Long-term Observation of 64 Patients with Roentgenographically Occult Lung Cancer Treated with External Irradiation and Intraluminal Irradiation Using Low-dose-rate Iridium

Abstract

Therapeutic results of intraluminal irradiation were analyzed in 64 patients with roentgenographically occult lung cancer (ROLC). The subjects were 64 patients who underwent intraluminal irradiation between 1987 and 2003. Radiotherapy was performed by combining external irradiation with intraluminal irradiation using low-dose-rate iridium (four 370-MBq wires) through a catheter with a spacer. The doses of radiation were 0-70 Gy (median value 46 Gy) by external irradiation and 10-60 Gy (median value 29.3 Gy) by intraluminal irradiation. The therapeutic effect was CR in 63 patients and PR in 1 patient, and local recurrence was observed in a PR case and in seven of the 63 patients who showed CR. The 5-year overall and relapse-free survival rates were 56 (95% CI, 43-69%) and 55% (95% CI, 43-68%), respectively. Fatal pulmonary hemorrhage was observed in one case. Considering the facts that ROLC often occurs as multiple cancers and that many patients with ROLC have reduced lung function, radiation therapy by a combination of intraluminal and external irradiation may replace surgery as the first choice for the treatment of this disease.