BACKGROUND Radiation therapy is effective in palliating pain from bone metastases. We investigated whether 8 Gy delivered in a single treatment fraction provides pain and narcotic relief that is equivalent to that of the standard treatment course of 30 Gy delivered in 10 treatment fractions over 2 weeks. METHODS A prospective, phase III randomized study of palliative radiation therapy was con...

Total radiation dose is not a reliable measure of biological effect when dose-per-fraction or dose-rate is changed. Large differences in biological effectiveness (per gray) are seen between the 2 Gy doses of external beam radiotherapy and the large boost doses given at high dose-rate from afterloading sources. The effects are profoundly different in rapidly or slowly proliferating tissues, that...

PURPOSE To correlate site and diameter of brain metastases with hippocampal sparing in patients treated by RapidArc (RA) technique on whole brain with simultaneously integrated boost (SIB). METHODS AND MATERIALS An RA plan was calculated for brain metastases of 1-2-3 cm of diameter. The whole brain dose was 32.25 Gy (15 fractions), and SIB doses to brain metastases were 63 Gy (2 and 3 cm) or ...

OBJECTIVE To evaluate the dose-response relationship in classical Kaposi's sarcoma (CKS) patients treated with external beam radiotherapy. METHODS Between 1993 and 2004, patients with CKS treated at the Department of Radiation Oncology, Gulhane Military Medical School, Ankara, Turkey were evaluated in this retrospective study. The median age at initial presentation was 60 years. First, we ana...

PURPOSE Interstitial brachytherapy (IBT) is used as an alternative to intracavitary radiotherapy in the management of cervical carcinoma. We have devised a new technique called interstitial brachytherapy guided intensity modulated radiotherapy (IBGIMRT) which can potentially reduce doses to organs at risk (OaRs). It utilizes IMRT planning on the target volume (TV) defined by implantation of IBT...

The present study compared the dosimetry of intensity-modulated radiation therapy (IMRT) and three-dimensional conformal radiation therapy (3D-CRT) techniques in patients treated for high-grade glioma. A total of 20 patients underwent computed tomography treatment planning in conjunction with magnetic resonance imaging fusion. Prescription dose and normal-tissue constraints were identical for t...

During deep space missions, astronauts will be exposed to low doses of charged particle irradiation. The long-term health effects of these exposures are largely unknown. We previously showed that low doses of oxygen ion (16O) irradiation induced acute damage to the hematopoietic system, including hematopoietic progenitor and stem cells in a mouse model. However, the chronic effects of low dose ...

Earlier, we reported that the local exposure of femoral bone marrow to a clinically-relevant course of fractionated radiotherapy [FxRT; 2.0 Gy (q24h x 5) --> 74 Gy] resulted in the delayed appearance of a stromal lesion which temporally appeared after exposures to a threshold dose of 20 Gy FxRT. To further define this threshold dose, the temporal recovery of blood-forming elements ("cobblestone...

Background: The purpose of this study was to evaluate nodal irradiation with conventional three-field's technique. Materials and Methods: Fifty patients with breast cancer were enrolled in this study. Computed tomography scans in the supine treatment position were imported into a treatment planning system. Levels I-III axillary and supraclavicular nodes were identified and their depths to the a...

PURPOSE Hypersensitivity to cell killing of exponentially growing cells exposed to X-rays and gamma rays has been reported for doses below about 0.5 Gy. The reported results have been interpreted to suggest that a dose of 0.5 Gy or less is not sufficient to trigger an inducible repair mechanism. The purpose of this study was to examine this suggested hypersensitivity after multiple low doses (0...