Three-year analysis of treatment efficacy, cosmesis, and toxicity by the American Society of Breast Surgeons MammoSite Breast Brachytherapy Registry Trial in patients treated with accelerated partial breast irradiation (APBI)

A comparative study of boost dose delivery techniques in breast cancer radiotherapy optimising efficacy and minimising toxicity

The present study aims to compare three techniques for delivering a boost absorbed dose: conventional reduced tangential (3D), volumetric modulated arc therapy (VMAT) and fields forward-planned technique boost (3DF). The study included 15 postoperative breast cancer patients who received a boost absorbed dose following breast-conserving surgery. The conformity index and homogeneity index were used to evaluate treatment outcomes, along with the average absorbed dose received by organs at risk (OAR). All the calculated dosimetric plans are carried out using Monaco Treatment Planning System (TPS). VMAT offers superior conformity, dose homogeneity and target coverage, it is associated with higher absorbed doses to OAR such as the heart and lung. In contrast, the 3D and 3DF techniques exhibit advantages in reducing absorbed doses to critical structures, potentially minimising the risk of cardiac and pulmonary complications. Each technique has its advantages and disadvantages. The choice of technique should be individualised, taking into account patient-specific factors and treatment goals and involves a multidisciplinary approach.

A prospective feasibility study of MammoSite accelerated partial breast irradiation for early breast Cancer

BACKGROUND

Accelerated partial breast irradiation is a potential alternative to standard whole breast irradiation, following breast-conserving surgery, in the management of breast cancer. The MammoSite applicator-based technique allows for the delivery of a higher dose of radiation to the tumour bed and adjacent area, over a shorter treatment period.

AIMS

To investigate the long-term feasibility of the MammoSite technique in early stage breast cancer in an Irish cohort.

METHODS

Sixty-two patients with early stage breast cancer were enrolled in this prospective study between November 2005 and October 2012 at the University Hospital Galway. A single-entry MammoSite applicator was inserted post-operatively. A CT scan was performed to assess the balloon to skin distance, the conformance of target tissue to balloon surface and balloon symmetry. A total dose of 34 Gy was delivered over 10 fractions twice daily.

RESULTS

Median follow-up was 10 years. 91.9% (57/62) completed the full course of MammoSite treatment. Technical issues with the MammoSite balloon precluded three patients from completing the full course of treatment. On last follow-up, 6.4% (4/62) of patients had developed an ipsilateral breast recurrence. Half of these recurrences occurred more than 10 years after the initial breast cancer treatment. The most common toxicities observed were fibrosis (67.7%), pain (61.3%) and skin erythema (35.5%).

CONCLUSION

The use of the MammoSite technique, as an alternative to standard whole breast irradiation, is feasible in a typical Irish clinical setting with integrated multidisciplinary team input.

Second breast-conserving therapy with interstitial brachytherapy (APBI) as a salvage treatment in ipsilateral breast tumor recurrence: a retrospective study of 40 patients

Purpose

Breast-conserving treatment (BCT) have emerged as an alternative to mastectomy in patients with ipsilateral breast tumor recurrence (IBTR). We evaluated survival outcomes and treatment-related toxicity in a series of 40 patients with IBTR, who underwent tumorectomy plus interstitial brachytherapy (APBI) as a salvage treatment.

Material and methods

Retrospective analysis included 40 patients diagnosed with IBTR and treated with intraoperative (26 patients) or post-operative (14 patients) multicatheter brachytherapy for APBI at our institution between June 2002 and October 2017. We assessed cosmesis, toxicity, overall survival (OS), and cancer-specific survival (CSS).

Results

Tumorectomy was performed in all cases, including intraoperative tumor margin assessment and sentinel node biopsy. Median age was 65 years (range, 41-92). The total prescribed dose was 32 Gy (8 fractions) in 19 patients and 34 Gy (10 fractions) in 20 patients. One elderly patient (age 92) received a single fraction of 16 Gy. Median follow-up was 61.5 months (range, 6-153). A median of 14 tubes were inserted. Mean treated V₁₀₀ was 115 cc. Two patients developed a second relapse at 3 and 5 years after salvage treatment: one patient underwent salvage mastectomy and remains alive 10 years after brachytherapy, and the second one developed both local relapse and bone metastasis. The disease is stable at present. Five-year OS and CSS rates were 85.3% and 97.5%, respectively. Two patients died from cancer-related causes. Acute and late toxicity rates were low; seven patients developed acute infectious mastitis. Late fibrosis > grade 3 and late mastitis were observed in 14 and 6 cases, respectively.

Conclusions

Second BCT with APBI as a salvage treatment in ipsilateral breast recurrence achieves good local disease control, with a satisfactory toxicity profile compared to mastectomy. This approach seems to be safe and effective, although more data from randomized trials are needed.

Advantages of intraoperative implant for interstitial brachytherapy for accelerated partial breast irradiation either frail patients with early-stage disease or in locally recurrent breast cancer

Purpose

To describe the intraoperative multicatheter implantation technique for accelerated partial breast irradiation (APBI) delivered with high-dose-rate brachytherapy (HDR-BT). Secondarily, to evaluate outcomes and toxicity in a series of 83 patients treated with this technique at our institution.

Material and methods

Retrospective analysis of a series of patients treated with HDR-BT APBI after intraoperative multicatheter interstitial implant between November 2006 and June 2017 at our institution. We assessed cosmesis, toxicity, overall survival (OS), and disease-free survival (DFS).

Results

Eighty-three patients were included: 59 patients (71.1%) with primary early-stage breast cancer and 24 (28.9%) with locally recurrent breast cancer. Tumorectomy was performed in all cases, with intraoperative tumor margin assessment and sentinel node biopsy. Median age was 82 years (range, 44-92). The total prescribed dose was 32 Gy (8 treatment fractions) in 60 patients (72.3%), and 34 Gy (10 fractions) in 23 patients (27.7%). Median follow-up was 40 months (range, 1-136 months). Three-year OS and DFS in the recurrent and primary cancer groups were 87% vs. 89%, and 96 % vs. 97.8%, respectively. Five patients died from non-cancer related causes. No local relapses were observed. Rates of acute and late toxicity were low in both groups. The cosmesis was good or excellent in most of patients treated for primary disease; in patients who underwent salvage brachytherapy for local recurrence, cosmesis was good in 49 patients and fair in 6.

Conclusions

This technique, although time-consuming, achieves good local disease control with a satisfactory toxicity profile in both early-stage and local recurrent breast cancer patients. It may be especially suitable for frail patients.

New Breast Cancer Radiotherapy Technology Confers Higher Complications and Costs Before Effectiveness Proven: A Medicare Data Analysis

A new breast cancer treatment, brachytherapy-based accelerated partial breast radiotherapy (RT), was adopted before long-term effectiveness evidence, potentially increasing morbidity and costs compared with whole breast RT. The aim of this study was to estimate complication rates and RT-specific and 1-year costs for a cohort of female Medicare beneficiaries diagnosed with breast cancer (N = 47 969). We analyzed 2005-2007 Medicare claims using multivariable logistic regression for complications and generalized linear models (log link, gamma distribution) for costs. Overall, 11% (n = 5296) underwent brachytherapy-based RT; 9.4% had complications. Odds of any complication were higher (odds ratio [OR]: 1.62; 95% confidence interval [CI]: 1.49-1.76) for brachytherapy versus whole breast RT, similarly to seroma (OR: 2.85; 95% CI: 1.97-4.13), wound complication/infection (OR: 1.72; 95% CI: 1.52-1.95), cellulitis (OR: 1.48; 95% CI: 1.27-1.73), and necrosis (OR: 2.07; 95% CI: 1.55-2.75). Mean RT-specific and 1-year total costs for whole breast RT were $6375, and $19 917, $4886, and $4803 lower than brachytherapy ( P < .0001). Multivariable analyses indicated brachytherapy yielded 76% higher RT costs (risk ratio: 1.76; 95% CI: 1.74-1.78, P < .0001) compared with whole breast RT. Brachytherapy had higher complications and costs before long-term evidence proved its effectiveness. Policies should require treatment registries with reimbursement incentives to capture surveillance data for new technologies.

Breast Cancer Patients' Preferences for Adjuvant Radiotherapy Post Lumpectomy: Whole Breast Irradiation vs. Partial Breast Irradiation-Single Institutional Study

This study was conducted to elucidate patients with early breast cancer preference for standard whole breast irradiation (WBI) or partial breast irradiation (PBI) following lumpectomy, as well as identify important factors for patients when making their treatment decisions. Based on relevant literature and ASTRO consensus statement guidelines, an educational tool and questionnaire were developed. Consenting, eligible women reviewed the educational tool and completed the trade-off questionnaire. Descriptive statistics were calculated, as well as chi-squares and a logistic regression model. Of the 90 patients who completed the study, 62 % preferred WBI, 30 % preferred PBI, 4 % required more information, and 3 % had no preferences. Of the patients who chose WBI, 58 % preferred hypofractionated RT, whereas 25 % preferred the conventional RT regimen. The majority of patients rated recurrence rate [WBI = 55/55 (100 %), PBI = 26/26 (100 %)] and survival [WBI = 54/55 (98 %), PBI = 26/26 (100 %)] as important factors contributing to their choice of treatment preference. Financial factors [WBI = 21/55 (38 %), PBI = 14/26 (53 %)] and convenience [WBI = 36/54 (67 %), PBI = 18/26 (69 %)] were rated as important less frequently. Significantly, more patients who preferred WBI also rated standard method of treatment as important when compared to patients who preferred PBI [WBI = 52/54 (96 %), PBI = 16/26 (61 %), χ ² = 16.63, p = 0.001]. The majority of patients with early breast cancer who were surveyed for this study preferred WBI as an adjuvant treatment post lumpectomy, yet there was a sizeable minority who preferred PBI. This was associated with the importance patients place on standard treatment. These results will help medical professionals treat patients according to patient values.

Advancements and Personalization of Breast Cancer Treatment Strategies in Radiation Therapy

Significant technologic advances in radiation treatment delivery now allow for more personalized delivery considerations which incorporate individual patient characteristics (such as tumor location and patient anatomy) and more precise delivery in the breast conservation or post-mastectomy setting. The combined advancements with other treatment modalities (i.e., systemic therapy, surgical management) have had direct effects on local-regional management and outcomes such that currently, local-regional relapses after definitive treatment for localized disease are now rarely experienced. Recent advances in the radiation therapy field have come from careful patient selection for a variety of three-dimensional treatment delivery techniques and alternatives to conventional tangential radiation. These advances have been demonstrated to diminished acute/long-term toxicity, minimized dose to surrounding normal tissue structures such as the heart and lung, and ultimately result in an improvement in the therapeutic ratio for radiation treatment. This chapter discusses recent radiation innovations and appropriate patient selection for their application, for a more personalized approach to radiation therapy for breast cancer patients.

Outcomes by molecular subtype after accelerated partial breast irradiation using single-entry catheters

PURPOSE

Tumor biology is being recognized as an important indicator of prognosis and risk of locoregional recurrence. Here, we determine actuarial recurrence rates by approximated molecular subtype for women treated with single-entry catheter accelerated partial breast irradiation (sAPBI).

METHODS AND MATERIALS

One thousand four hundred eighty-six women with invasive cancer having known ER, PR, and Her2 status and at least 1-year of followup were treated using MammoSite, Contura, or SAVI sAPBI from 2002 to 2014 at our institution. Actuarial recurrence rates were determined for the following four approximated molecular subtypes using the Kaplan-Meier method: luminal A (n = 1081), luminal B (n = 164), Her2 (n = 123), and triple-negative breast cancer (TNBC; n = 118).

RESULTS

With a median followup time of 3.3 years (range 1-13.6 years), the 5-year in-breast tumor recurrence rate was 2.6% overall, 2.1% for luminal A, 1.5% for luminal B, 4.9% for Her2, and 5.4% for TNBC. Luminal A and B subtypes, as compared with the more aggressive Her2 and TNBC subtypes combined, demonstrated lower 5-year in-breast tumor recurrence (2.1% vs. 5.1%, p = 0.021). The 5-year regional nodal recurrence rate was 1.4% overall, 1.4% for luminal A, 0% for luminal B, 1% for Her2, and 4.2% for TNBC. The 5-year locoregional control is 97.3% for luminal breast cancers and 93.8% for the more aggressive Her2 and TNBC subtypes collectively.

CONCLUSIONS

Luminal cancers demonstrated excellent 5-year locoregional control with sAPBI. Although caution should be used when treating patients with the more aggressive Her2 and TNBC subtypes, these subtypes have demonstrated higher LRR with mastectomy and whole-breast irradiation. Further randomized comparisons are needed to determine the optimal treatment for these higher risk patients.

Survival after Breast-Conserving Surgery with Whole Breast or Partial Breast Irradiation in Women with Early Stage Breast Cancer: A SEER Data-base Analysis

Randomized clinical trials have demonstrated equivalency in survival outcomes for early stage breast cancer patients treated with either mastectomy or breast-conserving surgery (BCS) with radiation. Recent, state-level data confirm comparable survival outcomes. Using Surveillance Epidemiology and End Research (SEER) data, we sought to evaluate survival outcomes among patients with early stage breast cancer treated with mastectomy, BCS with whole breast irradiation (BCS + WBI), or BCS with accelerated partial breast irradiation (BCS + APBI). Data on women 50 years or older diagnosed with a node negative invasive breast cancer (≤3 cm in size) between 1995 and 2009 were extracted from the SEER data base. Women treated with mastectomy alone or BCS with radiation were eligible for analysis. Kaplan-Meier estimates and Cox proportional hazard models were used to compare overall survival (OS) and cancer-specific survival (CSS) among the treatment groups. 150,171 women fulfilled inclusion criteria. OS was significantly improved among women treated with BCS and WBI or BCS and APBI compared to mastectomy alone. Adjusted hazard ratios for death in BCS with WBI or APBI (versus mastectomy alone) were 0.73 (95% CI: 0.71, 0.76) and 0.68 (95% CI: 0.58, 0.79), respectively. Adjusted CSS was also significantly improved in patients treated with BCS and WBI (HR 0.80, 95% CI: 0.76, 0.85) as compared to mastectomy. BCS with radiation (WBI or APBI) was associated with significantly improved OS and CSS, versus mastectomy alone. These results support the use of BCS with WBI or APBI (in well selected patients) for the treatment of breast cancer.

A Single-Site Retrospective, Nonrandomized Study of Accelerated Partial Breast Irradiation Brachytherapy for Early-Stage Breast Cancer Treatment to Evaluate Local Tumor Control, Cosmetic Outcome, and Toxicities

Purpose:

To evaluate the efficacy and safety of the accelerated partial breast irradiation brachytherapy with a combination of applicators at a community hospital cancer center.

Methods and Materials:

Between 2005 and 2009, 120 patients with early-stage breast cancer were being followed after treatment with accelerated partial breast irradiation brachytherapy using MammoSite, single or multilumen balloon, or Contura multilumen balloon. After their lumpectomy surgery, each patient was treated with Ir-192 high-dose rate unit following radiation therapy oncology group 0413 guidelines. The patients had multiple follow-ups at 6 months, 1 year, 2 years, 3 years, or more.

Results:

Based on the Harvard Breast Cosmesis Scale, 95.00% of patients described their cosmetic evaluation as the treated breast essentially the same as the opposite side (excellent) or minimal but identifiable effects were noticed from radiation (good). After a median follow-up of 36 months, the local recurrence rate was 1.66% and a disease-free survival is 98.3%. Forty-two patients reported 85 adverse events, which were fibrosis: 24.70%, hyperpigmentation: 20.00%, radiation skin reaction: 7.05%, seroma: 7.05%, breast pain: 7.05%, erythema: 5.88%, and other events were less than 5.00%. Of all the adverse events recorded, grade 1 to 3 events are 95.29% (n = 81), 2.35% (n = 2), and 2.35% (n = 2). There was no grade 4 or 5 events recorded.

Conclusions:

Our study has shown promising results for delivering radiation with MammoSite, single or multilumen balloon, or Contura multilumen balloon and has been successful in achieving local control in patients with early-stage breast cancer.

Comparative dosimetric findings using accelerated partial breast irradiation across five catheter subtypes

Purpose

Accelerated partial breast irradiation (APBI) with balloon and strut adjusted volume implants (SAVI) show promising results with excellent tumor control and minimal toxicity. Knowing the factors that contribute to a high skin dose, rib dose, and D₉₅ coverage may reduce toxicity, improve tumor control, and help properly predict patient outcomes following APBI.

Methods and materials

A retrospective analysis of 594 patients treated with brachytherapy based APBI at a single institution from May 2008 to September 2014 was grouped by applicator subtype. Patients were treated to a total of 34 Gy (3.4 Gy x 10 fractions over 5 days delivered BID) targeting a planning target volume (PTV) 1.0 cm beyond the lumpectomy cavity using a high dose rate source.

Results

SAVI devices had the lowest statistically significant values of D_maxSkin (81.00 ± 29.83), highest values of D₉₀ (101.50 ± 3.66), and D₉₅ (96.09 ± 4.55). SAVI-mini devices had the lowest statistically significant values of D_maxRib (77.66 ± 32.92) and smallest V₁₅₀ (18.01 ± 3.39). Multi-lumen balloons were able to obtain the smallest V₂₀₀ (5.89 ± 2.21). Strut-based applicators were more likely to achieve a D_maxSkin and a D_maxRib less than or equal to 100 %. The effect of PTV on V₁₅₀ showed a strong positive relationship (p < .001). PTV and D_maxSkin showed a weak negative relationship in multi-lumen applicators (p = .016) and SAVI-mini devices (p < .001). PTV and D_maxRib showed a weak negative relationship in multi-lumen applicators (p = .009), SAVI devices (p < .001), and SAVI-mini devices (p < .001).

Conclusion

PTV volume is strongly correlated with V₁₅₀ in all devices and V₂₀₀ in strut based devices. Larger PTV volumes result in greater V₁₅₀ and V₂₀₀, which could help predict potential risks for hotspots and resulting toxicities in these devices. PTV volume is also weakly negatively correlated with max skin dose and max rib dose, meaning that as the PTV volumes increase one can expect slightly smaller max skin and rib doses. Strut based applicators are significantly more effective in keeping skin and rib dose constraints under 125 and 100 % when compared to any balloon based applicator.

Changes in brachytherapy-based APBI patient selection immediately before and after publication of the ASTRO consensus statement

PURPOSE

In July 2009, American Society of Radiation Oncology (ASTRO) released a consensus statement (CS) to guide patient selection for accelerated partial breast irradiation (APBI). The goal of this study was to examine how practice patterns changed following the guideline's release.

METHODS

The Surveillance, Epidemiology, and End Results database was queried from 2008 to 2010 for females aged ≥20 years receiving breast conservation via brachytherapy. Among the APBI cohort, characteristics and CS grouping ("suitable," "cautionary," or "unsuitable") of patients receiving APBI in the 18 months before (January 2008 to June 2009) and after (July 2009 to December 2010) guideline publication were analyzed.

RESULTS

A total of 87,528 patients undergoing breast conservation therapy were identified. Of this, 4,253 patients (4.9%) received brachytherapy-based APBI. Limiting the analysis to patients not missing data that would affect their CS classification rendered 3,828 patients. The proportion of breast conservation patients receiving brachytherapy-based APBI before and after CS release remained the same (4.9% vs. 4.8%, p = 0.36). Among patients receiving brachytherapy-based APBI, the unsuitable category decreased (15.8 vs. 11.1%, p < 0.01), whereas the suitable category increased (37.7% vs. 42.1%, p = 0.03), and the cautionary category was stable (46.5% vs. 46.7% p = 0.90) after guideline publication. Joinpoint regression analysis failed to reveal that the changes in practice patterns corresponded with the CS publication date.

CONCLUSIONS

The period before and after publication of the ASTRO CS was associated with a decrease in "unsuitable" patients and an increase in "suitable" patients being treated with brachytherapy-based APBI. This trend began before guideline release and thus cannot be definitively attributed to the ASTRO CS.

Techniques for intraoperative radiation therapy for early-stage breast carcinoma

ABSTRACT 

Intraoperative radiation therapy (IORT) is a method of accelerated partial breast irradiation developed to replace other longer courses of radiotherapy with a single radiation session administered at the time of breast-conserving surgery. The purpose of this review is to summarize the advantages and disadvantages of breast IORT techniques that are currently available, as well to consider potential alternative techniques for breast IORT or ultra-short course breast radiotherapy. Furthermore, we highlight the published outcomes for the IORT treatment approaches including: electron therapy, superficial photon therapy and other techniques. Potential future directions of IORT are explored including novel IORT techniques utilizing intraoperative brachytherapy with in-room imaging and rapid treatment planning.

Multi-axis dose accumulation of noninvasive image-guided breast brachytherapy through biomechanical modeling of tissue deformation using the finite element method

PURPOSE

Noninvasive image-guided breast brachytherapy delivers conformal HDR (192)Ir brachytherapy treatments with the breast compressed, and treated in the cranial-caudal and medial-lateral directions. This technique subjects breast tissue to extreme deformations not observed for other disease sites. Given that, commercially-available software for deformable image registration cannot accurately co-register image sets obtained in these two states, a finite element analysis based on a biomechanical model was developed to deform dose distributions for each compression circumstance for dose summation.

MATERIAL AND METHODS

The model assumed the breast was under planar stress with values of 30 kPa for Young's modulus and 0.3 for Poisson's ratio. Dose distributions from round and skin-dose optimized applicators in cranial-caudal and medial-lateral compressions were deformed using 0.1 cm planar resolution. Dose distributions, skin doses, and dose-volume histograms were generated. Results were examined as a function of breast thickness, applicator size, target size, and offset distance from the center.

RESULTS

Over the range of examined thicknesses, target size increased several millimeters as compression thickness decreased. This trend increased with increasing offset distances. Applicator size minimally affected target coverage, until applicator size was less than the compressed target size. In all cases, with an applicator larger or equal to the compressed target size, > 90% of the target covered by > 90% of the prescription dose. In all cases, dose coverage became less uniform as offset distance increased and average dose increased. This effect was more pronounced for smaller target-applicator combinations.

CONCLUSIONS

The model exhibited skin dose trends that matched MC-generated benchmarking results within 2% and clinical observations over a similar range of breast thicknesses and target sizes. The model provided quantitative insight on dosimetric treatment variables over a range of clinical circumstances. These findings highlight the need for careful target localization and accurate identification of compression thickness and target offset.

Long-term results from the Contura multilumen balloon breast brachytherapy catheter phase 4 registry trial

PURPOSE

To describe the long-term outcomes from a completed, multi-institutional phase 4 registry trial using the Contura multilumen balloon (CMLB) breast brachytherapy catheter to deliver accelerated partial breast irradiation (APBI) in patients with early-stage breast cancer.

METHODS AND MATERIALS

Three hundred forty-two evaluable patients were enrolled by 23 institutions between January 2008 and February 2011. All patients received 34 Gy in 10 fractions, delivered twice daily. Rigorous target coverage and normal tissue dose constraints were observed.

RESULTS

The median follow-up time was 36 months (range, 1-54 months). For the entire patient cohort of 342 patients, 10 patients experienced an ipsilateral breast tumor recurrence (IBTR). Eight of these IBTR were classified as true recurrences/marginal miss (TRMM), and 2 were elsewhere failures (EF). Local recurrence-free survival was 97.8% at 3 years. For the entire cohort, 88% of patients had good to excellent overall cosmesis. The overall incidence of infection was 8.5%. Symptomatic seroma was reported in only 4.4% of patients. A separate analysis was performed to determine whether improved outcomes would be observed for patients treated at high-volume centers with extensive brachytherapy experience. Three IBTR were observed in this cohort, only 1 of which was classified as a TRMM. Local recurrence-free survival at high-volume centers was 98.1% at 3 years. Overall cosmetic outcome and toxicity were superior in patients treated at high-volume centers. In these patients, 95% had good to excellent overall cosmesis. Infection was observed in only 2.9% of patients, and symptomatic seroma was reported in only 1.9%.

CONCLUSION

Use of the CMLB for APBI delivery is associated with acceptable long-term local control and toxicity. Local recurrence-free survival was 97.8% at 3 years. Significant (grade 3) toxicity was uncommon, and no grade 4 toxicity was observed. Treatment at high-volume centers was associated with decreased late toxicity.

Diffusion of accelerated partial breast radiotherapy in the United States: physician-level and patient-level analyses

PURPOSE

To evaluate diffusion of brachytherapy-based accelerated partial breast radiotherapy (RT) in the United States, a new breast cancer treatment requiring 5 days twice daily, rather than daily treatment for 6-7 weeks. It has limited long-term effectiveness data compared with standard whole breast RT.

DATA AND METHODS

We used 2005-2008 Medicare claims for female Medicare beneficiaries receiving RT after breast-conserving surgery merged with physician and area-based data (n=74,254 patient-subjects; n=1901 physicians), applying logistic regression to estimate: (1) proportion of patients for whom the radiation oncologist used brachytherapy-based accelerated RT, and (2) probability a patient received brachytherapy-based accelerated RT, clustering on physician.

RESULTS

Use of accelerated partial breast RT increased over time (8% in 2005 to 17% in 2008). Physician-level analysis indicates rural physicians were less likely to perform accelerated RT [odds ratio (OR): 0.35-0.49; P<0.002)]; as were those licensed 20+years [OR: 0.54; 95% confidence interval (CI), 0.39-0.74]. Overall, 11.7% of patients received accelerated RT. Treatment post 2005 was associated with increasing odds of receiving accelerated RT (P<0.0001). Older age was associated with lower odds of receiving accelerated RT (reference, 66-69 years old, OR: 0.90, P<0.006), as was black (OR: 0.73;95% CI, 0.63-0.85) or other race (OR: 0.80; 95% CI, 0.65-1.00), living in rural areas (OR: 0.8; P<0.0001), or seeing an older physician [20+years postgraduation (OR: 0.7; 95% CI, 0.5-0.9)]. Patients living in counties with more hospitals with advanced RT facilities were more likely to undergo accelerated RT (OR: 1.4; 95% CI, 1.1-1.8).

DISCUSSION

This new technology appears to be in the early phase of diffusion across the United States and is more rapidly being taken up in younger, white patients living in urban and suburban areas with availability of advanced RT facilities. Rural and older patient populations are not tending to undergo the treatment.

Current role of modern radiotherapy techniques in the management of breast cancer

Breast cancer is the most common type of malignancy in females. Advances in systemic therapies and radiotherapy (RT) provided long survival rates in breast cancer patients. RT has a major role in the management of breast cancer. During the past 15 years several developments took place in the field of imaging and irradiation techniques, intensity modulated RT, hypofractionation and partial-breast irradiation. Currently, improvements in the RT technology allow us a subsequent decrease in the treatment-related complications such as fibrosis and long-term cardiac toxicity while improving the loco-regional control rates and cosmetic results. Thus, it is crucial that modern radiotherapy techniques should be carried out with maximum care and efficiency. Several randomized trials provided evidence for the feasibility of modern radiotherapy techniques in the management of breast cancer. However, the role of modern radiotherapy techniques in the management of breast cancer will continue to be defined by the mature results of randomized trials. Current review will provide an up-to-date evidence based data on the role of modern radiotherapy techniques in the management of breast cancer.

Decision to Adopt Medical Technology

Objective. To understand decision making concerning adoption and nonadoption of accelerated partial breast radiotherapy (RT) prior to long-term randomized trial evidence. Methods. A total of 36 radiation oncologists and surgeons were recruited through purposive and snowball sampling strategies from September 2010 through January 2013. Semistructured phone interviews were conducted and audio-recorded and lasted 20–45 minutes. Qualitative analysis was conducted using a framework approach, iteratively exploring key concepts and emerging issues raised by subjects. Interviews were transcribed and imported into Atlas.ti v6. Transcripts were independently coded by 3 researchers shortly after each interview, followed by consensus development on each coded transcript. Barriers and facilitators of adoption, practice patterns, and informational/educational sources concerning accelerated partial breast RT were all assessed to determine major themes. Results. Nearly half of physicians were surgeons (47%), and half were radiation oncologists (53%), with 61% overall in urban settings. Twenty-nine of the 36 physicians interviewed used brachytherapy-based partial breast RT. Five major factors were involved in physicians’ decisions to adopt accelerated partial breast RT: facilitators encouraging adoption (e.g., enthusiastic colleagues and patient convenience), financial and prestige incentives, pressures to adopt (e.g., potential declines in referrals), judgment concerning acceptable level of scientific evidence, and barriers (e.g., not having appropriate machinery or referral mechanism in place). If technology was adopted, clinical guideline adherence varied. Conclusions. Technology adoption is based on financial and social pressures, along with often-limited scientific evidence and what seems “best” for patients. For technology adoption and diffusion to be rational and evidence-based, we must encourage appropriate financial payment models to curb use outside of research studies and promote development of additional treatment registries until sufficient evidence is gathered.

Transforming growth factor β-1 (TGF-β1) is a serum biomarker of radiation induced fibrosis in patients treated with intracavitary accelerated partial breast irradiation: preliminary results of a prospective study

PURPOSE

To examine a relationship between serum transforming growth factor β -1 (TGF-β1) values and radiation-induced fibrosis (RIF).

METHODS AND MATERIALS

We conducted a prospective analysis of the development of RIF in 39 women with American Joint Committee on Cancer stage 0-I breast cancer treated with lumpectomy and accelerated partial breast irradiation via intracavitary brachytherapy (IBAPBI). An enzyme-linked immunoassay (Quantikine, R&D, Minneapolis, MN) was used to measure serum TGF-β1 before surgery, before IBAPBI, and during IBAPBI. Blood samples for TGF-β1 were also collected from 15 healthy, nontreated women (controls). The previously validated tissue compliance meter (TCM) was used to objectively assess RIF.

RESULTS

The median time to follow-up for 39 patients was 44 months (range, 5-59 months). RIF was graded by the TCM scale as 0, 1, 2, and 3 in 5 of 20 patients (25%), 6 of 20 patients (30%), 5 of 20 patients (25%), and 4 of 20 patients (20%), respectively. The mean serum TGF-β1 values were significantly higher in patients before surgery than in disease-free controls, as follows: all cancer patients (30,201 ± 5889 pg/mL, P=.02); patients with any type of RIF (32,273 ± 5016 pg/mL, P<.0001); and women with moderate to severe RIF (34,462 ± 4713 pg/mL, P<0.0001). Patients with moderate to severe RIF had significantly elevated TGF-β1 levels when compared with those with none to mild RIF before surgery (P=.0014) during IBAPBI (P≤0001), and the elevation persisted at 6 months (P≤.001), 12 months (P≤.001), 18 months (P≤.001), and 24 months (P=.12). A receiver operating characteristic (ROC) curve of TGF-β1 values predicting moderate to severe RIF was generated with an area under the curve (AUC)ROC of 0.867 (95% confidence interval 0.700-1.000). The TGF-β1 threshold cutoff was determined to be 31,000 pg/mL, with associated sensitivity and specificity of 77.8% and 90.0%, respectively.

CONCLUSIONS

TGF-β1 levels correlate with the development of moderate to severe RIF. The pre-IBAPBI mean TGF-β1 levels can serve as an early biomarker for the development of moderate to severe RIF after IBAPBI.

The RSSearch™ Registry: patterns of care and outcomes research on patients treated with stereotactic radiosurgery and stereotactic body radiotherapy

BACKGROUND

The RSSearch™ Registry is a multi-institutional, observational, ongoing registry established to standardize data collection from patients treated with stereotactic radiosurgery (SRS) and/or stereotactic body radiotherapy (SBRT). This report describes the design, patient demographics, lesion characteristics, and SRS/SBRT treatment patterns in RSSearch™. Illustrative patient-related outcomes are also presented for two common treatment sites--brain metastases and liver metastases.

MATERIALS AND METHODS

Thirty-nine US centers participated in RSSearch™. Patients screened for SRS/SBRT were eligible to be enrolled. Descriptive analyses were performed to assess patient characteristics, physician treatment practices, and clinical outcomes. Kaplan-Meier analysis was used to determine overall survival (OS), local progression-free (LPFS), and distant disease-free survival (DDFS).

RESULTS

From January, 2008-January, 2013, 11,457 patients were enrolled. The median age was 67 years (range 7-100 years); 51% male and 49% female. Forty-six percent had no prior treatment, 22% had received chemotherapy, 19% radiation therapy and 17% surgery. There were 11,820 lesions from 65 treatment locations; 54% extracranial and 46% intracranial. The most common treatment locations were brain/cranial nerve/spinal cord, lung, prostate and liver. Metastatic lesions accounted for the majority of cases (41.6%), followed by primary malignant (32.9%), benign (10.9%), recurrent (9.4%), and functional diseases (4.3%). SRS/SBRT was used with a curative intent in 39.8% and palliative care in 44.8% of cases. The median dose for all lesions was 30 Gy (range < 1-96.7 Gy) delivered in a median number of 3 fractions. The median dose for lesions in the brain/cranial nerve/spinal cord, lung, liver, pancreas and prostate was 24, 54, 45, 29 and 36.25 Gy, respectively. In a subset analysis of 799 patients with 952 brain metastases, median OS was 8 months. For patients with a Karnofsky performance score (KPS) > 70, OS was 11 months vs. 4 months for KPS ≤ 70. Six-month and 12-month local control was 79% and 61%, respectively for patients with KPS ≤ 70, and 85% and 74%, respectively for patients with KPS > 70. In a second subset analysis including 174 patients with 204 liver metastases, median OS was 22 months. At 1-year, LPFS and DDFS rates were 74% and 53%, respectively.

LPFS CONCLUSION

This study demonstrates that collective patterns of care and outcomes research for SRS/SBRT can be performed and reported from data entered by users in a common database. The RSSearch™ dataset represents SRS/SBRT practices in a real world setting, providing a useful resource for expanding knowledge of SRS/SBRT treatment patterns and outcomes and generating robust hypotheses for randomized clinical studies.

Fat Necrosis of the Breast Following Folinic Acid Extravasation

Case Report: We report here on a 58-year-old patient with abnormal findings in the left breast on screening mammography (October 2012). In May 2008 the patient was diagnosed with rectal cancer, subsequently treated by surgical resection followed by radiochemotherapy. In September 2011 the patient was diagnosed with peritoneal cancer. Extravasation of folinic acid occurred during palliative chemotherapy, which was delivered through a surgically implanted port, placed prepectorally on the left side. The patient had not previously undergone breast surgery. The abnormal finding in the left breast was located at the 1-2 o'clock position. The mammogram showed extensive hyperdense nodules with predominantly round, fine granular calcifications. On sonography, the findings presented as a hypoechogenic, inhomogenous, partially diffuse, partly solid, partly cystic mass with individual calcifications and reduced echogenicity in the dorsal aspect. Strong densification of the left breast was found at the corresponding position on palpation. On computed tomography (CT) done during follow-up for rectal cancer, new streaky/pitted densifications were noted in the left breast. Based on the patient's previous history and the results of the breast diagnostics a diagnosis of extensive fat necrosis after folinic acid extravasation was made. No further measures were taken. The patient will continue to be screened using mammography. Conclusion: A good knowledge of the mammographic and sonographic features of fat necrosis can reduce the number of unnecessary biopsies. Careful consideration of the patient's prior medical history is very important in breast diagnostics and may often be decisive for the correct diagnosis.

Brachytherapy in accelerated partial breast irradiation (APBI) - review of treatment methods

Breast conserving surgery (BCS) with following radiotherapy (EBRT) of the conserved breast became widely accepted in the last decades as the treatment of early invasive breast cancer. In an early stage of breast cancer, research has shown that the area requiring radiation treatment to prevent cancer from local recurrence is the breast tissue that surrounds the area where the initial cancer was removed. Accelerated partial breast irradiation (APBI) is an approach that treats only the lumpectomy bed with 1-2 cm margin, rather than the whole breast and as a result allows accelerated delivery of the radiation dose in four to five days. Published results of APBI are very promising. It is evident that APBI will play a role in the management of a selected group of early breast cancer. We discuss current status, indications, technical aspects and recently published results of APBI using different brachytherapy techniques.

Ductal carcinoma in situ: recent advances and future prospects

Introduction. This article reviews current management strategies for DCIS in the context of recent randomised trials, including the role of sentinel lymph node biopsy (SLNB), adjuvant radiotherapy (RT) and endocrine treatment. Methods. Literature review facilitated by Medline, PubMed, Embase and Cochrane databases. Results. DCIS should be managed in the context of a multidisciplinary team. Local control depends upon clear surgical margins (at least 2 mm is generally acceptable). SLNB is not routine, but can be considered in patients undergoing mastectomy (Mx) with risk factors for occult invasion. RT following BCS significantly reduces local recurrence (LR), particularly in those at high-risk. There remains a lack of level-1 evidence supporting omission of adjuvant RT in selected low-risk cases. Large, multi-centric or recurrent lesions should be treated by Mx and immediate reconstruction should be discussed. Adjuvant hormonal treatment may reduce the risk of LR in selected cases with hormone sensitive disease. Conclusion. Further research is required to determine the role of new RT regimes and endocrine therapies. Biological profiling and molecular analysis represent an opportunity to improve our understanding of tumour biology in DCIS to rationalise treatment. Reliable identification of low-risk lesions could allow treatment to be less radical.

Radiation techniques used in patients with breast cancer: Results of a survey in Spain

AIM

To evaluate the resources and techniques used in the irradiation of patients with breast cancer after lumpectomy or mastectomy and the status of implementation of new techniques and therapeutic schedules in our country.

BACKGROUND

The demand for cancer care has increased among the Spanish population, as long as cancer treatment innovations have proliferated. Radiation therapy in breast cancer has evolved exponentially in recent years with the implementation of three-dimensional conformal radiotherapy, intensity modulated radiotherapy, image guided radiotherapy and hypofractionation.

MATERIAL AND METHODS

An original survey questionnaire was sent to institutions participating in the SEOR-Mama group (GEORM). In total, the standards of practice in 969 patients with breast cancer after surgery were evaluated.

RESULTS

The response rate was 70% (28/40 centers). In 98.5% of cases 3D conformal treatment was used. All the institutions employed CT-based planning treatment. Boost was performed in 56.4% of patients: electrons in 59.8%, photons in 23.7% and HDR brachytherapy in 8.8%. Fractionation was standard in 93.1% of patients. Supine position was the most frequent. Only 3 centers used prone position. The common organs of risk delimited were: homolateral lung (80.8%) and heart (80.8%). In 84% histograms were used. An 80.8% of the centers used isocentric technique. In 62.5% asymmetric fields were employed. CTV was delimited in 46.2%, PTV in 65% and both in 38.5%. A 65% of the centers checked with portal films. IMRT and hypofractionation were used in 1% and in 5.5% respectively.

CONCLUSION

In most of centers, 3D conformal treatment and CT-based planning treatment were used. IMRT and hypofractionation are currently poorly implemented in Spain.

Acute toxicity and early cosmetic outcome in patients treated with multilumen balloon brachytherapy with skin spacing ≤ 7.0 millimeters

Purpose

To review institutional experience treating patients who underwent breast conserving surgery and adjuvant accelerated partial breast irradiation with multilumen balloon brachytherapy (MLB) with close skin spacing (≤7 mm).

Material and methods

Since July 2009, 26 patients with skin spacing ≤ 7.0 mm were treated with breast-conserving therapy and adjuvant MLB brachytherapy. Patients were treated with either the Contura or MammoSite ML catheter to a total dose of 34 Gy in 10 fractions. Patients were assessed for acute toxicity at the completion of treatment and 1-month post treatment. Cosmesis and late toxicity were assessed at three-month intervals thereafter.

Results

The median age of the patients was 56 years and median follow-up was 9 months. Sixteen patients had skin spacing of 5.0–7.0 mm, 10 with < 5.0 mm (median 5.8). The median percentage of the target (PTV_EVAL) receiving ≥ 95% of the prescription dose was 95.6%. The median volume of PTV_EVAL receiving ≥ 200% of the prescription dose was 6.1 cc. The maximum skin dose was 118.2% (median). The most commonly observed acute toxicity was grade 1-2 dermatitis (65.4%). The rate of post-treatment seroma and infection was 38.5% and 3.8%, respectively. Excellent/good cosmetic outcomes seen at the time of last follow-up was 92.3%.

Conclusions

MLB brachytherapy is safe and feasible in patients with close skin spacing, with acute toxicity and early cosmesis similar to other published series. These devices may broaden the application of balloon brachytherapy in patients previously excluded from this treatment based on anatomy.

Angular absorbed dose dependence of internal radiation-generating devices in radiotherapy

The angular dependence of the absorbed dose from internal radiation-generating devices located within a tumor mass is investigated. Given the systematics of proton and heavy-ion differential scattering cross sections, candidate internal radiation-generating devices will have a relatively constant absorbed dose output beyond a critical angle. Inside this angle, the absorbed dose output is suppressed because elastic and inelastic differential cross sections are peaked in the beam direction. This peaking increases in severity as the particle energy increases and suggests internal radiation-generating devices must have a limited rotation capability to compensate for the depression in the absorbed dose for angles near the beam direction.

Six-year analysis of treatment-related toxicities in patients treated with accelerated partial breast irradiation on the American Society of Breast Surgeons MammoSite Breast Brachytherapy registry trial

BACKGROUND

The American Society of Breast Surgeons (ASBrS) enrolled women in a registry trial to prospectively study patients treated with the MammoSite RTS device. This report presents 6-year data on treatment-related toxicities from the trial.

METHODS

A total of 1449 primary early-stage breast cancers were treated with accelerated partial breast irradiation (APBI) using the MammoSite device (34 Gy in 10 fractions) in 1440 women. Of these, 1255 case (87%) had invasive breast cancer (IBC) (median size = 10 mm) and 194 cases (13%) had ductal carcinoma in situ (DCIS) (median size = 8 mm). Median follow-up was 59 months. Fisher exact test was performed to correlate categorical covariates with toxicity.

RESULTS

Breast seromas were reported in 28% of cases (35.5% with open cavity and 21.7% with closed cavity placement). Also, 13% of all treated breasts developed symptomatic seromas, and 77% of these seromas developed during the 1st year after treatment. There were 172 cases (11.9%) that required drainage to correct. Use of chemotherapy and balloon fill >50 cc were associated with the development of symptomatic seromas. Also, 2.3% of patients developed fat necrosis (FN). The incidence of FN during years 1 and 2 were 0.9% and 0.8%, respectively. Seroma formation, use of hormonal therapy, breast infection, and A/B cup size were associated with fat necrosis. There were 138 infections (9.5%) recorded; 98% occurred during the 1st year after treatment. Chemotherapy and seroma formation were associated with the development of infections.

CONCLUSIONS

Treatment-related toxicities 6 years after treatment with APBI using the MammoSite device are similar to those reported with other forms of APBI with similar follow-up.

Partial breast irradiation delivered with proton beam: results of a phase II trial

BACKGROUND AND PURPOSE

A phase II trial sought to determine the safety and efficacy of proton beam irradiation to deliver partial breast radiotherapy after lumpectomy for early-stage breast cancer.

PATIENTS AND METHODS

Eligible patients included women with invasive nonlobular carcinoma ≤ 3 cm. Surgical therapy included lumpectomy with negative margins and negative axillary lymph nodes on sampling. Postoperative proton radiotherapy to the surgical bed with an additional 1-cm margin was delivered by 40 Gy in 10 fractions over a 2-week course. Patients received systemic therapy as recommended after proton treatment. Patients had clinical evaluations every 6 months and annual mammograms.

RESULTS

Fifty patients were enrolled; median follow-up was 48 months. All patients completed the prescribed treatment. Acute toxicities were limited to mild radiation dermatitis. Late skin toxicities included 3 grade 1 telangiectasias. There were no posttreatment infections or ulcerations and no cases of fat necrosis, rib fractures, radiation pneumonitis, or cardiac events. Actuarial 5-year overall survival and disease-free survival rates were 96% and 92%, respectively. No local failures occurred. Ipsilateral breast cancer developed in 1 patient 5.5 years after treatment. Dose-volume histogram analysis showed near-complete elimination of dose to the contralateral breast, lung, and heart.

CONCLUSION

Proton partial breast radiotherapy appeared to be a feasible method of treatment and provided excellent disease control within the ipsilateral breast. Treatment-related toxicity was minimal and no technical limitations prevented treatment delivery. The incidence of posttreatment complications may be less than that reported when using more invasive techniques; comparative trials should be considered.