Purpose: Therapeutic results were analyzed in 39 patients with roentgenographically occult lung cancer (ROLC), and the significance and optimal dose of this therapy were evaluated.
Methods and materials: The subjects were 39 patients who underwent intraluminal irradiation between May 1987 and August 1999. Radiotherapy was performed by combining external irradiation with intraluminal irradiation using middle-dose-rate iridium (four 370-MBq wires) through a catheter with a spacer, which held the source in the center of the bronchus. The doses of radiation 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 local 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 severe radiation injury was observed.
Conclusions: Considering that ROLC often occurs as multiple cancers and that many patients with ROLC have reduced lung function, radiation therapy by a combination of intraluminal irradiation and external irradiation is expected to replace surgery as the first choice for the treatment of this disease in the twenty-first century.