Abstract
Background: Pemetrexed is a folate antimetabolite used in the management of advanced adenocarcinoma of the lung. We sought to assess the impact of pemetrexed on intracranial disease control and radiation-related toxicity among patients with adenocarcinoma of the lung who received stereotactic radiation for brain metastases. Materials/Methods: We identified 149 patients with adenocarcinoma of the lung and newly diagnosed brain metastases without a targetable mutation receiving stereotactic radiation. Kaplan–Meier plots and Cox regression were employed to assess whether use of pemetrexed was associated with intracranial disease control and radiation necrosis. Results: Among the entire cohort, 105 patients received pemetrexed while 44 did not. Among patients who were chemotherapy-naïve, use of pemetrexed (n = 43) versus alternative regimens after stereotactic radiation (n = 24) was associated with a reduced likelihood of developing new brain metastases (HR 0.42, 95% CI 0.22–0.79, p = 0.006) and a reduced need for salvage brain-directed radiation therapy (HR 0.36, 95% CI 0.18–0.73, p = 0.005). Pemetrexed use was associated with increased radiographic necrosis. (HR 2.70, 95% CI 1.09–6.70, p = 0.03). Conclusions: Patients receiving pemetrexed after brain-directed stereotactic radiation appear to benefit from improved intracranial disease control at the possible expense of radiation-related radiographic necrosis. Whether symptomatic radiation injury occurs more frequently in patients receiving pemetrexed requires further study.
Original language | English |
---|---|
Pages (from-to) | 511-518 |
Number of pages | 8 |
Journal | Radiotherapy and Oncology |
Volume | 126 |
Issue number | 3 |
DOIs | |
State | Published - Mar 2018 |
Keywords
- Adenocarcinoma of Lung
- Adenocarcinoma/drug therapy
- Aged
- Antineoplastic Agents/administration & dosage
- Brain Neoplasms/drug therapy
- Brain/pathology
- Female
- Humans
- Kaplan-Meier Estimate
- Lung Neoplasms/drug therapy
- Male
- Middle Aged
- Necrosis
- Pemetrexed/administration & dosage
- Radiation Injuries/etiology
- Radiosurgery/adverse effects
- Retrospective Studies