Effectiveness of accelerated radiotherapy for patients with inoperable non-small cell lung cancer (NSCLC) and borderline prognostic factors without distant metastasis: a retrospective review.

PURPOSE: The standard treatment for patients with unresectable or medically inoperable non-small cell lung cancer (NSCLC) and good prognostic factors (e.g., weight loss [WL] < or = 5% and Karnofsky performance status [KPS] > or = 70) is induction chemotherapy followed by definitive radiotherapy to the primary site at 1.8-2.0 Gy per fraction with a total dose of 60-63 Gy to the target volume. Patients with poor prognostic factors usually receive radiotherapy alone, but the fractionation schedule and total dose have not been standardized. To attempt to optimize irradiation doses and schedule, we compared the effectiveness of accelerated radiotherapy (ACRT) alone to 45 Gy at 3 Gy per fraction with standard radiation therapy (STRT) of 60-66 Gy at 2 Gy per fraction in regard to tumor response, local control, distant metastasis, toxicity, and survival. METHODS AND MATERIALS: Fifty-five patients treated with radiation for NSCLC at The University of Texas M. D. Anderson Cancer Center between 1990 and 1994 were identified. All 55 patients had node-positive, and no distant metastasis (N+, M0) of NSCLC. Two cohorts were identified. One cohort (26 patients) had borderline poor prognostic factors (KPS less than 70 but higher than 50, and/or WL of more than 5%) and was treated with radiotherapy alone to 45 Gy over 3 weeks at 3 Gy/fraction (ACRT). The second cohort (29 patients) had significantly better prognostic factors (KPS > or = 70 and WL < or = 5%) and was treated to 60-66 Gy over 6 to 6 1/2 weeks at 2 Gy per fraction (STRT) during the same period.
RESULTS: In the first cohort treated by ACRT, the distribution of patients by AJCC stage was IIB 8%, IIIA 19%, and IIIB 73%. Sixty-two percent had KPS <70, and 76% had a WL of >5%. The maximum response rate as determined by chest X-ray was 60% among 45 of 55 patients who were evaluable for response: combined complete responses (20%) and partial responses (40%). Overall survival in these patients was 13% at 2 and 5 years, with a locoregional control rate of 42% and a freedom from distant metastasis rate of 54%. The ACRT cohort treated with 3 Gy per fraction had significantly lower KPS scores (p = 0.003) and greater WL (p = 0.063) than the cohort STRT treated with 2 Gy per fraction. However, treatment results and toxicity were not significantly different between the two cohorts in spite of significantly better prognostic factors in the STRT cohort.
CONCLUSIONS: Despite having worse prognostic factors, the cohort treated with radiotherapy alone to 45 Gy at 3 Gy per fraction over 3 weeks (ACRT) had response rates, locoregional control, and overall survival comparable to those in the cohort treated by a total dose of 60-66 Gy at 2 Gy per fraction over 6 to 6 1/2 weeks (STRT). Given that accelerated treatment schedules decrease treatment time and cost less, these may, in the current health care environment, be important factors for health care providers to consider in treating patients who have locally advanced NSCLC and borderline poor prognostic factors.