PMID- 36172673 OWN - NLM STAT- MEDLINE DCOM- 20220930 LR - 20230107 IS - 2476-762X (Electronic) IS - 1513-7368 (Print) IS - 1513-7368 (Linking) VI - 23 IP - 9 DP - 2022 Sep 1 TI - A Comprehensive Evaluation of Single Isocenter Multiple Target SRS Plans and the Analytical Relationship between Plan Quality Indices with the Number and Volume of Targets. PG - 3103-3112 LID - 90293 [pii] LID - 10.31557/APJCP.2022.23.9.3103 [doi] AB - OBJECTIVE: To study the relationship of plan quality indices with the number and volume of target for 5 to 10 brain metastases treated with LINAC-based Single Isocenter Multiple Target (SIMT) Stereotactic radiosurgery (SRS) planning and to determine the maximum volume of spherical targets treated without exceeding the normal tissue tolerances. METHODS: Spherical targets of 5 to 10 numbers per plan, with individual target volumes ranging from 0.025 cc to 11.5 cc, were simulated with randomly drawn planning target volumes (PTVs) within the brain. SIMT SRS plans were generated for the 21 Gy prescription dose with a 6 MV Flattening Filter Free photon beam. Target coverage, organ at risk sparing, plan quality indices, R50%, and gradient measure were studied. Mean brain dose, V12 for Brain minus PTV (BmP), V10, V12, V15, V18, V20, and V24 for brain volume were evaluated. Equations relating the gradient index, mean brain dose, and V12 (BmP) to the given number and volume of the targets were constructed. RESULTS: PTV coverage D98 was 98.77 +/- 1.37 %. The mean CIRTOG, QRTOG, HIRTOG, CIP, GI, and R50% of the individual targets were 1.02 +/- 0.08, 0.94 +/- 0.02, 1.49 +/- 0.11, 0.91 +/- 0.06, 4.74 +/- 2.3, and 4.95 +/- 2.67, respectively. The gradient measure achieved was in the range of 0.49 to 1.35 cm. The mean brain dose was in the range of 1.62 to 6.69 Gy. The mean V12 (BmP) per target obtained was 3.85 +/- 2.83 cc. CONCLUSION: Equations relating the number and volume of targets to the gradient measure, mean brain dose, V12 (BmP), and V10-24 can serve as a baseline for multiple brain metastases SIMT planning. The target volume for 5, 6, 7, 8, 9, and 10 targets that can be treated without exceeding V12 (BmP) is 6, 5, 4.7, 4, 3.7, and 3.4 cc, respectively, for the 21 Gy prescription dose. FAU - V, Hemalatha Priyadarsini AU - V HP AD - Tamil Nadu Medical Services Corporation Ltd, 417, Pantheon road, Egmore, Chennai, Tamil Nadu, India. AD - Department of Physics, School of Advanced Sciences, Vellore Institute of Technology, Vellore, Tamil Nadu, India. AD - Department of Radiation Oncology, Government Royapettah Hospital, 1, West Cott road, Royapettah, Chennai, Tamil Nadu, India. FAU - R, Murali AU - R M AUID- ORCID: 0000-0001-9943-2388 AD - Department of Physics, School of Advanced Sciences, Vellore Institute of Technology, Vellore, Tamil Nadu, India. FAU - N, Arunai Nambi Raj AU - N ANR AD - Department of Physics, School of Advanced Sciences, Vellore Institute of Technology, Vellore, Tamil Nadu, India. FAU - S, Saravanan AU - S S AD - Department of Radiation Oncology, Government Royapettah Hospital, 1, West Cott road, Royapettah, Chennai, Tamil Nadu, India. LA - eng PT - Journal Article DEP - 20220901 PL - Thailand TA - Asian Pac J Cancer Prev JT - Asian Pacific journal of cancer prevention : APJCP JID - 101130625 SB - IM MH - *Brain Neoplasms/pathology MH - Humans MH - *Radiosurgery MH - Radiotherapy Dosage MH - Radiotherapy Planning, Computer-Assisted MH - *Radiotherapy, Intensity-Modulated PMC - PMC9810297 OTO - NOTNLM OT - Gradient measure OT - VMAT OT - mean brain dose OT - multiple brain metastases OT - stereotactic radiosurgery COIS- The authors declare no conflict of interest. EDAT- 2022/09/30 06:00 MHDA- 2022/10/01 06:00 PMCR- 2022/11/01 CRDT- 2022/09/29 02:44 PHST- 2022/04/28 00:00 [received] PHST- 2022/09/29 02:44 [entrez] PHST- 2022/09/30 06:00 [pubmed] PHST- 2022/10/01 06:00 [medline] PHST- 2022/11/01 00:00 [pmc-release] AID - 90293 [pii] AID - 10.31557/APJCP.2022.23.9.3103 [doi] PST - epublish SO - Asian Pac J Cancer Prev. 2022 Sep 1;23(9):3103-3112. doi: 10.31557/APJCP.2022.23.9.3103.