This study aimed to compare the outcomes of 125I seed brachytherapy versus external beam radiation therapy (EBRT) for the palliation of painful bone metastases of lung cancer after one cycle of chemotherapy progression.

We analyzed retrospectively 158 patients with painful bone metastases secondary to lung cancer after one cycle of chemotherapy progression treated between June 2013 and May 2016. Seventy-six patients with 96 lesions received 125I brachytherapy (Group A), whereas 82 patients with 98 metastases received EBRT (Group B). Pain intensity on Brief Pain Inventory, percentage of patients with pain severity, and quality of life were recorded prior to treatment (T0), 2, 4, 6, 8, 12, 16, 20, and 24 weeks (T2, T4, T6, T8, T12, T16, T20, and T24) after treatment during a 24-hour period. Cost-effectiveness and number of treatment appointments were also compared between groups.

One hundred and fifty-eight patients had been treated. Visual analog scale for worst pain in Group A was significantly lower than in Group B at T2, T4, T6, T16, T20, and T24. Group A was superior to group B concerning quality of life scores (T2, T4, T20, and T24), cost-effectiveness, and number of treatment appointments. No significant differences were observed for complications.

Compared with EBRT, 125I seed brachytherapy can be an alternative method for painful bone metastases from lung cancer after one cycle of chemotherapy progression.