Search

Background and Purpose: The purpose of this study is to review our experience with platinum fiducials in terms of feasibility of placement and detectability by both MRI and orthogonal x-ray images used in robotic SABR. Materials and Methods: 29 consecutive SABR patients (30 tumors) treated using fiducial tracking between January 2011 and February 2012 were reviewed. A total of 108 fiducials implanted in or around various tumor sites were identified. The pixel value contrast (PVC) of fiducials seen on MRI mages and treatment unit x-ray images of patients and phantoms were analysed. Results: Migration rates were similar for PS versus GS and GC (6.2%). No difference was noted between the mean PVC in cirrhotic versus non-cirrhotic liver (60.4 vs. 47.9; p = 0.074). MRI sequences for tumors in the liver and other organs revealed a mean PVC for platinum superior to that of gold (p<0.001). No PVC difference was seen between gold and platinum on analysis of the treatment unit x-rays. Conclusion: Platinum seeds provide a superior detectability in comparison to gold seeds or coils on MRI images and are detected equally well by an image guidance system using orthogonal x-rays, making them a better choice for fiducial-based CT-MRI registration. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to determine whether the preradiation maximum standardized uptake value (SUVmax) of the primary tumor for [18F]-fluoro-2-deoxy-glucose positron emission tomography (FDG-PET) has a prognostic significance in patients with Stage T1 or T2N0 non-small cell lung cancer (NSCLC) treated with curative radiation therapy, whether conventional or stereotactic body radiation therapy (SBRT). Methods and Materials: Between January 2007 and December 2011, a total of 163 patients (180 tumors) with medically inoperable histologically proven Stage T1 or T2N0 NSCLC and treated with radiation therapy (both conventional and SBRT) were entered in a research ethics board approved database. All patients received pretreatment FDG-PET / computed tomography (CT) at 1 institution with consistent acquisition technique. The medical records and radiologic images of these patients were analyzed. Results: The overall survival at 2 years and 3 years for the whole group was 76% and 67%, respectively. The mean and median SUVmax were 8.1 and 7, respectively. Progression-free survival at 2 years with SUVmax <7 was better than that of the patients with tumor SUVmax ≥7 (67% vs 51%; P=.0096). Tumors with SUVmax ≥7 were associated with a worse regional recurrence-free survival and distant metastasis-free survival. In the multivariate analysis, SUVmax ≥7 was an independent prognostic factor for distant metastasis-free survival. Conclusion: In early-stage NSCLC managed with radiation alone, patients with SUVmax ≥7 on FDG-PET / CT scan have poorer outcomes and high risk of progression, possibly because of aggressive biology. There is a potential role for adjuvant therapies for these high-risk patients with intent to improve outcomes. [Copyright &y& Elsevier]

The prognosis of patients with metastatic liver disease remains dismal with a median survival of only 6-12 mo. As 80%-90% of patients are not candidates for surgical therapy, there is a need for effective non-surgical therapies that would improve outcomes in these patients. The body of evidence related to the use of stereotactic ablative radiotherapy (SABR) in metastatic liver disease has substantially grown and evolved over the past decade. This review summarizes the current evidence supporting liver SABR with particular attention given to patient selection, target delineation, organ at risk dose volume constraints, response evaluation imaging and the various SABR techniques for delivering ablative radiotherapy to the liver. Even though it is unclear what dose-fractionation scheme, delivery system, concomitant therapy or patient selection strategy yields the optimum liver SABR outcomes, clear and growing evidence is available that SABR is a safe and effective therapy for the treatment of oligometastatic liver disease.

Introduction: Stereotactic ablative body radiotherapy (SABR) is currently under study regarding its clinical application in management of patients with kidney tumors. CyberKnife can accurately deliver ablative tumor radiation doses while preserving kidney function. We report Canada's first use of CyberKnife SABR system in treating primary kidney tumors., Materials and Methods: Between January 2011 and February 2012, we treated three patients with renal tumors using CyberKnife SABR. Two patients had tumors in solitary kidney. The third patient had a recurrent tumor after two previous radiofrequency ablation treatments. Platinum seed fiducials were used for real time tumor tracking. Magnetic resonance imaging registration was used for tumor delineation in all cases. The patients were followed with regular renal scans and renal function tests., Results: The mean age was 79 years. Mean tumor size was 21.3 cm3. A dose of 39 Gy in 3 fractions was delivered. The post treatment follow up times were 15 months, 13 months and 12 months. Local control was obtained in all three patients. No acute or chronic toxicity was reported. Kidney functions remained unaffected after treatment., Conclusion: CyberKnife is technically feasible for treatment of medically inoperable renal tumors or tumors in a solitary kidney.