Radiotherapy for patients with medically inoperable Stage I nonsmall cell lung carcinoma: smaller volumes and higher doses--a review.

BACKGROUND: Surgical resection remains the treatment of choice for patients with stage I nonsmall cell lung carcinoma. However, there is a group of patients who are medically inoperable and are treated with radiotherapy alone. This review summarizes findings from published series of radiotherapy for patients with medically inoperable Stage I lung carcinoma.
METHODS: A literature search was used to identify studies of treatment with radiotherapy alone for patients with medically inoperable Stage I nonsmall cell lung carcinoma. Ten studies that utilized megavoltage irradiation to doses of >55 gray (Gy) in conventional fractionation were selected for analysis.
RESULTS: Radiotherapy doses were similar throughout the series, with a median dose of 60-66 Gy. However, treatment volumes varied considerably, from small "postage stamp" fields to comprehensive lymph node coverage. Averaging the results of these studies showed that approximately 15% of patients will be long term survivors, 25% will die of intercurrent disease, 30% will die of distant metastatic disease and 30% will die after local failure only. Eight of ten series report Grade 3-5 complications occurring in <2% of patients. Analysis of treatment factors affecting survival revealed a consistent benefit of higher radiotherapy doses in terms of local control or disease free survival. No benefit from prophylactic lymph node irradiation was demonstrated.
CONCLUSIONS: Despite the infirm nature of patients with medically inoperable Stage I lung carcinoma, the majority will ultimately die of uncontrolled lung carcinoma. Because complications are uncommon after doses of 60-66 Gy, trials of dose escalation to limited fields are indicated for patients with medically inoperable nonsmall cell carcinoma in an attempt to improve overall survival.