Assessing Deformable Image Registration Accuracy in Cervical Brachytherapy Using A 3D Model Phantom
Cervical brachytherapy (BT) is a critical component in the definitive treatment for patients with cervical cancer. Current American Brachytherapy Society and GEC-ESTRO Working group guidelines recommend a 3D treatment planning approach for cervical brachytherapy1-3. Tumor delineation using magnetic resonance imaging (MRI) is superior to CT-guided contouring, resulting in improved local control, cancer specific survival, and overall survival4. Unfortunately, the logistics and cost of obtaining post implantation MRI is impractical for most Radiation Oncology Departments.
We have read with great interest the GEC-ESTRO ACROP recommendations for head and neck cancer brachytherapy . In their article, the authors defined magnetic resonance imaging (MRI) as feasible for treatment planning. MRI is commonly used for diagnosis and staging of many diseases, and for target delineation. Benefit is well-known for brachytherapy and MRI guided brachytherapy (MRgBT), is recommended by gyn-GEC ESTRO for cervical cancer and more particularly in EMBRACE II protocol . Some teams have also developed MRI workflow for prostate brachytherapy .
Abstract BACKGROUND: Early prediction of response to concurrent chemoradiotherapy (cCRT) could aid to further optimize treatment regimens for locally advanced cervical cancer (LACC) in the future. PURPOSE: To explore whether quantitative parameters from baseline (pre-therapy) magnetic resonance imaging (MRI) and FDG-PET/computed tomography (CT) have potential as predictors of early response to cCRT. MATERIAL AND METHODS: Forty-six patients with LACC undergoing cCRT after staging with FDG-PET/CT and MRI were retrospectively analyzed. Primary tumor volumes were delineated on FDG-PET/CT, T2-weighted (T2W)-M...
Conclusions: The use of asynchronous MRI for target delineation, with co-registration to CT for each fraction of brachytherapy was associated with higher D90 to the HR-CTV. We observed slightly higher D2cc rectal doses with MRI, but cumulative rectal doses were within accepted thresholds. High-risk target volumes were not consistently increased or decreased, but MRI fusion was associated with target volume changes greater than 20% in over half of the treated patients. PMID: 32695201 [PubMed]
Authors: Zhao Z, Zhang N, Liu Y, Wu N, Mao Z, Yang W, Cheng G Abstract Purpose: To analyze the results of clinical utilization of ring applicator for combined intracavitary (IC)/interstitial (IS) image-guided brachytherapy (BT) technique in locally advanced cervical cancer (LACC), and to explore the application conditions of IC/IS BT approach with this applicator for Chinese patients. Material and methods: IC/IS BT was performed in total of 95 LACC patients, who already received external beam radiotherapy. In forty-three of these patients, utilization of ring applicator in brachytherapy was done, including IC/I...
ConclusionHybrid TRUS-CT as an imaging modality for contouring the CTVHR in IGABT for LACC is feasible and reproducible among multiple observers. TRUS-CT substantially reduces overestimation of the CTVHR volume of CT alone while maintaining similar interobserver variability.
Brachytherapy with a remote after-loading system (RALS) plays an important role in the treatment of cervical cancer [1,2]. Recent developments in three-dimensional (3D) planning using computed tomography (CT) and magnetic resonance imaging (MRI) allow the assessment of 3D dose distributions in brachytherapy, and the widespread use of 3D-image guided brachytherapy (3D-IGBT), dose evaluation facilitates the use of dose volume histogram (DVH) in addition to the dose at “point A” approach. The Gynecologic Brachytherapy Working Group of the Groupe Européen de Curiethérapie and European Society for Radi...
Authors: Crossley N, Tipton C, Meier T, Sudhoff M, Kharofa J Abstract Purpose: Magnetic resonance imaging (MRI)-guided adaptive brachytherapy is the standard of care for cervical cancer. Hybrid intracavitary/interstitial applicators for bulky tumor (high-risk clinical target volume [HR-CTV]> 30 cc) dose escalation is recommended in the EMBRACE II trial. The value of hybrid applicators for smaller HR-CTV (
Conclusions: The present study results show that all the dose parameters of HRCTV, bladder, and rectum with 60Co were comparable with those of 192Ir HDR source. The isodose distribution is more bulge out for 60Co in cranial-caudal direction compared to that of 192Ir. However, these differences can be reduced by treatment planning optimization techniques. The clinical plan evaluation in each slice and plane is necessary to explore the logistic and financial benefits of miniaturized 60Co source over 192Ir HDR source.
Conclusion: Conventional X-ray-based plans with moderate Point A doses deliver HRCTV D90 comparable to MRI-based plans in patients with no residual disease, and centrally placed residual disease, provided proper applicator placement and ideal geometry can be ensured. Soft-tissue image-based BT dose optimization ought to be considered in all patients with gross residual disease at the time of brachytherapy.
This phase II study evaluated the utility of magnetic resonance imaging (MRI) and positron emission tomography for planning radiation and brachytherapy in patients with postsurgical recurrence of cervical cancer.