Nathan R Bennion1, Timothy Malouff2, Vivek Verma2, Kyle Denniston2, Abhijeet Bhirud2, Weining Zhen2, Andrew Wahl2, Chi Lin2. 1. Department of Radiation Oncology, Nebraska Medicine, University of Nebraska Medical Center Campus, Omaha, Nebraska. Electronic address: nathan.bennion@unmc.edu. 2. Department of Radiation Oncology, Nebraska Medicine, University of Nebraska Medical Center Campus, Omaha, Nebraska.
Abstract
PURPOSE: Modern experiences in stereotactic radiosurgery (SRS) report noninvasive frameless techniques as an effective alternative to frame-based SRS. Frameless techniques potentially increase positional uncertainty and planning target volume margins are frequently used. Here, we compare rates of local control and radiation necrosis in frameless versus frame-based SRS. METHODS AND MATERIALS: Ninety-eight patients (170 lesions) with radiologic and clinical follow-up were analyzed. Group 1 contained 34 patients (61 lesions) immobilized with an invasive stereotactic frame. Group 2 had 64 patients (109 lesions) immobilized with a frameless SRS mask. Patient, tumor, and treatment characteristics were recorded, as were intervals to local recurrence and radiation necrosis (asymptomatic and symptomatic). RESULTS: Median patient age was 59 years (range, 25-89), and Karnofsky performance scale was 80 (range, 50-100). Median radiologic and clinical follow-up was 6.5 months (range, 0.7-44.3) and 7 months (range, 0.7-45.7). A median of 2 tumors were treated per course (range, 1-5) with a median dose of 18 Gy (range, 13-24 Gy). The median time to local failure was not reached, and Kaplan-Meier estimates of local failure were not statistically significant between groups (P = .303). Actuarial 6-month local failure rates were 7.2% in group 1 and 12.6% in group 2 (P = .295), with 12-month local failure rates of 14.5% and 26.8% (P = .185), respectively. There was no statistically significant difference in symptomatic (P = .391) or asymptomatic (P = .149) radiation necrosis. Six-month radiation necrosis was 0% in group 1 and 1.6% in group 2 (P = .311) with 12-month rates of 20.2% and 3.8%, respectively (P = .059). Median time to necrosis was not reached in group 1, but was 44 months in group 2. CONCLUSIONS: Frameless SRS demonstrates clinical outcomes comparable to frame-based techniques with respect to local failure and radiation necrosis.
PURPOSE: Modern experiences in stereotactic radiosurgery (SRS) report noninvasive frameless techniques as an effective alternative to frame-based SRS. Frameless techniques potentially increase positional uncertainty and planning target volume margins are frequently used. Here, we compare rates of local control and radiation necrosis in frameless versus frame-based SRS. METHODS AND MATERIALS: Ninety-eight patients (170 lesions) with radiologic and clinical follow-up were analyzed. Group 1 contained 34 patients (61 lesions) immobilized with an invasive stereotactic frame. Group 2 had 64 patients (109 lesions) immobilized with a frameless SRS mask. Patient, tumor, and treatment characteristics were recorded, as were intervals to local recurrence and radiation necrosis (asymptomatic and symptomatic). RESULTS: Median patient age was 59 years (range, 25-89), and Karnofsky performance scale was 80 (range, 50-100). Median radiologic and clinical follow-up was 6.5 months (range, 0.7-44.3) and 7 months (range, 0.7-45.7). A median of 2 tumors were treated per course (range, 1-5) with a median dose of 18 Gy (range, 13-24 Gy). The median time to local failure was not reached, and Kaplan-Meier estimates of local failure were not statistically significant between groups (P = .303). Actuarial 6-month local failure rates were 7.2% in group 1 and 12.6% in group 2 (P = .295), with 12-month local failure rates of 14.5% and 26.8% (P = .185), respectively. There was no statistically significant difference in symptomatic (P = .391) or asymptomatic (P = .149) radiation necrosis. Six-month radiation necrosis was 0% in group 1 and 1.6% in group 2 (P = .311) with 12-month rates of 20.2% and 3.8%, respectively (P = .059). Median time to necrosis was not reached in group 1, but was 44 months in group 2. CONCLUSIONS: Frameless SRS demonstrates clinical outcomes comparable to frame-based techniques with respect to local failure and radiation necrosis.
Authors: Michael T Milano; Jimm Grimm; Andrzej Niemierko; Scott G Soltys; Vitali Moiseenko; Kristin J Redmond; Ellen Yorke; Arjun Sahgal; Jinyu Xue; Anand Mahadevan; Alexander Muacevic; Lawrence B Marks; Lawrence R Kleinberg Journal: Int J Radiat Oncol Biol Phys Date: 2020-09-11 Impact factor: 8.013