On voxel-by-voxel accumulated dose for prostate radiation therapy using deformable image registration.

Since delivered dose is rarely the same with planned, we calculated the delivered total dose to ten prostate radiotherapy patients treated with rectal balloons using deformable dose accumulation (DDA) and compared it with the planned dose. The patients were treated with TomoTherapy using two rectal balloon designs: five patients had the Radiadyne balloon (balloon A), and five patients had the EZ-EM balloon (balloon B). Prostate and rectal wall contours were outlined on each pre-treatment MVCT for all patients. Delivered fractional doses were calculated using the MVCT taken immediately prior to delivery. Dose grids were accumulated to the last MVCT using DDA tools in Pinnacle3 TM (v9.100, Philips Radiation Oncology Systems, Fitchburg, USA). Delivered total doses were compared with planned doses using prostate and rectal wall DVHs. The rectal NTCP was calculated based on total delivered and planned doses for all patients using the Lyman model. For 8/10 patients, the rectal wall NTCP calculated using the delivered total dose was less than planned, with seven patients showing a decrease of more than 5% in NTCP. For 2/10 patients studied, the rectal wall NTCP calculated using total delivered dose was 2% higher than planned. This study indicates that for patients receiving hypofractionated radiotherapy for prostate cancer with a rectal balloon, total delivered doses to prostate is similar with planned while delivered dose to rectal walls may be significantly different from planned doses. 8/10 patients show significant correlation between rectal balloon anterior-posterior positions and some VD values

CogState computerized memory tests in patients with brain metastases: Secondary endpoint results of NRG oncology RTOG 0933

Whole brain radiotherapy (WBRT) is associated with memory dysfunction. As part of NRG Oncology RTOG 0933, a phase II study of WBRT for brain metastases that conformally avoided the hippocampal stem cell compartment (HA-WBRT), memory was assessed pre-and post-HA-WBRT using both traditional and computerized memory tests. We examined whether the computerized tests yielded similar findings and might serve as possible alternatives for assessment of memory in multi-institution clinical trials. Adult patients with brain metastases received HA-WBRT to 30 Gy in ten fractions and completed Hopkins Verbal Learning Test-Revised (HVLT-R), CogState International Shopping List Test (ISLT) and One Card Learning Test (OCLT), at baseline, 2 and 4 months. Tests’ completion rates were 52–53% at 2 months and 34–42% at 4 months. All baseline correlations between HVLT-R and CogState tests were significant (p B 0.003). At baseline, both CogState tests and one component of HVLT-R differentiated those who were alive at 6 months and those who had died (p B 0.01). At 4 months, mean relative decline was 7.0% for HVLT-R Delayed Recall and 18.0% for ISLT Delayed Recall. OCLT showed an 8.0% increase. A reliable change index found no significant changes from baseline to 2 and 4 months for ISLT Delayed Recall (z =-0.40, p = 0.34; z =-0.68, p = 0.25) or OCLT (z = 0.15, p = 0.56; z = 0.41, p = 0.66). Study findings support the possibility that hippocampal avoidance may be associated with preservation of memory test performance, and that these computerized tests also may be useful and valid memory assessments in multi-institution adult brain tumor trials