Reduction of radiotherapy-induced late complications in early breast cancer: the role of intensity-modulated radiation therapy and partial breast irradiation

Radiation-Induced Tissue Damage: Clinical Consequences and Current Treatment Options

Radiation therapy is a valuable tool in the treatment of numerous malignancies but, in certain cases, can also causes significant acute and chronic damage to noncancerous neighboring tissues. This review focuses on the pathophysiology of radiation-induced damage and the clinical implications it has for plastic surgeons across breast reconstruction, osteoradionecrosis, radiation-induced skin cancers, and wound healing. The current understanding of treatment modalities presented here include hyperbaric oxygen therapy, autologous fat grafting and stem cells, and pharmaceutical agents.

Postmastectomy Radiation Therapy (PMRT) before and after 2-Stage Expander-Implant Breast Reconstruction: A Systematic Review

Background: In those undergoing treatment for breast cancer, evidence has demonstrated a significant improvement in survival, and a reduction in the risk of local recurrence in patients who undergo postmastectomy radiation therapy (PMRT). There is uncertainty about the optimal timing of PMRT, whether it should be before or after tissue expander or permanent implant placement. This study aimed to summarize the data reported in the literature on the effect of the timing of PMRT, both preceding and following 2-stage expander-implant breast reconstruction (IBR), and to statistically analyze the impact of timing on infection rates and the need for explantation. Methods: A comprehensive systematic review of the literature was conducted using the PubMed/Medline, Ovid, and Cochrane databases without timeframe limitations. Articles included in the analysis were those reporting outcomes data of PMRT in IBR published from 2009 to 2017. Chi-square statistical analysis was performed to compare infection and explantation rates between the two subgroups at p < 0.05. Results: A total of 11 studies met the inclusion criteria for this study. These studies reported outcomes data for 1565 total 2-stage expander-IBR procedures, where PMRT was used (1145 before, and 420 after, implant placement). There was a statistically significant higher likelihood of infection following pre-implant placement PMRT (21.03%, p = 0.000079), compared to PMRT after implant placement (9.69%). There was no difference in the rate of explantation between pre-implant placement PMRT (12.93%) and postimplant placement PMRT (11.43%). Conclusion: This study suggests that patients receiving PMRT before implant placement in 2-stage expander–implant based reconstruction may have a higher risk of developing an infection.

Lymphangioma secondary to irradiation after mastectomy

Lymphangioma is a rare benign disease of the lymphatic vessels. Typically, they are primary conditions but may be acquired secondarily, such as those caused by irradiation during radiotherapy for the treatment of breast cancer. The local lymphatic obstruction provoked by irradiation causes the appearance of asymptomatic hyaline vesicles on the irradiated skin. The present report describes a 78-year-old female patient, who initially presented hyaline vesicles that progressed into multiple papules with serous exudation of a yellowish and odorless secretion on the area of chronic radiodermitis in right breast. Despite the rarity of the case, we emphasize the importance of knowledge regarding dermatological disease for early diagnosis and proper medical conduct.

Breast reconstruction with anatomical implants: A review of indications and techniques based on current literature

One important modality of breast cancer therapy is surgical treatment, which has become increasingly less mutilating over the last century. Breast reconstruction has become an integrated part of breast cancer treatment due to long-term psychosexual health factors and its importance for breast cancer survivors. Both autogenous tissue-based and implant-based reconstruction provides satisfactory reconstructive options due to better surgeon awareness of "the ideal breast size", although each has its own advantages and disadvantages. An overview of the current options in breast reconstruction is presented in this article.

A meta-analysis of implant-based breast reconstruction and timing of adjuvant radiation therapy

BACKGROUND

Implant-based breast reconstruction is the most common type of reconstruction after postmastectomy radiation therapy (PMRT). The impact of the timing of PMRT to a tissue expander or permanent implant is not well understood. The purpose of this systematic review was to evaluate outcomes in implant-based reconstruction and the timing of PMRT.

METHODS

A review of the English literature in the PubMed/MEDLINE database (2000-2016) was performed to identify all articles on implant-based breast reconstruction and PMRT. Cases from each study were grouped by PMRT to a tissue expander or PMRT to a permanent implant. Outcomes of interest included reconstructive failure and capsular contracture as overall rates and associations were pooled. Effect sizes (z values), risk ratios (RRs), and heterogeneity scores (I²) were calculated on meta-analysis.

RESULTS

There were 20 studies meeting inclusion criteria with 2348 patients identified. Pooled analysis revealed an overall rate of reconstructive failure of 17.6% and Baker grade III/IV capsular contracture of 37.5%. PMRT applied to tissue expanders resulted in higher rates of reconstructive failure compared with PMRT applied to permanent silicone implants (20% versus 13.4%, RR = 2.33, P = 0.0083, 95% confidence interval 1.24-4.35), but lower rates of capsular contracture (24.5% versus 49.4%, RR = 0.53, P = 0.083, 95% confidence interval 0.26-1.09).

CONCLUSIONS

Regardless of timing, PMRT applied to implant-based breast reconstruction was associated with high risk of reconstructive failure and capsular contracture. Surgeons should consider alternative strategies, such as autologous tissue reconstructions, in patients requiring PMRT.

Sparsity constrained split feasibility for dose-volume constraints in inverse planning of intensity-modulated photon or proton therapy

A split feasibility formulation for the inverse problem of intensity-modulated radiation therapy treatment planning with dose-volume constraints included in the planning algorithm is presented. It involves a new type of sparsity constraint that enables the inclusion of a percentage-violation constraint in the model problem and its handling by continuous (as opposed to integer) methods. We propose an iterative algorithmic framework for solving such a problem by applying the feasibility-seeking CQ-algorithm of Byrne combined with the automatic relaxation method that uses cyclic projections. Detailed implementation instructions are furnished. Functionality of the algorithm was demonstrated through the creation of an intensity-modulated proton therapy plan for a simple 2D C-shaped geometry and also for a realistic base-of-skull chordoma treatment site. Monte Carlo simulations of proton pencil beams of varying energy were conducted to obtain dose distributions for the 2D test case. A research release of the Pinnacle ³ proton treatment planning system was used to extract pencil beam doses for a clinical base-of-skull chordoma case. In both cases the beamlet doses were calculated to satisfy dose-volume constraints according to our new algorithm. Examination of the dose-volume histograms following inverse planning with our algorithm demonstrated that it performed as intended. The application of our proposed algorithm to dose-volume constraint inverse planning was successfully demonstrated. Comparison with optimized dose distributions from the research release of the Pinnacle ³ treatment planning system showed the algorithm could achieve equivalent or superior results.

Multibeam inverse intensity-modulated radiotherapy (IMRT) for whole breast irradiation: a single center experience in China

Purpose

To present the clinical experience in our cancer center with multibeam inverse intensity-modulated radiotherapy (IMRT) for early stage breast cancer (BC) patients with whole breast irradiation (WBI).

Methods

We retrospectively analyzed 622 patients with Stage 0 to III BC treated from 2008 to 2011 with wide local excision and WBI, using an inverse IMRT technique. All of the patients were prescribed a total dose of 50 Gy to the whole breast in 2-Gy fractions, followed by a tumor bed boost of 10 Gy in 5 fractions using an electron beam.

Results

Of all of the patients, 132 (21.2%) received whole breast plus regional lymph node (RLN) irradiation. 438 of 622 patients had records of acute skin toxicity based on common terminology criteria (CTC) for adverse events. Two hundred eighty (64%) patients had Grade 0/1 toxicity, 153 (35%) had Grade 2 and only 4 patients experienced grade 3 toxicity. Seventy patients (16%) had moist desquamation. Univariate analysis revealed that breast planning target volume was the only predictive factor for Grade ≥2 acute dermatitis (P = 0.002). After 4 years, 170 patients reported cosmetic results by self-assessment, of whom 151 (89%) patients reported good/excellent cosmetic results, and 17 (11%) patients reported fair assessments. For invasive cancer, the four-year rate of freedom from locoregional recurrence survival was 98.3%. Regarding carcinoma in situ, no patients experienced recurrence.

Conclusion

BC patients who underwent conservative surgery followed by inverse IMRT plan exhibited acceptable acute toxicities and clinical outcomes. Longer follow-up is needed.

["V" axillary incision for the management of tumors of upper outer quadrant and axillary tail of the breast: retrospective study and technical description]

INTRODUCTION

Tumors of the upper outer quadrant of the breast represent the most common location of breast malignant tumors. Although the choice of surgical approach should be dictated primarily by an imperative of oncological safety, esthetic and practical considerations of the surgeon as well as the esthetic demands of patients have become increasingly important with the development of breast conservative surgery.

MATERIALS AND METHODS

In this retrospective study, we reviewed 30 patients (mean age: 62.3 years) who were operated for a tumor of the upper outer quadrant (50 %) or the axillary tail (50 %) of the breast and who received a "V" axillary incision between 2008 and 2012. The incision draws a "V" that comprises a horizontal incision in an axilla fold associated with a vertical arcuate incision in a Langer line of the breast. The number and type of postoperative complications were collected. Patients were asked about the quality of their scar, position of the areola and breast shape was notified during consultations control.

RESULTS

The mean follow-up of patients was 32.7 months. No postoperative complications were observed. A percentage of 86.6 % of patients rated their scar result as excellent. We found no areolar malposition and no morphological deformation of the breast. The surgeons who performed this technique were very pleased with the wide exposure and the uniqueness of this incision fully respecting the architecture of the breast.

CONCLUSION

"V" axillary incision is a useful and easily reproducible technical option for the management of tumors of the upper outer quadrant and the axillary tail of the breast.

Computer simulation of pectoralis major muscle strain to guide exercise protocols for patients after breast cancer surgery

STUDY DESIGN

Descriptive study.

OBJECTIVES

To quantify and rank the order of strain (length change in proportion to the resting length) of 3 portions of the pectoralis major (PM) muscle during various exercises.

BACKGROUND

A biomechanical foundation on which to base exercise prescriptions for patients after breast cancer surgery is lacking.

METHODS

An interactive, 3-D, computer graphic simulation system, developed to study biomechanical properties of the musculoskeletal system, was used to simulate movements of the glenohumeral, scapulothoracic, and scapuloclavicular joints of the shoulder, and to estimate strain in 3 portions of the pectoralis major (PM) muscle throughout the motions. The computed tomography scans of 2 male cadavers and literature review formed the basis for the estimations used in the model. Strains in the clavicular, midsternum, and abdominal regions of the PM were expressed as percent strain: [(change in muscle length/resting length) × 100]. Exercise motions were based on PM muscle anatomy and published breast cancer rehabilitation protocols.

RESULTS

Strains of the PM regions ranged from -21% shortening of the clavicular region during flexion to 55% lengthening of the abdominal region during the overhead stretch. Strain between adjacent regions was most uniform for the movement of abduction with external rotation, and least uniform with flexion.

CONCLUSION

PM muscle lengthening estimates were not linearly proportioned to shoulder joint motions, and varied for 3 portions of the PM. This information may help clinicians and researchers to estimate lengthening of PM portions throughout measurable shoulder motions.

Irradiation of normal mouse tissue increases the invasiveness of mammary cancer cells

PURPOSE

Treatment of breast tumours frequently involves irradiating the whole breast to reach malignant microfoci scattered throughout the breast. In this study, we determined whether irradiation of normal tissues could increase the invasiveness of breast cancer cells in a mouse model.

MATERIALS AND METHODS

Non-irradiated MC7-L1 mouse mammary carcinoma cells were injected subcutaneously in irradiated and non-irradiated thighs of Balb/c mice. The invasion volume, tumour volume, blood vessel permeability and interstitial volumes were monitored by magnetic resonance imaging (MRI). Slices of normal tissue invaded by cancer cells were examined by histology. Activity of matrix metalloproteinase -2 and -9 (MMP -2 and -9) in healthy and irradiated tissues was determined, and the proliferation index of the invading cancer cells was evaluated.

RESULTS

Three weeks after irradiation, enhancement of MC7-L1 cells invasiveness in irradiated thighs was already detected by MRI. The tumour invasion volume continued to extend 28- to 37-fold compared to the non-irradiated implantation site for the following three weeks, and it was associated with an increase of MMP-2 and -9 activities in healthy tissues. The interstitial volume associated with invading cancer cells was significantly larger in the pre-irradiated sites; while the blood vessels permeability was not altered. Cancer cells invading the healthy tissues were proliferating at a lower rate compared to non-invading cancer cells.

CONCLUSION

Implantation of non-irradiated mammary cancer cells in previously irradiated normal tissue enhances the invasive capacity of the mammary cancer cells and is associated with an increased activity of MMP-2 and -9 in the irradiated normal tissue.

Mammographic density as a predictor of breast cancer outcome

Evaluation of: Cil T, Fishell E, Hanna W et al.: Mammographic density and the risk of breast cancer recurrence after breast-conserving surgery. Cancer 115, 5780–5787 (2009). This clinical investigation explored mammographic density, a strong etiologic risk factor for breast cancer, as a predictor of local breast cancer recurrence. The authors reported that women with intermediate and high breast density had a significantly elevated risk of developing a local breast cancer recurrence. However, this effect was observed only among patients who had not received radiotherapy. Only two previous reports have shown that mammographic density may be a prognostic factor, but the studies disagree on the role of radiotherapy as an effect modifier. Future studies that incorporate additional risk factors, such as obesity, need to examine the role of mammographic density in larger patient populations before including breast density in treatment decision models.

p53 and gamma radiation in the normal breast

PURPOSE

With the increasing use of radiation as adjuvant therapy in breast cancer, the effects of gamma radiation on the remaining normal breast are of increasing importance. The complexities of multiple cellular types within breast tissues and the role of the pleiotropic Tumour Protein 53 (TP53, p53) protein with its downstream transcriptional targets and cellular processes may be central to the effects on residual normal breast tissues.

CONCLUSION

While a detailed understanding of p53 protein-mediated responses in normal breast tissues remains elusive, p53 appears to have a pivotal role in the effects of gamma radiation on normal breast epithelium, but not stromal cells, which may account for the differing clinical effects of gamma radiation in women treated for breast cancer.

Radiation-induced complications after breast cancer radiation therapy: a pictorial review of multimodality imaging findings

The purpose of this pictorial essay is to illustrate the multimodality imaging findings of a wide spectrum of radiation-induced complications of breast cancer in the sequence of occurrence. We have classified radiation-induced complications into three groups based on the time sequence of occurrence. Knowledge of these findings will allow for the early detection of complications as well as the ability to differentiate tumor recurrence.

Are improvements needed in the management of severe acute skin reactions following completion of breast radiotherapy? A discussion of some possible service options

Radiotherapy is a critical component for many patients undergoing treatment for breast cancer. Most patients develop some degree of acute radiation skin reaction as a result of the treatment. Acute skin reactions range from faint erythema to moist desquamation and often peak within 1 month after completion of treatment.

The emphasis of radiotherapy skincare advice is often during treatment with less attention paid to post-radiotherapy skincare. This article highlights this gap in service provision at one radiotherapy centre and demonstrates the difficulties encountered when there is an inadequate support system. Possible options are discussed for the management of skin reactions after radiotherapy and the potential implications of adopting these strategies. The pragmatic solution introduced to Addenbrookes’ Hospital was to amend patient information providing a supplementary section for health-care professionals overseeing patient care after completion of treatment. This has gone some way to addressing this issue but still has limitations.

Provision of timely and consistent skincare advice and support is vital to provide high-quality patient care. This article emphasises the importance of standardisation of radiotherapy skincare and providing an effective support network for patients after completion of radiotherapy.

Measurements of Radiation-Induced Skin Changes in Breast-Cancer Radiation Therapy Using Ultrasonic Imaging

Skin injury is a common side effect of breast-cancer radiation therapy. Although physicians often observe skin toxicity, quantifying its severity remains a challenge. We present a novel quantitative ultrasonic technique to evaluate skin changes associated with radiotherapy. An in vivo study with twelve breast-cancer patients was conducted. All patients received a standard course of post-surgery radiation therapy. Each patient received ultrasound scans to the irradiated breast and the untreated (contra-lateral) breast. Radio-frequency (RF) backscatter signals and B-mode images were acquired simultaneously. To quantify the severity of skin injury, two metrics were calculated from the RF signals: skin thickness and Pearson correlation coefficient of the subcutaneous layer. Comparing to the non-irradiated skin, the average thickness of the irradiated skin increased by 40% (p=0.005) and the average correlation coefficient of the irradiated hypodermis decreased by 35% (p=0.02). This study demonstrates the feasibility of using a non-invasive ultrasonic technique to detect and quantify radiation-induced skin changes.

The use of radiation therapy after breast-conserving surgery in hormonally treated breast cancer patients is dependent on patient age, geographic region, and surgeon specialty

BACKGROUND

The use of radiation therapy (RT) after breast-conserving surgery (BCS) is inconsistent in patients treated with hormonal therapy (HT). We sought to identify factors influencing the decision to use RT in this setting.

METHODS

Patients in the North American Fareston vs. Tamoxifen Adjuvant (NAFTA) trial who had BCS were evaluated for factors influencing the use of RT using univariate and multivariate analyses.

RESULTS

Of the 1,811 patients enrolled in the NAFTA trial, 1,222 (67.4%) had BCS. Of these, 241 (19.7%) did not have RT. There were no significant differences in tumor grade, lymphovascular invasion, estrogen receptor status, or nodal status between those who received RT and those who did not. On univariate analyses, patients who did not receive RT were more likely to be older (median 72 versus 66 years, P < .001), have larger tumors (median 1.35 versus 1.10 cm, P = .009), and be progesterone negative (18.3% versus 13.1%, P = .048). Surgeons in the West were most likely to omit RT, whereas those in the Midwest were least likely to omit it (26.7% versus 7.2%, P < .001). Surgical oncologists were more likely to omit RT after BCS than general surgeons (21.8% versus 13.7%, P < .001). Academic affiliation (P < .001), number of breast procedures performed per year (P = .017), and the percentage of breast practice (P = .019) also correlated with whether or not RT was used. On multivariate analysis, patient age (P < .001), geographic region (P = .006), and surgeon specialty (P = .027) remained significant.

CONCLUSION

Patient age, geographic region, and surgeon training influence the decision to use RT after BCS in patients receiving HT.

A multicenter randomized trial of breast intensity-modulated radiation therapy to reduce acute radiation dermatitis

PURPOSE

Dermatitis is a frequent adverse effect of adjuvant breast radiotherapy. It is more likely in full-breasted women and when the radiation is distributed nonhomogeneously in the breast. Breast intensity-modulated radiation therapy (IMRT) is a technique that ensures a more homogeneous dose distribution.

PATIENTS AND METHODS

A multicenter, double-blind, randomized clinical trial was performed to test if breast IMRT would reduce the rate of acute skin reaction (notably moist desquamation), decrease pain, and improve quality of life compared with standard radiotherapy using wedges. Patients were assessed each week during and up to 6 weeks after radiotherapy.

RESULTS

A total of 358 patients were randomly assigned between July 2003 and March 2005 in two Canadian centers, and 331 were included in the analysis. Breast IMRT significantly improved the dose distribution compared with standard radiation. This translated into a lower proportion of patients experiencing moist desquamation during or up to 6 weeks after their radiation treatment; 31.2% with IMRT compared with 47.8% with standard treatment (P = .002). A multivariate analysis found the use of breast IMRT (P = .003) and smaller breast size (P < .001) were significantly associated with a decreased risk of moist desquamation. The use of IMRT did not correlate with pain and quality of life, but the presence of moist desquamation did significantly correlate with pain (P = .002) and a reduced quality of life (P = .003).

CONCLUSION

Breast IMRT significantly reduced the occurrence of moist desquamation compared with a standard wedged technique. Moist desquamation was correlated with increased pain and reduction in the quality of life.

Characterisation of 6MV and 10MV superficial build up dosimetry in tangential beam radiography

Introduction: Although tangential radiotherapy is one of the major treatments for breast cancer, little has been done to address the skin toxicity and general dose inhomogeneity experienced in patients with larger breasts that are treated with 6MV photons. From our understanding of radiation in tissue at depth, it is proposed that 10MV photons could have a clear role in such patients through improved dose distribution. However, a greater build up depth with 10MV could mean that this energy is unacceptable.

Aims: To quantify and characterise superficial build up dosimetry in tangential breast irradiation for 6MV and 10MV photons.

Methods: Using Thermoluminescent Dosimeters (TLD’S), a comparative study was carried out investigating dose at a range of superficial depths in a phantom irradiated by tangential fields. Each delivering 2Gy for 6MV and 10MV photons.

Results: There was a 0.10Gy difference in maximum dose over a depth of 10.8 mm between 6MV and 10MV photons, along with an average difference of dose at depth of 0.09Gy.

Conclusion: Evidence has been obtained that eliminates comprise to superficial tissue if 10MV photons are used. Furthermore, reinforcement towards a more homogenous dose distribution with 10MV photons has been established.

In vitro irradiation of basement membrane enhances the invasiveness of breast cancer cells

Following removal of the primary breast tumour by conservative surgery, patients may still have additional malignant foci scattered throughout the breast. Radiation treatments are not designed to eliminate all these residual cancer cells. Rather, the radiation dose is calculated to optimise long-term results with minimal complications. In a tumour, cancer cells are surrounded by a basement membrane, which plays an important role in the regulation of gene expression. Using an invasion chamber, we have shown that irradiation before cell plating of a reconstituted basement membrane (Matrigel; Becton Dickinson, Bedford, MA, USA) increased the invasiveness of the breast cancer cells MDA-MB-231. This radiation enhancement of invasion was associated with the upregulation of the pro-invasive gene matrix metalloproteinase (MMP)-2. The expression of membrane type 1 matrix metalloproteinase (MT1-MMP) and tissue inhibitor of metalloproteinase-2 (TIMP), which are required to activate the MMP-2, were also increased. Confirming the role of MMP-2 and MT1-MMP, radiation enhancement of cancer cell invasion was prevented by an MMP-2 inhibitor and an anti-MT1-MMP antibody. This study also demonstrated that radiation can potentially enhance the invasion ability by inducing the release of pro-invasive factors stored in the Matrigel. Conversely, no enhancement of invasiveness was observed with the low metastatic cell line MCF-7. This lack of invasiveness correlated with the absence of the MMP-2 activator MT1-MMP in the MCF-7 cells. Radiotherapy is an efficient modality to treat breast cancer which could be further improved by inhibiting the pro-invasive gene upregulated by radiation.

Morbidity after breast cancer treatment and physiotherapeutic performance

Breast cancer (BC) accounts for >30% of all new cancer patients among women but with increased early detection rates and improved adjuvant therapy, the 5-year survival rate presently reaches >85%. As the number of BC survivors increases, research into the sequelae of the cancer and its treatment on quality of life is a priority. Understanding the potential complications of treatment and developing effective rehabilitation techniques can reduce the impact of such effects on activities of daily life. The aim of this review is to discuss the major sequelae of treatment for BC, and the physiotherapist's role in the prevention and treatment of such complications. Breast cancer treatment can result in pulmonary and upper extremity morbidities that may manifest either early or late. Prevention and treatment of lymphoedema, scar adherence and pulmonary complications can be achieved. Additionally pain reduction and maintenance of range of movement, muscle strength and adequate posture are parts of physiotherapy, which is an important component in the rehabilitation of women with BC.

Moving to a High-tech Approach to the Irradiation of Early Breast Cancer: Is It Possible to Balance Efficacy, Morbidity and Resource Use?

There is substantial evidence documenting the potential morbidity associated with radiotherapy in early breast cancer. An appraisal of current standard radiation practice is therefore necessary, given that women are surviving longer, have an improved quality of life, and are overcoming subsequent side-effects caused by postoperative irradiation. New technology allows the application of more complex approaches. This discussion paper considers some of the benefits of the widespread use of new complex approaches, such as intensity-modulated radiotherapy (IMRT) in the light of staffing and equipment shortfalls, and possible consequences on waiting times for treatment. The discussion is considered under the following themes: (1) which women with breast cancer benefit from complex treatment approaches? (2) What is the role of treatment accuracy in limiting morbidity? And (3) what is the potential effect of complex breast irradiation approaches on service delivery? In the UK, and globally, many departments are struggling to meet waiting-time guidelines. The use of more complex approaches for breast irradiation may increase this difficulty. However, a number of simple technical changes can be used to enhance efficacy and reduce levels of normal tissue morbidity. A sub-set of women who are at greatest risk from normal tissue morbidity or reduced cosmesis should be accurately defined in order to allow departments to plan their treatment strategies with optimal use of resources.