GliaSite brachytherapy boost as part of initial treatment of glioblastoma multiforme: a retrospective multi-institutional pilot study.

PURPOSE: To report on a retrospective analysis of the cumulative experience from eight institutions using the GliaSite Radiotherapy System as a brachytherapy boost in the initial management of glioblastoma multiforme. METHODS AND MATERIALS: Eight institutions provided data on 20 patients with histologically proven glioblastoma multiforme with a median age of 59 years (range, 39-76) and median Karnofsky performance scale of 80 (range, 50-100). After maximal surgical debulking, patients were treated with GliaSite brachytherapy to a median dose of 50 Gy, followed by external beam radiotherapy to a median dose of 60 Gy (range, 46-60 Gy), for a cumulative dose escalation of 110 Gy (range, 84-130 Gy). RESULTS: The average survival for this study population was 11.4 months (range, 4-29). When the patients' survival was compared with that of historical controls according to their Radiation Therapy Oncology Group recursive partitioning analysis class, the average survival was increased by 3 months (95% confidence interval, 0.23-4.9) corresponding to a 43% increase (p = 0.033). Three patients (14%) experienced Radiation Therapy Oncology Group Grade 3 central nervous system toxicity. Of the treatment failures, 50% were >2 cm from the edge of the balloon. CONCLUSION: The results of this analysis have demonstrated that dose escalation (>100 Gy) with GliaSite is well tolerated and associated with minimal toxicity. Local control improved with the use of GliaSite brachytherapy. The putative survival advantage seen in this study needs to be interpreted with caution; nevertheless, the data provide sufficient justification to investigate the potential role of radiation dose escalation in conjunction with GliaSite in the initial treatment of glioblastoma multiforme.

GliaSite brachytherapy for treatment of recurrent malignant gliomas: a retrospective multi-institutional analysis.

OBJECTIVE: To review the cumulative experience of 10 institutions in treating recurrent malignant gliomas with the brachytherapy device, GliaSite Radiation Therapy System. METHODS: The patient population consisted of 95 patients with recurrent grade 3 or 4 gliomas, a median age of 51 years, and a median Karnofsky performance status score of 80. All patients had previously undergone resection and had received external beam radiotherapy as part of their initial treatment. After recurrence, each patient underwent maximal surgical debulking of their recurrent lesion and placement of an expandable balloon catheter (GliaSite) in the tumor cavity. The balloon was afterloaded with liquid I (Iotrex) to deliver a median dose of 60 Gy to an average depth of 1 cm with a median dose rate of 52.3 Gy/hr. Patients were carefully followed with serial magnetic resonance imaging and monthly examinations for tumor progression, side effects, and survival. RESULTS: The median survival for all patients, measured from date of GliaSite placement, was 36.3 weeks with an estimated 1 year survival of 31.1%. The median survival was 35.9 weeks for patients with an initial diagnosis of glioblastoma multiforme and 43.6 weeks for those with non- glioblastoma multiforme malignant gliomas. Analysis of the influence of various individual prognostic factors on patient survival demonstrated that only Karnofsky performance status significantly predicted for improved survival. There were three cases of pathologically documented radiation necrosis. CONCLUSION: Reirradiation of malignant gliomas with the GliaSite Radiation Therapy System after reresection seems to provide a modest survival benefit above what would be expected from surgery alone. This report not only confirms the initial results of the feasibility study but provides evidence that similar outcomes can be obtained outside of a clinical trial.

The effect of anterior cruciate ligament graft rotation on knee laxity and graft tension: An in vitro biomechanical analysis.

PURPOSE: The purpose of this study was to determine the effects of rotating a bone-patellar tendon- bone allograft during anterior cruciate ligament reconstruction on anteroposterior (AP) knee laxity and forces developed within the graft. TYPE OF STUDY: In vitro biomechanical study using human cadaveric knees. METHODS: Thirteen fresh-frozen knee specimens received bone-patella tendon-bone allografts that were pretensioned at 30 degrees of flexion to restore AP laxity to that of the intact knee. AP laxity was then measured at 0 degrees, 30 degrees, and 90 degrees of knee flexion with the graft in neutral rotation and in 90 degrees and 180 degrees of internal and external rotation. Five specimens received allografts that were rotated to 90 degrees internally and externally and then tensioned. Two knee specimens were used to measure the effects of graft rotation on graft force at full extension; 1 received 7 separate allografts and the other received 10 allografts. During testing, the potted end of the allograft that was connected to a tibial load cell was rotated. RESULTS: In specimens tensioned and then rotated, AP laxity at 30 degrees of knee flexion decreased an average of 0.9 mm with 90 degrees of graft rotation in either direction. At 180 degrees of external rotation, the mean decrease in laxity of 1.8 mm was significantly greater than that for 180 degrees of internal rotation (P <.05). When significant, all mean laxity reductions at 0 degrees and 90 degrees of flexion were less than those at 30 degrees of flexion. In specimens where the graft was rotated and then tensioned, rotation had no significant effect on laxity. With the exception of 90 degrees of external rotation, rotation of the graft increased graft tension at full extension; 90 degrees of internal rotation increased mean graft force by 11 N (P <.05). Rotating the graft 180 degrees in either direction increased mean graft force at full extension by 25 N (P <.05). CONCLUSIONS: Although minor, rotating the graft had significant effects on knee laxity and graft tension. In general, AP laxity decreased and graft tension increased with increasing rotation of the graft. The direction of rotation did not seem to be important. As a result, clinicians who choose to rotate their patellar tendon grafts can expect that the biomechanical changes in the graft with rotation will have little clinical importance.