Randomized Pilot Study of 20 Gy in 5 Fractions versus 27 Gy in 3 Fractions Radiotherapy for Treating Painful Bone Metastases: A Single Institution Experience.

PURPOSE: Radiotherapy is a very effective tool in the treatment of painful bone metastases. The aim of this study was to compare the palliative effect of radiotherapy between the standard fractionation schedule 20 Gy over 5 fractions (20Gy/5fr) and the high biological dose schedule 27 Gy over 3 fractions (27Gy/3fr) which is frequently used in Stereotactic body radio-surgery (SBRT). METHODS: Patients were randomized to receive (20Gy/5fr)or (27Gy/3fr). The primary aim of the study was pain relief using the numeric rating scale (NRS), after three months of radiation therapy. Secondary end points include pain relief immediately after finishing radiation therapy (within one week), and narcotic relief after three months of radiation therapy. RESULTS: Twenty-two patients with painful bone metastases were included. 12 patients received (20Gy/5fr) and 10 patients received (27Gy/3fr). Male patients were predominant on both arms (81.8%) with a mean age of 58 years [ranging between 19-72 years]. For pain relief after three months of radiation therapy, partial pain relief was documented in 9 patients (75%) with (20Gy/5fr) and in 8 patients (80%) with (27Gy/3fr) with a p- value of 0.6. Additionally, narcotic relief after three months was equal for both groups. For immediate pain relief, partial pain relief was seen in one patient (8%) with (20Gy/5fr) versus seven patients (70%) with (27Gy/3fr) with a p value of 0.06. The increase in immediate pain relief in the 27Gy arm was numerically but not statistically significant. CONCLUSION: SBRT and standard fractionation radiation therapy had equal effectiveness for pain relief, when the assessment was done after three months of radiation therapy. Interestingly, SBRT had a better immediate pain relief. 
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Contrast-Enhanced Perfusion MR Imaging to Differentiate Between Recurrent/Residual Brain Neoplasms and Radiation Necrosis

Purpose: To determine the value of dynamic susceptibility contrast enhanced (DSC) MRI (magnetic resonance imaging) perfusion in the characterization of newly developed/enlarging lesions within irradiated regions after treatment of brain tumors. Methods: This prospective cross-sectional study covered 23 patients, 12 females and 11 males. All cases initially presented with histologically proven malignant brain tumors and underwent surgical intervention followed by radiotherapy (+/- chemotherapy). On follow up imaging, they presented with newly developed/progressively enhancing mass lesions at the sites of the primary tumors. All patients then underwent conventional MRI, DSC MRI perfusion and MR spectroscopy. Results: In our study, we found DSC MR perfusion to be a useful non-invasive method for differentiating recurrent brain tumors from radiation necrosis. This approach allows hemodynamic measurements to be obtained within the brain as the relative cerebral blood volume (rCBV) to complement the anatomic information obtained with conventional contrast enhanced MR imaging. The sensitivity and specificity of DSC MR perfusion for differentiation were found to be 77.8% and 80.0%, respectively. Conclusion: DSC MR perfusion is a promising technique in differentiating recurrent brain tumors from radiation necrosis as it has acceptable spatial resolution and can be routinely performed in the same settings after conventional MRI.