Effect of hyperthermia combined with external radiation therapy in primary non-small cell lung cancer with direct bony invasion

Purpose: Local control in lung cancer directly invading the bone is extremely poor. Effects of regional hyperthermia combined with conventional external beam radiation therapy were evaluated. Materials and methods: Thirteen patients with non-small lung cancer (NSCLC) with direct bony invasion were treated with hyperthermia plus irradiation (hyperthermia group). The treatment outcome was compared with the historical treatment results in 13 patients treated with external radiation therapy alone (radiation alone group). In patients with no distant metastasis, radiation therapy at a total dose of 60-70 Gy was administered to both groups. Hyperthermia was performed for 45-60 min immediately after irradiation for two-four sessions with radiofrequency capacitive heating devices. Results: For primary response, 10 of the 13 tumours responded to the treatment (3 CR, 7 PR) in the hyperthermia group, whereas seven tumours responded (1 CR, 6 PR) in the radiation alone group. The 2-year local recurrence-free survival rate for clinical M-0 patients in the hyperthermia group and that in the radiation alone group were 76.1 and 16.9%, respectively. Three patients died of distant metastases within 2 years in the hyperthermia group, but two out of three tumours histologically disappeared, even in the autopsy examination. The 2-year overall survival rate for clinical M0 patients in the hyperthermia group and that in the radiation alone group were 44.4 and 15.4%, respectively. No severe pulmonary complication was observed in either group. Conclusions: Regional hyperthermia combined with conventional irradiation could be a tool to improve local control in patients with NSCLC deeply invading the chest wall.