OBJECTIVE
To study the clinical characteristics of lung cancer bone metastases and the efficiency of palliative radiotherapy.
Subjects and methods. The study that consisted of 3 stages analyzed 819 cases of treated patients with skeletal metastases of different primary locations. It included 71 (8.7%) patients with lung cancer skeletal metastases. The treatment efficiency was evaluated by the frequency of a complete general analgesic effect, by a relative reduction in pain syndrome, and by pain recurrence rates. The study protocol provided the use of a total focal dose of 13 to 26 Gy in 2—4 fractions of 6.5 Gy.
RESULTS
The mean duration of follow-up was 5.3 months (range 1—30 months). Spinal metastases were detected in most cases (32 (45.1%) patients); pelvic bones were noted to be affected in 14 (19.7%) cases; long bones were in 11 (15.5%) cases. The initial intensity of the pain syndrome was significantly higher in lung cancer; and the relative reduction of pain was lower than those in breast cancer metastases (p<0.01), the low probability of achieving complete pain relief was at the limit of significance (p=0.06). There were no significant differences in the efficiency of radiation therapy depending on the tumor morphology (p=0.36). However, attention is drawn to the higher frequency of a complete analgesic effect in presence of bone metastases from adenocarcinoma versus squamous cell carcinoma (50% vs 18.2%). The probability of living without pain syndrome progression at 6 and 12 months was 70%, and that of complete pain relief within the same period was 40 and 34%, respectively.
CONCLUSION
Based on the findings, lung cancer skeletal metastases should be classified as relatively radioresistant lesions with the probability of achieving a complete analgesic effect in less than half of the cases. At the same time, the high overall efficiency of irradiation at a dose of 26 Gy in 4 fractions of 6.5 Gy and good treatment tolerability allow this radiation therapy procedure to be considered as an optimal option for use in clinical practice.
