Use of genetic algorithm for PTV optimization in single isocenter multiple metastases radiosurgery treatments with Brainlab Elements™
| Autor: | José Alejandro Rojas-López, Carlos Daniel Venencia, Rogelio Manuel Díaz Moreno |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
business.industry
medicine.medical_treatment Radiotherapy Planning Computer-Assisted Biophysics General Physics and Astronomy Isocenter Radiotherapy Dosage General Medicine Ptv margin Radiosurgery 030218 nuclear medicine & medical imaging Conformity index 03 medical and health sciences 0302 clinical medicine Margin (machine learning) 030220 oncology & carcinogenesis medicine Radiology Nuclear Medicine and imaging Radiotherapy Intensity-Modulated Nuclear medicine business Maximum displacement Algorithms Mathematics |
| Zdroj: | Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB). 86 |
| ISSN: | 1724-191X |
| Popis: | Purpose To optimize PTV margins for single isocenter multiple metastases stereotactic radiosurgery through a genetic algorithm (GA) that determines the maximum effective displacement of each target (GTV) due to rotations. Method 10 plans were optimized. The plans were created with Elements Multiple Mets™ (Brainlab AG, Munchen, Germany) from a predefined template. The mean number of metastases per plan was 5 ± 2 [3,9] and the mean volume of GTV was 1.1 ± 1.3 cc [0.02, 5.1]. PTV margin criterion was based on GTV-isocenter distance and target dimensions. The effective displacement to perform specific rotational combination (roll, pitch, yaw) was optimized by GA. The original plans were re-calculated using the PTV optimized margin and new dosimetric variations were obtained. The D mean , D 99 , Paddick conformity index (PCI), gradient index (GI) and dose variations in healthy brain were studied. Results Regarding targets located shorter than 50 mm from the isocenter, the maximum calculated displacement was 2.5 mm. The differences between both PTV margin criteria were statistically significant for D mean (p = 0.0163), D 99 (p = 0.0439), PCI (p = 0.0242), GI (p = 0.0160) and for healthy brain V 12 (p = 0.0218) and V 10 (p = 0.0264). Conclusion The GA allows to determine an optimized PTV margin based on the maximum displacement. Optimized PTV margins reduce the detriment of dosimetric parameters. Greater PTV margins are associated with an increase in healthy brain volume. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect