The histopathological evaluation of the effectiveness of melatonin as a protectant against acute lung injury induced by radiation therapy in a rat model.

PURPOSE: This study presents the histopathological evaluation of the effectiveness of melatonin as a protectant against acute lung injury induced by radiation therapy. MATERIALS AND METHODS: Thirty-two Wistar rats were divided into four groups. The rats in Group 1 received melatonin and underwent radiation therapy. The rats in Group 2 received no melatonin and underwent radiation therapy. The rats in Group 3 received melatonin and underwent sham radiation therapy. The rats in Group 4 received no melatonin and underwent sham radiation therapy. Melatonin was administered at a dose of 100 mg/kg using an intraperitoneal injection. Radiation therapy was delivered on a Cobalt-60 unit using a single fraction of 18 Gy through an anterior portal covering the right lung in entirety. The rats underwent euthanasia at 6 weeks following radiation therapy. The lungs were dissected and blinded histopathological evaluation was performed. RESULTS: Concerning the right lung, a decrease in intra-alveolar edema and intra-alveolar erythrocytes was observed despite an increase in activated macrophages, intra-alveolar fibrosis, hyaline arteriosclerosis and alveolar wall thickness for the rats in Group 1 as compared to the rats in Group 2. Concerning the left lung, a decrease in alveolar neutrophils and intra-alveolar erythrocytes was evident despite an increase in activated macrophages, hyaline arteriosclerosis and alveolar wall thickness for the rats in Group 1 as compared to the rats in Group 2. CONCLUSIONS: This study puts forward the histopathological evidence regarding the effectiveness of melatonin as a protectant against acute lung injury induced by radiation therapy through restrained inflammation, regrettably at the expense of promoted fibrosis. The effectiveness of melatonin as a protectant against acute lung injury induced by radiation therapy needs to be evaluated further for the unresolved concerns regarding the safety.

The use of recursive partitioning analysis grouping in patients with brain metastases from non-small-cell lung cancer.

BACKGROUND: This study evaluates the use of recursive partitioning analysis (RPA) grouping in an attempt to predict the survival probabilities in patients with brain metastases from non-small-cell lung cancer (NSCLC). METHODS: Seventy-two patients with brain metastases from NSCLC treated with radiation therapy were included in the study. Sixty-three patients were male and nine patients were female. Their median age was 57 years and their median Karnofsky performance status was 70. At the time of brain metastases, there was no evidence of the intrathoracic disease in 27 patients and the extrathoracic disease was limited to the intracranial disease in 42 patients. In accordance with RPA grouping, 12 patients were in Group 1, 24 patients were in Group 2, and 36 patients were in Group 3. Radiation therapy was delivered to the whole brain at a dose of 30 Gy in 10 fractions in most of the patients. RESULTS: The median survival time was 7 months for Group 1, 5 months for Group 2 and 3 months for Group 3. The survival probability at 1 year was 50% for Group 1, 26% for Group 2 and 14% for Group 3. CONCLUSIONS: This study presents evidence supporting the use of RPA grouping in an attempt to predict the survival probabilities in patients with brain metastases from NSCLC.