A Novel Form of Breast Intraoperative Radiation Therapy With CT-Guided High-Dose-Rate Brachytherapy: Results of a Prospective Phase 1 Clinical Trial

Very accelerated partial breast irradiation in 1 or 2 days: Late toxicity and early oncological outcome of the GEC-ESTRO VAPBI cohort

PURPOSE

To analyze late toxicity after very accelerated partial breast irradiation (VAPBI) for low-risk breast cancer.

MATERIALS

Methods: In this retrospective, observational, international multicenter study (HDH F20220713143949), patients with low-risk breast cancer underwent lumpectomy + vAPBI (high-dose rate multicatheter interstitial brachytherapy-MIBT). VAPBI was performed with 4(4x6.2 Gy/2d), 3(3x7.45 Gy/2d) or 1 fraction (1x16Gy or 1x18Gy/1d). Primary endpoint was late toxicity. Secondary endpoints were cumulative incidence of breast cancer local relapse (LR) and distant metastatic relapse (DMR) and specific (SS) and overall (OS) survivals. Prognostic factors for late toxicity were analyzed.

RESULTS

From 01/2012 to 06/2022, 516 pts with early breast cancer were enrolled. Median follow-up was 44 months [95 %CI 39-46]. Median age was 71 years [40-100]. Median tumor size was 12 mm [1-35]. VAPBI delivered 1, 3 and 4 fractions for 205pts (39.7 %), 167pts (32.4 %) and 144pts (28 %) respectively. 221 late toxicity events were observed in 168pts (32.6 %) (Fibrosis, dyschromia, pain and telangiectasia). Grade 2 and 3 late toxicities were observed in 7.2 and 0.6 % respectively (no G4) with no difference between 1 and ≥ 2 treatment days. CTV > 50 cc (p = 0.007) and V150 > 40 % (p = 0.027) were prognostic factors for G ≥ 2 late toxicity. Four-year cumulative incidence rates of LR and DMR were 2 % [95 %CI 0-3] and 1 % [95 %CI 0-2] respectively.

CONCLUSIONS

VAPBI based on 1 or ≥ 2 days of MIBT represents an attractive de-escalation of irradiation approach for low-risk breast cancer. Late toxicity profile appears acceptable while early oncological outcome shows encouraging local control. Longer follow-up is warranted in order to confirm these preliminary results.

Intraoperative Radiation Therapy Delivered by Brachytherapy in Breast Cancer: An Interim Analysis of a Phase 2 Trial

PURPOSE

Intraoperative breast cancer radiotherapy (IORT) offers an alternative to external beam radiotherapy (EBRT) after breast-conserving surgery (BCS). The Intraoperative brachytherapy (IOBT) trial applies high dose rate (HDR) brachytherapy with a new applicator prototype as IORT after BCS. In this interim analysis of the IOBT trial, we present the oncological safety and toxicity of the method METHODS: Eligible patients were women, ≥ 50 years old with an unifocal nonlobular, estrogen-receptor-positive, HER2-negative breast cancer, cN0, ≤ 3 cm, treated with BCS and sentinel node biopsy (SNB). Toxicity was registered according to the LENT-SOMA scale. Cumulative incidence of local (LR) and regional recurrence (RR) were calculated through cumulative incidence function whereas overall survival (OS) was illustrated through Kaplan-Meier curve.

RESULTS

Until February 2023, 155 women (median age 68 years) were included in the trial. Twenty-nine women (18.7%) received supplemental EBRT, mostly due to positive SNB. Three-year cumulative incidence of LR and RR were 1.0% (CI 95 % 0.1%-2.3%) and 2.1% (CI 95% 0.8%-4.2%) respectively. Five- year cumulative incidence of LR and RR were 3.9% (CI 95% 1.8%-6.4%) and 2.1% (CI 95% 0.8%-4.2%) respectively. Five-year OS was 96.3% (CI 95% 93.6%-98.4%). Side effects were limited, low grade, and transient.

CONCLUSION

Acknowledging the short median follow-up time at interim analysis, our initial results indicate that delivering IORT through HDR brachytherapy in carefully selected breast cancer patients is feasible and oncological safe so far. A long-term follow-up is essential to confirm the initial results.

Novel Form of Breast Intraoperative Radiation Therapy with CT-Guided High-Dose-Rate Brachytherapy: Interim Results of a Prospective Phase-II Clinical Trial

BACKGROUND

Precision breast intraoperative radiation therapy (PB-IORT) is a novel method of IORT that uses customized CT-based treatment plans and high-dose-rate (HDR) brachytherapy. We conducted a phase-II multi-institution trial to evaluate the efficacy of PB-IORT.

STUDY DESIGN

Between 2015 and 2022, 3 centers enrolled women aged 45 years and older with invasive or in situ carcinoma measuring 3 cm or smaller and N0 status (n = 358). Breast-conserving surgery was performed, and a multilumen balloon catheter was placed in the lumpectomy bed. CT images were used to create customized HDR brachytherapy plans that delivered 12.5 Gy to the tumor bed. The primary outcome assessed was the 5-year rate of index quadrant tumor recurrence. An interim analysis was conducted after one-third of eligible participants completed 5 years of follow-up. This trial is registered with clinicaltrials.gov (NCT02400658).

RESULTS

The cohort comprised 153 participants with a median age of 64 years and median follow-up time of 5.9 years. The estimated 5-year index quadrant tumor recurrence rate and overall survival were 5.08% (95% CI 2.23 to 9.68) and 95.1%, respectively. Locoregional (ipsilateral breast and axilla) and distant recurrence rates were each 1.96%. Seven deaths occurred during the first 5 years of follow-up, with only 1 attributable to breast cancer. Overall, 68.6% of patients experienced any adverse effects, and 4 cases of breast-related severe toxicities were observed.

CONCLUSIONS

This study presents the results of a planned interim analysis of a phase-II trial investigating PB-IORT and demonstrates the efficacy and safety of single-fraction, CT-based, HDR brachytherapy after breast-conserving surgery. These findings provide valuable insights into the use of PB-IORT as a treatment modality.

First clinical application of image-guided intraoperative electron radiation therapy with real time intraoperative dose calculation in recurrent rectal cancer: technical procedure

Intraoperative radiation therapy (IORT) is a radiation technique applying a single fraction with a high dose during surgery. We report the first abdomino-pelvic application of an image-guided intraoperative electron radiation therapy with intraoperative real time dose calculation based on the individual intraoperative patient anatomy. A patient suffering from locoregionally recurrent rectal cancer after treatment with neoadjuvant re-chemoradiation was chosen for this approach. After surgical removal of the recurrence, an adequate IORT applicator was placed as usual. A novel mobile imaging device (ImagingRing, MedPhoton) was positioned around the patient covering the region to be treated with the IORT-applicator in place. It allowed the acquisition of three-dimensional intraoperative cone-beam computed tomography images suitable for dose calculation using an automated scaling (heuristic object and head scatter as well as hardening corrections) of Hounsfield units. After image acquisition confirmed the correct applicator position, the images were transferred to our treatment planning system for intraoperative dose calculation. Treatment could be accomplished using the calculated dose distribution. We herein describe the details of the procedure including necessary adjustments in the typically used IORT equipment and work flow. We further discuss the pros and cons of this new approach generally overcoming a decade long limitation of IORT procedures as well as future perspectives regarding IORT treatments.

Three-Fraction Accelerated Partial Breast Irradiation (APBI) Delivered With Interstitial Brachytherapy Is Safe: First Results From the Tri-fraction Radiation Therapy Used to Minimize Patient Hospital Trips (TRIUMPH-T) Trial

PURPOSE

Shorter courses of breast radiotherapy are offered as an alternative to 4 weeks of whole-breast irradiation after lumpectomy, including brachytherapy. A prospective phase 2multi-institution clinical trial to study 3-fraction accelerated partial breast irradiation delivered by brachytherapy was conducted.

METHODS AND MATERIALS

The trial treated selected breast cancers after breast-conserving surgery with brachytherapy applicators that delivered 22.5 Gy in 3 fractions of 7.5 Gy. The planning treatment volume was 1 to 2 cm beyond the surgical cavity. Eligible women were age ≥45 years with unicentric invasive or in situ tumors ≤3 cm excised with negative margins and with positive estrogen or progesterone receptors and no metastases to axillary nodes. Strict dosimetric parameters were required to be met and follow up information was collected from the participating sites.

RESULTS

Two hundred patients were prospectively enrolled; however, a total of 185 patients who were enrolled were followed for a median of 3.63 years. Three-fraction brachytherapy was associated with low chronic toxicity. There was excellent or good cosmesis in 94% of patients. There were no grade 4 toxicities. Grade 3 fibrosis at the treatment site was present in 1.7% and 32% percent had grades 1 or 2 fibrosis at the treatment site. There was 1 rib fracture. Other late toxicities included 7.4% grade 1 hyperpigmentation, 2% grade 1 telangiectasias, 1.7% symptomatic seromas, 1.7% abscessed cavities, and 1.1% symptomatic fat necrosis. There were 2 (1.1%) ipsilateral local recurrences, 2 (1.1%) nodal recurrences and no distant recurrences. Other incidents included one contralateral breast cancer and 2 second malignancies (lung).

CONCLUSIONS

Ultra-short breast brachytherapy is feasible and has excellent toxicity and could be an alternative to standard 5-day, 10 fraction accelerated partial breast irradiation in eligible patients. Patients from this prospective trial will continue to be followed to evaluate long-term outcomes.

Factors Associated With Cosmetic Outcomes After Treatment With a Novel Form of Breast Intraoperative Radiation Therapy

INTRODUCTION

Precision breast intraoperative radiation therapy (PB-IORT) incorporates computed tomography-guided treatment planning and high dose rate brachytherapy to deliver a single dose of highly conformal radiational therapy. The purpose of this study is to determine factors associated with poor cosmetic outcomes after treatment with PB-IORT.

METHODS

The study included all consecutive participants enrolled in an ongoing phase II clinical trial that had completed a minimum of 12 mo of follow-up. A poor cosmetic outcome was defined as scoring "fair" or "poor" on the Harvard Cosmesis evaluation, or "some" or "very much" on any of the three general cosmesis categories. Statistical analysis was performed utilizing R.

RESULTS

The final cohort included 201 participants, of which 181 (90%) had an overall good/excellent cosmetic outcome. Group 1 consisted of 162 (81%) participants who reported only excellent/good cosmetic outcomes. Group 2 consisted of 39 (19%) participants who reported some aspect of a poor cosmetic outcome. On multivariable analysis, participants with ductal carcinoma in situ were significantly more likely to experience a poor cosmetic outcome (odds ratio 2.45, 95% confidence interval 1.03-5.82, P = 0.04), and those who received subsequent whole breast irradiation were also more likely to have a poor cosmetic outcome (odds ratio 10.20, 95% confidence interval CI 1.04-99.95, P = 0.04).

CONCLUSIONS

Patients with need for further radiation after PB-IORT are at increased risk for a poor cosmetic outcome. Larger balloon volume and distance between the skin do not have deleterious effects on cosmetic outcomes.

Breast brachytherapy: Building a bright future on the foundation of a rich history of advancement in technology, technique, and patient-centered care

For over 20 years, the concept of accelerated partial breast irradiation (APBI) has received considerable attention. Initially concentrating on the appropriateness of APBI as an alternative treatment to whole breast radiotherapy, investigation and innovation evolved towards dose delivery and technique appropriateness. The purpose of this article is to review the pertinent literature that supports the role brachytherapy serves in delivering APBI and the recognized brachytherapy techniques for dose delivery. Publications establishing techniques utilizing multicatheter brachytherapy, single-entry brachytherapy applicators, permanent breast seed implantation brachytherapy, noninvasive breast brachytherapy and electronic brachytherapy are described. The use of brachytherapy for repeat breast conservation therapy is additionally reviewed. A historical perspective and potential direction of future investigation and innovation are presented.

Long-Term Adherence to Adjuvant Endocrine Therapy Following Various Radiotherapy Modalities in Early Stage Hormone Receptor Positive Breast Cancer

INTRODUCTION

We compared the rates of long-term adjuvant endocrine therapy (AET) adherence after various radiation therapy (RT) modalities among patients with early stage breast cancer.

MATERIALS AND METHODS

Medical records from patients with stage 0, I, or IIA (tumors ≤3 cm), hormone receptor (HR) positive breast cancer that received adjuvant radiation therapy (RT) from 2013 to 2015 at a single institution were retrospectively reviewed. All patients received breast conserving surgery (BCS) followed by adjuvant RT via one of the following modalities: whole breast radiotherapy (WBI), partial breast irradiation (PBI) with either external beam radiation therapy (EBRT) or fractionated intracavitary high-dose rate (HDR) brachytherapy, or single fraction HDR-brachytherapy intraoperative-radiation therapy (IORT).

RESULTS

One hundred fourteen patients were reviewed. Thirty patients received WBI, 41 PBI, and 43 IORT with a median follow up of 64.2, 72.0, and 58.6 months, respectively. For the entire cohort, AET adherence was approximately 64% at 2 years and 56% at 5 years. Among patients in the IORT clinical trial, adherence to AET was approximately 51% at 2 years and 40% at 5 years. After controlling for additional factors, DCIS histology (vs invasive disease) and IORT (compared to other radiation modalities) were associated with decreased endocrine therapy adherence (P < 0.05).

CONCLUSION

DCIS histology and receipt of IORT were associated with lower rates of adherence to AET at 5 years. Our findings suggest that examination of the efficacy of RT interventions such as PBI and IORT in patients who do not receive AET is warranted.

Intraoperative radiation therapy in the management of early stage breast cancer

Adjuvant radiotherapy (RT) following breast conserving surgery (BCS) is associated with an improvement in local control and a reduction in breast cancer mortality. While traditionally delivered with whole breast irradiation (WBI), novel approaches have looked to reduce the duration, target volume, and toxicity of adjuvant RT. One such approach is intraoperative radiation therapy (IORT), which delivers radiation at the time of surgery with 80-90% of patients not requiring additional WBI. The current review presents IORT techniques and outcomes from modern series evaluating IORT as monotherapy or as a tumor bed boost. Based on two randomized trials (TARGIT-A and ELIOT) with recent updates, concern regarding higher rates of local recurrence with IORT exist, whether using electrons or low-energy techniques. In contrast, data is promising regarding IORT used as a boost, with ongoing studies evaluating its role prospectively. With respect to toxicity, the data suggest IORT is associated with comparable to slightly lower rates of toxicity though there may be a higher risk of seroma requiring aspiration and fat necrosis with IORT. Given current data and guidelines, WBI or other partial breast techniques should remain the standard of care in early stage breast cancer patients, while IORT should not be utilized outside of prospective clinical trials at this time.

Partial breast irradiation: An updated consensus statement from the American brachytherapy society

PURPOSE

In recent years, results with mature follow-up have been reported for several Phase III trials randomizing women to receive whole breast irradiation (WBI) versus varying modalities of partial breast irradiation (PBI). It is important to recognize that these methods vary in terms of volume of breast tissue treated, dose per fraction, and duration of therapy. As such, clinical and technical guidelines may vary among the various PBI techniques.

METHODS

Members of the American Brachytherapy Society with expertise in PBI performed an extensive literature review focusing on the highest quality data available for the numerous PBI options offered in the modern era. Data were evaluated for strength of evidence and published outcomes were assessed.

RESULTS

The majority of women enrolled on randomized trials of WBI versus PBI have been age >45 years with tumor size <3 cm, negative margins, and negative lymph nodes. The panel also concluded that PBI can be offered to selected women with estrogen receptor negative and/or Her2 amplified breast cancer, as well as ductal carcinoma in situ, and should generally be avoided in women with extensive lymphovascular space invasion.

CONCLUSIONS

This updated guideline summarizes published clinical trials of PBI methods. The panel also highlights the role of PBI for women facing special circumstances, such as history of cosmetic breast augmentation or prior breast irradiation, and discusses promising novel modalities that are currently under study, such as ultrashort and preoperative PBI. Updated consensus guidelines are also provided to inform patient selection for PBI and to characterize the strength of evidence to support varying PBI modalities.

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.

Effects of a novel form of intraoperative radiation therapy on quality of life among patients with early-stage breast cancer

PURPOSE

To investigate patient-perceived quality of life (QOL) among patients treated with a novel form of breast intraoperative radiation therapy (PB-IORT).

METHODS AND MATERIALS

Patients treated with PB-IORT as part of a phase II clinical trial from 2013 to 2020 were identified. Patients were given the European Organization for Research and Treatment of Cancer (EORTC) core 30-item Quality of Life Questionnaire (QLQ-C30) encompassing global health, functionality, and symptomatology at baseline, 1-month, 6-months, 12-months, and 24-months after PB-IORT. Scores were on a 100-point scale with change greater than 10 considered clinically significant. Scores at interval follow-up were compared to baseline using repeated measure modeling with an unstructured covariance matrix.

RESULTS

The cohort consisted of 303 patients, a majority of which were White (84.2%) with a median age of 64 years (IQR: 52, 76). One month after PB-IORT, a decline from baseline in physical (-2.5, 95% CI: -4.4 - -0.55, p = 0.01), role (-7.6, 95% CI: -11.7 - -3.5, p < 0.001), and social functioning (-3.0, 95% CI: -5.5 - -0.42, p = 0.02) were observed, which correlated with increased fatigue (8.4, 95% CI: 5.5-11.3, p < 0.001). At 6 months, nearly all QOL measures returned to baseline or improved. There were no statistically or clinically significant differences from baseline in overall global health. All functional and symptom scale differences were less than 10, indicating minimal clinical significance.

CONCLUSIONS

PB-IORT has minimal negative impact on QOL, further supporting this patient-centered treatment approach for early-stage breast cancer.

Intraoperative Radiotherapy Is Not a Better Alternative to Whole Breast Radiotherapy as a Therapeutic Option for Early-Stage Breast Cancer

Objective

Intraoperative radiotherapy (IORT) in early-stage breast cancer has been studied over the years. However, it has not been demonstrated whether IORT is more suitable as a therapeutic option for early-stage breast cancer than whole breast radiotherapy (WBRT). Therefore, we performed a meta-analysis to compare the efficacy and safety of IORT to those of WBRT as therapeutic options for early-stage breast cancer patients receiving breast-conserving surgery (INPLASY2020120008).

Methods

PubMed, Embase, and Cochrane Library databases were searched from inception to October 2021. Computerized and manual searches were adopted to identify eligible randomized control trials from online databases. Risk ratio (RR) and 95% confidence intervals (CI) were calculated by random-effect models to assess the relative risk. Potential publication bias was quantified by Begg’s and Egger’s tests.

Results

Based on our inclusion criteria, 10 randomized control trials involving 5,698 patients were included in this meta-analysis. This meta-analysis showed that the IORT group was associated with a higher local recurrence risk (RR = 2.111, 95% CI, 1.130–3.943, p = 0.0191), especially in the long-term follow-up subgroup or published after 2020 subgroup or Caucasian subgroup (RR = 2.404, 95% CI, 1.183–4.885, p = 0.0154). Subgroup analysis showed that the IORT group had a higher recurrence risk than the WBRT group in the polycentric randomized controlled trial subgroup (RR = 1.213, 95% CI, 1.030–1.428, p = 0.0204). Pooled analysis showed that there was no statistically significant difference in overall survival, recurrence-free survival, distant metastasis-free survival, and cancer-specific survival between IORT and WBRT groups. Additionally, the risk of skin toxicity was reduced, but the incidences of fat toxicity, edema, and scar calcification were significantly increased in the patients who underwent IORT in comparison to those who underwent WBRT.

Conclusion

This meta-analysis revealed that IORT was not a better alternative to WBRT. More large-scale and well-designed clinical trials with longer follow-up periods are encouraged to further investigate the value of IORT.

Systematic Review Registration

https://inplasy.com/inplasy-2020-12-0008/.

Delivery of Adjuvant Radiation in 5 Days or Less After Lumpectomy for Breast Cancer: A Systematic Review

BACKGROUND

Recent data have been published supporting the application of ultra-short radiation therapy (RT) regimens for women with early stage breast cancer following breast conserving surgery (BCS). What has remained controversial is whether and how to apply accelerated whole breast irradiation (AWBI) or accelerated partial breast irradiation (APBI) approaches in these patients, as well as the consideration of intraoperative RT (IORT) for this population.

METHODS

We performed a systematic review of the literature searching for randomized and prospective data published evaluating ultra-short RT delivered in 5-days or less with APBI, AWBI, or IORT.

RESULTS

We identified two randomized studies applying AWBI (n=5,011 patients) with 5 to 10 year follow up, which supported the use of ultra-short course AWBI (5 fractions in one week) as compared to hypofractionated WBI. We identified six randomized trials evaluating APBI (as compared to WBI) in 5 days or less (n= 8,415) with numerous (n=55) prospective studies as well, with the data supporting short course APBI as compared to WBI. Finally, we identified two randomized trials evaluating IORT; however, both trials demonstrated elevated rates of recurrence with IORT as compared to WBI.

CONCLUSIONS

The current body of data available for ultra-short adjuvant RT regimens delivered in 5-days or less after BCS overwhelming support their utilization. While data for both exists, APBI regimens have, by far, greater numbers of patients and longer follow-up as compared to AWBI. Also, given increased rates of recurrence seen with IORT with long-term follow-up, this should not be considered a standard approach at this time.

Brachytherapy: An emblematic example of extreme hypofractionated regimen

In order to provide more convenient irradiation regimens for patient comfort, radiation facility organization and health expenses, new hypofractionated protocols have been evaluated. Moderately (dose/fraction: 2.3 to 3Gy), then ultra (dose/fraction: 5.2 to 6.1Gy) hypofractionated irradiations were first validated. The current question is: is it possible to go forward using extreme hypofractionated regimens (EHR) based on 1 to 3 fractions. Different irradiation techniques are under investigation. However, brachytherapy remains the smartest way to deliver a high dose in a small volume. We report prospective and retrospective study results which evaluated EHR for breast and prostate brachytherapy. While oncological outcome and toxicity profile appear extremely encouraging for low-risk breast cancer after a 1 to 4 fractions (6.25 to 20Gy/fraction), the use of a single fraction of 19 to 23Gy appears debatable for prostate cancer. Brachytherapy represents an emblematic example of EHR but longer follow-up and more mature results are awaited in order to specify the right indications and refine the EQD2 calculation method including new biological and technical factors.

Intraoperative Radiotherapy with Balloon-Based Electronic Brachytherapy System-A Systematic Review and First Bulgarian Experience in Breast Cancer Patients

(1) Background: We aimed to analyze currently available studies with intraoperative radiotherapy (IORT) as a choice of treatment where the Xoft Axxent^® electronic brachytherapy (eBx) system was used as a single-dose irradiation and an exclusive radiotherapy approach at the time of surgery in patients with early breast cancer (EBC). We also compared the results of the systematic review to the Bulgarian experience. (2) Methods and Materials: We performed a systematic review of the studies published before February 2021, which investigate the application of a single-fraction 20 Gy radiation treatment, delivered at the time of lumpectomy in EBC patients with the Xoft Axxent^® eBx System. A systematic search in PubMed, Scopus, and ScienceDirect was performed. The results are reported following the PRISMA guidelines. The criteria on patients’ selection for IORT (the additional need for EBRT), cosmetic outcomes, and recurrence rate from the eligible studies are compared to the treatment results in Bulgarian patients. (3) Results: We searched through 1032 results to find 17 eligible studies. There are no published outcomes from randomized trials. When reported, the cosmetic outcomes in most of the studies are defined as excellent. The observed recurrence rate is low (1–5.8%). Still, the number of patients additionally referred to postoperative external breast radiotherapy (EBRT) is up to 31%. Amongst the 20 patients treated in Bulgaria, the cosmetic outcomes are also evaluated as excellent, five of which (25%) are referred for EBRT. Within median follow-up of 39 months, there was one local and one distal recurrence. (4) Conclusions: Current evidence demonstrates the Xoft Axxent^® eBx system as a safe and feasible technique for IORT delivery in EBC patients. There are no randomized controlled trials conducted at this time point to prove its long-term effectiveness. Better patient selection and a reimbursement strategy have to be proposed to extend the application of this technique in Bulgaria.

ndocrine therapy with accelerated artial breast irradiatin or exclusive ultra-accelerated artial breast irradiation for women aged ≥ 60 years with arly-stage breast cancer (EPOPE): The rationale for a GEC-ESTRO randomized phase III-controlled trial

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Epidemiologic data confirm the increase of breast cancer incidence in the elderly.

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The risk of recurrence of breast cancer is basically low.

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De-escalation breast cancer adjuvant therapy is justified in selected elderly patients.

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Ultra-accelerated breast irradiation with endocrine therapy omission is under debate.

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Prospective randomized trial is warranted.

Purpose

Breast cancer in the elderly has become a public health concern; there is a need to re-design its treatment with a view to de-escalation. Our paper sets out the rationale for a phase 3 randomized trial to evaluate less burdensome adjuvant procedures that remain effective and efficient.

Materials and methods

For low-risk breast cancer in the elderly, adjuvant treatment has been adjusted in order to make it more suitable and efficient. Hypofractionated radiation therapy based on accelerated or non-accelerated regimens as well as accelerated and ultra-accelerated partial breast irradiation (APBI) protocols were reviewed. Withdrawal of radiation (RT) or endocrine therapies (ET) from the adjuvant procedure were also investigated. Based on molecular and APBI classifications, inclusion criteria were discussed.

Results

Phase 3 randomized trials which compared standard vs. accelerated/non-accelerated hypofractionated regimens confirmed that the latter were non-inferior in terms of local control. Similarly, except for intraoperative-based techniques, APBI achieved non-inferior local control rates compared to whole breast irradiation for low-risk breast cancer. In phase 2 prospective trials using ultra APBI, encouraging results were observed regarding oncological outcome and toxicity profile. In phase 3 trials, adjuvant ET without RT significantly increased the rate of local relapse with no impact on overall survival while RT alone proved effective. Elderly patients aged 60 or more with low-risk, luminal A breast cancer were chosen as the target population in a phase 3 randomized trial comparing APBI + 5-year ET vs. uAPBI (16 Gy 1f) alone.

Conclusion

To investigate de-escalation adjuvant treatment for elderly breast cancer patients, we have defined a road map for testing more convenient strategies. This EPOPE phase 3 randomized trial is supported by the GEC-ESTRO breast cancer working group.

APBI Versus Ultra-APBI in the Elderly With Low-Risk Breast Cancer: A Comparative Analysis of Oncological Outcome and Late Toxicity

PURPOSE

Accelerated partial breast irradiation (APBI) represents a validated technique for low-risk breast cancer. Recently, ultra-APBI (uAPBI) using fewer than 5 fractions was described in the literature. We compared clinical outcomes and late toxicity after APBI or uAPBI in older patients.

METHODS AND MATERIALS

Two cohorts of older patients (aged ≥70 years) with low-risk breast cancer treated with APBI (interstitial brachytherapy) were analyzed retrospectively. A total dose of 34 Gy in10 fractions (APBI) or 16 Gy in 1 fraction (uAPBI) was delivered from 2004 to 2012 and from 2013 to 2018, respectively. Oncologic outcome analyzed the cumulative incidence of local relapse, regional relapse, and distant metastases with disease-free survival, cause-specific survival, and overall survival. Late toxicity and cosmetic results were investigated.

RESULTS

One hundred fifty-seven patients (APBI, n = 109 patients; uAPBI, n = 48 patients) underwent APBI according to the same selection criteria. Apart from the median follow-up (97 vs 72 months for APBI and uAPBI; P < .002), no significant difference was noted between the 2 groups. Regarding 6-year oncologic outcome, no significant difference was observed between APBI and uAPBI for local recurrence (1.3% vs 0%; P = .4), regional recurrence (2.5% vs 2.3%; P = .9), distant metastases (4.3% vs. 2.4%; P = .6), disease-free survival (85.2% vs. 82.2%; P = .8), cause-specific survival (96.7% vs. 96.2%; P = .9), and overall survival (86.7% vs. 82.2%; P = .7). Regarding late toxicity, no significant difference was observed between APBI and uAPBI (total complication number, 45 vs 33%; P = .173) with only grade 1 (88.4% vs. 95%) and grade 2 (11.6% vs. 5%) late toxicities (P = .677). Similarly, no significant difference was observed for excellent/good cosmetic results between the 2 cohorts (P = .98).

CONCLUSIONS

We report the first study comparing APBI versus uAPBI in a cohort of older patients with low-risk breast cancer. No significant difference was found between the 2 treatment groups regarding oncologic outcome, late toxicity, and cosmetic result. uAPBI based on a single fraction of brachytherapy represents an attractive option for therapeutic de-escalation in older patients 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.

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.

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.

Recent advances in de-intensification of radiotherapy in elderly cancer patients

Cancer in the elderly remains an evolving issue and a health challenge. Several improvements in the radiotherapy field allow the delivery of higher doses/fractions with a safe toxicity profile, permitting the reduction of radiation treatment protocols in the elderly. Regarding breast, prostate, and lung cancer, the under-representation of older patients in clinical trials limits the extension of treatment recommendations to elderly patients in routine clinical practice. Among the feasible alternatives to standard whole breast radiotherapy (WBRT) in older patients are shorter courses using higher hypofractionation (HF) and accelerated partial breast irradiation (APBI). The boost continues to be used in women at high risk of local recurrence but is less widely accepted for women at lower risk and patients over 70 years of age. Regarding prostate cancer, there are no published studies with a focus on the elderly. Current management decisions are based on life expectancy and geriatric assessment. Regimens of HF and ultra-HF protocols are feasible strategies for older patients. Several prospective non-randomized studies have documented the safe delivery of ultra-HF for patients with localized prostate cancer, and multiple phase III trials and meta-analyses have confirmed that the HF regimen should be offered with similar acute toxicity regardless of patient age and comorbidity. A recent pooled analysis from two randomized trials comparing surgery to stereotactic body radiation therapy (SBRT) in older adult patients with early stage non-small cell lung cancer did show comparable outcomes between surgery and SBRT. Elderly cancer patients are significantly under-represented in all clinical trials. Thus, the inclusion of older patients in clinical studies should be strongly encouraged to strengthen the evidence base for this age group. We suggest that the creation of oncogeriatric coordination units may promote individualized care protocols, avoid overtreatment with aggressive and unrecommended therapies, and support de-escalating treatment in elderly cancer patients.

Modern Approaches for Breast Brachytherapy

Breast brachytherapy represents a radiation technique that can be utilized as both monotherapy and as a tumor bed boost following breast conserving surgery. As monotherapy, the rationale for brachytherapy is that the majority of residual disease and therefore recurrences occur in close proximity to the lumpectomy cavity; for boost treatment, brachytherapy represents a technique that provided a more conformal approach prior to 3D treatment planning, and more recently can be used in conjunction with oncoplastic surgery. Multiple guidelines are available to assist clinicians with patient selection for accelerated partial breast irradiation (APBI), and recent guidelines support brachytherapy as an appropriate technique to deliver APBI. Modern breast brachytherapy can be performed with interstitial or applicator-based brachytherapy with multilumen and strut devices offering the ability to provide greater skin, chest wall, and normal breast sparing than previous devices. Novel strategies are being evaluated, including high dose rate perioperative/intraoperative radiotherapy, permanent breast seed implants, and noninvasive breast brachytherapy. Additionally, studies are evaluating shorter courses of brachytherapy. Multiple Level I studies are now available supporting interstitial brachytherapy to deliver APBI while prospective data and the National Surgical Adjuvant Breast and Bowel Project B-39/Radiation Therapy Oncology Group 0413 trial are available with applicator brachytherapy and provide standardized prescriptions, target volume definitions, and dosimetric goals.

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.

Single-Institution Phase 1/2 Prospective Clinical Trial of Single-Fraction, High-Gradient Adjuvant Partial-Breast Irradiation for Hormone Sensitive Stage 0-I Breast Cancer

PURPOSE

We sought to evaluate the feasibility and tolerability of a novel accelerated partial breast irradiation regimen delivered in a single fraction postoperatively.

METHODS AND MATERIALS

We enrolled 50 patients with low-risk, hormone-sensitive breast cancer from 2015 to 2018 on a prospective phase 1/2 trial to receive single-fraction, high-gradient partial-breast irradiation (SFHGPBI) 2 to 8 weeks after lumpectomy for node-negative, invasive, or in situ breast cancer. The high gradient was achieved by prescribing 20 Gy to the surgical bed and 5 Gy to the breast tissue within 1 cm of the surgical bed simultaneously in 1 fraction using external beam.

RESULTS

The median age was 65 (range, 52-84). Ten patients (20%) had small-volume ductal carcinoma in situ while the remainder had stage I disease. At a median follow-up of 25 months, we evaluated toxicity, patient- and physician-reported cosmesis, patient-reported quality of life (QOL), and initial tumor control. There was no Common Terminology Criteria for Adverse Events v4.0 grade 3+ toxicity. Only 34% of patients experienced grade 1 erythema. Good-to-excellent pretreatment cosmesis was present in 100% and 98% per physicians and patients, respectively, and did not change post-SFHGPBI. Quantitative cosmesis by percentage of breast retraction assessment significantly improved over time during the post-SFHGPBI period per mixed repeated measures modeling (P = .0026). QOL per European Organization for Research and Treatment of Cancer QOL Questionnaires C30 and BR-23 did not decline other than temporarily in the systemic therapy effects and hair loss domains, both of which returned to pretreatment values. There was 1 noninvasive in-breast recurrence in a separate untreated quadrant 18 months post-SFHGPBI and 1 isolated axillary recurrence 30 months post-SFHGPBI, both salvaged successfully. There were no distant recurrences or cancer-related deaths observed.

CONCLUSIONS

Accelerated partial-breast irradiation delivered in a single fraction postoperatively using external beam techniques is a novel, feasible, well-tolerated regimen. SFHGPBI does not adversely affect cosmesis or QOL as reported by both physicians and patients. Initial tumor control rates are excellent, with longer follow-up required to confirm efficacy.

Normal tissue dose and risk estimates from whole and partial breast radiation techniques

PURPOSE

To compare radiation dose to organs at risk in patients with early-stage breast cancer treated with lumpectomy and intraoperative radiation therapy with CT-guided HDR brachytherapy (precision breast IORT; PB-IORT) and those treated with external beam whole breast irradiation (WB-DIBH) or partial breast irradiation (PB-DIBH) with deep inspiratory breath hold.

METHODS

We retrospectively identified 52 consecutive patients with left-sided breast cancers treated with either PB-IORT (n = 17, 76% outer breast) on a phase I clinical trial, adjuvant PB-DIBH (n = 18, 56% outer breast, 6% cavity boost), or WB-DIBH (n = 17, 76% outer breast, 53% with lumpectomy cavity boost). Conventional (2 Gy/fraction) or moderate hypofractionation (2.66 Gy/fraction) was prescribed for the external beam cohorts and 12.5 Gy in 1 fraction to 1 cm from the balloon surface was prescribed to the HDR brachytherapy cohort. CT-based planning was used for all patients. Organ at risk doses and excess risk ratios (ERR) for secondary lung cancers, contralateral breast cancers, and cardiac toxicity were compared between treatment techniques.

RESULTS

Compared to WB-DIBH and PB-DIBH, PB-IORT resulted in lower ipsilateral lung V5, V10, V20, mean, and max dose (P < .05). Mean ipsilateral lung BED_3Gy was as follows: 1.32 Gy for PB-IORT, 4.33 Gy for WB-DIBH, 3.35 Gy for PB-DIBH. The ERR for lung cancer was lowest for PB-IORT (P < .001). There was significantly higher contralateral breast max dose but lower mean BED_3Gy for WB-DIBH compared with PB-IORT (P = .012, P = .011, respectively). Mean contralateral breast BED_3Gy was as follows: 0.10 Gy for PB-IORT, 0.06 Gy for WB-DIBH, and 0.08 Gy for PB-DIBH. The ERR for contralateral breast cancer was low for all breast techniques, but WB-DIBH showed lower ERR compared to PB-IORT (P = .019). Mean heart BED_2Gy was higher with PB-IORT at 1.26 Gy compared to 0.48 Gy and 0.24 Gy for WB-DIBH and PB-DIBH, respectively (P < .001).

CONCLUSIONS

Patients with early-stage breast cancer treated with PB-IORT and with tissue-sparing external beam techniques all received low organ at risk doses, but PB-IORT resulted in far lower ipsilateral lung dose compared with external beam techniques. Our data indicate the lowest mean contralateral breast BED in the WB-DIBH group, likely due to the simplicity of the field design in low-risk patients using tangential whole breast radiation. External beam using DIBH results in lowest heart dose, but all techniques were well within recommended heart constraints.

Five-year oncological outcome after a single fraction of accelerated partial breast irradiation in the elderly

Background

To update the clinical outcome of an elderly women cohort with early breast cancer who underwent accelerated partial breast irradiation (APBI) based on a post-operative single fraction of multicatheter interstitial high dose–rate brachytherapy (MIB).

Material and methods

A single institution retrospective cohort study was performed focusing on elderly patients (≥ 65 years old) presenting a low-risk breast carcinoma treated by lumpectomy plus axillary evaluation followed by MIB APBI. A single fraction of 16 Gy was prescribed on the 100% isodose. Clinical outcome at 5 years was reported based on local relapse free survival (LRFS), specific survival (SS) and overall survival (OS). Late toxicity was evaluated. Cosmetic results were evaluated clinically by the physician.

Results

Between January 2012 and August 2015, 48 women (51 lesions) were treated. Median age was 77.7 years (range: 65–92) with a median tumor size of 12 mm (range: 3–32). Five patients (pts) presented an axillary lymph node involvement (4 Nmic, 1 N1). Invasive ductal carcinoma was the most frequent histology type (86.3%). With a median follow–up of 64 months (range: 56–71), no local relapse occurred while 1 pt. developed an axillary relapse (2.1%). No Grade 3 or higher late toxicity was observed while 16 late toxicities occurred (G1: 14 events [87.5%) mainly G1 breast fibrosis). The rate of excellent cosmetic outcome was 76.4%.

Conclusion

We confirmed the safety of the process and remained encouraging clinical outcome of a post-operative single fraction of MIB ABPI in the elderly. This approach leads to consider a very APBI as an attractive alternative to intra-operative radiation therapy while all the patients will be good candidates for APBI in regards to the post-operative pathological report.

The American Brachytherapy Society consensus statement on intraoperative radiation therapy

PURPOSE

Although radiation therapy has traditionally been delivered with external beam or brachytherapy, intraoperative radiation therapy (IORT) represents an alternative that may shorten the course of therapy, reduce toxicities, and improve patient satisfaction while potentially lowering the cost of care. At this time, there are limited evidence-based guidelines to assist clinicians with patient selection for IORT. As such, the American Brachytherapy Society presents a consensus statement on the use of IORT.

METHODS

Physicians and physicists with expertise in intraoperative radiation created a site-directed guideline for appropriate patient selection and utilization of IORT.

RESULTS

Several IORT techniques exist including radionuclide-based high-dose-rate, low-dose-rate, electron, and low-energy electronic. In breast cancer, IORT as monotherapy should only be used on prospective studies. IORT can be considered in the treatment of sarcomas with close/positive margins or recurrent sarcomas. IORT can be considered in conjunction with external beam radiotherapy for retroperitoneal sarcomas. IORT can be considered for colorectal malignancies with concern for positive margins and in the setting of recurrent gynecologic cancers. For thoracic, head and neck, and central nervous system malignancies, utilization of IORT should be evaluated on a case-by-case basis.

CONCLUSIONS

The present guidelines provide clinicians with a summary of current data regarding IORT by treatment site and guidelines for the appropriate patient selection and safe utilization of the technique. High-dose-rate, low-dose-rate brachytherapy methods are appropriate when IORT is to be delivered as are electron and low-energy based on the clinical scenario.

Accelerated partial breast irradiation in the elderly: 5-Year results of the single fraction elderly breast irradiation (SiFEBI) phase I/II trial

PURPOSE

To evaluate the clinical outcomes of a very-accelerated partial breast irradiation (vAPBI) in the elderly based on a single fraction of multicatheter interstitial high-dose rate brachytherapy (MIB). Mature results with a median follow-up of 5 years.

METHODS AND MATERIALS

From November 2012 to September 2014, 26 patients (pts) (≥70) with early breast cancer were enrolled in a prospective phase II trial (NCT01727011). After lumpectomy, intraoperative catheter implant was performed for postoperative APBI (single fraction 16 Gy). Surveillance was performed twice a year after APBI. Oncologic outcome (local [LRFS], metastasis-free survival, cancer-specific survival, and overall survival [OS]) as well as late toxicity and cosmetic outcome were investigated.

RESULTS

Median age was 77 years [69-89]. After a median follow-up of 63 months [60-68], 5-year LRFS, metastasis-free survival, cancer-specific survival, and overall survival rates were 100%, 95.5%, 100%, and 88.5%, respectively. Late toxicity was observed in 5 pts (19.2%) with a total of five events: 3 pts G1 (60%); and 2 pts G2 (40%). The observed late side effects were breast pain in 1 pt (G2 cytosteatonecrosis with occasional acetaminophen consumption), hypopigmentation (puncture site) in 2 pts (G1) and breast fibrosis in 2 pts (G1: 1 pt; G2: 1 pt). Cosmetic evaluation was excellent for 21 pts (81%) and good for 2 pts (19%).

CONCLUSION

For elderly with early breast cancer, a vAPBI using a single fraction of postoperative MIB (16 Gy) provides excellent oncologic results, mainly in terms of local control and cancer death. Late toxicity and cosmetic profile are acceptable.

Hypofractionated radiation therapy for invasive breast cancer: From moderate to extreme protocols

Adjuvant irradiation is the standard treatment after breast conservative surgery. Normofractionated regimen with an overall treatment time of 5 to 6 weeks is often considered as a limiting factor for irradiation compliance. In order to answer this issue, moderate and more recently extreme hypofractionated protocols appeared. We report here oncological outcomes and toxicity of hypofractionated breast irradiation. After defining the frame of moderate and extreme hypofractionated breast irradiations based on overall treatment time, patient selection criteria were listed. According to their levels of proof, the results of moderate and extreme hypofractionated breast irradiation were analysed. Overall treatment time for moderate hypofractionated breast irradiation ranged from 3 to 4 weeks, while for extreme hypofractionated breast irradiation, it was less than 1 week. For moderate hypofractionated breast irradiation, whole breast irradiation was currently performed with or without lymph node irradiation. Moderate hypofractionated breast irradiation has proven to be as safe and as efficient as normofractionated breast irradiation with level IA evidence. For extreme hypofractionated breast irradiation, phase III randomized trials confirmed that accelerated partial breast irradiation was non-inferior in terms of local control compared to normofractionated whole breast irradiation (with external beam radiation therapy and multicatheter brachytherapy), with similar acute and late toxicity. While the use of intraoperative breast irradiation remains under debate, new very accelerated partial breast irradiation (overall treatment time not exceeding 2 days) protocols emerged with encouraging results. Accelerated partial breast irradiation is warranted for extreme hypofractionated breast irradiation and is indicated for low-risk breast cancers. Moderate and extreme hypofractionated breast irradiation regimens are validated and can be routinely proposed according to patient selection criteria.

Dynamic Modulated Brachytherapy (DMBT) Balloon Applicator for Accelerated Partial Breast Irradiation

PURPOSE

To propose a novel high-dose-rate brachytherapy applicator for balloon-based dynamic modulated brachytherapy (DMBT) for accelerated partial breast irradiation (APBI) and to demonstrate its dosimetric advantage compared to the widely used Contura applicator.

METHODS AND MATERIALS

The DMBT balloon device consists of a fixed central channel enabling real-time, in vivo dosimetry and an outer motion-dynamic, adjustable-radius channel capable of moving to any angular position within the balloon. This design allows placement of dwell positions anywhere within the balloon volume, guaranteeing optimal placement and generation of the applicator and treatment plan, respectively. Thirteen clinical treatment plans for patients with early-stage breast cancer receiving APBI after lumpectomy using Contura were retrospectively obtained under institutional review board approval. New treatment plans were created by replacing the Contura with the DMBT device. DMBT plans were limited to 4 angular positions and an outer channel radius of 1.5 cm. The new plans were optimized to limit dose to ribs and skin while maintaining target coverage similar to that of the clinical plan.

RESULTS

Similar target coverage was obtained for the DMBT plans compared with clinical Contura plans. Across all patients the mean (standard deviation) reductions in D0.1 cc to the ribs and skin were 6.70% (6.28%) and 5.13% (6.54%), respectively. A threshold separation distance between the balloon surface and the organ at risk (OAR), below which dosimetric changes of greater than 5% were obtained, was observed to be 12 mm for ribs and skin. When both OARs were far from the balloon, DMBT plans were of similar quality to Contura plans, as expected.

CONCLUSIONS

This study demonstrates the superior ability of the APBI DMBT applicator to spare OARs while achieving target coverage comparable to current treatment plans, especially when in close proximity. The DMBT balloon may enable new modes of dynamic high-dose-rate treatment delivery and allow for ultrahypofractionated dose regimens to be safely used.

Long-Term Outcomes of Three-Dimensional High-Dose-Rate Brachytherapy for Locally Recurrent Early T-Stage Nasopharyngeal Carcinoma

Background: Brachytherapy (BT) is one of the techniques available for retreatment of patients with locally recurrent nasopharyng eal carcinoma (rNPC). In this study, we evaluated the treatment outcome and late toxicities of three-dimensional high-dose-rate brachytherapy (3D-HDR-BT) for patients with locally rNPC. Materials and Methods: This is a retrospective study involving 36 patients with histologically confirmed rNPC from 2004 to 2011. Of the 36 patients, 17 underwent combined-modality treatment (CMT) consisting of external beam radiotherapy (EBRT) followed by 3D-HDR-BT, while the other 19 underwent 3D-HDR-BT alone. The median dose of EBRT for the CMT group was 60 (range, 50-66) Gy, with an additional median dose of BT of 16 (range, 9-20) Gy. The median dose for the 3D-HDR-BT group was 32 (range, 20-36) Gy. The measured treatment outcomes were the 5- and 10-year locoregional recurrence-free survival (LRFS), disease-free survival (DFS), overall survival (OS), and late toxicities. Results: The median age at recurrence was 44.5 years. The median follow-up period was 70 (range, 6-142) months. The 5-year LRFS, DFS, and OS for the entire patient group were 75.4, 55.6, and 74.3%, respectively, while the 10-year LRFS, DFS, and OS for the entire patient group were 75.4, 44.2, and 53.7%, respectively. The 10-year LRFS in the CMT group was higher than that in the 3D-HDR-BT-alone group (93.8 vs. 58.8%, HR: 7.595, 95%CI: 1.233-61.826, p = 0.025). No grade 4 late radiotherapy-induced toxicities were observed. Conclusions: 3D-HDR-BT achieves favorable clinical outcomes with mild late toxicity in patients with locally rNPC.

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.

Three-Fraction Accelerated Partial Breast Irradiation (APBI) Delivered With Brachytherapy Applicators Is Feasible and Safe: First Results From the TRIUMPH-T Trial

PURPOSE

Shorter courses of accelerated partial-breast irradiation delivered as single-fraction intraoperative therapy are now offered as an alternative to 4 to 6 weeks of whole-breast irradiation after lumpectomy. However, this approach has potential shortcomings in patient selection and target volume definition and in dosimetric, radiobiological, and logistical issues. We designed a prospective, phase 2, multi-institution clinical trial to study 2- or 3-day accelerated partial breast irradiation delivered with brachytherapy applicators.

METHODS AND MATERIALS

This trial treats select breast cancers after breast-conserving surgery with brachytherapy applicators that deliver 22.5 Gy in 3 fractions of 7.5 Gy. The planning treatment volume was 1 to 1.5 cm beyond the surgical cavity. Eligible women were aged ≥45 years with unicentric invasive or in situ tumors ≤3.0 cm with positive estrogen or progesterone receptors and no metastasis to axillary nodes that have been excised with negative margins. Strict dosimetric parameters were required to be met before acceptance into the trial.

RESULTS

A group of 200 patients was prospectively enrolled and followed for a minimum of 6 months. Two- or 3-day brachytherapy was associated with low acute or subacute toxicity, 97.25% excellent or good cosmetic outcomes, and excellent local control in select breast cancers.

CONCLUSIONS

Ultrashort breast brachytherapy is dosimetrically feasible and can be delivered with excellent short-term tolerance and low toxicity.

Dosimetric evaluation and systematic review of radiation therapy techniques for early stage node-negative breast cancer treatment

Radiation therapy (RT) is essential in treating women with early stage breast cancer. Early stage node-negative breast cancer (ESNNBC) offers a good prognosis; hence, late effects of breast RT becomes increasingly important. Recent literature suggests a potential for an increase in cardiac and pulmonary events after RT. However, these studies have not taken into account the impact of newer and current RT techniques that are now available. Hence, this review aimed to evaluate the clinical evidence for each technique and determine the optimal radiation technique for ESNNBC treatment. Currently, six RT techniques are consistently used and studied: 1) prone positioning, 2) proton beam RT, 3) intensity-modulated RT, 4) breath-hold, 5) partial breast irradiation, and 6) intraoperative RT. These techniques show dosimetric promise. However, limited data on late cardiac and pulmonary events exist due to challenges in long-term follow-up. Moving forward, future studies are needed to validate the efficacy and clinical outcomes of these current techniques.

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.

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.

Consensus on management of metastatic colorectal cancer in Central America and the Caribbean: San José, Costa Rica, August 2016

Colorectal cancer (CRC) is the third most common cancer in men and the second most common in women worldwide. In Latin America and the Caribbean, it has a mortality of 56%. The median overall survival for patients with metastatic colorectal cancer (mCRC) is currently estimated as ~30 months, which has substantially improved through strategic changes in treatment and in the management of patients. As opposed to other metastatic cancers where first-line regimens are often determined, mCRC requires special attention because there is controversy in the possible combinations of the available drugs and the different periods of duration for each patient. Each combination must seek to be effective and to generate the minimum adverse effects as possible. Instead of giving the first-line regimen until the tumour progresses, treatment is often individualised. Furthermore, up to 60% of colorectal tumours are considered non-mutated or wild-type CRC. Not harbouring mutations in the RAS family of genes or mutations in the signalling pathways of the epidermal growth factor receptor causes a null response to anti-epidermal growth factor receptor antibody therapy, which implies even more complex considerations regarding its management. The primary objective of this consensus is to address the main scenarios of mCRC in order to warrant the most appropriate therapeutic intervention for these patients in the Central American and the Caribbean (CAC) region. This can lead to better clinical outcomes as well as quality of life for palliative patients. This document includes the formal expert consensus recommendations for scenarios of mutated and non-mutated mCRC, including synchronous or metachronous disease, management of mCRC with liver and lung metastasis, resectable, potentially resectable or non-resectable tumours and local in the CAC context.

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.

Integration of free-hand 3D ultrasound and mobile C-arm cone-beam CT: Feasibility and characterization for real-time guidance of needle insertion

This work presents development of an integrated ultrasound (US)-cone-beam CT (CBCT) system for image-guided needle interventions, combining a low-cost ultrasound system (Interson VC 7.5MHz, Pleasanton, CA) with a mobile C-arm for fluoroscopy and CBCT via use of a surgical tracker. Imaging performance of the ultrasound system was characterized in terms of depth-dependent contrast-to-noise ratio (CNR) and spatial resolution. US-CBCT system was evaluated in phantom studies simulating three needle-based procedures: drug delivery, tumor ablation, and lumbar puncture. Low-cost ultrasound provided flexibility but exhibited modest CNR and spatial resolution that is likely limited to fairly superficial applications within a ∼10cm depth of view. Needle tip localization demonstrated target registration error 2.1-3.0mm using fiducial-based registration.