Current modalities of accelerated partial breast irradiation

Increased Risk for Ipsilateral Breast Tumor Recurrence in Invasive Lobular Carcinoma after Accelerated Partial Breast Irradiation Brachytherapy

BACKGROUND

The suitability criteria for accelerated partial breast irradiation (APBI) from the American Brachytherapy Society (ABS), American Society for Radiation Oncology (ASTRO), and The Groupe Européende Curiethérapie European SocieTy for Radiotherapy & Oncology (GEC-ESTRO) have significant differences.

MATERIALS AND METHODS

This is a single institution retrospective review of 946 consecutive patients with invasive breast cancer who underwent lumpectomy and APBI intracavitary brachytherapy from 2003 to 2018. Overall survival (OS), breast cancer-specific survival (BCSS), relapse-free survival (RFS), and ipsilateral breast tumor recurrence (IBTR) were estimated with Kaplan-Meier method.

RESULTS

Median follow-up time was 60.2 months. Median age was 68 years (46-94 years). The majority of patients had estrogen receptor (ER)-positive disease (94%). There were 821 (87%) cases of invasive ductal carcinoma and 68 cases (7%) of invasive lobular carcinoma (ILC). The 5-year OS, BCSS, RFS, and IBTR were 93%, 99%, 90%, and 1.5%, respectively. Upon univariate analysis, ILC (hazard ratio [HR], 4.6; p = .008) and lack of nodal evaluation (HR, 6.9; p = .01) were risk factors for IBTR. The 10-year IBTR was 2.5% for IDC and 14% for ILC. While the ABS and ASTRO criteria could not predict IBTR, the GEC-ESTRO intermediate risk group was associated with inferior IBTR (p = .04) when compared to both low risk and high risk groups. None of the suitability criteria was able to predict RFS.

CONCLUSION

These results show that APBI is an effective treatment for patients with invasive breast cancer. Expansion of the current eligibility criteria should be considered, although prospective validation is needed. Caution is required when considering APBI for patients with ILC.

IMPLICATIONS FOR PRACTICE

In a large retrospective review of 946 patients with early breast cancer treated with partial mastectomy and accelerated partial breast irradiation (APBI) intracavitary brachytherapy, this study demonstrates durable local control. Patients deemed unsuitable or high risk by the American Brachytherapy Society, American Society for Radiation Oncology, and European Society for Radiotherapy and Oncology guidelines were not at increased risk for ipsilateral breast tumor recurrence (IBTR), suggesting that expansion of the current criteria should be considered. Importantly, however, these results demonstrate that caution should be taken when considering APBI for patients with invasive lobular carcinoma, as these patients had relatively high risk for IBTR (10-year IBTR, 14%).

Radiotherapy Delivered before CDK4/6 Inhibitors Mediates Superior Therapeutic Effects in ER+ Breast Cancer

PURPOSE

Recent preclinical data suggest that cyclin-dependent kinase 4/6 (CDK4/6) inhibition may be harnessed to sensitize estrogen receptor-positive (ER⁺) breast cancer to radiotherapy. However, these findings were obtained in human ER⁺ breast cancer cell lines exposed to subclinical doses of CDK4/6 inhibitors with limited attention to treatment schedule. We investigated the activity of radiotherapy combined with the prototypic CDK4/6 inhibitor palbociclib placing emphasis on therapeutic schedule.

EXPERIMENTAL DESIGN

We combined radiotherapy and palbociclib in various doses and therapeutic schedules in human and mouse models of ER⁺ and ER-negative (ER^-) breast cancer, including an immunocompetent mouse model that recapitulates key features of human luminal B breast cancer in women. We assessed proliferation, cell death, cell-cycle control, and clonogenic survival in vitro, as well as tumor growth, overall survival, and metastatic dissemination in vivo.

RESULTS

Radiotherapy and palbociclib employed as standalone agents had partial cytostatic effects in vitro, correlating with suboptimal tumor control in vivo. However, while palbociclib delivered before focal radiotherapy provided minimal benefits as compared with either treatment alone, delivering focal radiotherapy before palbociclib mediated superior therapeutic effects, even in the absence of p53. Such superiority manifested in vitro with enhanced cytostasis and loss of clonogenic potential, as well as in vivo with improved local and systemic tumor control.

CONCLUSIONS

Our preclinical findings demonstrate that radiotherapy delivered before CDK4/6 inhibitors mediates superior antineoplastic effects compared with alternative treatment schedules, calling into question the design of clinical trials administering CDK4/6 inhibitors before radiotherapy in women with ER⁺ breast cancer.

A reliable skin toxicity predictor in permanent breast seed implant brachytherapy

PURPOSE

To establish skin dose-outcome relationships using a reliable metric in permanent breast seed implant (PBSI).

METHODS

Sixty-seven consecutive patients who underwent PBSI at our institution were included. Skin doses were calculated using two skin dose indices: maximum point dose to the skin surface, D_max, and D_0.2cc for a 2-mm internal skin rind (a surrogate to the dose to 1 cm² area of skin) from CT-based postoperative treatment plans. Toxicity data were extracted from patients' charts and photographs. The associations between skin dose and skin toxicity were investigated using the analysis of variance, and the predictive performance of skin dose measures was evaluated using receiver operating characteristic curves.

RESULTS

For acute reactions, 49.3% of patients had Grade 1, 4.5% Grade 2, and 1.5% Grade 3 toxicity. For telangiectasia at 3 years, very minor and minimally apparent telangiectasia was observed in 25% of patients. Moderate but asymptomatic telangiectasia was observed in 9.1% of cases. Both metrics were significantly associated with the occurrence of acute toxicity and telangiectasia at 3 years (p < 0.01). The predictive values for D_max and D_0.2cc were 0.779 and 0.763, respectively, (p < 0.0001) for acute skin toxicity and 0.786 and 0.810 for telangiectasia (p < 0.0002). Extreme dose outliers (up to 878 Gy) and a high variability were observed for D_max but not for D_0.2cc, illustrating the superior reliability of D_0.2cc.

CONCLUSION

D_0.2cc, as an alternate skin dose measure to D_max, is a robust metric for measuring skin dose that is simple to calculate, yet is clinically relevant and not prone to inaccuracies inherent to point dose measurement.

3 fraction pencil-beam scanning proton accelerated partial breast irradiation: early provider and patient reported outcomes of a novel regimen

Background and purpose

To report dosimetry and early adverse effects, aesthetic, and patient-reported outcomes of a prospective study of 3-fraction pencil-beam scanning (PBS) proton accelerated partial irradiation (APBI).

Materials and methods

Eligibility included women age ≥ 50 years with estrogen receptor positive (ER+), sentinel lymph node negative invasive or in-situ breast cancer measuring ≤2.5 cm. The prescription was 21.9 Gy (RBE 1.1) in 3 daily fractions to the post-operative tumor bed with a 1 cm expansion. Toxicities were collected using Common Terminology Criteria for Adverse Events (CTCAE) version 4.0, 10-point Linear Analog Scale Assessment, Patient-Reported Outcomes Version of the CTCAE, and the Harvard Breast Cosmesis Scale.

Results

Seventy-six women were treated between 2015 and 2017. The median breast volume receiving 50% of prescription or more was 28%. Median mean heart, mean ipsilateral lung, and maximum skin dose were 0 Gy, 0.1 Gy, and 20.6 Gy, respectively. With a median follow-up of 12 months, no treatment-related toxicity grade ≥ 2 has been observed. Most common grade 1 adverse events were dermatitis (68%) and skin hyperpigmentation (18%). At 12 months, the only persistent toxicities were one patient with grade 1 breast edema and one patient with a grade 1 seroma. 90% of patients reported quality of life as ≥7 out of 10 (0 indicating “as bad as it can be” and 10 indicating “as good as it can be”) and 98% of patients reported excellent or good cosmesis.

Conclusion

3-fraction PBS proton APBI is well tolerated with low rates of physician and patient reported early adverse effects. Follow-up is ongoing to assess late toxicities and disease control outcomes. Further investigation of this novel adjuvant treatment strategy is warranted.

Three-Fraction Intracavitary Accelerated Partial Breast Brachytherapy: Early Provider and Patient-Reported Outcomes of a Novel Regimen

PURPOSE

To report early adverse events and patient-reported outcomes (PROs) of 3-fraction intracavitary catheter-based partial breast brachytherapy (ICBB).

MATERIALS AND METHODS

Eligible women ≥50 years of age with ≤2.5-cm, lymph node-negative invasive or in situ breast cancer underwent breast-conserving surgery and placement of a brachytherapy applicator. ICBB was initiated on the second weekday after surgery and prescribed to 21 Gy in 3 once-daily fractions. Common Terminology Criteria for Adverse Events, version 4.0; 10-point linear analog scale assessment; the PRO version of the Common Terminology Criteria for Adverse Events; and the Harvard Breast Cosmesis Scale were used for provider and patient-reported assessments.

RESULTS

Seventy-three women were treated for invasive (79%) or in situ (21%) breast cancer. The median time to completion of surgery and radiation therapy was 6 days. After 14-months median follow-up, 2 patients (3%) had developed breast infections that resolved with oral antibiotics. There was no other treatment-associated adverse event grade ≥2. The grade 1 seroma rate at 3 months was 20%, which dropped to 8% at 12 months; no events required intervention. At 12 months, 91% of patients reported an overall quality of life score as ≥8 of 10, and patient-reported cosmesis was good or excellent in 95%. All patients are alive without relapse at the last follow-up.

CONCLUSIONS

Three-fraction ICBB is associated with low rates of early provider and patient- reported adverse events and compares favorably with early outcomes of more protracted ICBB regimens, including twice-daily (3.4 Gy × 10) fractionation studied in the National Surgical Adjuvant Breast and Bowel Project (NSABP) B-39. Further investigation is warranted.

Carbon Fiducial Image Guidance Increases the Accuracy of Lumpectomy Cavity Localization in Radiation Therapy for Breast Cancer

PURPOSE

We investigated the feasibility and accuracy of using carbon fiducials to localize the lumpectomy cavity with 2-dimensional kV imaging for early stage breast cancer radiation therapy.

METHODS AND MATERIALS

Carbon fiducials were placed intraoperatively in the periphery of the lumpectomy cavity. Nine patients received whole breast irradiation with a boost, and 2 patients received 3-dimensional conformal partial breast irradiation. A total of 89 fractions were assessed for setup errors relative to a predefined gold standard, cone beam computed tomography (CBCT) match to the lumpectomy cavity, using the following 4 setup methods: (1) Align skin tattoos with lasers; (2) match bone with 2-dimensional-2-dimensional (2D/2D) kV onboard imaging (OBI); (3) match the whole breast with CBCT; and (4) match carbon fiducials with 2D/2D kV OBI. The margin for the planning target volume (PTV) was calculated by 2 standard deviations of the setup errors, and compared among the 4 setup methods. Setup errors for patients treated with free breathing and patients with deep inspiration breath hold were also compared.

RESULTS

The carbon fiducials were sufficiently visible on OBI for matching and introduced minimal artifacts. Of the 4 alignment methods, 2D/2D OBI match to fiducials resulted in the smallest setup errors. The PTV margin was 12 mm for aligning skin tattoos using lasers, 9.2 mm for matching bone on OBI, 6.5 mm for matching breast on CBCT, and 3.5 mm for matching fiducials on 2D/2D OBI. Compared with free breathing, deep inspiration breath hold generally reduced the standard deviations of the setup errors, but further investigation would be needed.

CONCLUSIONS

Matching to carbon fiducials increased the localization accuracy to the lumpectomy cavity. This reduces residual setup error and PTV margins, facilitating tissue sparing without diminishing treatment efficacy.

Development of a 3D ultrasound guidance system for permanent breast seed implantation

PURPOSE

Permanent breast seed implantation (PBSI) is a promising radiotherapy technique for early-stage breast cancer, completed in a single visit by permanently implanting 103 Pd seeds using needles inserted through a template and guided by two-dimensional (2D) ultrasound (US). However, operator dependence has been highlighted as a limitation of this procedure. Consequently, we propose and have developed an intraoperative guidance system using three-dimensional (3D) US and an instrumented mechanical arm to provide intraoperative 3D imaging and needle template tracking.

METHODS

A mechatronic 3D US scanner reconstructs a 3D image from 150 2D images. A tracked mechanical arm mounted to the scanner locates four fiducial points on the template, registering the template to the 3D image. 3D reconstruction was validated for linear and volumetric measurement accuracy using phantoms of known geometry. In vivo breast US image quality was evaluated in a healthy volunteer. The encoded arm was calibrated and validated using a jig with divots at known locations relative to the scanner and the scanner registered to the 3D US image using intersecting strings in a fluid-filled test jig. Template registration accuracy was assessed using a machined test jig. Tracking accuracy was assessed in a liquid medium by comparing tracked and imaged needle tip positions. Finally, the system was used to guide a mock procedure in a patient-specific phantom and micro-CT imaging used to evaluate its accuracy.

RESULTS

Geometric validation showed median distances within ±1.1% of expected values and volumetric validation showed differences of ≤4.1%. Tracking arm point measurements showed an average error of 0.43 mm and 3D US volume registration showed target registration error ≤0.9 mm. Mean template registration accuracy in each axis of translation/rotation was ≤1.3 mm/1.0°. Mean needle-targeting error was 2.5 mm and 1.6° for needle tips and trajectories, respectively. Mean needle tip and angular errors of the phantom procedure were 2.1 mm and 2.6°. Modeled seed displacement of the phantom procedure showed mean error of 2.6 mm and a maximum of 3.8 mm.

CONCLUSIONS

A 3D US guidance system for PBSI has been developed. Benchtop performance and image quality in volunteer scans are satisfactory. A phantom PBSI procedure was successfully delivered using the system with maximum seed error within dosimetric benchmarks (<5 mm). Translation of the device into the clinic is forthcoming.

Cosmetic changes following surgery and accelerated partial breast irradiation using HDR interstitial brachytherapy : Evaluation by a multidisciplinary/multigender committee

BACKGROUND

Patients with early-stage breast cancer can benefit from adjuvant accelerated partial breast irradiation (APBI) following breast-conserving surgery (BCS). This work reports on cosmetic results following APBI using multicatheter high-dose-rate interstitial brachytherapy (HDR-IBT).

PATIENTS AND METHODS

Between 2006 and 2014, 114 patients received adjuvant APBI using multicatheter HDR-IBT. For each patient, two photographs were analyzed: the first was taken after surgery (baseline image) and the second at the last follow-up visit. Cosmesis was assessed by a multigender multidisciplinary team using the Harvard Breast Cosmesis Scale. Dose-volume histogram (DVH) parameters and the observed cosmetic results were investigated for potential correlations.

RESULTS

The median follow-up period was 3.5 years (range 0.6-8.5 years). The final cosmetic scores were 30% excellent, 52% good, 14.5% fair, and 3.5% poor. Comparing the baseline and follow-up photographs, 59.6% of patients had the same score, 36% had a better final score, and 4.4% had a worse final score. Only lower target dose nonuniformity ratio (DNR) values (0.3 vs. 0.26; p = 0.009) were significantly associated with improved cosmetic outcome vs. same/worse cosmesis.

CONCLUSION

APBI using multicatheter HDR-IBT adjuvant to BCS results in favorable final cosmesis. Deterioration in breast cosmesis occurs in less than 5% of patients. The final breast cosmetic outcome in patients treated with BCS and APBI using multicatheter HDR-IBT is influenced primarily by the cosmetic result of the surgery. A lower DNR value is significantly associated with a better cosmetic outcome.

[Current status of hypofractionated external beam radiotherapy for early-stage breast cancer]

The benefits of adjuvant radiotherapy following lumpectomy for early-stage breast cancer are well established. The most widely used method consists of roughly twenty-five fractions of whole-breast irradiation. In recent years, there has been a growing trend towards hypofractionated external beam radiotherapy regimens. Many of these techniques have been shown to be equivalent in terms of tumor control and cosmetic results while minimizing inconvenience and costs both to the patient and health care system. Here, we present the various hypofractionation modalities, patient selection criteria, consensus guideline recommendations and a look at future indications.

Accelerated partial breast irradiation through brachytherapy for ductal carcinoma in situ: factors influencing utilization and risks of second breast tumors

The purpose of this study was to examine influencing factors and outcomes of accelerated partial breast irradiation through brachytherapy (APBIb) versus whole breast irradiation (WBI) for ductal carcinoma in situ (DCIS). From the Surveillance Epidemiology and End Results program of the US National Cancer Institute, we identified 40,749 women who were diagnosed with first primary DCIS between 2002 and 2011 and treated with breast-conserving surgery and radiotherapy. A multi-level logistic regression analysis was performed to estimate odds ratios of APBIb use. Hazard ratios (HRs) of developing ipsilateral breast tumors (IBTs) and contralateral breast tumors (CBTs) were analyzed in 1962 patients with APBIb and 7203 propensity score-matched patients with WBI, using Cox proportional hazards regression. Overall, 2212 (4.5 %) of 40,749 women (the whole cohort) received APBIb. Factors associated with the increased use of APBIb included older age, non-Hispanic white race/ethnicity, smaller tumor size, hormone receptor positivity, comedo subtypes, and urban residence. During the 46-month follow-up, 74 (0.8 %) and 131 (1.4 %) of 9165 propensity score-matched patients developed IBTs and CBTs, respectively. Compared with WBI, APBIb was associated with a significantly increased risk of IBTs (HR 1.74; 95 % CI 1.06-2.85) but not CBTs (OR 0.91; 95 % CI 0.59-1.41). This population-based study suggests that APBIb use for DCIS was influenced by patient and tumor characteristics as well as urbanization of residence. We observed a moderately increased IBT risk associated with APBIb versus WBI, suggesting that APBIb should be used with caution for DCIS before data from randomized controlled trials with long-term follow-ups are available.

Patients' satisfaction in early breast cancer treatment: Change in treatment over time and impact of HER2-targeted therapy

Although breast cancer remains a major cause of cancer death, its related death rate has dropped in the last years through early tumor detection and better available treatments. With the development of innovative techniques and new molecules as well as new routes of administration, local treatment and adjuvant therapy of early breast cancer have evolved, from mutilating, time-consuming and/or painful procedures to breast-conservative ones, sparing healthy tissues, reducing the total dose of treatment and the treatment time which in turn reduce the occurrence and severity of toxicity. In parallel with these improvements leading to an increase in survival rate, patients' health-related quality of life has become a major concern. This review aims at describing the evolution of early breast cancer treatment, and its impact on patients' quality of life, convenience, and satisfaction, including a special insight into emerging human epidermal growth factor receptor 2 (HER2)-targeted therapy.

Intraoperative full-dose of partial breast irradiation with electrons delivered by standard linear accelerators for early breast cancer

Purpose. To assess feasibility, efficacy, toxicity, and cosmetic results of intraoperative radiotherapy (IORT) with electrons delivered by standard linear accelerators (Linacs) during breast conserving surgeries for early infiltrating breast cancer (BC) treatment. Materials and Methods. A total of 152 patients with invasive ductal carcinoma (T ≤ 3.0 cm) at low risk for local relapses were treated. All had unicentric lesions by imaging methods and negative sentinel node. After a wide local excision, 21 Gy were delivered on the parenchyma target volume with electron beams. Local recurrences (LR), survival, toxicity, and cosmetic outcomes were analyzed. Results. The median age was 58.3 years (range 40–85); median follow-up was 50.7 months (range 12–101.5). There were 5 cases with LR, 2 cases with distant metastases, and 2 cases with deaths related to BC. The cumulative incidence rates of LR, distant metastases, and BC death were 3.2%, 1.5%, and 1.5%, respectively. Complications were rare, and the cosmetic results were excellent or good in most of the patients. Conclusions. IORT with electrons delivered by standard Linacs is feasible, efficient, and well tolerated and seems to be beneficial for selected patients with early infiltrating BC.

Ten Trends Transforming Cancer Care and Their Effects on Space Planning for Academic Medical Centers

Objective:

This article aims to define the major trends currently affecting space needs for academic medical center (AMC) cancer centers. It will distinguish between the trends that promote the concentration of services with those that promote decentralization as well as identify opportunities for achieving greater effectiveness in cancer care space planning.

Background:

Changes in cancer care—higher survival rates, increased clinical trials, new technology, and changing practice models—increasingly fill hospitals’ and clinicians’ schedules and strain clinical space resources. Conflicts among these trends are concentrating some services and dispersing others. As a result, AMCs must expand and renovate intelligently to continue providing state-of-the-art, compassionate care.

Conclusions:

Although the typical AMC cancer center can expect to utilize more space than it would have 10 years ago, a deeper understanding of the cancer center enterprise can lead to opportunities for more effectively using available facility resources. Each AMC must determine for itself the appropriate balance of patient volume, clinical activity, and services between its main hospital campus and satellite branches. As well, space allocation should be flexible, as care trends, medical technology, and the provider’s own priorities shift over time. The goal isn’t necessarily more space—it’s better space.

Design, synthesis, docking study and cytotoxic activity evaluation of some novel letrozole analogs

Background

Breast cancer is the most common type of female cancer. One class of hormonal therapy for breast cancer drugs -non steroidal aromatase inhibitors- are triazole analogues. In this work, some derivatives of these drugs was designed and synthesized. All synthesized compounds were evaluated for their cytotoxic activities on breast cancer cell lines (MDA-MB-231, T47D and MCF-7).

Methods

Our synthetic route for designed compounds started from 4-bromotolunitrile which was reacted with 1H-1,2,4-triazole to afford 4-(4-cyanobenzyl)-1,2,4-triazole. The reaction of later compound with aromatic aldehydes led to formation of the designed compounds. Eleven novel derivatives 1a-k were tested for their cytotoxic activities on three human breast cancer cell lines.

Results

Among the synthesized compound, 4-[2-(3-chlorophenyl)-1-(1H-1,2,4-triazol-1-yl)ethenyl]benzonitrile (1c) showed the highest activity against MCF-7 and MDA-MB-231 cell lines and 4-[2-(4-methoxyphenyl)-1-(1H-1,2,4-triazol-1-yl)ethenyl]benzonitrile (1 h) exhibited highest activity against T47D cell line. According to cytotoxic activities results, compound 4-[2-(4-dimethylamino)-1-(1H-1,2,4-triazol-1-yl)ethenyl]benzonitrile (1 k) showed comparative activity against T47D and MDA-MB-231 cell lines with compound (1 h) and our reference drug Etoposide.

Conclusion

In the process of anti-cancer drug discovery, to find new potential anti-breast cancer agents, we designed and synthesized a novel series of letrozole analogs. Cytotoxicity evaluation revealed that compounds (1c) and (1 k) were the most potent compounds with comparative activity with Etoposide. The results revealed that π-π interactions are responsible for the enzyme inhibitions of compounds (1 c) and (1 k).

Accelerated partial irradiation for breast cancer: systematic review and meta-analysis of 8653 women in eight randomized trials

BACKGROUND AND PURPOSE

Accelerated partial breast irradiation (APBI) is the strategy that allows adjuvant treatment delivery in a shorter period of time in smaller volumes. This study was undertaken to assess the effectiveness and outcomes of APBI in breast cancer compared with whole-breast irradiation (WBI).

MATERIAL AND METHODS

Systematic review and meta-analysis of randomized controlled trials of WBI versus APBI. Two authors independently selected and assessed the studies regarding eligibility criteria.

RESULTS

Eight studies were selected. A total of 8653 patients were randomly assigned for WBI versus APBI. Six studies reported local recurrence outcomes. Two studies were matched in 5 years and only one study for different time of follow-up. Meta-analysis of two trials assessing 1407 participants showed significant difference in the WBI versus APBI group regarding the 5-year local recurrence rate (HR=4.54, 95% CI: 1.78-11.61, p=0.002). Significant difference in favor of WBI for different follow-up times was also found. No differences in nodal recurrence, systemic recurrence, overall survival and mortality rates were observed.

CONCLUSIONS

APBI is associated with higher local recurrence compared to WBI without compromising other clinical outcomes.