliminary results of computed tomography (CT)-guided interstitial high-dose-rate (HDR) brachytherapy in combination with regional positive lymph node intensity-modulated radiotherapy(IMRT) in patients with locally advanced peripheral non-small cell lung cancer (NSCLC). Thirty-two patients with histologically confirmed NSCLC were eligible in a prospective phase I/II trial. All patients should sign informed consent.Primary tumors were treated via HDR brachytherapy. A single 30 Gy dose was delivered to the 90% isodose line of the gross lung tumor volume. A total dose of at least 70 Gy was administered to the 95% isodose line of the planning target volume of malignant lymph nodes using 6-MV X-rays. The patients received concurrent or sequential chemotherapy.( We have been described in the previous article.) We focus on the late radiation toxicity and life quality, especially on the lung function of enrolled patient. The stratified analysis was used to estimate the relationship between the location of the primary lesion and the radiation toxicity. The median follow-up was 41months (range, 14–62 months). There are 22 patients who were followed up more than 3 years.There were five cases of mild pneumothorax after the brachytherapy. Grade 3 or 4 acute hematologic toxicity was observed in seven patients. During follow-up, there is no case of 1-degreee radiation pneumonia or above, according to late toxicity criteria of RTOG. The overall response rates (complete and partial) for the primary mass and positive lymph nodes were 100% and 94.5%, respectively. The 3-year overall survival (OS) rate were 40.8%, respectively, with a median OS of 25.3 months.The 3-years local control(LC) rate for the primary tumor is 78.1%,with a median LC of 29.1 months. HDR brachytherapy in combination with regional positive lymph node is feasible for peripheral locally advanced NSCLC.The results showed excellent local control and overall survival, with no significantly increase the incidence of radiation injury.