SU-E-T-157: Evaluation and Comparison of Doses to Pelvic Lymph Nodes and to Point B with 3D Image Guided Treatment Planning for High Dose Brachytherapy for Treatment of Cervical Cancer

2014 ◽  
Vol 41 (6Part13) ◽  
pp. 259-259
Author(s):  
N. Bhandare
Keyword(s):  
Cervical Cancer ◽  
Lymph Nodes ◽  
Treatment Planning ◽  
High Dose ◽  
3D Image ◽  
Pelvic Lymph Nodes ◽  
Image Guided

scholarly journals Intra-fractional dosimetric analysis of image-guided intracavitary brachytherapy of cervical cancer

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Junfang Yan ◽  
Jiawei Zhu ◽  
Kai Chen ◽  
Lang Yu ◽  
Fuquan Zhang
Keyword(s):  
Cervical Cancer ◽  
Treatment Planning ◽  
Organs At Risk ◽  
Cone Beam Ct ◽  
Ct Scanning ◽  
Target Volume ◽  
High Dose Rate ◽  
Intracavitary Brachytherapy ◽  
High Dose ◽  
Image Guided

Abstract Background To assess the intra-fractional dosimetric variations of image-guided brachytherapy of cervical cancer. Methods A total of 38 fractions (9 patients) undergoing brachytherapy for cervical cancer underwent a CT scanning for treatment planning (planning CT) and a Cone-beam CT (CBCT) scanning immediately prior to delivery (pre-delivery CBCT). The variations of volumes as well as the dosimetric impact from treatment planning to delivery (intra-application) were evaluated. The dose volume histogram parameters including volume, D90 of high-risk clinical target volume (HRCTV) and D2cc of organs at risk (OARs) were recorded. Results The relative differences (mean ± 1SD) of the volume and D90 HRCTV across the two scans were − 2.0 ± 3.3% and − 1.2 ± 4.5%, respectively. The variations of D2cc for bladder, rectum, sigmoid and small intestine are − 0.6 ± 17.1%, 9.3 ± 14.6%, 7.2% ± 20.5% and 1.5 ± 12.6%, respectively. Most of them are statistically nonsignificant except the D2cc for rectum, which showed a significant increase (P = 0.001). Using 5% and 10% uncertainty of physical dose for HRCTV at a 6 Gy × 5 high-dose-rate schedule, the possibility of total equivalent doses in 2 Gy fractions (EQD2) lower than 85 Gy is close to 0% and 3%, respectively. Performing similar simulation at 15% and 20% uncertainty of a 4 Gy physical dose for OARs, the possibility of total EQD2 dose exceeding 75 Gy is about 70%. Less than 1% of the total EQD2 of OARs would exceed 80 Gy. Conclusions Average intra-fractional dosimetric variation of HRCTV was small in an interval of less than 1 h, and the possibility of total EQD2 exceeding 85 Gy is higher than 97%. The intra-fractional dosimetric variations of OARs might result in an overdose for OARs in a single fraction or the whole treatment. It is necessary to detect unfavorable anatomical changes by re-imaging and take interventions to minimize applied doses and reduce the risk of complications.

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