Direction modulated brachytherapy (DMBT) for treatment of cervical cancer: A planning study with192Ir,60Co, and169Yb HDR sources
| Autor: | Ali S. Meigooni, D Han, A Soliman, Shahram Mashouf, Amir Owrangi, Habib Safigholi, William Y. Song |
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| Rok vydání: | 2017 |
| Předmět: |
Cervical cancer
medicine.medical_specialty business.industry medicine.medical_treatment Brachytherapy Tungsten alloy Planning target volume General Medicine Dose distribution medicine.disease 030218 nuclear medicine & medical imaging Surgery 03 medical and health sciences 0302 clinical medicine 030220 oncology & carcinogenesis Planning study medicine Clinical case business Energy source Nuclear medicine |
| Zdroj: | Medical Physics. 44:6538-6547 |
| ISSN: | 0094-2405 |
| Popis: | Purpose To evaluate plan quality of a novel MRI-compatible direction modulated brachytherapy (DMBT) tandem applicator using 192Ir, 60Co, and 169Yb HDR brachytherapy sources, for various cervical cancer high-risk clinical target volumes (CTVHR). Materials and Methods The novel DMBT tandem applicator has six peripheral grooves of 1.3-mm diameter along a 5.4-mm thick nonmagnetic tungsten alloy rod. Monte Carlo (MC) simulations were used to benchmark the dosimetric parameters of the 192Ir, 60Co, and 169Yb HDR sources in a water phantom against the literature data. 45 clinical cases that were treated using conventional tandem-and-ring applicators with 192Ir source (192Ir-T&R) were selected consecutively from intErnational MRI-guided BRAchytherapy in CErvical cancer (EMBRACE) trial. Then, for each clinical case, 3D dose distribution of each source inside the DMBT and conventional applicators were calculated and imported onto an in-house developed inverse planning optimization code to generate optimal plans. All plans generated by the DMBT tandem-and-ring (DMBT T&R) from all three sources were compared to the respective 192Ir-T&R plans. For consistency, all plans were normalized to the same CTVHR D90 achieved in clinical plans. The D2cm3 for organs at risk (OAR) such as bladder, rectum, and sigmoid, and D90, D98, D10, V100, and V200 for CTVHR were calculated. Results In general, plan quality significantly improved when a conventional tandem (Con.T) is replaced with the DMBT tandem. The target coverage metrics were similar across 192Ir-T&R and DMBT T&R plans with all three sources (p>0.093). 60Co-DMBT T&R generated greater hot spots and less dose homogeneity in the target volumes compared with the 192Ir- and 169Yb-DMBT T&R plans. Mean OAR doses in the DMBT T&R plans were significantly smaller (P |
| Databáze: | OpenAIRE |
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