CT-on-rails-guided HDR brachytherapy: single-room, rapid-workflow treatment delivery with integrated image guidance

The effect of one-room CT guided brachytherapy on procedure time and cost in the treatment of cervical cancer

PURPOSE

Brachytherapy is associated with improved overall survival in cervical cancer patients, but the utilization seems hindered by high costs and relatively low reimbursement, particularly in the US. A one-room brachytherapy suite with CT (ORBT) could optimize the treatment workflow. By eliminating transport and waiting times, limiting applicator movement, and providing real-time applicator placement feedback, treatment time and costs could potentially be reduced. This study assesses the potential value of implementing ORBT in cervical cancer treatment.

METHODS AND MATERIALS

A variable cost model was developed to compare current (multi-room) brachytherapy workflows (MBRT) to ORBT, taking into account staff utilization, staff, equipment and consumables costs and room expenses. Two current care scenarios were simulated; applicator placement performed in the operating room (S1), and applicator placement performed in a brachytherapy suite (S2). For both scenarios literature reported fraction times of MBRT were compared to a range of ORBT times. Sensitivity analyses were performed to determine the influence of input parameters.

RESULTS

In scenario one, the results showed yearly savings of $45,572 up to $339,439 (USD), assuming a 5% and 20% reduction in fraction duration, respectively, in ORBT compared to MRBT. In scenario two, ORBT does not result in costs savings at 5% to 15% improvement. Therefore, only when ORBT results in a >20% improvement of fraction time, cost will be saved.

CONCLUSIONS

The results indicate that reducing procedure time (using ORBT) can lead to cost savings, depending on the current workflow. Savings seem to depend mostly on applicator placement location, number of patients per year, and involved personnel.

Comprehensive commissioning of a cone beam CT imaging ring for treatment of HDR GYN patients

PURPOSE

A new mobile cone beam computed tomography (CBCT) imaging ring (IRm, Elekta, v2.10.6, Veenendaal, Netherlands) has recently been proposed for brachytherapy to improve procedure efficiency. We describe the commissioning process and end-to-end tests for GYN HDR brachytherapy employing IRm CBCT imaging.

MATERIALS AND METHODS

Commissioning included imaging isocenter test, 3D image quality, 2D imaging quality, image dose, and tube characteristics. CIRS HDR GYN phantom and Venezia CT/MR gynecological applicator were used to perform end-to-end (E2E) tests and optimize workflow. Venezia applicator and four interstitial needles were inserted into the phantom and IRm CBCT images were acquired. Phantom and applicator were scanned with CT scanner (Siemens SOMATOM go.Open Pro) using department's pelvis imaging protocol. MR imaging was performed using 0.35T MR Linac TRUFI pulse sequence. CBCT images were registered to CT and MR using rigid registration to assess image quality and applicator geometry fidelity.

RESULTS

All physics tests passed within acceptance tolerances. Registration of CBCT images to MR and CT scans was acceptable for applicator placement. Applicator registration of CBCT images to CT demonstrated excellent agreement of most distal source dwell position (<1 mm). Slice thickness was also measured to be 1.25 mm, within 0.5 mm of its nominal value.

CONCLUSION

Based on E2E and commissioning results, IRm is an appropriate tool for brachytherapy treatment planning. This study demonstrated good image quality in GYN phantom and Venezia applicator using the IRm. Distal source dwell position agreement between CBCT and CT was acceptable for clinical use.

Brachytherapy Workflow Practices: Analysis of Different Workflow Scenarios in Patients With Cervical Cancer and Impact on IGBT Implementation-An IAEA Study

PURPOSE

The workflow of brachytherapy (BT) is an essential aspect of treatment to consider in image-guided brachytherapy (IGBT). It has an overarching effect influencing patient throughput and the number of cancer treatments that can be performed as it occupies equipment, space, and personnel. There is limited research addressing this issue. Under the International Atomic Energy Agency's Coordinated Research Activity titled IGBT for cervix cancer: An implementation study, our study analyzes various scenarios in the clinical workflow of BT delivery for cervical cancer. It aims to determine the extent to which these scenarios allow the routine implementation of IGBT. With this information, current barriers and individualized adaptations to efficient workflows can be identified to enhance the global application of IGBT, leading to better cervical cancer treatment.

MATERIALS AND METHODS

A web-based poll of questions regarding practices in BT workflow was presented to 62 participants from low-, lower middle-, upper middle-, and high-income countries (19 countries).

RESULTS

This study highlighted diversity in BT practices across countries, income levels, and regions. It identified variations in workflow, patient throughput, and resource availability, which can have implications for the efficiency and quality of BT treatments. Scenario A, utilizing multiple locations for the steps of the BT procedure, was the most commonly used. The availability of resources, such as imaging devices and trained personnel, varied among the participating centers and remained challenging for IGBT implementation and sustainability.

CONCLUSION

The design of the BT facility plays a vital role in improving efficiency, with a dedicated BT suite contributing to an efficient workflow but limiting patient throughput, especially for high-volume centers. Although IGBT is effective, its implementation requires consideration of various logistical challenges and should be individualized.

A comparative study using time-driven activity-based costing in single-fraction breast high-dose rate brachytherapy: An integrated brachytherapy suite vs. decentralized workflow

INTRODUCTION

Precision breast intraoperative radiation therapy (PB-IORT) is a novel approach to adjuvant radiation therapy for early-stage breast cancer performed as part of a phase II clinical trial at two institutions. One institution performs the entire procedure in an integrated brachytherapy suite which contains a CT-on-rails imaging unit and full anesthesia capabilities. At the other, breast conserving surgery and radiation therapy take place in two separate locations. Here, we utilize time-driven activity-based costing (TDABC) to compare these two models for the delivery of PB-IORT.

METHODS

Process maps were created to describe each step required to deliver PB-IORT at each institution, including personnel, equipment, and supplies. Time investment was estimated for each step. The capacity cost rate was determined for each resource, and total costs of care were then calculated by multiplying the capacity cost rates by the time estimate for the process step and adding any additional product costs.

RESULTS

PB-IORT costs less to deliver at a distributed facility, as is more commonly available, than an integrated brachytherapy suite ($3,262.22 vs. $3,996.01). The largest source of costs in both settings ($2,400) was consumable supplies, including the brachytherapy balloon applicator. The difference in costs for the two facility types was driven by personnel costs ($1,263.41 vs. $764.89). In the integrated facility, increased time required by radiation oncology nursing and the anesthesia attending translated to the greatest increases in cost. Equipment costs were also slightly higher in the integrated suite setting ($332.60 vs. $97.33).

CONCLUSIONS

The overall cost of care is higher when utilizing an integrated brachytherapy suite to deliver PB-IORT. This was primarily driven by additional personnel costs from nursing and anesthesia, although the greatest cost of delivery in both settings was the disposable brachytherapy applicator. These differences in cost must be balanced against the potential impact on patient experience with these approaches.

Real-time Doppler ultrasound to identify vessels and guide needle placement for gynecologic interstitial brachytherapy

PURPOSE

Doppler ultrasound (US) gives real-time information regarding anatomy and blood vessel location to guide needle placement for gynecologic interstitial (IS) brachytherapy (BT). We retrospectively assessed Doppler US images for vessel quantity, size, and distribution in cervical cancer patients undergoing high-dose-rate BT at our institution.

METHODS AND MATERIALS

Eleven consecutive patients undergoing IS high-dose-rate BT implants for cervical cancer between 2015 and 2017 were included. Transrectal Doppler US was used for real-time image guidance. US images were retrospectively evaluated. Vessel quantity, size, and distribution at superior and inferior levels of the cervix were recorded. Correlation of vessel quantity with tumor size and International Federation of Gynecology and Obstetrics stage was evaluated.

RESULTS

Average vessel quantity was 4.2 in the inferior cervix and 3.8 in the superior cervix (range 1-11). Median vessel diameter was 2 mm in the inferior cervix and 2 mm in the superior cervix (range 1-6 mm). The most common location was posterolateral (3:00-5:00 and 7:00-9:00), outer third (78% of vessels inferiorly, 64% of vessels superiorly). Vessel quantity was correlated to initial tumor size superiorly (p = 0.04, paired t-test) but not inferiorly (p = 0.31, paired t-test). There was no correlation between vessel quantity and International Federation of Gynecology and Obstetrics stage (p > 0.05, analysis of variance). Doppler US was successfully used to guide needle placement away from visualized blood vessels with no incidents of hemorrhage in these patients.

CONCLUSIONS

Doppler US is a useful tool to guide needle placement for IS BT for cervical cancer. Vessel quantity varied with increased vessel quantity seen higher in the cervix for larger tumors. Vessels were most commonly distributed in the outer third of the posterolateral cervix.

Artificial neural network based gynaecological image-guided adaptive brachytherapy treatment planning correction of intra-fractional organs at risk dose variation

PURPOSE

Intra-fractional organs at risk (OARs) deformations can lead to dose variation during image-guided adaptive brachytherapy (IGABT). The aim of this study was to modify the final accepted brachytherapy treatment plan to dosimetrically compensate for these intra-fractional organs-applicators position variations and, at the same time, fulfilling the dosimetric criteria.

MATERIAL AND METHODS

Thirty patients with locally advanced cervical cancer, after external beam radiotherapy (EBRT) of 45-50 Gy over five to six weeks with concomitant weekly chemotherapy, and qualified for intracavitary high-dose-rate (HDR) brachytherapy with tandem-ovoid applicators were selected for this study. Second computed tomography scan was done for each patient after finishing brachytherapy treatment with applicators in situ. Artificial neural networks (ANNs) based models were used to predict intra-fractional OARs dose-volume histogram parameters variations and propose a new final plan.

RESULTS

A model was developed to estimate the intra-fractional organs dose variations during gynaecological intracavitary brachytherapy. Also, ANNs were used to modify the final brachytherapy treatment plan to compensate dosimetrically for changes in 'organs-applicators', while maintaining target dose at the original level.

CONCLUSIONS

There are semi-automatic and fast responding models that can be used in the routine clinical workflow to reduce individually IGABT uncertainties. These models can be more validated by more patients' plans to be able to serve as a clinical tool.

Evaluation of Delivery Costs for External Beam Radiation Therapy and Brachytherapy for Locally Advanced Cervical Cancer Using Time-Driven Activity-Based Costing

PURPOSE

To evaluate the delivery costs, using time-driven activity-based costing, and reimbursement for definitive radiation therapy for locally advanced cervical cancer.

METHODS AND MATERIALS

Process maps were created to represent each step of the radiation treatment process and included personnel, equipment, and consumable supplies used to deliver care. Personnel were interviewed to estimate time involved to deliver care. Salary data, equipment purchasing information, and facilities costs were also obtained. We defined the capacity cost rate (CCR) for each resource and then calculated the total cost of patient care according to CCR and time for each resource. Costs were compared with 2016 Medicare reimbursement and relative value units (RVUs).

RESULTS

The total cost of radiation therapy for cervical cancer was $12,861.68, with personnel costs constituting 49.8%. Brachytherapy cost $8610.68 (66.9% of total) and consumed 423 minutes of attending radiation oncologist time (80.0% of total). External beam radiation therapy cost $4055.01 (31.5% of total). Personnel costs were higher for brachytherapy than for the sum of simulation and external beam radiation therapy delivery ($4798.73 vs $1404.72). A full radiation therapy course provides radiation oncologists 149.77 RVUs with intensity modulated radiation therapy or 135.90 RVUs with 3-dimensional conformal radiation therapy, with total reimbursement of $23,321.71 and $16,071.90, respectively. Attending time per RVU is approximately 4-fold higher for brachytherapy (5.68 minutes) than 3-dimensional conformal radiation therapy (1.63 minutes) or intensity modulated radiation therapy (1.32 minutes).

CONCLUSIONS

Time-driven activity-based costing was used to calculate the total cost of definitive radiation therapy for cervical cancer, revealing that brachytherapy delivery and personnel resources constituted the majority of costs. However, current reimbursement policy does not reflect the increased attending physician effort and delivery costs of brachytherapy. We hypothesize that the significant discrepancy between treatment costs and physician effort versus reimbursement may be a potential driver of reported national trends toward poor compliance with brachytherapy, and we suggest re-evaluation of payment policies to incentivize quality care.

Cervical cancer brachytherapy in Canada: A focus on interstitial brachytherapy utilization

PURPOSE

Brachytherapy (BT) techniques for cervical cancer in Canada have changed over the last decade, with evolution to high-dose-rate and image-guided BT. However, there are currently no national data on the use of interstitial BT (IBT). The purpose of this study was to document IBT utilization in Canadian centers, as well as update details of cervical cancer BT practices.

METHODS AND MATERIALS

All Canadian centers with gynecologic BT services (n = 33) were identified, and one gynecology radiation oncologist per center was sent a 33-item e-mail questionnaire regarding their center's practice for cervical cancer BT in 2015. Responses were reported and compared with practice patterns identified in a 2012 Canadian survey.

RESULTS

The response rate was 85% (28/33 centers). The majority (93%) of respondents used high-dose-rate BT, similar to the 2012 survey; 96% of centers had transitioned to three-dimensional (MRI/CT)-based planning in 2015 vs. 75% in 2012 (p = 0.03); 57% centers incorporated MRI for treatment planning in 2015 compared to 38% in 2012 (p = 0.15); the majority (13/16) using a combination of MRI and CT; 50% (14/28 centers) had the capacity to perform IBT, whereas 71% of those that did not referred patients to other centers. Of centers performing IBT, the majority (11/14) used template-based techniques with a median of 6 (range 2-20) needles/catheters and an average of 4 (range 1-5) fractions. Catheters were placed using: strategy based on pre-op imaging (21%), intra-op ultrasound (50%), intra-op MRI (7%), and intra-op CT (21%). The most common dose/fractionation schedules were 6 Gy × 5 fractions (40%), 8 Gy × 3 fractions (19%), and 7 Gy × 4 fractions (15%).

CONCLUSIONS

In Canada, treatment of cervical cancer continues to evolve. IBT has been adopted by half of the responding centers. As more centers move to MRI-based image-guided treatment planning, IBT will become an even more integral part of cervical cancer treatment.

Parallelized patient-specific quality assurance for high-dose-rate image-guided brachytherapy in an integrated computed tomography-on-rails brachytherapy suite

PURPOSE

To describe a parallelized patient-specific quality assurance (QA) program designed to ensure safety and quality in image-guided high-dose-rate brachytherapy in an integrated computed tomography (CT)-on-rails brachytherapy suite.

MATERIALS AND METHODS

A patient-specific QA program has been modified for the image-guided brachytherapy (IGBT) program in an integrated CT-on-rails brachytherapy suite. In the modification of the QA procedures of Task Group-59, the additional patient-specific QA procedures are included to improve rapid IGBT workflow with applicator placement, imaging, planning, treatment, and applicator removal taking place in one room.

RESULTS

The IGBT workflow is partitioned into two groups of tasks that can be performed in parallel by two or more staff members. One of the unique components of our implemented workflow is that groups work together to perform QA steps in parallel and in series during treatment planning and contouring. Coordinating efforts in this systematic way enable rapid and safe brachytherapy treatment while incorporating 3-dimensional anatomic variations between treatment days.

CONCLUSIONS

Implementation of these patient-specific QA procedures in an integrated CT-on-rails brachytherapy suite ensures confidence that a rapid workflow IGBT program can be implemented without sacrificing patient safety or quality and deliver highly-conformal dose to target volumes. These patient-specific QA components may be adapted to other IGBT environments that seek to provide rapid workflow while ensuring quality.

Accelerated partial breast irradiation with brachytherapy: patient selection and technique considerations

Accelerated partial breast irradiation (APBI) through breast brachytherapy is a relatively recent development in breast radiotherapy that has gained international favor because of its reduction in treatment duration and normal tissue irradiation while maintaining favorable cancer-specific and cosmetic outcomes. Despite the fact that several large national trials have not reported final results yet, many providers are currently offering APBI to select patients and APBI is listed as a treatment option for selecting patients in the National Comprehensive Cancer Network guidelines. Multiple consensus guidelines exist in selecting patients for APBI, some with conflicting recommendations. In this review, the existing patient selection guidelines are reported, compared, and critiqued, grouping them in helpful subcategories. Unique patient and technical selection factors for APBI with brachytherapy are explored.

Severe gastrointestinal complications in the era of image-guided high-dose-rate intracavitary brachytherapy for cervical cancer

PURPOSE

The purposes of this analysis are to report a modern series of severe gastrointestinal toxic effects after definitive chemoradiotherapy in the treatment of locally advanced cervical cancer at our institution and to review the existing literature on factors that contribute to toxic effects and preventive strategies and management.

METHODS

Our institution's cervical cancer cohort was evaluated for patients with late grade 3 to 4 gastrointestinal toxic effects who were retrospectively reviewed for clinical or dosimetric parameters that could have contributed to late toxic effects. A review of the published literature was performed to identify factors associated with late toxic effects, prophylactic agents, and corrective therapy.

FINDINGS

Five of 85 patients were identified as having late grade 3 to 4 gastrointestinal toxic effects with a median follow-up of 13.3 months. Two of 5 patients developed late grade 3 toxic effects, and 3 of 5 developed late grade 4 toxic effects. Three of the 5 patients reviewed ultimately required permanent colostomies. Cumulative median dose (in equivalent dose in 2-Gy fractions) of clinical target volume to the hottest 90% was 107.2 Gy, rectal dose to the hottest 2 cc (D2cc) was 81.7 Gy, sigmoid D2cc was 61.7 Gy, and bladder D2cc was 79.5 Gy. No patient had evidence of disease recurrence in the pelvis. One patient developed oligometastatic disease in the suprarenal gland and was successfully salvaged with adrenalectomy.

IMPLICATIONS

Despite its risk of toxic effects, intracavitary brachytherapy remains a critical component of the treatment of locally advanced cervical cancer. Even with modern radiotherapy planning and delivery techniques, extra attention is warranted to continue to strive for optimal outcomes.