Author(s): Mantini G, Valentini V, Meduri B, Margaritora S, Balducci M,
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Abstract PURPOSE: Low-dose radiotherapy (LDR) (<50 cGy) induces enhanced cell killing in vitro via the hyper-radiation sensitivity phenomenon. Aim of this study was to evaluate the safety and efficacy of a palliative regimen combining pemetrexed and LDR (as a chemopotentiator) on patients affected by recurrent non-small-cell lung cancer (NSCLC). METHODS AND MATERIALS: Eligible patients had an ECOG performance status ≤2, one prior chemotherapy regimen for advanced NSCLC, adequate organ function, measurable lesions. Patients received pemetrexed (500 mg/m(2) IV) and concurrent LDR (40 cGy bid on days 1 and 2) delivered to target pulmonary or metastatic disease. This cycle was repeated fourfold every 21 days. The accrual was determined by the single proportion powered analysis (α=0.05, power=0.8) with H0 ("bad" response probability, 9\% according to literature) and H1 ("good" response probability, 35\% ongoing study); 19 is the number required. RESULTS: Nineteen patients with stage III and IV disease were enrolled. Only one patient experienced neutropenia grade 4. All patients are evaluable for clinical response of irradiated lesion: overall response rate was 42\%. CONCLUSIONS: Low-dose radiotherapy combined with pemetrexed has a similar toxicity profile to chemotherapy alone. The response rate of this novel approach is encouraging, since it was higher than what was reported for pemetrexed alone (42\% versus 9.1\%). Additional scientific investigation of this new treatment paradigm is warranted. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.
This article was published in Radiother Oncol
and referenced in Journal of Nuclear Medicine & Radiation Therapy