Dosimetric comparison of volumetric modulated arc therapy with TrueBeam LINAC and hypofractionated radiosurgery with gamma knife ICON for large (>10cm3) skull base meningiomas
Journal of X-Ray Science and Technology, cilt.30, sa.6, ss.1201-1211, 2022 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 30 Sayı: 6
- Basım Tarihi: 2022
- Doi Numarası: 10.3233/xst-221264
- Dergi Adı: Journal of X-Ray Science and Technology
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, EMBASE, INSPEC, MEDLINE
- Sayfa Sayıları: ss.1201-1211
- Anahtar Kelimeler: Dosimetric study, gamma knife, LINAC, meningioma
- İstanbul Medipol Üniversitesi Adresli: Evet
Özet
BACKGROUND: Multi Fractionated stereotactic radiosurgery (MF-SRS) of Linac has an essential role in the treatment of skull base meningiomas (sbMNG). However, Gamma Knife Icon (GK) allows MF-SRS using mask immobilization with onboard image guidance. OBJECTIVE: This dosimetric study aims to investigate whether equivalent plan quality can be achieved with Volumetric Modulated Arc Therapy (VMAT) in patients with large sbMNG (>10 cm3) previously treated with GK. METHODS: Twenty patients with the median target volume of 19.7cm3 are re-planned by using VMAT with 20Gy in 5 fractions. Plan qualities are compared to tumor coverage, paddick conformity index (PCI), gradient index (GI), V4Gy, V10Gy, V12Gy, optic chiasm V20Gy, brainstem V23Gy, optic nerve V25Gy volumes, and maximum doses for all. Additionally, beam-on time and approximate planning time are also analyzed and compared. RESULTS: All plans provide adequate clinical requirements. First, the CI is comparable for the GK and VMAT (0.99±0.01 vs. 1.13±0.20; p=0.18). Second, VMAT has a significantly higher GI than GK (3.81±0.35 vs. 2.63±0.09; p<0.001). Third, the PCI is significantly higher in GK than VMAT (0.76±0.05 vs. 0.70±0.07; p<0.001). The lower GI of the GK also results in significantly lower V4Gy (156.1±43.8 vs. 207.5±40.1 cm3, p<0.001) and V10Gy (26.1±9.0 vs. 28.9±7.7 cm3, p<0.001) compared to VMAT. Last, the VMAT reduces beam-on time (4.8±0.5 vs. 19±1.1min.; p<0.001). CONCLUSION: Although both systems have succeeded in creating effective plans in clinical practice, the GK reveals more effective lower normal brain tissue doses. However, the shorter treatment time with LINAC, excluding the total procedure time, can be considered advantageous over GK.