TY - JOUR
T1 - Tumor volume threshold for achieving improved conformity in VMAT and Gamma Knife stereotactic radiosurgery for vestibular schwannoma
AU - Kim, Hyun
AU - Potrebko, Peter
AU - Rivera, Amanda
AU - Liu, Haisong
AU - Eldredge-Hindy, Harriet B.
AU - Gunn, Vickie
AU - Werner-Wasik, Maria
AU - Andrews, David W.
AU - Evans, James J.
AU - Farrell, Christopher J.
AU - Judy, Kevin
AU - Shi, Wenyin
N1 - Publisher Copyright:
© 2015 Elsevier Ireland Ltd. All rights reserved.
PY - 2015/5/1
Y1 - 2015/5/1
N2 - Background and purpose: Recent advances in multileaf collimator field shaping technology and inverse planning software have resulted in highly conformal LINAC based stereotactic radiosurgery (SRS) plans with minimal dose to critical structures. This modeling study compares Gamma Knife (GK) and LINAC SRS for vestibular schwannoma (VS). Materials and methods: 76 treatment plans from nineteen patients with VS were planned using GK forward planning and volumetric arc therapy (VMAT) inverse planning software. VMAT plans were generated with 1 coplanar, 3 and 5 non-coplanar arcs. Dose to normal structures and beam-on time (dose rate 600 MU/min) were compared using Kruskal-Wallis and Dunn's post hoc test. Results: Median tumor volume was 1.2 cm3 (range 0.1-4.8 cm3). A peripheral tumor dose of 12 Gy was prescribed. Tumor coverage was >99.8%. VMAT plans had lower target D2% and mean dose, as well as decreased beam-on time, compared to GK plans (p < 0.0001). Paddick conformity index in VMAT 5 arc plans was superior to that of GK plans for targets >0.5 cm3 (p = 0.002). Similar dose to cochlea, normal brain tissue and brainstem was observed. Conclusion: VMAT should be considered as a safe, alternative modality to GK for VS SRS treatment, especially for tumors larger than 0.5 cm3.
AB - Background and purpose: Recent advances in multileaf collimator field shaping technology and inverse planning software have resulted in highly conformal LINAC based stereotactic radiosurgery (SRS) plans with minimal dose to critical structures. This modeling study compares Gamma Knife (GK) and LINAC SRS for vestibular schwannoma (VS). Materials and methods: 76 treatment plans from nineteen patients with VS were planned using GK forward planning and volumetric arc therapy (VMAT) inverse planning software. VMAT plans were generated with 1 coplanar, 3 and 5 non-coplanar arcs. Dose to normal structures and beam-on time (dose rate 600 MU/min) were compared using Kruskal-Wallis and Dunn's post hoc test. Results: Median tumor volume was 1.2 cm3 (range 0.1-4.8 cm3). A peripheral tumor dose of 12 Gy was prescribed. Tumor coverage was >99.8%. VMAT plans had lower target D2% and mean dose, as well as decreased beam-on time, compared to GK plans (p < 0.0001). Paddick conformity index in VMAT 5 arc plans was superior to that of GK plans for targets >0.5 cm3 (p = 0.002). Similar dose to cochlea, normal brain tissue and brainstem was observed. Conclusion: VMAT should be considered as a safe, alternative modality to GK for VS SRS treatment, especially for tumors larger than 0.5 cm3.
KW - Gamma knife
KW - Radiosurgery
KW - VMAT
KW - Vestibular schwannoma
UR - http://www.scopus.com/inward/record.url?scp=84931567293&partnerID=8YFLogxK
U2 - 10.1016/j.radonc.2015.03.031
DO - 10.1016/j.radonc.2015.03.031
M3 - Article
C2 - 25998805
AN - SCOPUS:84931567293
SN - 0167-8140
VL - 115
SP - 229
EP - 234
JO - Radiotherapy and Oncology
JF - Radiotherapy and Oncology
IS - 2
ER -