Pride, Prejudice, or Science: Attitudes Towards the Results of the TARGIT-A Trial of Targeted Intraoperative Radiation Therapy for Breast Cancer

Accelerated Partial Breast Irradiation Using 5 Daily Fractions: A Prospective, Phase 2, Multicenter Trial of Cosmetic Outcomes and Toxicity-ACCEL Final Results

PURPOSE

This study investigated the cosmetic degradation and toxicity for an accelerated partial breast irradiation (APBI) prescription delivered in 5 fractions over 1 week and compared the outcomes with those of whole breast irradiation (WBI).

METHODS AND MATERIALS

The trial was a multicenter, single-arm, phase 2 prospective cohort study. Eligible women 50 years of age or older with estrogen receptor-positive and human epidermal growth factor receptor 2-negative invasive ductal carcinoma or ductal carcinoma in situ after breast-conserving surgery received 27 Gy in 5 daily fractions of APBI. The primary endpoint was noninferiority of 2-year cosmesis using the RAPID trial's WBI arm as the control arm. A global consensus cosmetic score using a European Organisation for Research and Treatment of Cancer rating scale score of excellent, good, fair, or poor for each patient at baseline and 2 years was generated by a panel of 5 radiation oncologists using photographs of treated and untreated breasts.

RESULTS

From 2016 to 2019, 298 eligible women were enrolled. By the 2-year follow-up, 76 patients had been lost or withdrawn and 3 had died, resulting in 219 patients available for complete, 2-year photographic cosmetic evaluation. The median follow-up for all participants was 4.7 years (IQR, 3.8-5.5 years). No patient had a fair or poor cosmetic score at the 2-year evaluation. Cosmesis was better or unchanged for 97% of patients and worse for 3% (excellent to good), and no cosmetic failures occurred. The confidence intervals were 0.88 (0.86-0.90) and 1.00 (0.99-1.00) for the RAPID and ACCEL trials, respectively.

CONCLUSIONS

Cosmetic degradation with 5 daily treatments of the ACCEL trial's APBI intervention is noninferior to the WBI arm of the RAPID trial.

Long-Term Results of the TARGIT-A Trial: More Questions than Answers

Background

During the last decade, partial breast irradiation (PBI) has gained traction as a relevant treatment option for patients with early-stage low-risk breast cancer after breast-conserving surgery. The TARGIT-A prospective randomized trial compared a "risk-adapted" intraoperative radiotherapy (IORT) approach with 50-kv X-rays (INTRABEAM®) as the PBI followed by optional whole-breast irradiation (WBI) and conventional adjuvant WBI in terms of observed 5-year in-breast recurrence rates. Recently, long-term data were published. Since the first publication of the TARGIT-A trial, a broad debate has been emerged regarding several uncertainties and limitations associated with data analysis and interpretation. Our main objective was to summarize the data, with an emphasis on the updated report and the resulting implications.

Summary

From our point of view, the previously unresolved questions still remain and more have been added, especially with regard to the study design, a change in the primary outcome measure, the significant number of patients lost to follow-up, and the lack of a subgroup analysis according to risk factors and treatment specifications.

Key Message

Taking into account the abovementioned limitations of the recently published long-term results of the TARGIT-A trial, the German Society of Radiation Oncology (DEGRO) Breast Cancer Expert Panel adheres to its recently published recommendations on PBI: "the 50-kV system (INTRABEAM) cannot be recommended for routine adjuvant PBI treatment after breast-conserving surgery."

Partial breast irradiation versus whole breast radiotherapy for early breast cancer

BACKGROUND

Breast-conserving therapy for women with breast cancer consists of local excision of the tumour (achieving clear margins) followed by radiotherapy (RT). Most true recurrences occur in the same quadrant as the original tumour. Whole breast radiotherapy (WBRT) may not protect against the development of a new primary cancer developing in other quadrants of the breast. In this Cochrane Review, we investigated the delivery of radiation to a limited volume of the breast around the tumour bed (partial breast irradiation (PBI)) sometimes with a shortened treatment duration (accelerated partial breast irradiation (APBI)).

OBJECTIVES

To determine whether PBI/APBI is equivalent to or better than conventional or hypofractionated WBRT after breast-conserving therapy for early-stage breast cancer.

SEARCH METHODS

On 27 August 2020, we searched the Cochrane Breast Cancer Group Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL and three trial databases. We searched for grey literature: OpenGrey (September 2020), reference lists of articles, conference proceedings and published abstracts, and applied no language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) without confounding, that evaluated conservative surgery plus PBI/APBI versus conservative surgery plus WBRT. Published and unpublished trials were eligible.

DATA COLLECTION AND ANALYSIS

Two review authors (BH and ML) performed data extraction, used Cochrane's risk of bias tool and resolved any disagreements through discussion, and assessed the certainty of the evidence for main outcomes using GRADE. Main outcomes were local recurrence-free survival, cosmesis, overall survival, toxicity (subcutaneous fibrosis), cause-specific survival, distant metastasis-free survival and subsequent mastectomy. We entered data into Review Manager 5 for analysis.

MAIN RESULTS

We included nine RCTs that enrolled 15,187 women who had invasive breast cancer or ductal carcinoma in-situ (6.3%) with T1-2N0-1M0 Grade I or II unifocal tumours (less than 2 cm or 3 cm or less) treated with breast-conserving therapy with negative margins. This is the second update of the review and includes two new studies and 4432 more participants. Local recurrence-free survival is probably slightly reduced (by 3/1000, 95% CI 6 fewer to 0 fewer) with the use of PBI/APBI compared to WBRT (hazard ratio (HR) 1.21, 95% confidence interval (CI) 1.03 to 1.42; 8 studies, 13,168 participants; moderate-certainty evidence). Cosmesis (physician/nurse-reported) is probably worse (by 63/1000, 95% CI 35 more to 92 more) with the use of PBI/APBI (odds ratio (OR) 1.57, 95% CI 1.31 to 1.87; 6 studies, 3652 participants; moderate-certainty evidence). Overall survival is similar (0/1000 fewer, 95% CI 6 fewer to 6 more) with PBI/APBI and WBRT (HR 0.99, 95% CI 0.88 to 1.12; 8 studies, 13,175 participants; high-certainty evidence). Late radiation toxicity (subcutaneous fibrosis) is probably increased (by 14/1000 more, 95% CI 102 more to 188 more) with PBI/APBI (OR 5.07, 95% CI 3.81 to 6.74; 2 studies, 3011 participants; moderate-certainty evidence). The use of PBI/APBI probably makes little difference (1/1000 less, 95% CI 6 fewer to 3 more) to cause-specific survival (HR 1.06, 95% CI 0.83 to 1.36; 7 studies, 9865 participants; moderate-certainty evidence). We found the use of PBI/APBI compared with WBRT probably makes little or no difference (1/1000 fewer (95% CI 4 fewer to 6 more)) to distant metastasis-free survival (HR 0.95, 95% CI 0.80 to 1.13; 7 studies, 11,033 participants; moderate-certainty evidence). We found the use of PBI/APBI in comparison with WBRT makes little or no difference (2/1000 fewer, 95% CI 20 fewer to 20 more) to mastectomy rates (OR 0.98, 95% CI 0.78 to 1.23; 3 studies, 3740 participants, high-certainty evidence).

AUTHORS' CONCLUSIONS

It appeared that local recurrence-free survival is probably worse with PBI/APBI; however, the difference was small and nearly all women remain free of local recurrence. Overall survival is similar with PBI/APBI and WBRT, and we found little to no difference in other oncological outcomes. Some late effects (subcutaneous fibrosis) may be worse with PBI/APBI and its use is probably associated with worse cosmetic outcomes. The limitations of the data currently available mean that we cannot make definitive conclusions about the efficacy and safety or ways to deliver PBI/APBI. We await completion of ongoing trials.

Cost-effectiveness analysis of intraoperative radiation therapy versus external beam radiation therapy for the adjuvant treatment of early breast cancer: A systematic review

Background: Breast-conserving surgery (BCS) is the recommended treatment for early breast cancer. After BCS. Whole-breast external beam radiotherapy (WB-EBRT) is the standard of care. A possible alternative to post-operative WB-EBRT is intraoperative radiation therapy (IORT). The objectives of this systematic review were to analyses the cost-effectiveness of IORT versus EBRT for early-stage breast cancer and to assess the reporting quality of the included studies to inform future studies.

Methods: A systematic literature search was carried out in five main databases (PubMed, Scopus, Embase, Cochrane library, and Web of Science) to identify original studies published to June 25, 2020. We included all full economic evaluation studies (cost-effectiveness analysis (CEA), cost-utility analysis (CUA), and cost-benefit analysis (CBA), Model-based or trial-based) that assessed and compared IORT and EBRT in patients with early operable breast cancer. Study outcomes included cost per life-years gained or cost per quality-adjusted life-years (QALYs) gained or in monetary units or incremental cost-effectiveness ratio (ICER). The quality of the included articles was assessed using the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) checklist. This review has been conducted and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

Results: Of 1155 studies identified, eight studies met the inclusion criteria. In four studies, IORT was associated with lower costs and higher effectiveness than EBRT. In three studies, the dominant option was EBRT. In these studies, IORT also had lower costs and lower effectiveness than EBRT. Existing evidence suggests that IORT can be a cost-effective alternative to early breast cancer treatment by reducing therapeutic costs. Variables of cost-effectiveness were treatment costs, health state utilities, local and distant recurrence rates, and the probabilities of metastasis after treatment, recurrent cancer and death for both IORT and EBRT. The reporting quality of the included studies was "high" in five, "medium quality" in one and "low" in two studies.

Conclusion: Current evidence is sparse, and the number of studies was small but this evidence proposes that IORT can be a potential cost-saving strategy to the health systems for the adjuvant treatment of early breast cancer if the technology was carried out routinely in eligible patients. However, these results should be interpreted with caution because of the heterogeneity of studies and possible publication bias.

Use of an ultrasound imaging device within the applicator to evaluate placement and support treatment planning for breast brachytherapy and intraoperative radiation therapy

PURPOSE

We evaluated the use of ultrasound imaging within a brachytherapy applicator as a method for applicator positioning, evaluation, and treatment planning in a series of in vitro, cadaver, and human studies.

METHODS AND MATERIALS

We evaluated the performance of a prototype system comprising a small ultrasound imaging catheter inserted within the lumen of a balloon brachytherapy catheter. We tested the device in an ultrasound phantom, in human breast tissue, and in an endoscopic ultrasound catheter in cadaveric breast tissue. We evaluated the visualization of adjacent tissue to consider future development of a similar system for use in brachytherapy and intraoperative radiation therapy.

RESULTS

Based on the ultrasound images obtained in an ultrasound phantom, cadaveric breast, and human participants, we observed that an ultrasound imaging catheter placed within the lumen of a brachytherapy applicator can effectively image adjacent tissue, ribs, and air voids, with appropriate quality to support clinical use. We observed high correlation in clinically useful information detected on ultrasound and comparative CT, with ultrasound spatial resolution near 1 mm (spatially variant).

CONCLUSIONS

The findings from our pilot work suggest that real-time ultrasound imaging, operated from within the applicator, is a promising technique for image guidance and treatment planning during brachytherapy and intraoperative radiation therapy. Further expansion of this technology for clinical use will require development of a cohesive system of components to suit specific clinical applications.

DEGRO practical guideline for partial-breast irradiation

PURPOSE

This consensus statement from the Breast Cancer Working Group of the German Society for Radiation Oncology (DEGRO) aims to define practical guidelines for accelerated partial-breast irradiation (APBI).

METHODS

Recent recommendations for relevant aspects of APBI were summarized and a panel of experts reviewed all the relevant literature. Panel members of the DEGRO experts participated in a series of conferences, supplemented their clinical experience, performed a literature review, and formulated recommendations for implementing APBI in clinical routine, focusing on patient selection, target definition, and treatment technique.

RESULTS

Appropriate patient selection, target definition for different APBI techniques, and basic rules for appropriate APBI techniques for clinical routine outside of clinical trials are described. Detailed recommendations for APBI in daily practice, including dose constraints, are given.

CONCLUSION

Guidelines are mandatory to assure optimal results of APBI using different techniques.

Clinical Implication of Dosimetry Formalisms for Electronic Low-Energy Photon Intraoperative Radiation Therapy

PURPOSE

Intraoperative radiation therapy (IORT) using the INTRABEAM, a miniature x-ray source, has shown to be effective in treating breast cancer. However, recent investigations have suggested a significant deviation between the reported and delivered doses. In this work, the dose delivered by INTRABEAM in the TARGIT breast protocol was investigated, along with the dose from the Xoft Axxent, another source used in breast IORT.

METHODS AND MATERIALS

The absorbed dose from the INTRABEAM was determined from ionization chamber measurements using: (a) the manufacturer-recommended formula (Zeiss V4.0 method), (b) a Monte Carlo calculated chamber conversion factor (C_Q method), and (c) the formula consistent with the TARGIT breast protocol (TARGIT method). The dose from the Xoft Axxent was determined from ionization chamber measurements using the Zeiss V4.0 method and calculated using the American Association of Physicists in Medicine TG-43 formalism.

RESULTS

For a nominal TARGIT prescription of 20 Gy, the dose at the INTRABEAM applicator surface ranged from 25.2 to 31.7 Gy according to the C_Q method for the largest (5 cm) and smallest (1.5 cm) diameter applicator, respectively. The Zeiss V4.0 method results were 7% to 10% lower (23.2 to 28.6 Gy). At 1 cm depth, the C_Q and Zeiss V4.0 absorbed doses were also larger than those predicted by the TARGIT method. The dose at 1 cm depth from the Xoft Axxent for a surface dose of 20 Gy was slightly less than INTRABEAM (3%-7% compared with C_Q method). An exception was for the 3 cm applicator, where the Xoft dose was appreciably lower (31%).

CONCLUSIONS

The doses delivered in the TARGIT breast protocol with INTRABEAM were significantly greater than the prescribed 20 Gy and depended on the size of spherical applicator used. Breast IORT treatments with the Xoft Axxent received less dose compared with TARGIT INTRABEAM, which could have implications for studies comparing clinical outcomes between the 2 devices.

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.

Patient preferences for adjuvant radiotherapy in early breast cancer are strongly influenced by treatment received through random assignment

OBJECTIVE

TARGIT-A randomised women with early breast cancer to receive external beam radiotherapy (EBRT) or intraoperative radiotherapy (TARGIT-IORT). This study aimed to identify what extra risk of recurrence patients would accept for perceived benefits and risks of different radiotherapy treatments.

METHODS

Patient preferences were determined by self-rated trade-off questionnaires in two studies: Stage (1) 209 TARGIT-A participants (TARGIT-IORTn = 108, EBRTn = 101); Stage (2) 123 non-trial patients yet to receive radiotherapy (pre-treatment group), with 85 also surveyed post-radiotherapy. Patients traded-off risks of local recurrence in preference selection between TARGIT-IORT and EBRT.

RESULTS

TARGIT-IORT patients were more accepting of IORT than EBRT patients with 60% accepting the highest increased risk presented (4%-6%) compared to 12% of EBRT patients, and 2% not accepting IORT at all compared to 43% of EBRT patients. Pre-treatment patients were more accepting of IORT than post-treatment patients with 23% accepting the highest increased risk presented compared to 15% of post-treatment patients, and 15% not accepting IORT at all compared to 41% of pre-treatment patients.

CONCLUSIONS

Breast cancer patients yet to receive radiotherapy accept a higher recurrence risk than the actual risk found in TARGIT-A. Measured patient preferences are highly influenced by experience of treatment received. This finding challenges the validity of post-treatment preference studies.

Comparison of heart dose in early-stage left-sided breast cancers treated with intraoperative radiation therapy or whole-breast irradiation with deep inspiratory breath hold

PURPOSE

To compare heart dose between patients treated with lumpectomy and either intraoperative radiation therapy (IORT) with CT-guided high-dose-rate brachytherapy (precision breast IORT [PB-IORT]) or whole-breast irradiation with deep inspiratory breath hold (WBI-DIBH) for early-stage left-sided breast cancers.

METHODS AND MATERIALS

We retrospectively identified the 17 patients with left-sided breast cancers treated with PB-IORT on a phase I clinical trial and 17 patients with left-sided tumors who had undergone lumpectomy and adjuvant WBI-DIBH. Dosimetric data were obtained. T-testing was performed and biologically effective doses (BEDs) were calculated using an α/β ratio of 2 Gy.

RESULTS

Mean heart dose was significantly lower with WBI-DIBH compared with PB-IORT (0.61 vs. 0.87 Gy, p = 0.006). Mean heart BED was lower with WBI-DIBH (0.62 vs. 1.3 Gy₂, p = 0.0001). Nominal maximum heart dose was higher with WBI-DIBH (11.37 vs. 4.81 Gy, p = 0.004). Maximum heart dose BED was similar between WBI-DIBH and IORT, 16.63 vs. 19.36 Gy (p = 0.64), respectively. No difference was found in mean left anterior descending artery dose: 2.18 Gy with WBI-DIBH and 1.89 Gy with IORT (p = 0.446). The maximum left anterior descending doses were 9.63 Gy and 3.62 Gy with WBI-DIBH and IORT, respectively (p = 0.016). Distance from the heart to the lumpectomy cavity was inversely associated with heart dose for PB-IORT, but not for WBI-IORT.

CONCLUSIONS

Heart doses were low in both groups. Expected increase in cardiac risk at these doses is minimal. It is unlikely that there will be a clinically significant difference in cardiac toxicity in patients treated with WBI-DIBH or PB-IORT. Further research is needed to evaluate the actual clinical impact of the observed cardiac doses delivered with these modalities.

Targeted Intraoperative Radiotherapy Tumour Bed Boost during Breast-Conserving Surgery after Neoadjuvant Chemotherapy - a Subgroup Analysis of Hormone Receptor-Positive HER2-Negative Breast Cancer

Introduction

In a previous study our group showed a beneficial effect of targeted intraoperative radiotherapy (TARGIT-IORT) as an intraoperative boost on overall survival after neoadjuvant chemotherapy (NACT) compared to an external boost (EBRT). In this study we present the results of a detailed subgroup analysis of the hormone receptor (HR)-positive HER2-negative patients.

Methods

In this cohort study involving 46 patients with HR-positive HER2-negative breast cancer after NACT, we compared the outcomes of 21 patients who received an IORT boost to those of 25 patients treated with an EBRT boost. All patients received whole breast radiotherapy.

Results

Median follow-up was 49 months. Whereas disease-free-survival and breast cancer-specific mortality were not significantly different between the groups, the 5-year Kaplan-Meier estimate of overall mortality was significantly lower by 21% with IORT, p = 0.028. Non-breast cancer-specific mortality was significantly lower by 16% with IORT, p = 0.047.

Conclusion

Although our results have to be interpreted with caution, we have shown that the improved overall survival demonstrated previously could be reproduced in the HR-positive HER2-negative subgroup. These data give further support to the inclusion of such patients in the TARGIT-B (Boost) randomised trial that is testing whether IORT boost is superior to EBRT boost.

Health economics of targeted intraoperative radiotherapy (TARGIT-IORT) for early breast cancer: a cost-effectiveness analysis in the United Kingdom

OBJECTIVE

The clinical effectiveness of targeted intraoperative radiotherapy (TARGIT-IORT) has been confirmed in the randomised TARGIT-A (targeted intraoperative radiotherapy-alone) trial to be similar to a several weeks' course of whole-breast external-beam radiation therapy (EBRT) in patients with early breast cancer. This study aims to determine the cost-effectiveness of TARGIT-IORT to inform policy decisions about its wider implementation.

SETTING

TARGIT-A randomised clinical trial (ISRCTN34086741) which compared TARGIT with traditional EBRT and found similar breast cancer control, particularly when TARGIT was given simultaneously with lumpectomy.

METHODS

Cost-utility analysis using decision analytic modelling by a Markov model. A cost-effectiveness Markov model was developed using TreeAge Pro V.2015. The decision analytic model compared two strategies of radiotherapy for breast cancer in a hypothetical cohort of patients with early breast cancer based on the published health state transition probability data from the TARGIT-A trial. Analysis was performed for UK setting and National Health Service (NHS) healthcare payer's perspective using NHS cost data and treatment outcomes were simulated for both strategies for a time horizon of 10 years. Model health state utilities were drawn from the published literature. Future costs and effects were discounted at the rate of 3.5%. To address uncertainty, one-way and probabilistic sensitivity analyses were performed.

MAIN OUTCOME MEASURES

Quality-adjusted life-years (QALYs).

RESULTS

In the base case analysis, TARGIT-IORT was a highly cost-effective strategy yielding health gain at a lower cost than its comparator EBRT. Discounted TARGIT-IORT and EBRT costs for the time horizon of 10 years were £12 455 and £13 280, respectively. TARGIT-IORT gained 0.18 incremental QALY as the discounted QALYs gained by TARGIT-IORT were 8.15 and by EBRT were 7.97 showing TARGIT-IORT as a dominant strategy over EBRT. Model outputs were robust to one-way and probabilistic sensitivity analyses.

CONCLUSIONS

TARGIT-IORT is a dominant strategy over EBRT, being less costly and producing higher QALY gain.

TRIAL REGISTRATION NUMBER

ISRCTN34086741; post results.

The impact of the use of intraoperative radiotherapy on costs, travel time and distance for women with breast cancer in the Mexico City Metropolitan Area

BACKGROUND AND OBJECTIVES

The low availability and poor access to external beam radiotherapy (EBRT) in developing countries makes it hard for women with breast cancer to receive breast conservation. We studied the effect of providing intraoperative radiotherapy (IORT) on the travel time, distance, and costs of in the Mexico City Metropolitan Area (MCMA).

METHODS

Sixty-nine patients treated between January 2013 and September 2014 were analyzed. Travel distance and transit time was calculated using Google Maps. The time and distance patients living in the MCMA treated with IORT would have spent if they had received EBRT was calculated. Cost analysis for each modality was performed.

RESULTS

71% (n = 49) lived in the MCMA. Sixteen (33%) received additional EBRT and 33 (66%) received IORT only. Mean driving distance and transit time of those 33 women was 132.6 km (SD 25.7) and 66 min (SD 32.9). Patients from the MCMA receiving IORT alone avoided 990 visits, 43 700 km and 65 400 min in transit. IORT led to a 12% reduction in costs per patient.

CONCLUSIONS

By reducing costs and time needed for patients to receive radiotherapy, IORT could potentially enhance access to breast conservation in resource-limited developing countries.

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.

Current controversies in radiotherapy for breast cancer

Multimodal treatment approaches have substantially improved the outcome of breast cancer patients in the last decades. Radiotherapy is an integral component of multimodal treatment concepts used in curative and palliative intention in numerous clinical situations from precursor lesions such as ductal carcinoma in situ (DCIS) to advanced breast cancer. This review addresses current controversial topics in radiotherapy with special consideration of DCIS, accelerated partial breast irradiation (APBI) and regional nodal irradiation (RNI) and provides an update on the clinical practice guidelines of the Breast Cancer Expert Panel of the German Society of Radiation Oncology (DEGRO).

Accelerated Partial Breast Irradiation: Executive summary for the update of an ASTRO Evidence-Based Consensus Statement

PURPOSE

To update the accelerated partial breast irradiation Consensus Statement published in 2009 and provide guidance on use of intraoperative radiation therapy (IORT) for partial breast irradiation in early-stage breast cancer, based on published evidence complemented by expert opinion.

METHODS AND MATERIALS

A systematic PubMed search using the same terms as the original Consensus Statement yielded 419 articles; 44 articles were selected. The authors synthesized the published evidence and, through a series of conference calls and e-mails, reached consensus regarding the recommendations.

RESULTS

The new recommendations include lowering the age in the "suitability group" from 60 to 50 years and in the "cautionary group" to 40 years for patients who meet all other elements of suitability (Table 1). Patients with low-risk ductal carcinoma in situ, as per Radiation Therapy Oncology Group 9804 criteria, were categorized in the "suitable" group. The task force agreed to maintain the current criteria based on margin status. Recommendations for the use of IORT for breast cancer patients include: counseling patients regarding the higher risk of ipsilateral breast tumor recurrence with IORT compared with whole breast irradiation; the need for prospective monitoring of long-term local control and toxicity with low-energy radiograph IORT given limited follow-up; and restriction of IORT to women with invasive cancer considered "suitable."

CONCLUSION

These recommendations will provide updated clinical guidance regarding use of accelerated partial breast irradiation for radiation oncologists and other specialists participating in the care of breast cancer patients.

An international randomised controlled trial to compare TARGeted Intraoperative radioTherapy (TARGIT) with conventional postoperative radiotherapy after breast-conserving surgery for women with early-stage breast cancer (the TARGIT-A trial)

BACKGROUND

Based on our laboratory work and clinical trials we hypothesised that radiotherapy after lumpectomy for breast cancer could be restricted to the tumour bed. In collaboration with the industry we developed a new radiotherapy device and a new surgical operation for delivering single-dose radiation to the tumour bed - the tissues at highest risk of local recurrence. We named it TARGeted Intraoperative radioTherapy (TARGIT). From 1998 we confirmed its feasibility and safety in pilot studies.

OBJECTIVE

To compare TARGIT within a risk-adapted approach with whole-breast external beam radiotherapy (EBRT) over several weeks.

DESIGN

The TARGeted Intraoperative radioTherapy Alone (TARGIT-A) trial was a pragmatic, prospective, international, multicentre, non-inferiority, non-blinded, randomised (1 : 1 ratio) clinical trial. Originally, randomisation occurred before initial lumpectomy (prepathology) and, if allocated TARGIT, the patient received it during the lumpectomy. Subsequently, the postpathology stratum was added in which randomisation occurred after initial lumpectomy, allowing potentially easier logistics and a more stringent case selection, but which needed a reoperation to reopen the wound to give TARGIT as a delayed procedure. The risk-adapted approach meant that, in the experimental arm, if pre-specified unsuspected adverse factors were found postoperatively after receiving TARGIT, EBRT was recommended. Pragmatically, this reflected how TARGIT would be practised in the real world.

SETTING

Thirty-three centres in 11 countries.

PARTICIPANTS

Women who were aged ≥ 45 years with unifocal invasive ductal carcinoma preferably ≤ 3.5 cm in size.

INTERVENTIONS

TARGIT within a risk-adapted approach and whole-breast EBRT.

MAIN OUTCOME MEASURES

The primary outcome measure was absolute difference in local recurrence, with a non-inferiority margin of 2.5%. Secondary outcome measures included toxicity and breast cancer-specific and non-breast-cancer mortality.

RESULTS

In total, 3451 patients were recruited between March 2000 and June 2012. The following values are 5-year Kaplan-Meier rates for TARGIT compared with EBRT. There was no statistically significant difference in local recurrence between TARGIT and EBRT. TARGIT was non-inferior to EBRT overall [TARGIT 3.3%, 95% confidence interval (CI) 2.1% to 5.1% vs. EBRT 1.3%, 95% CI 0.7% to 2.5%; p = 0.04; P_{non-inferiority} = 0.00000012] and in the prepathology stratum (n = 2298) when TARGIT was given concurrently with lumpectomy (TARGIT 2.1%, 95% CI 1.1% to 4.2% vs. EBRT 1.1%, 95% CI 0.5% to 2.5%; p = 0.31; P_{non-inferiority} = 0.0000000013). With delayed TARGIT postpathology (n = 1153), the between-group difference was larger than 2.5% and non-inferiority was not established for this stratum (TARGIT 5.4%, 95% CI 3.0% to 9.7% vs. EBRT 1.7%, 95% CI 0.6% to 4.9%; p = 0.069; P_{non-inferiority} = 0.06640]. The local recurrence-free survival was 93.9% (95% CI 90.9% to 95.9%) when TARGIT was given with lumpectomy compared with 92.5% (95% CI 89.7% to 94.6%) for EBRT (p = 0.35). In a planned subgroup analysis, progesterone receptor (PgR) status was found to be the only predictor of outcome: hormone-responsive patients (PgR positive) had similar 5-year local recurrence with TARGIT during lumpectomy (1.4%, 95% CI 0.5% to 3.9%) as with EBRT (1.2%, 95% CI 0.5% to 2.9%; p = 0.77). Grade 3 or 4 radiotherapy toxicity was significantly reduced with TARGIT. Overall, breast cancer mortality was much the same between groups (TARGIT 2.6%, 95% CI 1.5% to 4.3% vs. EBRT 1.9%, 95% CI 1.1% to 3.2%; p = 0.56) but there were significantly fewer non-breast-cancer deaths with TARGIT (1.4%, 95% CI 0.8% to 2.5% vs. 3.5%, 95% CI 2.3% to 5.2%; p = 0.0086), attributable to fewer deaths from cardiovascular causes and other cancers, leading to a trend in reduced overall mortality in the TARGIT arm (3.9%, 95% CI 2.7% to 5.8% vs. 5.3%, 95% CI 3.9% to 7.3%; p = 0.099]. Health economic analyses suggest that TARGIT was statistically significantly less costly than EBRT, produced similar quality-adjusted life-years, had a positive incremental net monetary benefit that was borderline statistically significantly different from zero and had a probability of > 90% of being cost-effective. There appears to be little uncertainty in the point estimates, based on deterministic and probabilistic sensitivity analyses. If TARGIT were given instead of EBRT in suitable patients, it might potentially reduce costs to the health-care providers in the UK by £8-9.1 million each year. This does not include environmental, patient and societal costs.

LIMITATIONS

The number of local recurrences is small but the number of events for local recurrence-free survival is not as small (TARGIT 57 vs. EBRT 59); occurrence of so few events (< 3.5%) also implies that both treatments are effective and any difference is unlikely to be large. Not all 3451 patients were followed up for 5 years; however, more than the number of patients required to answer the main trial question (n = 585) were followed up for > 5 years.

CONCLUSIONS

For patients with breast cancer (women who are aged ≥ 45 years with hormone-sensitive invasive ductal carcinoma that is up to 3.5 cm in size), TARGIT concurrent with lumpectomy within a risk-adapted approach is as effective as, safer than and less expensive than postoperative EBRT.

FUTURE WORK

The analyses will be repeated with longer follow-up. Although this may not change the primary result, the larger number of events may confirm the effect on overall mortality and allow more detailed subgroup analyses. The TARGeted Intraoperative radioTherapy Boost (TARGIT-B) trial is testing whether or not a tumour bed boost given intraoperatively (TARGIT) boost is superior to a tumour bed boost given as part of postoperative EBRT.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN34086741 and ClinicalTrials.gov NCT00983684.

FUNDING

University College London Hospitals (UCLH)/University College London (UCL) Comprehensive Biomedical Research Centre, UCLH Charities, Ninewells Cancer Campaign, National Health and Medical Research Council and German Federal Ministry of Education and Research (BMBF). From September 2009 this project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 73. See the NIHR Journals Library website for further project information.

Partial breast irradiation for early breast cancer

BACKGROUND

Breast-conserving therapy for women with breast cancer consists of local excision of the tumour (achieving clear margins) followed by radiotherapy (RT). RT is given to sterilize tumour cells that may remain after surgery to decrease the risk of local tumour recurrence. Most true recurrences occur in the same quadrant as the original tumour. Whole breast radiotherapy (WBRT) may not protect against the development of a new primary cancer developing in other quadrants of the breast. In this Cochrane review, we investigated the delivery of radiation to a limited volume of the breast around the tumour bed (partial breast irradiation (PBI)) sometimes with a shortened treatment duration (accelerated partial breast irradiation (APBI)).

OBJECTIVES

To determine whether PBI/APBI is equivalent to or better than conventional or hypo-fractionated WBRT after breast-conserving therapy for early-stage breast cancer.

SEARCH METHODS

We searched the Cochrane Breast Cancer Group Specialized Register (4 May 2015), the Cochrane Central Register of Controlled Trials (CENTRAL) (2015, Issue 5), MEDLINE (January 1966 to 4 May 2015), EMBASE (1980 to 4 May 2015), CINAHL (4 May 2015) and Current Contents (4 May 2015). We searched the International Standard Randomised Controlled Trial Number Register (5 May 2015), the World Health Organization's International Clinical Trials Registry Platform (4 May 2015) and ClinicalTrials.gov (17 June 2015). We searched for grey literature: OpenGrey (17 June 2015), reference lists of articles, several conference proceedings and published abstracts, and applied no language restrictions.

SELECTION CRITERIA

Randomized controlled trials (RCTs) without confounding, that evaluated conservative surgery plus PBI/APBI versus conservative surgery plus WBRT. Published and unpublished trials were eligible.

DATA COLLECTION AND ANALYSIS

Two review authors (BH and ML) performed data extraction and used Cochrane's 'Risk of bias' tool, and resolved any disagreements through discussion. We entered data into Review Manager 5 for analysis.

MAIN RESULTS

We included seven RCTs and studied 7586 women of the 8955 enrolled.Local recurrence-free survival appeared worse for women receiving PBI/APBI compared to WBRT (hazard ratio (HR) 1.62, 95% confidence interval (CI) 1.11 to 2.35; six studies, 6820 participants, low-quality evidence). Cosmesis (physician-reported) appeared worse with PBI/APBI (odds ratio (OR) 1.51, 95% CI 1.17 to 1.95, five studies, 1720 participants, low-quality evidence). Overall survival did not differ with PBI/APBI (HR 0.90, 95% CI 0.74 to 1.09, five studies, 6718 participants, high-quality evidence).Late radiation toxicity (subcutaneous fibrosis) appeared worse with PBI/APBI (OR 6.58, 95% CI 3.08 to 14.06, one study, 766 participants, moderate-quality evidence). Acute skin toxicity appeared reduced with PBI/APBI (OR 0.04, 95% CI 0.02 to 0.09, two studies, 608 participants). Telangiectasia (OR 26.56, 95% CI 3.59 to 196.51, 1 study, 766 participants) and radiological fat necrosis (OR 1.58, 95% CI 1.02 to 2.43, three studies, 1319 participants) appeared worse with PBI/APBI. Late skin toxicity (OR 0.21, 95% CI 0.01 to 4.39, two studies, 608 participants) and breast pain (OR 2.17, 95% CI 0.56 to 8.44, one study, 766 participants) appeared not to differ with PBI/APBI.'Elsewhere primaries' (new primaries in the ipsilateral breast) appeared more frequent with PBI/APBI (OR 3.97, 95% CI 1.51 to 10.41, three studies, 3009 participants).We found no clear evidence of a difference for the comparison of PBI/APBI with WBRT for the outcomes of: cause-specific survival (HR 1.08, 95% CI 0.73 to 1.58, five studies, 6718 participants, moderate-quality evidence), distant metastasis-free survival (HR 0.94, 95% CI 0.65 to 1.37, four studies, 3267 participants, moderate-quality evidence), relapse-free survival (HR 1.36, 95% CI 0.88 to 2.09, three studies, 3811 participants), loco-regional recurrence-free survival (HR 1.80, 95% CI 1.00 to 3.25, two studies, 3553 participants) or mastectomy rates (OR 1.20, 95% CI 0.77 to 1.87, three studies, 4817 participants, low-quality evidence). Compliance was met: more than 90% of the women in all studies received the RT they were assigned to receive. We found no data for the outcomes of costs, quality of life or consumer preference.

AUTHORS' CONCLUSIONS

It appeared that local recurrence and 'elsewhere primaries' (new primaries in the ipsilateral breast) are increased with PBI/APBI (the difference was small), but we found no evidence of detriment to other oncological outcomes. It appeared that cosmetic outcomes and some late effects were worse with PBI/APBI but its use was associated with less acute skin toxicity. The limitations of the data currently available mean that we cannot make definitive conclusions about the efficacy and safety or ways to deliver of PBI/APBI. We await completion of ongoing trials.

Reduced Mortality With Partial-Breast Irradiation for Early Breast Cancer: A Meta-Analysis of Randomized Trials

PURPOSE

With earlier detection and more effective treatment, mortality from breast cancer continues to fall and it has become increasingly important to reduce the toxicity of treatments. Partial-breast radiation therapy, which focuses radiation to the tumor bed, may achieve this aim. We analyzed mortality differences in randomized trials of partial-breast irradiation (PBI).

METHODS AND MATERIALS

We included data from published randomized trials of PBI (alone or as part of a risk-adapted approach) versus whole-breast irradiation (WBI) for invasive breast cancer suitable for breast-conserving therapy. We identified trials using PubMed and Google searches with the terms "partial breast irradiation" OR "intraoperative radiotherapy" OR "IMRT" OR ("accelerated" AND "radiation") AND "randomised/randomized," as well as through discussion with colleagues in the field. We calculated the proportion of patients who had events in each randomized arm at 5 years' follow-up and created a forest plot using Stata, version 14.1.

RESULTS

We identified 9 randomized trials of PBI versus WBI in invasive breast cancer; 5-year outcomes were available for non-breast cancer mortality in 5 trials (n=4489) and for breast cancer mortality in 4 trials (n=4231). The overall mortality was 4.9%. There was no detectable heterogeneity between the trials for any of the outcomes. There was no difference in the proportion of patients dying of breast cancer (difference, 0.000% [95% confidence interval (CI), -0.7 to +0.7]; P=.999). Non-breast cancer mortality with PBI was lower than with WBI (difference, 1.1% [95% CI, -2.1% to -0.2%]; P=.023). Total mortality with PBI was also lower than with WBI (difference, 1.3% [95% CI, -2.5% to 0.0%]; P=.05).

CONCLUSIONS

Use of PBI instead of WBI in selected patients results in a lower 5-year non-breast cancer and overall mortality, amounting to a 25% reduction in relative terms. This information should be included when breast-conserving therapy is proposed to a patient.

Radiation therapy (RT) after breast-conserving surgery (BCS) in 2015--The year of radiation therapy advances

Surgery associated with radiation therapy is the standard treatment for early breast cancer. This paper reviews the new evidence on local control and survival, the indications of lymph-node irradiation, and the long-term results of large prospective trials. New shorter fractionation schemes allow a reduction in the constraints of daily treatment courses over several weeks, and recent technical improvements in treatment delivery will improve cancer outcomes in terms of local control, decreased toxicity and long-term sequelae. Research should focus on identifying molecular markers for radiation sensitivity while designing specific, targeted modulators of the radiation response in early breast cancer.

Accelerated Partial Breast Irradiation in Clinical Practice

Accelerated partial breast irradiation (APBI) has been under clinical investigation for more than 15 years. There are several technical approaches that are clinically established, e.g. brachytherapy, intraoperative radiotherapy (IORT), or external-beam radiotherapy. The understanding of the underlying biology, optimal technical procedures, patient selection criteria, and imaging changes during follow-up has increased enormously. After completion of several phase III trials using brachytherapy or IORT, APBI is currently increasingly used either in phase IV studies, registries, or in selected patients outside of clinical studies. Consensus statements about suitable patients are available from several international and national societies like ASTRO, ESTRO, and DEGRO. One may expect that 15-25% of patients undergoing breast-conserving surgery may qualify for APBI, i.e. patients with small invasive ductal breast cancer without clinical lymph node involvement.