ESTRO ACROP consensus guideline for target volume delineation in the setting of postmastectomy radiation therapy after implant-based immediate reconstruction for early stage breast cancer

Special Techniques of Adjuvant Breast Carcinoma Radiotherapy

Modern radiotherapy techniques are designed to permit reduced irradiation of healthy tissue, resulting in a diminished risk of adverse effects and shortened recovery times. Several randomized studies have demonstrated the benefits of increased dosage to the tumor bed area in combination with whole breast irradiation (WBI). Conventional WBI treatment following breast-conserving procedures, which required 5-7 weeks of daily treatments, has been reduced to 3-4 weeks when using hyperfractionated regimens. The dosage administration improves local control, albeit with poorer cosmesis. The method of accelerated partial breast irradiation (APBI) shortens the treatment period whilst reducing the irradiated volume. APBI can be delivered using intraoperative radiation, brachytherapy, or external beam radiotherapy. Currently available data support the use of external beam partial breast irradiation in selected patients. Modern radiotherapy techniques make it possible to achieve favorable cosmesis in most patients undergoing immediate breast reconstruction surgery, and studies confirm that current methods of external beam radiation allow an acceptable coverage of target volumes both in the reconstructed breast and in the regional lymphatic nodes.

Post-mastectomy radiation therapy with helical tomotherapy in patients with or without immediate implant-based reconstruction: a single institution experience

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We report very low doses to the heart and lung for PMRT with Helical Tomotherapy.

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Breast implant improves dosimetric results with reduced heart and lung doses.

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No local recurrence was seen in the posterior part of implants.

Introduction

We report on our experience of using Helical Tomotherapy (HT) in the context of post-mastectomy radiation therapy (PMRT) with or without immediate implant-based breast Reconstruction (IBR).

Material and methods

The study included a total of 173 patients who underwent PMRT with HT between 2013 and 2015 in our institution (87 immediate breast reconstructions with retropectoral implants (IBR + ), 86 without reconstructions (IBR-)). The chest wall target volume included subcutaneous tissue and pectoralis muscle and excluded the posterior region of the implant as well as the ribs.

Results

Median time to initiation of the first adjuvant treatment from mastectomy was similar between the two groups (p = 0.134). Dose coverage to the chest wall was significantly improved for the IBR + group (V95% = 95.1 % versus 92.0 %; p < 0.0001). The irradiated volume of the ipsilateral lung was significantly decreased in the IBR + group with a median V20Gy of 11.6 %, compared to 15.2 % for the control group (p < 0.0001). The median heart V15Gy was also significantly lower in the IBR + group than in the control group (1.7 vs 2.5 %; p = 0.0280). The reconstruction failure rate was 14.9% (n = 13). After a median follow-up of 65 months, loco regional recurrence rate was low in both groups: 3 patients (3.4%) in the IBR + group and 5 patients (5.8%) in the control group, without any local recurrence in the posterior part of the implant.

Conclusions

The presence of a breast implant reduces cardiac and pulmonary doses during Tomotherapy irradiation, without compromising oncological outcomes.

Proton Therapy for Breast Cancer: A Consensus Statement From the Particle Therapy Cooperative Group Breast Cancer Subcommittee

Radiation therapy plays an important role in the multidisciplinary management of breast cancer. Recent years have seen improvements in breast cancer survival and a greater appreciation of potential long-term morbidity associated with the dose and volume of irradiated organs. Proton therapy reduces the dose to nontarget structures while optimizing target coverage. However, there remain additional financial costs associated with proton therapy, despite reductions over time, and studies have yet to demonstrate that protons improve upon the treatment outcomes achieved with photon radiation therapy. There remains considerable heterogeneity in proton patient selection and techniques, and the rapid technological advances in the field have the potential to affect evidence evaluation, given the long latency period for breast cancer radiation therapy recurrence and late effects. In this consensus statement, we assess the data available to the radiation oncology community of proton therapy for breast cancer, provide expert consensus recommendations on indications and technique, and highlight ongoing trials' cost-effectiveness analyses and key areas for future research.

Willingness to Receive Periodic Health Examination Based on the Health Belief Model Among the Elderly in Rural China: A Cross-Sectional Study

PURPOSE

This study aimed to explore factors affecting behavioral intention of receiving periodic health examinations (hereafter, BIE) among people aged 60 and over in rural China, namely, Shandong Province, using the extended health belief model (EHBM).

PATIENTS AND METHODS

Participants were selected using stratified multi-stage random sampling. Three cities were selected based on economic level. Subsequently, three counties and three villages were selected from each sample city and county. Finally, 30 respondents were selected from each sample village. Face-to-face surveys were conducted using a structured questionnaire between March and September 2017. Multiple linear regression was conducted to investigate the association between BIE and eight dimensions of EHBM: perceived susceptibility, perceived severity, perceived benefits, perceived barriers, perceived self-efficacy, cues to action, health knowledge, and social support.

RESULTS

Of the 509 rural respondents aged 60 years and older, the average score of behavioral intention was 4.43±0.80. Multivariate linear regression analysis demonstrated poor BIE among participants who were men, were current smoker, were current drinker, were aged 70 years or over, had lower social support, and perceived lower self-efficacy, less benefits, and more barriers. Among them, barriers were found to have the strongest association with BIE (B'=-0.556; p<0.001). Qualitative interviews revealed that reasons for not receiving periodic health examinations (PHE) included pain, cost, difficulty in finding a health care provider, time and scheduling, potential lack of trust in the physician, and value of the PHE.

CONCLUSION

This study highlighted the importance of psychological variables in the acceptance of PHE among the elderly in rural China and provided insights for further intervention designs targeting identified groups and performed by general practitioners. Addressing medical mistrust, strengthening, and enhancing one's social support network and health communication channels, such as bulletin boards, may serve to facilitate BIE.

Post-mastectomy radiation therapy in breast reconstruction: a patterns of care study of the Korean Radiation Oncology Group

PURPOSE

The details of breast reconstruction and radiation therapy (RT) vary between institutions; therefore, we sought to investigate the practice patterns of radiation oncologists who specialize in breast cancer.

MATERIALS AND METHODS

We identified the practice patterns and inter-hospital variations from a multi-center cohort of women with breast cancer who underwent post-mastectomy RT (PMRT) to the reconstructed breast at 16 institutions between 2015 and 2016. The institutions were requested to contour the target volume and produce RT plans for one representative case with five different clinical scenarios and answer questionnaires which elicited infrastructural information. We assessed the inter-institutional variations in RT in terms of the target, normal organ delineation, and dose-volume histograms.

RESULTS

Three hundred fourteen patients were included; 99% of them underwent immediate reconstruction. The most irradiated material was tissue expander (36.9%) followed by transverse rectus abdominis musculocutaneous flap (23.9%) and silicone implant (12.1%). In prosthetic-based reconstruction with tissue expander, most patients received PMRT following partial deflation. Conventional fractionation and hypofractionation RT were used in 66.6% and 33.4% patients, respectively (commonest: 40.05 Gy in 15 fractions [17.5%]). Furthermore, 15.6% of the patients received boost RT and 53.5% were treated with bolus. Overall, 15 physicians responded to the questionnaires and six submitted their contours and RT plans. There was a significant variability in target delineations and RT plans between physicians, and between clinical scenarios.

CONCLUSION

Adjuvant RT following post-mastectomy reconstruction has become a common practice in Korea. The details vary significantly between institutions, which highlights an urgent need for standard protocol in this clinical setting.

A Retrospective Dosimetric Analysis of the New ESTRO-ACROP Target Volume Delineation Guidelines for Postmastectomy Volumetric Modulated Arc Therapy After Implant-Based Immediate Breast Reconstruction

Purpose: The European Society of Radiation & Oncology and Advisory Committee on Radiation Oncology Practice (ESTRO-ACROP) presented new guidelines for clinical target volume (CTV) delineation in post-mastectomy radiation therapy (PMRT) after implant-based immediate breast reconstruction (IBR-i). This study evaluated the dosimetric characteristics, dosimetric accuracy, and delivery accuracy of these guidelines in volumetric modulated arc therapy (VMAT). Methods and Materials: This retrospective study included 15 patients with left breast cancer who underwent mastectomy with tissue expander placement followed by PMRT. An experienced radiation oncologist delineated the CTV twice on the same image datasets based on the ESTRO-ACROP (EA-TVD) and conventional target volume delineation (C-TVD) guidelines. All VMAT plans, which used a double partial arc, were generated using six MV photons. Clinically relevant dose-volume parameters for organs at risk were compared. Dosimetric accuracy of the treatment plans and delivery accuracy were assessed. Results: Target volume of EA-TVD was significantly smaller than that of C-TVD. Although no statistically significant difference was noted in the target coverage between the two VMAT plans, EA-TVD VMAT significantly reduced the mean heart dose (3.99 ± 1.02 vs. 5.84 ± 1.78 Gy, p = 0.000), the maximum left anterior descending coronary artery (LAD) dose (9.43 ± 3.04 vs. 13.97 ± 6.04 Gy, p = 0.026), and the mean LAD dose (4.52 ± 1.31 vs. 6.35 ± 2.79 Gy, p = 0.028) compared with C-TVD VMAT. No significant difference was observed with respect to the total monitor units, plan complexity, and delivery quality assurance. Conclusions: This is the first study to show significant dose reduction for the normal heart and LAD tissue offered by the EA-TVD, while maintaining dosimetric and delivery accuracy, in PMRT after IBR-i in VMAT for left-sided breast cancer patients.