Phase I/II study of treatment of locally advanced (T3T4) non-oat cell lung cancer with high dose radiotherapy (rapid fractionation): Radiation Therapy Oncology Group Study.

The Radiation Therapy Oncology Group (RTOG) completed a pilot study to test the feasibility of high dose of radiation therapy and its impact on tumor control and survival. From April 1, 1983 through May 1985, a total of 56 patients were treated on this protocol. All patients had locally advanced disease without distant metastases. The treatment regimen consisted of delivering 7500 cGy in 28 fractions over 5.5 weeks to the tumor, while the nodal bearing areas received 5040 cGy in the same period (daily dose to the mediastinum was 180 cGy; daily dose to gross tumor was 268 cGy). This is a considerably higher dose, with a TDF of 142 compared with a TDF of 92 (conventional fractionation of 6000 cGy in 6 weeks), which is the highest dose used in previous RTOG studies. Doses in this protocol (7500 cGy) was corrected for lung transmission whereas doses in prior RTOG protocols (6000 cGy) were uncorrected. Thus, after correction dose of 6600 cGy was calculated and coded for comparison. All short-term toxicities were acceptable, and the only major toxicity was one third-degree esophagitis in a patient with a follow-up of 12 months. Forty-four out of fifty-six patients received prescribed dose of irradiation. There were 17 complete responders and 15 partial responders, with an overall response rate of 32 out of 44 (72.7%). At the time of this report, there were 9 patients alive (NED); 5 died without tumor; and the remainder died of tumor or unknown.