A Phase I//II Study of Computed Tomography-Guided Interstitial High-Dose-Rate Brachytherapy in Combination with Regional Positive Lymph Node Intensity-Modulated Radiation Therapy for Locally Advanced Peripheral Non-Small Cell Lung Cancer

Abstract

To evaluate the therapeutic results and toxicity of computed tomography (CT)-guided interstitial high-dose-rate (HDR) brachytherapy in combination with regional positive lymph node intensity-modulated radiotherapy(IMRT) for patients with locally advanced peripheral non-small cell lung cancer (NSCLC). This studies was a phase I /II trial reporting 3-year survival data as well as the incidence of toxicities.Thirty-two patientswith histologically proven T1–3 N1-2 M0(IIb/IIIa/IIIb:3/9/20) non-small cell lung cancer were enrolled in the prospective phase I/II trial.Written informed consent was obtained from each participant.Primary tumors were treated via HDR brachytherapy. The dose to 90% of the gross lung tumor volume, D90%, received at single 30 Gy. The dose to 95% of the planning target volume of malignant lymph nodes , D95%, received at least 70Gy. The patients received concurrent or sequential chemotherapy.( We have been described in the previous article). We assessed treatment efficacy, radiation toxicity and life quality, especially on the lung function of the recruited patients. The stratified analysis was used to estimate the relationship between the size and location of the primary lesion and the radiation toxicity. The median follow-up was 46 months (range, 19–67 months). There are 25 patients who were followed up more than 3 years. After the brachtherapy, 5 patients developed mild pneumothorax. Grade 3 or 4 acute hematologic toxicity was observed in seven patients, which mainly include leukopenia. 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 50%, respectively, with a median OS of 27.8 months.The 3-years local control(LC) rate for the primary tumor is 80.8%,with a median LC of 32.1months. HDR brachytherapy in combination with regional positive lymph node radiotherapy results in good tolerability and promising outcome in patients with peripheral locally advanced NSCLC.A single dose of 30Gy delivered to primary tumor has showed excellent local control, with no significantly increase the incidence of radiation injury.