Three-dimensional conformal planning using low-segment multi-criteria optimization for hippocampal avoidance whole brain radiotherapy

• Published in: Journal of radiation oncology Vol. 5; no. 3; pp. 249 - 255
• Main Authors: Zhang, Xin, Penagaricano, Jose, Ganesh, Narayanasamy, Griffin, Robert J., Maraboyina, Sanjay, Paudel, Nava, Corry, Peter, Morrill, Steven
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.09.2016; Springer Nature B.V
• Subjects: Cancer Research; Imaging; Medicine; Medicine & Public Health; Multiple criterion; Oncology; Original Research; Radiology; Radiotherapy; Surgery; Surgical Oncology; Hippocampus avoidance whole brain radiotherapy (HA-WBRT); Radiation therapy oncology group (RTOG) 0933; Multi-criteria optimization (MCO); Whole brain radiotherapy (WBRT); RayStation
• ISSN: 1948-7894; 1948-7908
• DOI: 10.1007/s13566-016-0263-6

Objective Hippocampus avoidance whole brain radiotherapy (HA-WBRT) has been shown to reduce the risk of neurocognitive dysfunction. This type of treatment has the potential of insurance company payment denial due to increased cost of intensity-modulated radiotherapy (IMRT), while the accepted modality for WBRT is three-dimensional conformal radiotherapy (3DCRT). The purpose of this study is to assess 3DCRT HA-WBRT treatment plans using multi-criteria optimization (MCO) to meet RTOG 0933 criteria. Methods Ten patients with brain metastases were selected, and HA-WBRT treatment plans with MCO 3DCRT technique (MCO-3D) were generated. MCO-3D plans were compared with plans using MCO IMRT techniques (MCO-IMRT). Evaluation parameters included D 98 % and D 2 % of PTV, dose homogeneity index, and D max and D 100 % of the hippocampi. Results For MCO-IMRT plans, PTV D 2 % and hippocampi D max and D 100 % met RTOG 0933 objectives in all ten patients (PTV D 2 %  < 37.5Gy; hippocampi D max  < 16Gy and D 100 %  < 9 Gy). One patient met the RTOG 0933 PTV D 98 % objective (PTV D 98 %  > 25Gy) and 9/10 patients met acceptable variation (PTV D 98 %  < 25 Gy). For MCO-3D plans, PTV D 2 % met RTOG033 objective for all patients: 1/10 patients for PTV D 98 %, 6/10 patients for hippocampi D max , and 7/10 patients for hippocampi D 100 % met RTOG 0933 objective. All the other patients met the RTOG 0933 acceptable variation requirement (PTV D 98 %  < 25 Gy; Hippocampi D max  < 17Gy and D 100 %  < 10 Gy). Conclusion All dosimetric parameters of MCO-3D plans met the criteria of at least acceptable variation per RTOG 0933. The statistic comparison results showed that there were some minor statistical differences between MCO-IMRT and MCO-3D; however, the biological difference was not of clinical importance. This may be helpful in cases where there is denial of patient’s medical insurance coverage due to the use of IMRT for HA-WBRT.