scholarly journals Impact of different treatment plans on EQD2 for intracavitary brachytherapy of cervical cancer

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Osman Vefa Gul ◽  
Gokcen Inan ◽  
Hamit Basaran
Keyword(s):  
Cervical Cancer ◽  
Small Intestine ◽  
Organs At Risk ◽  
External Beam Radiotherapy ◽  
High Dose Rate ◽  
Intracavitary Brachytherapy ◽  
High Dose ◽  
Dose Volume Histograms ◽  
Significant Difference ◽  
Treatment Plans

Abstract Background Cancer is one of the leading causes of death worldwide. According to GLOBOCAN estimates, there were 341,831 deaths from cervical cancer in 185 countries in 2020. The aim of this study was to compare equieffective dose (EQD2) at 2 Gy per fraction by using dose volume histograms (DVHs) derived from external beam radiotherapy (EBRT) and high-dose rate brachytherapy (HDR-BRT) treatment plans used in cervical cancer radiotherapy. Methods Fifteen patients with stage IIB-IIIB cervical cancer were included in this retrospective study. Treatment with three-dimensional conformal radiotherapy (3D-CRT) or intensity-modulated radiotherapy (IMRT) was planned for all patients in 28 fractions, with a total of 50.4 Gy to be delivered to the whole pelvic region. After EBRT, manual optimization (MO) or inverse optimization (IO) HDR-BRT plans were created in 4 fractions with a total of 28 Gy. The plans obtained were grouped as IMRT + IO, IMRT + MO, 3DCRT + IO, and 3DCRT + MO by calculating EQD2s among these plans. D90, D95, and D98 values were compared in all plans for CTVHR total EQD2. In addition, EQD2 values ​for critical organs at risk (OARs) such as rectum, bladder, small intestine, and sigmoid were compared in all plans for volumes of 2 cm3, 1 cm3, and 0.1 cm3, respectively. Results There was no significant difference between the treatment groups in terms of CTVHR D90 and CTVIR D90 values; However, CTVHR D95 (p = 0.000) and CTVHR D98 (p = 0.000) values ​were found to be better in IMRT + IO technique. The IMRT + IO technique provided better protection for 2 cm3, 1 cm3, and 0.1 cm3 volumes of OARs compared to other techniques. Conclusions Considering all parameters such as CTVHR, CTVIR, rectum, bladder, small intestine, and sigmoid, combination of IMRT + IO treatment option was found to be significantly superior in total EQD2 calculations compared to other plans.

scholarly journals Comparison of Two Inverse Planning Algorithms for Cervical Cancer Brachytherapy

2020 ◽  
Author(s):  
Qi Fu ◽  
Yingjie Xu ◽  
Jing Zuo ◽  
Jusheng An ◽  
Manni Huang ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Dwell Time ◽  
Organs At Risk ◽  
Clinical Decision ◽  
Assessment Method ◽  
High Dose Rate ◽  
High Dose ◽  
Inverse Planning ◽  
Significant Difference ◽  
Treatment Plans

Abstract Purpose: To compare two methods, the hybrid inverse planning optimization (HIPO) algorithm and the inverse planning simulated annealing (IPSA) algorithm, for cervical cancer brachytherapy and provide suggestions for their usage.Material and methods: This study consisted of 24 cervical cancer patients treated with CT image-based high-dose-rate brachytherapy using various combinations of tandem/ovoid applicator and interstitial needles. For fixed catheter configurations, plans were retrospectively optimized with two methods: IPSA and HIPO. The dosimetric parameters with respect to target coverage, localization of high dose volume (LHDV), conformal index (COIN), and sparing of organs at risk (OARs) were evaluated. A plan assessment method which combines a graphical analysis and a scoring index was used to compare the quality of two plans for each case. The characteristics of dwell time distributions of the two plans were also analyzed.Results: Both IPSA and HIPO can produce clinically acceptable treatment plans. The rectum D2cc was slightly lower for HIPO as compared to IPSA (p=0.002). All other dosimetric parameters for targets and OARs were not significantly different between the two algorithms. The generated radar plots and scores intuitively presented the plan properties and enabled to reflect the clinical priorities for the treatment plans. Different characteristics were observed between the dwell time distributions generated by IPSA and HIPO. Conclusions: Despite significant difference in dwell time distributions, both the two algorithms could generate high-quality treatment plans. With the help of the plan assessment method, the clinical decision on the optimal plan can be made quickly and consistently for each patient.

scholarly journals Toxicity Outcome Using Bladder-Rectum Spacer Balloon Versus Vaginal Gauze Packing in Brachytherapy in Cervical Cancer.

2021 ◽  
Author(s):  
Nagarjun Ballari ◽  
Sakshi Rana ◽  
Bhavana Rai ◽  
Srinivasa Gowda ◽  
Suja Bhargavan ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Randomized Study ◽  
High Dose Rate ◽  
Intracavitary Brachytherapy ◽  
High Dose ◽  
Clinical Trial Registry ◽  
Gauze Packing ◽  
Dosimetric Data ◽  
Significant Difference

Abstract BACKGROUNDTo compare the clinical impact in terms of toxicity outcomes with RayshieldTM bladder rectum spacer balloon (BRSB) versus vaginal gauze packing (VGP) in patients treated with high dose rate intracavitary brachytherapy for carcinoma cervix.RESULTSFollow-up and dosimetric data of patients in whom BRSB and VGP were used in a previously reported randomized study were retrieved, 8. Out of 80 patients analysed, late toxicities assessment (according to Common Terminology Criteria for Adverse Events version 4.0 (CTCAE v4). was possible in 65 patients as 14 patients were lost to follow-up and one patient died. Grade 2 bladder toxicity was observed in 2 patients in each arm. Only 1 patient in VGP arm experienced grade 3 proctitis while none of the patient in BRSB arm had ³Grade 2 rectal toxicity. Vaginal toxicity was comparable in both the arms.CONCLUSION No significant difference was observed in bladder and rectal toxicities using the BRSB versus VGP. BRSB can be considered as an alternative to VGP in intracavitary brachytherapy for cervical cancer using tandem- ovoid applicatorsThe study was approved by the institute ethics committee and registered under Clinical Trial Registry of India (CTRI/2009/091/000840).

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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