Fast dose optimization for rotating shield brachytherapy

© 2017 American Association of Physicists in Medicine..

PURPOSE: To provide a fast computational method, based on the proximal graph solver (POGS) - A convex optimization solver using the alternating direction method of multipliers (ADMM), for calculating an optimal treatment plan in rotating shield brachytherapy (RSBT). RSBT treatment planning has more degrees of freedom than conventional high-dose-rate brachytherapy due to the addition of emission direction, and this necessitates a fast optimization technique to enable clinical usage.

METHODS: The multi-helix RSBT (H-RSBT) delivery technique was investigated for five representative cervical cancer patients. Treatment plans were generated for all patients using the POGS method and the commercially available solver IBM ILOG CPLEX. The rectum, bladder, sigmoid colon, high-risk clinical target volume (HR-CTV), and HR-CTV boundary were the structures included in our optimization, which applied an asymmetric dose-volume optimization with smoothness control. Dose calculation resolution was 1 × 1 × 3 mm3 for all cases. The H-RSBT applicator had 6 helices, with 33.3 mm of translation along the applicator per helical rotation and 1.7 mm spacing between dwell positions, yielding 17.5° emission angle spacing per 5 mm along the applicator.

RESULTS: For each patient, HR-CTV D90 , HR-CTV D100 , rectum D2cc , sigmoid D2cc , and bladder D2cc matched within 1% for CPLEX and POGS methods. Also, similar EQD2 values between CPLEX and POGS methods were obtained. POGS was around 18 times faster than CPLEX. For all patients, total optimization times were 32.1-65.4 s for CPLEX and 2.1-3.9 s for POGS.

CONCLUSIONS: POGS reduced treatment plan optimization time approximately 18 times for RSBT with similar HR-CTV D90 , organ at risk (OAR) D2cc values, and EQD2 values compared to CPLEX, which is significant progress toward clinical translation of RSBT.

Medienart:

E-Artikel

Erscheinungsjahr:

2017

Erschienen:

2017

Enthalten in:

Zur Gesamtaufnahme - volume:44

Enthalten in:

Medical physics - 44(2017), 10 vom: 15. Okt., Seite 5384-5392

Sprache:

Englisch

Beteiligte Personen:

Cho, Myung [VerfasserIn]
Wu, Xiaodong [VerfasserIn]
Dadkhah, Hossein [VerfasserIn]
Yi, Jirong [VerfasserIn]
Flynn, Ryan T [VerfasserIn]
Kim, Yusung [VerfasserIn]
Xu, Weiyu [VerfasserIn]

Links:

Volltext

Themen:

Brachytherapy
Cancer treatment planning
Gynecological cancer
Journal Article
Optimization
Rotating shield brachytherapy

Anmerkungen:

Date Completed 23.05.2018

Date Revised 13.11.2018

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1002/mp.12486

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM274195631