Whole-brain radiation fails to boost intracerebral gefitinib concentration in patients with brain metastatic non-small cell lung cancer: a self-controlled, pilot study.

Purpose: Whole-brain radiation therapy (WBRT) is generally considered as an efficient strategy to improve blood-brain barrier (BBB) permeability by damaging BBB structure and is therefore, used as a promising pretreatment of chemotherapy. However, the impact of radiotherapy on leaky BBB is still controversial for the reason that BBB of metastatic brain tumor lesion had been breached by tumor metastasizing. Herein, we conducted a self-controlled study to evaluate the effect of WBRT on the permeability of BBB in non-small cell lung cancer (NSCLC) patients with brain metastases (BM).

Method: A prospective self-controlled research was performed. Radiation-naive NSCLC patients with BM were enrolled and treated with gefitinib for 2 weeks, and then concurrently combined with WBRT for 2 weeks. Plasma and cerebrospinal fluid (CSF) before and after WBRT were collected on day 15 and 29 after the initiation of gefitinib treatment. The concentrations of gefitinib in these samples were measured by HPLC.

Results: Three patients were enrolled and evaluated. The concentrations of gefitinib in plasma and CSF pre-WBRT were comparable to those of post-WBRT. Consequently, no significant change was noted in the CSF-to-plasma ratios of gefitinib before and after WBRT (2.79 ± 1.47 vs. 2.35 ± 1.74 %, p = 0.123).

Conclusions: The WBRT may not affect the BBB permeability by determining the concentration of gefitinib in NSCLC patients with BM.