We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Dosimetric comparison of intensity modulated radiosurgery with dynamic conformal arc radiosurgery for small cranial lesions.
- Authors
Calvo-Ortega, Juan F.; Delgado, David; Moragues, Sandra; Pozo, Miquel; Casals, Joan
- Abstract
<bold>Aims: </bold>To dosimetrically compare the fixed gantry intensity modulated radiosurgery (IMRS) with dynamic conformal arc radiosurgery (DCARS) for cranial lesions. This study investigates whether IMRS can be an adequate dosimetric alternative to DCARS for cranial stereotactic radiosurgery (SRS).<bold>Subjects and Methods: </bold>Forty-five SRS procedures for solitary brain metastasis (range: 0.44-29.18 cm 3) performed at our institution were selected for this study. Two plans were generated per patient: One IMRS plan using a multileaf collimation (MLC) of 5 mm, and one DCARS plan designed with a 3 mm micro-MLC. Dosimetric comparison metrics include the target coverage (Cov), conformity index (CI), homogeneity index (HI), gradient index (GI), and volume of the normal brain tissue receiving ≥12 Gy (V12). In addition, maximum doses to organs at risk (OAR) (brainstem, optic apparatus and cochlea) were compared for both techniques.<bold>Results: </bold>Compared to DCARS, IMRS improved mean CI (IMRS: 0.81 vs.<bold>Dcars: </bold>0.63, P < 0.001), with no significant difference in target Cov (IMRS: 0.99 vs.<bold>Dcars: </bold>0.99, P > 0.05), HI (IMRS: 1.22 vs.<bold>Dcars: </bold>1.24, P > 0.05), GI (IMRS: 5.44 vs.<bold>Dacrs: </bold>5.44, P > 0.05). A weak significant difference in V12 (IMRS: 4.6 cm 3 vs. 5.2 cm 3, P = 0.033) was obtained. Subgroup analysis per target volume (small: <1 cm 3, intermediate: ≤1 cm 3 and <5 cm 3 and large: ≥5 cm 3) only revealed the statistically difference for CI metric (P < 0.001). No significant differences were found for maximum dose to the OAR.<bold>Conclusions: </bold>We have shown that IMRS provides the dosimetric advantages compared with DCARS. Based on the dosimetric findings in this study, fixed gantry IMRS technique can be adopted as a standard procedure for cranial SRS when micro-MLC technology is not available on the linear accelerator.
- Subjects
RADIATION dosimetry; STEREOTACTIC radiosurgery; BRAIN metastasis; HOMOGENEITY; LINEAR accelerators in medicine; BRAIN tumor diagnosis; ANTHROPOMETRY; BRAIN tumors; COMPUTERS in medicine; RADIATION doses; RADIATION measurements; RADIOSURGERY; RADIOTHERAPY
- Publication
Journal of Cancer Research & Therapeutics, 2016, Vol 12, Issue 2, p852
- ISSN
0973-1482
- Publication type
journal article
- DOI
10.4103/0973-1482.163680