External irradiation and intraluminal irradiation using middle-dose-rate iridium in patients with roentgenographically occult lung cancer

Purpose: Therapeutic results were analyzed in 39 patients with roentgenogra phically occult lung cancer (ROLC), and the significance and optimal dose o f this therapy were evaluated. Methods and Materials: The subjects were 39 patients who underwent intralum inal irradiation between May 1987 and August 1999, Radiotherapy was perform ed by combining external irradiation with intraluminal irradiation using mi ddle-dose-rate iridium (four 370-MBq wires) through a catheter with a space r, which held the source in the center of the bronchus, The doses of radiat ion were 22-66 Gy (median value 45 Gy) by external irradiation and 10-46 Gy (median value 28 Gy) by intraluminal irradiation. Results: The therapeutic effect was CR in 38 patients and PR in 1, and loca l recurrence was observed in a PR case and 3 of the 38 patients who showed CR, The 3-year and 5-year relapse-free survival rates were both 87%, No sev ere radiation injury was observed. Conclusions: Considering that ROLC often occurs as multiple cancers and tha t many patients with ROLC have reduced lung function, radiation therapy by a combination of intraluminal irradiation and external irradiation is expec ted to replace surgery as the first choice for the treatment of this diseas e in the twenty-first century. (C) 2001 Elsevier Science Inc.