Feasibility of hippocampal avoidance whole brain radiation in patients with hippocampal involvement: Data from a prospective study
| Autor: | Paul J. Catalano, Grace M. Lee, Nayan Lamba, Brian M. Alexander, Paul D. Brown, Iquan Usta, Daniel N. Cagney, Shyam K. Tanguturi, John G. Phillips, Cindy Hancox, Daphne A. Haas-Kogan, Ayal A. Aizer, Luke A. Besse, Itai Pashtan, Fred Hacker |
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| Rok vydání: | 2020 |
| Předmět: |
medicine.medical_treatment
Hippocampal formation Hippocampus 030218 nuclear medicine & medical imaging 03 medical and health sciences 0302 clinical medicine medicine Dosimetry Hippocampus (mythology) Humans Radiology Nuclear Medicine and imaging Prospective Studies Prospective cohort study Radiological and Ultrasound Technology business.industry Radiotherapy Planning Computer-Assisted Hippocampal avoidance medicine.disease Radiation therapy Oncology 030220 oncology & carcinogenesis Feasibility Studies Cranial Irradiation Nuclear medicine business Neurocognitive Organ Sparing Treatments Brain metastasis |
| Zdroj: | Medical dosimetry : official journal of the American Association of Medical Dosimetrists. 46(1) |
| ISSN: | 1873-4022 |
| Popis: | Purpose Among patients with brain metastases, hippocampal avoidance whole brain radiation (HA-WBRT) preserves neurocognitive function relative to conventional WBRT but the feasibility of hippocampal sparing in patients with metastases in/near the hippocampus is unknown. We identified the incidence of hippocampal/perihippocampal metastases and evaluated the feasibility of HA-WBRT in such patients. Materials/Methods Dosimetric data from 34 patients randomized to HA-WBRT (30 Gy/10 fractions) in a phase III trial (NCT03075072) comparing HA-WBRT to stereotactic radiation in patients with 5 to 20 brain metastases were analyzed. Patients with metastases in/near the hippocampi received HA-WBRT with prioritization of tumor coverage over hippocampal avoidance. Target coverage and hippocampal sparing metrics were compared between patients with targets in/near the hippocampus versus not. Results In total, 9 of 34 (26%) patients had targets in the hippocampus and an additional 5 of 34 (15%) patients had targets in the hippocampal avoidance zone (HAZ, hippocampus plus 5 mm expansion) but outside the hippocampus. Patients with targets within the hippocampus and those with targets in the HAZ but outside the hippocampus were spared 34% and 73% of the ipsilateral mean biologically equivalent prescription dose, respectively. Of the latter cohort, 88% and 25% met conventional hippocampal sparing metrics of Dmin ≤ 9 Gy and Dmax ≤ 16 Gy, respectively. Among 11 patients with unilateral hippocampal/perihippocampal involvement, the uninvolved/contralateral hippocampus was limited to Dmin ≤ 9 Gy and Dmax ≤ 17 Gy in all cases. Conclusions In this study, a substantial percentage of patients with 5 to 20 brain metastases harbored metastases in/near the hippocampus. In such cases, minimizing hippocampal dose while providing tumor coverage was feasible and may translate to neurocognitive protection. |
| Databáze: | OpenAIRE |
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