Second line palliative endobronchial radiotherapy with HDR Ir 192 in recurrent lung carcinoma.

PURPOSE: To observe the efficiency of reirradiation with high dose rate intraluminal brachytherapy in symptomatic palliation of recurrent endobronchial tumors. MATERIALS AND METHODS: Between January 1994 and June 1998, 21 patients diagnosed with recurrent endobronchial tumors following external beam radiotherapy were treated palliatively with high dose rate intraluminal irradiation at Hacettepe University Oncology Institute. A single fraction of 10 Gy was prescribed to the specified area in 9 patients and 15 Gy to 12. RESULTS: Endobronchial treatment improved the performance and reduced symptomatology in 17 (81%) patients. Ten dyspneic patients (10/14, 71%) recovered clinically with an accompanying radiological downstaging. The median symptomatic palliation was 45 days (range, 0-9 months), and the overall median survival was 5.5 months (range, 4-12 months). The palliative intrabronchial brachytherapy was well tolerated, with the exception of in one patient with a fatal hemorrhage, and another with medically salvaged bronchospasm and intrabronchial edema. CONCLUSION: Recurrent patients with a history of previous thoracic external beam irradiation can be effectively palliated with high dose rate endobronchial reirradiation if the symptoms are directly related to the endobronchial tumor.

Protective effects of melatonin on the ionizing radiation induced DNA damage in the rat brain.

Melatonin is an endogenously produced antioxidant with radioprotective actions while ionizing radiation is a well-known cytotoxic and mutagenic agent of which the biological results are attributable to its free radical producing effects. The effect of melatonin on the DNA strand breakage and lipid peroxidation induced by ionizing radiation in the rat brain were investigated in order to clarify its radioprotective ability. The DNA strand breakage in rat brain exposed to 1000 cGy ionizing radiation was assessed by alkaline single cell gel electrophoresis and the lipid peroxidation was evaluated by measuring thiobarbituric acid reactive substances (TBARS) concentrations. A significant increase in DNA damage (p < 0.05) and TBARS concentrations (p < 0.01) was found in the radiation treated rat brain. Pre-treatment of rats with intraperitoneal doses of 100 mg/kg melatonin provided a significant decrease in the DNA strand breakage and lipid peroxidation. Our results indicate that melatonin can protect brain cells from oxidative damage induced by ionizing radiation.

Reverse seeding of recurrent intraspinal malignant meningioma.

Meningiomas are common intracranial and intraspinal tumors and constitute 15-20% of all primary brain tumors. Ten to 15% of all meningiomas are considered malignant. The main treatment of meningiomas is surgical resection. Meningioma recurrence following surgery is frequent. However, it is not clear whether recurrent meningiomas, close or distant to the primary resection site, arise from incomplete resection, dissemination of tumor fragments or from independent tumor growth. We herein describe a 40-year-old woman with intraspinal malignant meningioma recurring each time upwards, i.e. apparently by reverse way of seeding, via cerebrospinal fluid.