Involved-field radiotherapy is effective for patients 70 years old or more with early stage non-small cell lung cancer.

BACKGROUND AND PURPOSE

Non-small cell lung cancer (NSCLC) accounts for approximately 80-85% of all lung cancers, especially in patients 70 years old or more. In this study, we investigated the efficacy and safety of involved-field radiotherapy (IFRT) for patients 70 years old or more with early stage NSCLC.

PATIENTS AND METHODS

We conducted a multicenter prospective study in elderly patients with NSCLC treated with intensity-modulated radiotherapy (IMRT). From January 1999 to December 2001, 80 patients with medically inoperable or refused surgery early stage (I/II) NSCLC were eligible for toxicity and treatment response analysis. IMRT plans were designed to deliver 66.6 Gy to involved-field that included only the primary tumor and clinically enlarged lymph nodes using six equidistant coplanar 6-MV beams. Elective nodal failure (ENF) was defined as a recurrence in an initially uninvolved lymph node in the absence of local failure.

RESULTS

The objective response rate of all patients was 88.6% with a median overall survival (OS) time of 38 months and the 1-, 2- and 5-year OS rates and local progression-free survival (LPFS) rates were 65.8%, 55.7%, 25.3% and 84.8%, 59.5%, 34.2%, respectively. The medians OS time for patients with gross tumor volume (GTV) >100.8 cm3 and GTV < or =100.8 cm3 were 13 and 50 months, respectively (p=0.0001). Only 29 patients (36.7%) with ENF were identified, with a median time to treatment failure of 55 months (range, 49-61 months) after treatment. There were no treatment-related deaths or grade 4 toxicity. Grade 3 toxicities were esophagitis (1.3%), radiation pneumonitis (3.8%) and hematological effects (2.5%).

CONCLUSIONS

This study indicated that IFRT using IMRT did not cause a significant amount of failure in lymph node regions not included in the tumor volume and improved outcomes in elderly patients. Therefore, IFRT is an acceptable technique in the treatment of elderly inoperable NSCLC.