Three irradiation treatment options including radiosurgery for brain metastases from primary lung cancer

Abstract

Purpose: To determine local control and survival rates in 92 patients with 145 brain metastases treated with three options of radiotherapy including stereotactic radiosurgery (SR).

Methods: Between July 1994 and August 2002, 92 consecutive patients with 145 metastases were treated with a SR, 34 with initially SR alone, 22 initially with an association of whole-brain radiotherapy (WBRT) and 36 with SR alone for recurrent new brain metastasis after WBRT. At time of treatment, extracranial disease was controlled in 46 (50%) and uncontrolled in 46 (50%). Pathologies were adenocarcinoma in 54 cases (59%), squamous cell carcinoma in 14 cases (15%), small cell carcinoma in 10 cases (11%) and miscellaneous in 14 cases (15%). All patients underwent only one treatment fraction for 1 or 2 metastases in 73 cases (83%) and for more than 2 metastases for the others.

Results: The characteristics of patients and metastases in the group treated initially with SR alone and in the group treated initially with WBRT+SR were comparable. Median follow-up was 29 months (18-36). Overall, the median and the 1- and 2-year rates of overall survival were, respectively, 9 months, 37 and 20%. A controlled extracranial disease, a high Karnofsky index and a low number of metastasis were independent prognostic factor of overall survival, respectively, HR 0.53 (95% CI 0.31-0.90, P=0.01), HR 0.95 (95% CI 0.92-0.97, P=0.0002), and HR 0.48 (95% CI 0.25-0.90, P=0.02). Thirteen metastases were not controlled (9%). Six-month and 1-year local control rate were, respectively, 93 and 86%. High delivered dose was an independent prognostic factor of local control, HR 0.41 (95% CI 0.18-0.95, P=0.03). A controlled extracranial disease was favourable independent prognostic factor of brain free-disease free survival, HR 0.47 (95% CI 0.2-0.98, P=0.04). Although there was a trend of a better local control, overall and brain disease free survivals rates in the WBRT+SR group compared to SR alone one, the difference were not statistically different.

Conclusion: Local control and survival rates are acceptable for a palliative treatment for the three option of treatment. In this series, the number of patients is not enough great to conclude to the necessity of the association of WBRT to SR. Re-irradiation is a safe treatment after new metastases appeared in previously irradiated area.