Low-Kilovoltage, Single-Dose Intraoperative Radiation Therapy for Breast Cancer: Results and Impact on a Multidisciplinary Breast Cancer Program

Application of Intraoperative Radiotherapy in Early-Stage Breast Cancer Patients in a Clinical Setting

Background: Intraoperative radiation therapy (IORT) has gained popularity in recent years as an alternative to external beam whole breast radiation therapy (WBRT) for early-stage breast cancer. Here, we report 43-month recurrence and survival outcomes in a multiethnic cohort treated with IORT in a clinical context. Method: Two hundred and eleven patients with low-risk features were treated with IORT for early-stage breast cancer from 2014 to 2021. Selection criteria were based on Group Europeen de Curietherapie-European Society for Therapeutic Radiology and Oncology (GEC-ESTRO) guidelines: preferably unifocal intraductal carcinoma (IDC), aged > 50, tumor size ≤ 2.0 cm, and without lymph node involvement. All patients received 20 Gy of radiation dose during the lumpectomy. Information on patient and tumor characteristics was collected. Results: The mean age of this cohort was 67.5 years; 95.2% of patients are Jewish, and the rest are Bedouins (4.7%). Most tumors were intraductal carcinoma (97.2%) and stage 1 (94.8%). The mean follow-up time was 43.4 months. Bedouins had larger tumor sizes (mean 1.21 vs. 1.13 cm) and were younger at diagnosis than Jewish patients (mean 65.4 vs. 67.6 years), although the differences are not significant. The overall recurrence rate was 1.4%. One case of local recurrence (0.5%) and two cases of metastasis (0.9%) were observed during the study period. One patient died from metastasis. Conclusion: Our findings suggest that IORT in selected low-risk patients can achieve an excellent prognosis with low rates of recurrence and metastasis.

Comparison of adverse events in partial- or whole breast radiotherapy: investigation of cosmesis, toxicities and quality of life in a meta-analysis of randomized trials

PURPOSE/OBJECTIVE

Adjuvant whole breast radiotherapy and systemic therapy are part of the current evidence-based treatment protocols for early breast cancer, after breast-conserving surgery. Numerous randomized trials have investigated the therapeutic effects of partial breast irradiation (PBI) compared to whole breast irradiation (WBI), limiting the treated breast tissue. These trials were designed to achieve equal control of the disease with possible reduction in adverse events, improvements in cosmesis and quality of life (QoL). In this meta-analysis, we aimed to investigate the differences between PBI and WBI in side effects and QoL.

MATERIAL/METHODS

We performed a systematic literature review searching for randomized trials comparing WBI and PBI in early-stage breast cancer with publication dates after 2009. The meta-analysis was performed using the published event rates and the effect-sizes for available acute and late adverse events. Additionally, we evaluated cosmetic outcomes as well as general and breast-specific QoL using the EORTC QLQ-C30 and QLQ-BR23 questionnaires.

RESULTS

Sixteen studies were identified (n = 19,085 patients). PBI was associated with a lower prevalence in any grade 1 + acute toxicity and grade 2 + skin toxicity (OR = 0.12; 95% CI 0.09-0.18; p < 0.001); (OR = 0.16; 95% CI 0.07-0.41; p < 0.001). There was neither a significant difference in late adverse events between the two treatments, nor in any unfavorable cosmetic outcomes, rated by either medical professionals or patients. PBI-technique using EBRT with twice-daily fractionation schedules resulted in worse cosmesis rated by patients (n = 3215; OR = 2.08; 95% CI 1.22-3.54; p = 0.007) compared to WBI. Maximum once-daily EBRT schedules (n = 2071; OR = 0.60; 95% CI 0.45-0.79; p < 0.001) and IORT (p = 0.042) resulted in better cosmetic results grade by medical professionals. Functional- and symptom-based QoL in the C30-scale was not different between PBI and WBI. Breast-specific QoL was superior after PBI in the subdomains of "systemic therapy side effects" as well as "breast-" and "arm symptoms".

CONCLUSION

The analysis of multiple randomized trials demonstrate a superiority of PBI in acute toxicity as well breast-specific quality of life, when compared with WBI. Overall, late toxicities and cosmetic results were similar. PBI-technique with a fractionation of twice-daily schedules resulted in worse cosmesis rated by patients.

Global adoption of single-shot targeted intraoperative radiotherapy (TARGIT-IORT) for breast cancer—better for patients, better for healthcare systems

Micro abstract

Targeted intraoperative radiotherapy (TARGIT-IORT) is delivered immediately after lumpectomy for breast cancer. We estimated its impact. At least 44,752 patients with breast cancer were treated with TARGIT-IORT in 260 centres in 35 countries, saving &gt;20 million miles of travel and preventing ~2,000 non–breast cancer deaths. The TARGIT-IORT website (https://targit.org.uk/travel) provides maps and tools to find the nearest centre offering TARGIT-IORT and travel savings.

Background

Targeted intraoperative radiotherapy (TARGIT-IORT) delivers radiotherapy targeted to the fresh tumour bed exposed immediately after lumpectomy for breast cancer. TARGIT-A trial found TARGIT-IORT to be as effective as whole-breast radiotherapy, with significantly fewer deaths from non–breast cancer causes. This paper documents its worldwide impact and provides interactive tools for clinicians and patients.

Method

Centres using TARGIT-IORT provided the date of the first case and the total number of patients. We plotted these data on a customised Google Map. An interactive web-based tool provided directions to the closest centre. Using the data from the TARGIT-A trial, we estimated the total savings in travel miles, carbon footprint, and the number of non–breast cancer deaths that might be prevented.

Results

Data from 242 (93%) of the 260 centres treating patients from 35 countries were available. From the first patient treated in 1998 to early 2020, at least 44,752 women with breast cancer have been treated with TARGIT-IORT. The TARGIT-IORT website (https://targit.org.uk/travel) displays the Google Map of centres with number of cases and an interactive tool for patients to find the nearest centre offering TARGIT-IORT and their travel savings. Scaling up to the already treated patients, &gt;20 million miles of travel would have been saved and about 2,000 deaths prevented.

Conclusion

One can ascertain the number of patients treated with a novel treatment. These data show how widely TARGIT-IORT has now been adopted and gives an indication of its beneficial worldwide impact on a large number of women with breast cancer.

Ultra-Short Fraction Schedules as Part of De-intensification Strategies for Early-Stage Breast Cancer

Adjuvant radiation therapy (RT) following breast-conserving surgery (BCS) represents a standard approach for most patients treated with breast-conserving therapy (BCT) for early-stage breast cancer. The first-generation of adjuvant RT schedules delivered daily treatment to the whole breast over 5-7 weeks. Although efficacious, this presented patients with a protracted course of treatment, reducing compliance and quality of life. While hypofractionated whole-breast irradiation (WBI) has become the standard, and part of the second-generation of RT regimens, it still requires 3-4 weeks. Concurrently, partial-breast irradiation (PBI) has also been explored as a technique to complete RT in a much shorter time period (1-3 weeks). There are now seven trials confirming the efficacy of this shorter treatment approach compared with standard WBI. In an effort to further reduce treatment duration, ultra-short WBI and PBI regimens have recently emerged as the third-generation of breast radiation schedules, allowing for the completion of treatment in 5 days or less. With respect to WBI, recent data from the FAST-Forward trial (which evaluated five fractions of WBI delivered in 1 week) demonstrated no difference in clinical outcomes at 5 years, with limited difference in toxicity, compared with hypofractionated 3-week WBI. Regarding PBI, published data on five-fraction regimens delivered in 2 weeks have also demonstrated comparable outcomes at 10 years, with reduced toxicities with long-term follow-up. This report will review additional ongoing studies evaluating even shorter courses of adjuvant RT treatment (one to five fractions), including single-fraction PBI or WBI.

Efficacy analysis of intraoperative radiotherapy in patients with early-stage breast cancer

Background

To analyze the clinical efficacy of intraoperative radiotherapy (IORT) after breast-conserving surgery (BCS) in patients with early-stage breast cancer (BC), and to investigate the relationship between its influencing factors and clinical efficacy and prognosis.

Methods

A total of 73 patients with early-stage BC who underwent IORT after BCS in our hospital were selected in this research.

Results

Kaplan-Meier survival analysis was used to analyze the related factors of BCS and IORT of disease-free survival (DFS) and overall survival (OS). It was found that only age (χ² = 14.035, P = 0.003) was statistically positively correlated with the patient’s DFS, and local recurrence and metastasis rate and mortality were higher in patients over 70 years old. Log rank test was used to analyze multiple factors. Only the diameter of the applicator (χ² = 70.378, P < 0.05) was statistically significant with wound complications, and the larger the diameter, the higher incidence of wound complications. The remaining risk factors did not increase the incidence of wound complications. COX multivariate analysis showed that age was an independent risk factor for DFS rate and the risk factor had no significant effect on the OS rate of patients undergoing IORT after BCS.

Conclusions

IORT may be a safe form of treatment for the selected patients with early-stage BC, and can achieve satisfactory esthetic effect. Larger applicator diameters may increase the incidence of wound complications. Age is an independent risk factor for DFS in early-stage BC patients undergoing IORT after BCS.

Toxicity and cosmetic outcomes after treatment with a novel form of breast IORT

PURPOSE

Intraoperative radiation therapy (IORT), a form of accelerated partial breast irradiation (APBI), is an appealing alternative to postoperative whole breast irradiation for early-stage breast cancer. The purpose of this study was to examine the toxicity and cosmetic outcomes of patients treated with a novel form of breast IORT (precision breast IORT; PB-IORT), that delivers a targeted, higher dose of radiation than conventional IORT.

METHODS AND MATERIALS

The first 204 patients treated with PB-IORT in a Phase II clinical trial (NCT02400658) with 12 months of followup were included. Trial inclusion criteria were age ≥45 years, invasive or in situ breast cancer, tumor size ≤3 cm, and node negative. Toxicity and cosmetic scoring were performed at 6 and 12 months.

RESULTS

98 patients (48%; 95% CI, 41-55%) experienced toxicity. Seven Grade 3 toxicities occurred (3.4%; 95% CI, 1.4-6.9%). Most patients (95%) had excellent or good cosmetic outcomes (95% CI, 91-98%) at 12 months. Most patients (94%) had little or no pigmentation change (95% CI, 90-97%), 88% little to no size change (95% CI, 82-92%), and 87% experienced minimal shape change (95% CI, 82-92%).

CONCLUSIONS

Overall, Grade 3+ toxicity was rare and cosmetic outcomes were excellent. Severe toxicity with PB-IORT is similar to that reported in the TARGIT trial (3.3% rate of major toxicity) but lower than APBI (NSABP-39, 10.1% Grade 3/4 toxicities). We propose that the toxicity of PB-IORT compared with TARGIT and NSABP-39 is related to the radiation dose and delivery schedule. PB-IORT offers low-toxicity and good cosmetic outcomes when compared with other forms of APBI.

A Network Meta-Analysis of Surgical Treatment in Patients With Early Breast Cancer

BACKGROUND

In early breast cancer treatment, the preferred surgical regimen remains a topic of controversy, and conventional pairwise meta-analysis cannot provide a hierarchy based on clinical trial evidence. Therefore, a network meta-analysis was performed both for direct and indirect comparisons and to assess the survival outcomes of surgical regimens.

METHODS

Randomized clinical trials comparing different surgical regimens for the treatment of early breast cancer were identified. Overall survival (OS) and disease-free-survival (DFS) were analyzed using random-effects network meta-analysis on the hazard ratio (HR) scale and calculated as combined HRs and 95% confidence intervals (CIs). All statistical tests were two-sided.

RESULTS

The network meta-analysis compared 11 different surgical regimens that consisted of 13 and 17 direct comparisons between strategies for OS (34 trials; n = 23 587 patients) and DFS (32 trials; n = 22 552 patients), respectively. The values of surface under the cumulative ranking for OS and DFS after mastectomy (M)+radiotherapy (RT) were observed to be the largest. Breast-conserving surgery (BCS)+axillary node sampling+RT almost achieved the threshold for inferiority compared with the other surgical treatment arms and was statistically significantly associated with worse OS (HR = 0.51, 95% CI = 0.24 to 0.94; HR = 0.48, 95% CI = 0.22 to 0.92; HR = 0.51, 95% CI = 0.23 to 0.96). No statistically significant difference between BCS+sentinel lymph node biopsy (SLNB)+RT vs BCS+SLNB+intraoperative RT was observed in carrying out network meta-analysis (HR = 0.95, 95% CI = 0.64 to 1.36).

CONCLUSIONS

M+RT has the most favorable survival outcomes among the various surgical regimens for the treatment of early breast cancer patients. For patients who receive BCS, SNLB has more favorable outcomes than axillary node sampling. Intraoperative RT and postoperative RT have similar outcomes in patients who receive SLNB.

Time-driven activity-based costing of a novel form of CT-guided high-dose-rate brachytherapy intraoperative radiation therapy compared with conventional breast intraoperative radiation therapy for early stage breast cancer

INTRODUCTION

Intraoperative radiation therapy is an emerging option for adjuvant therapy for early stage breast cancer, although it is not currently considered standard of care in the United States. We applied time-driven activity-based costing to compare two alternative methods of breast intraoperative radiation therapy, including treatment similar to the techniques employed in the TARGIT-A clinical trial and a novel version with CT-guidance and high-dose-rate (HRD) brachytherapy.

METHODS AND MATERIALS

Process maps were created to describe the steps required to deliver intraoperative radiation therapy for early stage breast cancer at each institution. The components of intraoperative radiation therapy included personnel, equipment, and consumable supplies. The capacity cost rate was determined for each resource. Based on this, the delivery costs were calculated for each regimen. For comparison across centers, we did not account for indirect facilities costs and interinstitutional differences in personnel salaries.

RESULTS

The CT-guided, HRD form of intraoperative radiation therapy costs more to deliver ($4,126.21) than the conventional method studied in the TARGIT-A trial ($1,070.45). The cost of the brachytherapy balloon applicator ($2,750) was the primary driver of the estimated differences in costs. Consumable supplies were the largest contributor to the brachytherapy-based approach, whereas personnel costs were the largest contributor to costs of the standard form of intraoperative radiation therapy.

CONCLUSIONS

When compared with the more established method of intraoperative radiation therapy using a portable superficial photon unit, the delivery of treatment with CT guidance and HDR brachytherapy is associated with substantially higher costs. The excess costs are driven primarily by the cost of the disposable brachytherapy balloon applicator and, to a lesser extent, additional personnel costs. Future work should include evaluation of a less expensive brachytherapy applicator to increase the anticipated value of brachytherapy-based intraoperative radiation therapy.

Accelerated Partial Breast Irradiation: A New Standard of Care?

Background

Breast-conserving therapy including lumpectomy and adjuvant whole breast irradiation (WBI) has become the standard therapy for early-stage breast cancer (EBC). Without WBI, the recurrence rate is significantly increased. However, when selecting patients at a low a priori risk of local recurrence only a small breast-cancer-specific mortality benefit, but no overall survival improvement, was detected for WBI. As most recurrences occur close to the lumpectomy cavity, accelerated partial breast irradiation (APBI) delivered exclusively to a limited volume of tissue around the initial lumpectomy site, has gained increased attention and is now discussed as an alternative to WBI for selected EBC patients.

Summary

Numerous techniques for APBI (interstitial brachytherapy, external beam-based APBI, intraoperative radiotherapy, MR-guided radiotherapy) allow treatment delivery in a shorter period of time, and radiation oncologists expect to further reduce side effects by using these new techniques, with improvements in cosmetics and quality of life. In this review, we aim to describe the existing evidence for the feasibility and effectiveness of different APBI techniques used in modern radiotherapy.

Key Messages

APBI has provided outcomes similar to WBI combined with potentially reduced toxicity. While appropriate patient selection persists to be crucial for acceptable recurrence rates, the precise definition of patients suitable for APBI remains a matter of discussion. As long-term data are often still lacking, special attention should be paid to late side effects and long-term outcomes. Decision-making on appropriate treatment techniques should take into account not only local control rates, but also the impact on the patient's quality of life.

Accelerated partial breast irradiation-Redefining the treatment target for women with early stage breast cancer

Following breast conserving surgery, the standard of care has been to deliver adjuvant radiation therapy directed to the whole breast (WBI) over a period of 3-7 weeks. Over the past decade, increasing data have supported the concept that treatment to the whole breast may not be required in selected patients, allowing for the emergence of partial breast irradiation (PBI). Multiple randomized trials with 5-10 years of follow-up have been published documenting the safety and efficacy associated with PBI using multiple techniques. Questions that remain to be answered include (a) what is the optimal PBI technique for each clinical scenario, (b) are there additional patients that can be effectively managed with PBI approaches, and (c) are there different techniques/dose schedules that allow for further reduction in treatment duration and/or toxicities? Partial breast irradiation represents a standard approach for appropriately selected patients. PBI provides comparable clinical outcomes to WBI while allowing for a reduction in the duration treatment and the potential for reduced toxicities. Future studies may also help to better define which patients require no radiation, PBI, hypofractionated WBI or conventional WBI, based upon patient, clinical, pathologic features as well as potentially using tumor genetics.

Implementation of an HDR brachytherapy-based breast IORT program: Initial experiences

PURPOSE

A multidisciplinary team at our institution developed a novel method of intraoperative breast radiation therapy (precision breast intraoperative radiation therapy [PB-IORT]) that uses high-dose-rate brachytherapy with CT on-rails imaging to deliver high-dose, customized radiotherapy to patients with early-stage breast cancer. This report summarizes our program's experience developing and implementing PB-IORT.

METHODS AND MATERIALS

Literature on PB-IORT was reviewed including published articles and abstracts. To evaluate case volume, all patients with a breast cancer diagnosis who underwent breast surgery or breast radiation (2010-2017) at our academic institution were identified. Patients were stratified into pre-IORT and post-IORT eras with initiation of our PB-IORT program in October 2013. Overall trends in surgical and radiation therapy volume in each era were analyzed by linear regression. Travel distance for all surgical patients was calculated using Google Maps (Alphabet Inc.) and then compared between IORT and non-IORT patients.

RESULTS

Data from a PB-IORT Phase 1 trial found that the primary endpoints were met and that PB-IORT is feasible and safe. The direct health system's delivery costs for PB-IORT exceed those of 16-fraction whole-breast irradiation when accounting for consumable supplies (multilumen balloon applicator = $2,750 per patient). There was a significant increase in yearly growth of breast cancer surgical volume with PB-IORT.

CONCLUSIONS

Accrual rates for the ongoing Phase II trial have been quicker than expected in an area where more research is needed. The rapid accrual indicates patient interest and demand for this treatment and that it is very feasible to get more data from randomized trials.

Using the new INTRABEAM mobile intraoperative radiotherapy system during surgery for pancreatic cancer: a case report

Background

Pancreatic cancer is one of the most common fatal malignancies and has a poor prognosis. Surgical treatment is the most important treatment method, but there is a low rate of radical excision; moreover, the postoperative recurrence rate is high, with a local recurrence rate greater than 50%. The usefulness of intraoperative radiotherapy for pancreatic cancer has previously been examined. However, prior research was based on the traditional high-energy electron beam, which causes serious radiation toxicity. Therefore, the tumor radiation dose was limited, subsequently limiting the effect. In contrast, there is also a low-energy X-ray radiation system called INTRABEAM®. Use of INTRABEAM has been applied clinically, but the treatment effect of INTRABEAM in pancreatic cancer has not been reported.

Case presentation

We present a case of a 56-year-old Chinese man with local advanced pancreatic cancer with invasion of the coeliac trunk artery and origin of the portal vein. He underwent distal pancreatectomy and splenectomy along with intraoperative radiotherapy using a portable INTRABEAM radiation system. The radiotherapy dose was 10 Gy and irradiation time was 27.4 minutes. There were no obvious postoperative complications. His abdominal pain was alleviated after surgery, and no obvious tumor recurrence has been observed in short-term follow-up.

Conclusions

We believe that it is safe to apply intraoperative radiotherapy using the INTRABEAM radiation system in pancreatic cancer. This approach appears promising for further future development.

Intraoperative radiotherapy with the Intrabeam® device for the treatment of resectable pancreatic adenocarcinoma

INTRODUCTION

The application of intraoperative radiation therapy to the tumor bed after resection of pancreatic cancer has been shown to be beneficial in the local control of the disease. The objective of this study was to evaluate the preliminary outcomes after the application of a single intraoperative dose to the tumor bed with a new intraoperative radiotherapy device (Intrabeam^®) in terms of viability, safety and short-term results.

METHODS

We studied 5 patients who underwent pancreaticoduodenectomy for resectable pancreatic cancer in which a radiotherapy boost (5Gy) was intraoperatively applied to the tumoral bed using the portable Intrabeam^® device, a low-energy point-source X-ray. Postoperative complications, hospital stay and mortality, recurrences and short-term survival were analyzed.

RESULTS

Mean patient age was 68 years. All patients had a T3-stage tumor and one of them N1. In 3 patients, R0 resection was performed, while R1 resection was conducted in 2. Perioperative mortality was 0%. The only complications included delayed gastric emptying and postoperative hemorrhage. There were no pancreatic fistulas. During follow-up (mean: 11.2 months), there was a relapse in the patient who had undergone R1 resection.

CONCLUSIONS

The application of radiotherapy with the Intrabeam^® device in selected patients has not resulted in increased perioperative morbidity or mortality; therefore, this is a safe procedure for the treatment of resectable cancer.

Utility of CT imaging in a novel form of high-dose-rate intraoperative breast radiation therapy

INTRODUCTION

Intraoperative radiation therapy (IORT) is an alternative to whole breast radiation following breast conserving surgery. Conventional breast IORT is limited by lack of cross-sectional imaging. In response, our institution developed Precision Breast IORT (PB-IORT) which utilizes intraoperative computed tomography (CT) images for confirmation of brachytherapy applicator placement and for treatment planning. The purpose of this study was to determine the utility of CT imaging in PB-IORT in the first 103 patients treated in two prospective clinical trials.

METHODS

We retrospectively reviewed the first 103 patients treated with PB-IORT. All patients underwent breast surgery and placement of a multi-lumen brachytherapy applicator. Patients had a CT scan followed by high-dose-rate (HDR) brachytherapy. Endpoints were the number of patients having more than one CT during PB-IORT and the number of treatment plans having image-based modifications.

RESULTS

After initial CT scan, 27 patients (26.2%) had findings prompting surgical applicator adjustment. One patient underwent an additional scan to localize a biopsy clip and aid in excision to negative margin. Eighty-one patients (78.6%) had dosimetry modifications based on CT findings with 36 plans (35.0%) adjusted to protect the skin or chest wall and 45 plans (43.7%) to protect both the skin and chest wall.

CONCLUSIONS

Computed tomography findings prompted treatment alterations in the majority of patients treated with PB-IORT to enhance tissue conformity and to sculpt the radiation dose away from normal tissues. CT imaging is unique to PB-IORT. These findings suggest the potential clinical superiority of PB-IORT given its allowance for patient-specific alterations.

Intraoperative Radiotherapy for Breast Cancer Treatment in a Rural Community

BACKGROUND

Access to health care poses particular challenges for patients living in rural communities. Intraoperative radiotherapy (IORT) offers a treatment alternative to traditional whole-breast radiation therapy (WBRT) for select patients. This study aimed to analyze the use of IORT for patients undergoing breast-conserving surgery at an academic institution located in a rural state.

METHODS

A retrospective review analyzed all patients at a single institution with a diagnosis of ductal carcinoma in situ (DCIS) or invasive breast cancer from April 2012 to January 2017 who were undergoing breast-conserving surgery with either IORT or WBRT. Student's t test or Fisher's exact test was used to make statistical comparisons.

RESULTS

Patients undergoing IORT (n = 117) were significantly older than patients treated with WBRT (n = 191) (65.6 vs 58.6 years; p < 0.001) and had smaller tumors on both preoperative imaging (1.04 vs 1.66 cm; p < 0.05) and final pathology (0.99 vs 1.48 cm; p < 0.05). Patients receiving IORT lived farther from the treating facility than patients treated with WBRT (67.2 vs 30.8 miles; p < 0.05). To account for biases created in the IORT selection criteria, subgroup analysis was performed for women receiving WBRT who fulfilled IORT selection criteria, and distance traveled remained significant (67.2 vs 31.4 miles; p < 0.05). Neither recurrence nor survival differed between the IORT and WBRT groups. Medicare reimbursement for IORT was approximately 50% more than for WBRT.

CONCLUSIONS

For women from rural communities, IORT appears to be an attractive option because these women tend to be older and to live farther from the treatment facility.

Evaluation of the Effect of Source Geometry on the Output of Miniature X-ray Tube for Electronic Brachytherapy through Simulation

OBJECTIVE

The use of miniature X-ray source in electronic brachytherapy is on the rise so there is an urgent need to acquire more knowledge on X-ray spectrum production and distribution by a dose. The aim of this research was to investigate the influence of target thickness and geometry at the source of miniature X-ray tube on tube output.

METHOD

Five sources were simulated based on problems each with a specific geometric structure and conditions using MCNPX code. Tallies proportional to the output were used to calculate the results for the influence of source geometry on output.

RESULTS

The results of this work include the size of the optimal thickness of 5 miniature sources, energy spectrum of the sources per 50 kev and also the axial and transverse dose of simulated sources were calculated based on these thicknesses. The miniature source geometric was affected on the output x-ray tube.

CONCLUSION

The result of this study demonstrates that hemispherical-conical, hemispherical and truncated-conical miniature sources were determined as the most suitable tools.

Intraoperative Radiation for Breast Cancer with Intrabeam™: Factors Associated with Decreased Operative Times in Patients Having IORT for Breast Cancer

Introduction

Intraoperative radiation with Intrabeam™ (IORT) for breast cancer is a newer technology recently implemented into the operating room (OR). This procedure requires time and coordination between the surgeon and radiation oncologist, who both perform their treatments in a single operative setting. We evaluated the surgeons at our center, who perform IORT and their OR times to examine changes in OR times following implementation of this new surgical procedure. We hypothesized that IORT is a technique for which timing could be improved with the increasing number of cases performed.

Methods

A prospectively maintained IRB approved database was queried for OR times (incision and close) in patients who underwent breast conserving surgery (BCS), sentinel lymph node biopsy with and without IORT using the Intrabeam™ system at our institution from 2011 to 2015. The total OR times were compared for each surgeon individually and over time. Next, the OR times of each surgeon were compared to each other. Continuous variables were summarized and then a prediction model was created using IORT time, OR time, surgeon, and number of cases performed.

Results

There were five surgeons performing IORT at our institution during this time period with a total of 96 cases performed. There was a significant difference observed in baseline surgeon-specific OR time for BSC (p = 0.03) as well as for BCS with IORT (p < 0.05), attributable to surgeon experience. The average BCS times were faster than the BCS plus IORT procedure times for all surgeons. The overall mean OR time for the entire combined surgical and radiation procedure was 135.5 min. The most common applicator sizes used were the 3.5 and 4 cm, yielding an average 21 min IORT time. Applicator choice did not differ over time (p = 0.189). After adjusting for IORT time and surgeon, the prediction model estimated that surgeons decreased the total BCS plus IORT OR time at a rate of −4.5 min per each additional 10 cases performed.

Conclusion

Surgeon experience and applicator size are related to OR times for performing IORT for breast cancer. OR time for IORT in breast cancer treatment can be improved over time, even among experienced surgeons.

Intraoperative radiation therapy for breast cancer patients: current perspectives

Accelerated partial breast irradiation (APBI) provides an attractive alternative to whole breast irradiation (WBI) through normal tissue radiation exposure and reduced treatment duration. Intraoperative radiation therapy (IORT) is a form of APBI with the shortest time interval, as it delivers the entirety of a planned radiation course at the time of breast surgery. However, faster is not always better, and IORT has been met with healthy skepticism. Patients treated with IORT have an increased compliance and overall satisfaction when compared to patients treated with WBI. However, early randomized trial results demonstrated an increased rate of recurrence after IORT, slowing its widespread adoption. Despite these controversies, IORT utilization is increasing nationally and several novel developments are aimed at continuing to minimize the risk of recurrence and treatment-related toxicity while maximizing the patient experience.

The INTRABEAM® Photon Radiotherapy System for the adjuvant treatment of early breast cancer: a systematic review and economic evaluation

BACKGROUND

Initial treatment for early breast cancer is usually either breast-conserving surgery (BCS) or mastectomy. After BCS, whole-breast external beam radiotherapy (WB-EBRT) is the standard of care. A potential alternative to post-operative WB-EBRT is intraoperative radiation therapy delivered by the INTRABEAM(®) Photon Radiotherapy System (Carl Zeiss, Oberkochen, Germany) to the tissue adjacent to the resection cavity at the time of surgery.

OBJECTIVE

To assess the clinical effectiveness and cost-effectiveness of INTRABEAM for the adjuvant treatment of early breast cancer during surgical removal of the tumour.

DATA SOURCES

Electronic bibliographic databases, including MEDLINE, EMBASE and The Cochrane Library, were searched from inception to March 2014 for English-language articles. Bibliographies of articles, systematic reviews, clinical guidelines and the manufacturer's submission were also searched. The advisory group was contacted to identify additional evidence.

METHODS

Systematic reviews of clinical effectiveness, health-related quality of life and cost-effectiveness were conducted. Two reviewers independently screened titles and abstracts for eligibility. Inclusion criteria were applied to full texts of retrieved papers by one reviewer and checked by a second reviewer. Data extraction and quality assessment were undertaken by one reviewer and checked by a second reviewer, and differences in opinion were resolved through discussion at each stage. Clinical effectiveness studies were included if they were carried out in patients with early operable breast cancer. The intervention was the INTRABEAM system, which was compared with WB-EBRT, and study designs were randomised controlled trials (RCTs). Controlled clinical trials could be considered if data from available RCTs were incomplete (e.g. absence of data on outcomes of interest). A cost-utility decision-analytic model was developed to estimate the costs, benefits and cost-effectiveness of INTRABEAM compared with WB-EBRT for early operable breast cancer.

RESULTS

One non-inferiority RCT, TARGeted Intraoperative radioTherapy Alone (TARGIT-A), met the inclusion criteria for the review. The review found that local recurrence was slightly higher following INTRABEAM than WB-EBRT, but the difference did not exceed the 2.5% non-inferiority margin providing INTRABEAM was given at the same time as BCS. Overall survival was similar with both treatments. Statistically significant differences in complications were found for the occurrence of wound seroma requiring more than three aspirations (more frequent in the INTRABEAM group) and for a Radiation Therapy Oncology Group toxicity score of grade 3 or 4 (less frequent in the INTRABEAM group). Cost-effectiveness base-case analysis indicates that INTRABEAM is less expensive but also less effective than WB-EBRT because it is associated with lower total costs but fewer total quality-adjusted life-years gained. However, sensitivity analyses identified four model parameters that can cause a switch in the treatment option that is considered cost-effective.

LIMITATIONS

The base-case result from the model is subject to uncertainty because the disease progression parameters are largely drawn from the single available RCT. The RCT median follow-up of 2 years 5 months may be inadequate, particularly as the number of participants with local recurrence is low. The model is particularly sensitive to this parameter.

CONCLUSIONS AND IMPLICATIONS

A significant investment in INTRABEAM equipment and staff training (clinical and non-clinical) would be required to make this technology available across the NHS. Longer-term follow-up data from the TARGIT-A trial and analysis of registry data are required as results are currently based on a small number of events and economic modelling results are uncertain.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013006720.

FUNDING

The National Institute for Health Research Health Technology Assessment programme. Note that the economic model associated with this document is protected by intellectual property rights, which are owned by the University of Southampton. Anyone wishing to modify, adapt, translate, reverse engineer, decompile, dismantle or create derivative work based on the economic model must first seek the agreement of the property owners.

TARGIT-R (Retrospective): North American Experience with Intraoperative Radiation Using Low-Kilovoltage X-Rays for Breast Cancer

BACKGROUND

Single-dose intraoperative radiotherapy (IORT) is an emerging treatment for women with early stage breast cancer. The objective of this study was to define the frequency of IORT use, patient selection, and outcomes of patients treated in North America.

METHODS

A multi-institutional retrospective registry was created, and 19 institutions using low-kilovoltage IORT for the treatment of breast cancer entered data on patients treated at their institution before July 31, 2013. Patient selection, IORT treatment details, complications, and recurrences were analyzed.

RESULTS

From 2007 to July 31, 2013, a total of 935 women were identified and treated with lumpectomy and IORT. A total of 822 patients had at least 6 months' follow-up documented and were included in the analysis. The number of IORT cases performed increased significantly over time (p < 0.001). The median patient age was 66.8 years. Most patients had disease that was <2 cm in size (90 %) and was estrogen positive (91 %); most patients had invasive ductal cancer (68 %). Of those who had a sentinel lymph node procedure performed, 89 % had negative sentinel lymph nodes. The types of IORT performed were primary IORT in 79 %, secondary IORT in 7 %, or planned boost in 14 %. Complications were low. At a median follow-up of 23.3 months, crude in-breast recurrence was 2.3 % for all patients treated.

CONCLUSIONS

IORT use for the treatment of breast cancer is significantly increasing in North America, and physicians are selecting low-risk patients for this treatment option. Low complication and local recurrence rates support IORT as a treatment option for selected women with early stage breast cancer.

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.

Techniques for intraoperative radiation therapy for early-stage breast carcinoma

ABSTRACT 

Intraoperative radiation therapy (IORT) is a method of accelerated partial breast irradiation developed to replace other longer courses of radiotherapy with a single radiation session administered at the time of breast-conserving surgery. The purpose of this review is to summarize the advantages and disadvantages of breast IORT techniques that are currently available, as well to consider potential alternative techniques for breast IORT or ultra-short course breast radiotherapy. Furthermore, we highlight the published outcomes for the IORT treatment approaches including: electron therapy, superficial photon therapy and other techniques. Potential future directions of IORT are explored including novel IORT techniques utilizing intraoperative brachytherapy with in-room imaging and rapid treatment planning.

Intraoperative radiotherapy for breast cancer: the lasting effects of a fleeting treatment

In well-selected patients who choose to pursue breast conservation therapy (BCT) for early-stage breast cancer, partial breast irradiation (PBI) delivered externally or intraoperatively, may be a viable alternative to conventional whole breast irradiation. Two large, contemporary randomized trials have demonstrated breast intraoperative radiotherapy (IORT) to be noninferior to whole breast external beam radiotherapy (EBRT) when assessing for ipsilateral breast tumor recurrence in select patients. Additionally, IORT and other PBI techniques are likely to be more widely adopted in the future because they improve patient convenience by offering an accelerated course of treatment. Coupled with these novel techniques for breast radiotherapy (RT) are distinct toxicity profiles and unique cosmetic alterations that differ from conventional breast EBRT and have the potential to impact disease surveillance and patient satisfaction. This paper will review the level-one evidence for treatment efficacy as well as important secondary endpoints like RT toxicity, breast cosmesis, quality of life, patient satisfaction, and surveillance mammography following BCT with IORT.

Evaluating radiotherapy options in breast cancer: does intraoperative radiotherapy represent the most cost-efficacious option?

INTRODUCTION

This study analyzed the cost-efficacy of intraoperative radiation therapy (IORT) compared with whole-breast irradiation (WBI) and accelerated partial-breast irradiation (APBI) for early-stage breast cancer.

MATERIALS AND METHODS

Data for this analysis came from 2 phase III trials: the TARGIT (Targeted Intraoperative Radiotherapy) trial and the ELIOT (Electron Intraoperative Radiotherapy) trial. Cost analyses included a cost-minimization analysis and an incremental cost-effectiveness ratio analysis including a quality-adjusted life-year (QALY) analysis. Cost analyses were performed comparing IORT with WBI delivered using 3-dimensional conformal radiotherapy (3D-CRT), APBI 3D-CRT, APBI delivered with intensity-modulated radiotherapy (IMRT), APBI single-lumen (SL), APBI multilumen (ML), and APBI interstitial (I).

RESULTS

Per 1000 patients treated, the cost savings with IORT were $3.6-$4.3 million, $1.6-$2.4 million, $3.6-$4.4 million, $7.5-$8.2 million, and $2.8-$3.6 million compared with WBI 3D-CRT, APBI IMRT, APBI SL, APBI ML, and APBI I, respectively, with a cost decrement of $1.6-$2.4 million compared with APBI 3D-CRT based on data from the TARGIT trial. The costs per QALY for WBI 3D-CRT, APBI IMRT, APBI SL, APBI ML, and APBI I compared with IORT were $47,990-$60,002; $17,335-$29,347; $49,019-$61,031; $108,162-$120,173; and $36,129-$48,141, respectively, based on data from the ELIOT trial. These results are consistent with APBI and WBI being cost-effective compared with IORT.

CONCLUSION

Based on cost-minimization analyses, IORT represents a potential cost savings in the management of early-stage breast cancer. However, absolute reimbursement is misleading, because when additional medical and nonmedical costs associated with IORT are factored in, WBI and APBI represent cost-effective modalities based on cost-per-QALY analyses. They remain the standard of care.