First analysis of patient demographics, technical reproducibility, cosmesis, and early toxicity

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

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

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Breast brachytherapy

Accelerated partial breast irradiation with brachytherapy is a treatment method with a very low risk profile. In fact, accelerated partial breast irradiation brachytherapy has been proven in randomized trials to have fewer late side effects than whole-breast irradiation. Notably, Grade 3 late side effects are extremely rare, and excellent to good cosmetic results are observed in well over 90% of patients. In this article, published side effects of breast brachytherapy are reviewed and appropriate management discussed.

Surgical Clips in Breast-conserving Surgery: Do they Represent the Tumour Bed Accurately?

INTRODUCTION

Radiotherapy after Breast-Conserving Surgery (BCS) is a standard treatment for breast cancer. Currently, surgical clips are used to determine the tumour bed before radiotherapy planning. This study aimed to evaluate the migration of these clips on mammograms.

METHODS

The study was conducted on 121 females who were treated with radiotherapy after BCS at their first radiologic control examination 6 months after the end of treatment. MLO and CC views of all cases were evaluated regarding the clips. The distance between the surgical scar centre and the centre of the area covered by the clips was measured on both MLO and CC projections and recorded separately. This distance was determined as the clip displacement. A displacement ≤10 mm was recorded as no displacement.

RESULTS

The clips were out of the images and were not evaluated in 45 cases (37.2%) on CC and in 9 cases (7.4%) on MLO projections. There were no clip displacements in 37 (30.6%) cases on CC and in 43 (35.5%) cases on MLO views. The amount of displacement ranged from 11 to 56 mm with a mean of 24.38 mm on CC views, while on MLO projections, displacement ranged from 11 to 66 mm with a mean of 24.42 mm.

CONCLUSION

A clip displacement of greater than 10 mm was found in 64.5% of cases on MLO views. Therefore, we believe that the reliability of these clips for accurate delineation of the tumour bed in radiotherapy planning is controversial and other methods must be added.

Quantitative assessment of radiodermatitis through a non-invasive objective procedure in patients with breast cancer

Assessment of skin condition is necessary for providing advice regarding skin self-care to patients with breast cancer who have undergone radiation therapy. Acute and chronic phases of radiodermatitis were analyzed in patients using objective assessment tools in the present study. A total of 18 women who received radiation therapy for breast cancer were enrolled in the present study and their skin surface temperature (SST), hydration level of the skin surface (HL), melanin intensity (MI) and erythema intensity (EI) were measured prior to radiation therapy and six months thereafter. Furthermore, skin condition was assessed using the Common Terminology Criteria for Adverse Events (CTCAE). EI and MI levels at the irradiated site peaked upon the completion of radiation therapy and declined to baseline at 6 months. In contrast, SST levels were elevated at the irradiated site during radiation therapy (P<0.05) and plateaued after its completion. The same parameters in non-irradiated control sites remained unchanged during the study period. HL reached the minimum in irradiated and non-irradiated sites upon completion of radiation therapy. Although HL returned to baseline in the non-irradiated site 6 months after radiation therapy, it remained low in the irradiated site. No relationship between the CTCAE and EI level was observed. In conclusion, the present study demonstrated that objective assessment tools, including SST and EI levels, were useful for assessing skin condition during radiodermatitis. The combination of the CTCAE and objective assessment tools will enable a more accurate assessment of radiodermatitis.

Skin dose assessment with treatment planning system (TPS) and skin reaction evaluation of early breast cancer patients treated via an intraoperative radiation therapy (IORT) device

Purpose

To assess skin dose and incidence of skin reactions in early breast cancer patients treated via Intrabeam™ intraoperative radiation therapy (IORT) device.

Materials and methods

In total, 250 breast cancer patients treated with a single fraction of 20 Gy using 50 kV photon were recruited. The applicator to skin distance (ASD) was measured before the initiation of the radiation and the skin dose in each patient was accordingly calculated based on the treatment planning system (TPS).

Results

The average skin doses calculated were equal to 7·91, 5·83, 3·96 and 2·14 Gy for 6–10, 10–15, 15–20 and 20–30 mm ASD values, respectively. It is noticeable that the skin doses could be lower than the TPS measurements up to 45%, mostly due to lack of backscatter radiation in breast tissue compared with the full scatter condition in the Zeiss water phantom. Finally, only three patients showed low-grade skin reactions 1 week after IORT. A review of the related literature also revealed the incidence of lower skin complications among patients treated via Intrabeam™ compared with MammoSite™ machine.

Conclusions

The Intrabeam™ TPS did not seem to be very reliable for accurate skin dosimetry. However, breast cancer treatment using Intrabeam™ could result in fewer incidences of skin reactions than MammoSite™ machine.

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.

A PHASE II TRIAL OF BALLOON-CATHETER PARTIAL BREAST BRACHYTHERAPY OPTIMIZATION IN THE TREATMENT OF STAGE 0, I AND IIA BREAST CARCINOMA

OBJECTIVES

(a) To prospectively determine if multidwell position dose delivery can decrease skin dose and resultant toxicity over single dwell balloon-catheter partial breast irradiation, and (b) to evaluate whether specific skin parameters could be safely used instead of skin-balloon distance alone for predicting toxicity and treatment eligibility.

METHODS

A single-arm phase II study using a Simon two-stage design was performed on 28 women with stage 0-II breast cancer. All patients were treated with multiple dwell position balloon-catheter brachytherapy. The primary endpoint was ≥ grade 2 skin toxicity. Initial entry required a balloon-skin distance ≥ 7 mm. Based on the toxicity in the first 16 patients, additional patients were treated irrespective of skin-balloon distance as long as the Dmax to 1 mm skin thickness was < 130%.

RESULTS

Compared to the phantom single dwell plans, multidwell planning yielded superior PTV coverage as per median V90, V95 and V100, but had slightly worse V150, V200 and DHI. Dmax to skin was decreased by multidwell planning at multiple skin thicknesses. The most common acute toxicity was grade 1 erythema (57%), and only two patients (7%) developed acute grade 2 toxicity (erythema). Late grade 1 fibrosis was seen in 32%. No patients experienced grade 3, 4, or 5 toxicity.

CONCLUSIONS

Multidwell position planning for balloon-catheter brachytherapy results in lower skin doses with equal to superior PTV coverage and an overall low rate of initial skin toxicity. Our data suggest that limiting the Dmax to < 130% to 1 mm thick skin is achievable and results in minimal toxicity.

A Phase I/II Trial to Evaluate the Technical Feasibility of Partial Breast Irradiation with Three-Dimensional Conformal Radiation Therapy in Korean Women with Stage I Breast Carcinoma: An Initial Report of the Korean Radiation Therapy Oncology Group (KROG) Study 0804

PURPOSE

This prospective study was designed to verify the technical feasibility of partial breast irradiation in breast cancer patients with small breasts, which are commonly encountered in Korean women.

MATERIALS AND METHODS

A total of 40 Gy, administered in 10 fractions on consecutive days (one fraction per day), was prescribed to the isocenters of the fields using three-dimensional conformal radiotherapy (3-DCRT). For all patients, treatment planning and dose parameters strictly adhered to the constraints set forth in the Radiation Therapy Oncology Group (RTOG) 0319 protocol. This study was designed such that if fewer than five of the first 42 evaluable patients received unacceptable scores, the treatment would be considered reproducible.

RESULTS

Ten treatment plans (23.8%) were determined to have major variations. There was no major variation in planning target volume (PTV) coverage. The ipsilateral and contralateral breast dose limitations were not met in four (9.5%) and four cases (9.5%), respectively. Major variations in ipsilateral and contralateral lung dose limitations were observed in two cases (4.8%). Major variations in the heart and thyroid dose limitations were observed in one (2.4%) and one case (2.4%), respectively. In multivariate analysis, a ratio of PTV to ipsilateral breast volume (PTV/IB) > 0.16 was the only significant factor that statistically affected major variations.

CONCLUSION

We concluded that partial breast irradiation using 3-DCRT could not be reproduced in Korean breast cancer patients, particularly small-volumed breast surrogated as PTV/IB > 0.16. The dominant cause was the major variation in surrounding normal breast tissues.

Timing of infectious complications following breast-conserving therapy with catheter-based accelerated partial breast irradiation

BACKGROUND

Accelerated partial breast irradiation (APBI) has been used as an alternative to whole-breast irradiation as part of breast-conserving therapy. Indications and outcomes are topics of ongoing investigation. Previous publications have focused on early postoperative infections and reported low rates of delayed infection. We investigated the pattern of infection after catheter-based APBI at our institution.

METHODS

Patients who underwent single-entry catheter-based APBI were identified from an institutional prospective registry including data regarding comorbidities and outcomes. Time of infection was calculated from the date of definitive catheter insertion and classified as early (≤30 days) or delayed.

RESULTS

A total of 91 breast cancer patients were treated with APBI and enrolled in the registry from 2009 to 2011. The median follow-up was 484 days. Breast infection occurred in 13 (14.3 %), with 3 (3.3 %) occurring within 30 days of catheter placement and 10 (11.0 %) in a delayed fashion. Four patients required hospital admission, five underwent percutaneous aspiration, and one underwent incision and drainage. Eight were treated as outpatients with oral antibiotics alone.

CONCLUSIONS

Consistent with other reports, we found an overall infection rate of 14.3 % with single-entry catheter-based APBI. There were substantially fewer infections in the early postoperative period than reported elsewhere, but there were more delayed infections. The intensive follow-up in our study likely identified late infections that may not have otherwise been recognized. Vigilance for infectious complications must continue beyond the immediate treatment period in patients undergoing catheter-based APBI. These infections can range in severity but typically can be managed in an outpatient setting.

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.

Characterization and treatment of local recurrence following breast conservation for ductal carcinoma in situ

PURPOSE

The optimal treatment strategy for ductal carcinoma in situ (DCIS) continues to evolve and should consider the consequences of initial treatment on the likelihood, type, and treatment of recurrences.

METHODS

We conducted a retrospective cohort study using two data sources of patients who experienced a recurrence (DCIS or invasive cancer) following breast-conserving surgery (BCS) for index DCIS: patients with an index DCIS diagnosed from 1997 to 2008 at the academic institutions of the National Comprehensive Cancer Network (NCCN; N = 88) and patients with an index DCIS diagnosed from 1990 to 2001 at community-based integrated healthcare delivery sites of the Health Maintenance Organization Cancer Research Network (CRN) (N = 182).

RESULTS

Just under half of local recurrences in both cohorts were invasive cancer. While 40 % of patients in both cohorts underwent mastectomy alone at recurrence, treatment of the remaining patients varied. In the earlier CRN cohort, most other patients underwent repeat BCS (39 %) with only 18 % receiving mastectomy with reconstruction, whereas only 16 % had repeat BCS and 44 % had mastectomy with reconstruction in the NCCN cohort. Compared with patients not treated with radiation, those who received radiation for index DCIS were less likely to undergo repeat BCS (NCCN: 6.6 vs. 37 %, p = 0.001; CRN: 20 vs. 48 %, p = 0.0004) and more likely to experience surgical complications after treatment of recurrence (NCCN: 15 vs. 4 %, p = 0.17; CRN: 40 vs. 25 %, p = 0.09).

CONCLUSION

We found that treatment of recurrences after BCS and subsequent complications may be affected by the use of radiotherapy for the index DCIS. Initial treatment of DCIS may have long-term implications that should be considered.

Day to day treatment variations of accelerated partial breast brachytherapy using a multi-lumen balloon

Purpose

To evaluate the variations of multi-lumen balloon (MLB)-based brachytherapy from simulation day to treatment day and their dosimetric impacts during accelerated partial breast irradiation (APBI).

Material and methods

A total of 42 CT images scanned from seven patients were evaluated with regards to daily variation due to of: 1) internal uncertainty: size and shape of balloon, seroma volume; 2) geometrical uncertainty-random: length of each catheter was measured for each fraction (total 70); 3) geometrical uncertainty-systematic: virtual systematic errors were tested by offsetting dwell positions. The original plans (as group A) had a mean value of 96.8% on V₉₅ of the PTV_Eval. Plans were rerun (as group B) such that the mean value of the V₉₅ was relaxed to 90.4%. By applying the reference plan to each daily CT image, variations of target coverage under different sources of error were evaluated.

Results

Shape and size of the balloon had means of < 1 mm decreased in diameter and < 0.4 cm³ decreased in volume; the mean seroma volume increased by 0.2 cm³. This internal variation has a mean of < 1% difference for both V₉₀ and V₉₅. The geometrical uncertainty made a mean deviation of 2.7 mm per root of sum of square. It caused the degradations of V₉₀ and V₉₅ by mean values of 1.0% and 1.2%, respectively. A systematic error of 3 mm and 4 mm would degrade both of V₉₀ and V₉₅ by 4% and 6%, respectively. The degradations on target coverage of the plans in group A were statistically the same as those in group B.

Conclusions

Overall, APBI treatments with MLB based brachytherapy are precise from day to day. However, minor variation due to daily treatment uncertainties can still degrade tumor bed coverage to an unacceptable coverage when V₉₅ of the original plan is close to 90%.

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.

On the feasibility of treating to a 1.5 cm PTV with a commercial single-entry hybrid applicator in APBI breast brachytherapy

Purpose

To evaluate and determine whether 30 patients previously treated with the SAVI™ device could have been treated to a PTV_EVAL created with a 1.5 cm expansion. This determination was based upon dosimetric parameters derived from current recommendations and dose-response data.

Material and methods

Thirty patients were retrospectively planned with PTV_EVALs generated with a 1.5 cm expansion (PTV_EVAL_1.5). Plans were evaluated based on PTV_EVAL_1.5 coverage (V90, V95, V100), skin and rib maximum doses (0.1 cc maximum dose as a percentage of prescription dose), as well as V150 and V200 for the PTV_EVAL_1.5. The treatment planning goal was to deliver ≥90% of the prescribed dose to ≥90% of the PTV_EVAL_1.5. Skin and rib maximum doses were to be ≤125% of the prescription dose and preferably ≤100% of the prescription dose. V150 and V200 were not allowed to exceed 52.5 cc and 21 cc, respectively. Plans not meeting the above criteria were recomputed with a 1.25 cm expanded PTV_EVAL and re-evaluated.

Results

Based on the above dose constraints, 30% (9/30) of the patients evaluated could have been treated with a 1.5 cm PTV_EVAL. The breakdown of cases successfully achieving the above dose constraints by applicator was: 0/4 (0%) 6-1, 6/15 (40%) 8-1, and 3/11 (27%) 10-1. For these PTV_EVAL_1.5 plans, median V90% was 90.3%, whereas the maximum skin and rib doses were all less than 115.2% and 117.6%, respectively. The median V150 and V200 volumes were 39.2 cc and 19.3, respectively. The treated PTV_EVAL_1.5 was greater in volume than the PTV_EVAL by 41.7 cc, and 60 cc for the 8-1, and 10-1 applicators, respectively. All remaining plans (17) successfully met the above dose constraints to be treated with a 1.25 cm PTV_EVAL (PTV_EVAL_1.25). For the PTV_EVAL_1.25 plans, V90% was 93.7%, and the maximum skin and rib doses were all less than 109.2% and 102.5%, respectively. The median V150 and V200 volumes were 41.2 cc and 19.3, respectively. The treated PTV_EVAL_1.25 was greater in volume than the PTV_EVAL by 16 cc, 24.9 cc, and 33.5 cc for the 6-1, 8-1 and 10-1 applicators, respectively.

Conclusions

It is dosimetrically possible to treat beyond the currently advised 1.0 cm expanded PTV_EVAL. Most patients should be able to be treated with a 1.25 cm PTV_EVAL and a select group with a 1.5 cm PTV_EVAL. Applicator size appears to determine the ability to expand to a 1.5 cm PTV_EVAL, as smaller devices were not as propitious in this regard. Further studies may identify additional patient groups that would benefit from this approach.

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.

[Conformal accelerated partial breast irradiation: state of the art]

Breast conserving treatment (breast conserving surgery followed by whole breast irradiation) has commonly been used in early breast cancer since many years. New radiation modalities have been recently developed in early breast cancers, particularly accelerated partial breast irradiation. Three-dimensional conformal accelerated partial breast irradiation is the most commonly used modality of radiotherapy. Other techniques are currently being developed, such as intensity-modulated radiotherapy, arctherapy, and tomotherapy. The present article reviews the indications, treatment modalities and side effects of accelerated partial breast irradiation.

Impact of partial versus whole breast radiation therapy on fatigue, perceived stress, quality of life and natural killer cell activity in women with breast cancer

Introduction

This pilot study used a prospective longitudinal design to compare the effect of adjuvant whole breast radiation therapy (WBRT) versus partial breast radiation therapy (PBRT) on fatigue, perceived stress, quality of life and natural killer cell activity (NKCA) in women receiving radiation after breast cancer surgery.

Methods

Women (N = 30) with early-stage breast cancer received either PBRT, Mammosite brachytherapy at dose of 34 Gy 10 fractions/5 days, (N = 15) or WBRT, 3-D conformal techniques at dose of 50 Gy +10 Gy Boost/30 fractions, (N = 15). Treatment was determined by the attending oncologist after discussion with the patient and the choice was based on tumor stage and clinical need. Women were assessed prior to initiation of radiation therapy and twice after completion of radiation therapy. At each assessment, blood was obtained for determination of NKCA and the following instruments were administered: Perceived Stress Scale (PSS), Functional Assessment of Cancer Therapy-Fatigue (FACT-F), and Functional Assessment of Cancer Therapy-General (FACT-G). Hierarchical linear modeling (HLM) was used to evaluate group differences in initial outcomes and change in outcomes over time.

Results

Fatigue (FACT-F) levels, which were similar prior to radiation therapy, demonstrated a significant difference in trajectory. Women who received PBRT reported progressively lower fatigue; conversely fatigue worsened over time for women who received WBRT. No difference in perceived stress was observed between women who received PBRT or WBRT. Both groups of women reported similar levels of quality of life (FACT-G) prior to initiation of radiation therapy. However, HLM analysis revealed significant group differences in the trajectory of quality of life, such that women receiving PBRT exhibited a linear increase in quality of life over time after completion of radiation therapy; whereas women receiving WBRT showed a decreasing trajectory. NKCA was also similar between therapy groups but additional post hoc analysis revealed that better quality of life significantly predicted higher NKCA regardless of therapy.

Conclusions

Compared to WBRT, PBRT results in more rapid recovery from cancer-related fatigue with improved restoration of quality of life after radiation therapy. Additionally, better quality of life predicts higher NKCA against tumor targets, emphasizing the importance of fostering quality of life for women undergoing adjuvant radiation therapy.

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.

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.

Tumor bed-to-skin distance using accelerated partial-breast irradiation with the strut-adjusted volume implant device

PURPOSE

Because of the risk of skin toxicity with single dwell position, single-lumen brachytherapy devices are sometimes contraindicated for tumor cavities 5-7mm from the skin surface. We discuss the use of multicatheter device to treat patients with tumor bed-to-skin distances <7mm.

METHODS AND MATERIALS

We treated 117 patients with accelerated partial-breast irradiation brachytherapy: 77 single-lumen and 40 multicatheter devices. A subset of 12 patients treated with SAVI(®) had bed-to-skin spacing <7mm. All patients had Tis-2N0 ductal carcinoma with negative margins. A total dose of 34.0Gy in 10 fractions was delivered twice daily. Planning target volume was created using computed tomography-based three-dimensional planning with a 1.0-cm expansion of the lumpectomy cavity. Skin dose was measured dosimetrically, with skin constraints <125% of the prescription. Toxicities were graded, and patients were assessed at various intervals.

RESULTS

Of the patients treated with the multicatheter device, 0% (0/12) had their device pulled. At 2 weeks after treatment, fewer than 50% of the patients had skin toxicities of Grades 1-2, all of which resolved by 6 months. The cosmetic outcome was good to excellent at followup.

CONCLUSIONS

Multicatheter devices permit well-tolerated accelerated partial-breast irradiation in patients with tumor cavities near the skin surface for which the single-lumen device may not be appropriate.

Factors associated with optimal long-term cosmetic results in patients treated with accelerated partial breast irradiation using balloon-based brachytherapy

PURPOSE

To evaluate factors associated with optimal cosmetic results at 72 months for early-stage breast cancer patients treated with Mammosite balloon-based accelerated partial breast irradiation (APBI).

METHODS AND MATERIALS

A total of 1,440 patients (1,449 cases) with early-stage breast cancer undergoing breast-conserving therapy were treated with balloon-based brachytherapy to deliver APBI (34 Gy in 3.4-Gy fractions). Cosmetic outcome was evaluated at each follow-up visit and dichotomized as excellent/good (E/G) or fair/poor (F/P). Follow-up was evaluated at 36 and 72 months to establish long-term cosmesis, stability of cosmesis, and factors associated with optimal results.

RESULTS

The percentage of evaluable patients with excellent/good (E/G) cosmetic results at 36 months and more than 72 months were 93.3% (n = 708/759) and 90.4% (n = 235/260). Factors associated with optimal cosmetic results at 72 months included: larger skin spacing (p = 0.04) and T1 tumors (p = 0.02). Using multiple regression analysis, the only factors predictive of worse cosmetic outcome at 72 months were smaller skin spacing (odds ratio [OR], 0.89; confidence interval [CI], 0.80-0.99) and tumors greater than 2 cm (OR, 4.96, CI, 1.53-16.07). In all, 227 patients had both a 36-month and a 72-month cosmetic evaluation. The number of patients with E/G cosmetic results decreased only slightly from 93.4% at 3 years to 90.8% (p = 0.13) at 6 years, respectively.

CONCLUSIONS

APBI delivered with balloon-based brachytherapy produced E/G cosmetic results in 90.4% of cases at 6 years. Larger tumors (T2) and smaller skin spacing were found to be the two most important independent predictors of cosmesis.

Toxicity and cosmesis outcomes after single fraction partial breast irradiation in early stage breast cancer

Background

To report the clinical outcome after a Single Shot 3D-CRT PBI (SSPBI) in breast cancer patients after conservative surgery (ClinicalTrials.gov Identifier: NCT01316328).

Methods

A dose of 18Gy (in the first 4 patients) and 21Gy (in the remaining 60 patients) was prescribed in a single session and delivered to the index area (i.e. the area of breast including the primary tumor bed and the surrounding tissue) using 3D-CRT with patients in prone position. Acute and late toxicity was assessed using the National Cancer Institute's CTC for Adverse Events. Cosmesis was defined based on modified Harvard criteria. Differences between dosimetric or clinical parameters of patients with/without G2 or more late toxicity or unsatisfactory (poor or fair) cosmetic outcome were evaluated with the Mann-Whitney test. Odds ratios and 95% confidence interval were calculated for cosmesis and fibrosis. Univariate and multivariate analyses(UVA/MVA) were used to determine covariates associated with an increase in fibrosis or fat necrosis rate.

Results

Sixty four patients were enrolled. With a median follow-up of 3 years, G2 and G3 subcutaneous fibrosis was detected in 20(31%) and in 8(13%) patients, and ≥G2 fat necrosis was observed in 2(3%) patients. Good to excellent, fair and poor cosmesis was observed in 38(59%), 23(36%) and 3(5%) patients, respectively. Based on UVA, the breast volume receiving more than 21Gy (V₂₁Gy) was found to be a predictor of the ≥G1 or ≥G2 fibrosis/fat necrosis. Based on MVA, V₂₁Gy was confirmed as a predictor for ≥G1 fibrosis/fat necrosis, the results correlated as a trend for ≥G2. Cosmesis was correlated with whole breast (WB) mean dose (p = 0.030).

Conclusion

Our choice of a single dose of 21Gy significantly increased the treatment related toxicity. However, this should not discourage novel SSPBI approaches with lower equivalent doses.

Partial breast irradiation techniques in early breast cancer

Whole breast irradiation represents an integral part of combined breast-conserving treatment of early breast cancer. A new concept includes replacing traditionally fractionated whole breast postoperative radiotherapy by accelerated partial breast irradiation. The latter involves a variety of techniques and may be applied intraoperatively or shortly after the surgery. The intraoperative techniques include photon or electron external beam irradiation and interstitial high dose rate (HDR) brachytherapy, whereas the postoperative techniques comprise interstitial brachytherapy, be it HDR, pulse dose rate (PDR) or low dose rate (LDR), intracavitary brachytherapy and external beam radiotherapy using electrons, photons or protons. This article presents accelerated partial breast irradiation techniques, ongoing phase III trials evaluating their value and recommendations for clinical practice.

Objective method to report planner-independent skin/rib maximal dose in balloon-based high dose rate (HDR) brachytherapy for breast cancer

PURPOSE

An objective method was proposed and compared with a manual selection method to determine planner-independent skin and rib maximal dose in balloon-based high dose rate (HDR) brachytherapy planning.

METHODS

The maximal dose to skin and rib was objectively extracted from a dose volume histogram (DVH) of skin and rib volumes. A virtual skin volume was produced by expanding the skin surface in three dimensions (3D) external to the breast with a certain thickness in the planning computed tomography (CT) images. Therefore, the maximal dose to this volume occurs on the skin surface the same with a conventional manual selection method. The rib was also delineated in the planning CT images and its maximal dose was extracted from its DVH. The absolute (Abdiff = [D(max) Man - D (max)DVH]) and relative (Rediff[%] = 100 x ([D(max)Man-D(max)DVH])/D(max)DVH) maximal skin and rib dose differences between the manual selection method (D(max)Man) and the objective method (D(max)DVH) were measured for 50 balloon-based HDR (25 MammoSite and 25 Contura) patients.

RESULTS

The average +/- standard deviation of maximal dose difference was 1.67% +/- 1.69% of the prescribed dose (PD). No statistical difference was observed between MammoSite and Contura patients for both Abdiff and Rediff[%] values. However, a statistically significant difference (p value < 0.0001) was observed in maximal rib dose difference compared with maximal skin dose difference for both Abdiff (2.30% +/- 1.71% vs 1.05% +/- 1.43%) and Rediff[%] (2.32% +/- 1.79% vs 1.21% +/- 1.41%). In general, rib has a more irregular contour and it is more proximally located to the balloon for 50 HDR patients. Due to the inverse square law factor, more dose difference was observed in higher dose range (D(max) > 90%) compared with lower dose range (D(max) < 90%): 2.16% +/- 1.93% vs 1.19% +/- 1.25% with p value of 0.0049. However, the Rediff[%] analysis eliminated the inverse square factor and there was no statistically significant difference (p value = 0.8931) between high and low dose ranges.

CONCLUSIONS

The objective method using volumetric information of skin and rib can determine the planner-independent maximal dose compared with the manual selection method. However, the difference was < 2% of PD, on average, if appropriate attention is paid to selecting a manual dose point in 3D planning CT images.

Electronic brachytherapy as adjuvant therapy for early stage breast cancer: a retrospective analysis

PURPOSE

This multicenter, retrospective study evaluated treatment and clinical outcomes of patients with early stage breast cancer who received adjuvant high-dose rate (HDR) electronic brachytherapy (EBT) treatment post-lumpectomy using the Axxent(®) EBT system. Dosimetric data from the EBT treatment plans were compared with those based on iridium-192 HDR brachytherapy.

MATERIAL AND METHODS

Medical records of 63 patients with early stage breast cancer (Tis, T1a, T1b, T1c, and T2) who were treated post-lumpectomy with EBT alone or in combination with external beam radiation therapy were reviewed. The prescribed EBT dose was 34 Gy (10 fractions over 5 days, 3.4 Gy each) to 1 cm from the balloon surface. Dosimetry data from 12 patients were compared with these of treatment plans using an iridium-192 source prepared for the same 12 patients.

RESULTS

The majority of patients (90.5%) were older than 50 years and had one or more risk factors for breast cancer (80.6%). Tumor sizes were 0.1 cm to 3.5 cm (mean 1.3 cm). Median follow-up was 7 months (1 to 18 months) post-EBT. Balloon applicators were implanted 0 to 85 days (mean 13.4 days) post-lumpectomy/re-excision. The most common adverse events were erythema, rash dermatitis, and pain or breast tenderness. No recurrences were reported. Dosimetric analyses demonstrated comparable target coverage, increased high-dose regions, and a significantly reduced dose to the ipsilateral breast and lungs as well as the heart with EBT as compared with the iridium-192 treatment plans.

CONCLUSION

This retrospective, multicenter study showed that postsurgical adjuvant radiation therapy for early stage breast cancer can be administered using the EBT system with similar toxicity outcomes to those reported with iridium-192 brachytherapy. EBT offers a convenient, portable, nonisotope alternative to HDR brachytherapy using iridium-192.

Five-year outcome of patients classified in the "unsuitable" category using the American Society of Therapeutic Radiology and Oncology (ASTRO) Consensus Panel guidelines for the application of accelerated partial breast irradiation: an analysis of patients treated on the American Society of Breast Surgeons MammoSite® Registry trial

PURPOSE

We applied the ASTRO Consensus Panel (CP) guidelines for the application of accelerated partial breast irradiation (APBI) to patients treated with this technique on the ASBS MammoSite® registry trial to determine potential differences in outcome of patients classified in the "unsuitable" category.

METHODS

Of 1,449 cases treated with APBI on the registry trial, 176 fit the criteria for the unsuitable category: 130 cases were <50 years of age, 13 had positive margins, 38 had positive nodes, 6 had tumors >3 cm, and 9 had an EIC >3 cm. Rates of ipsilateral breast tumor recurrence (IBTR) and regional nodal failure (RNF) were assessed. Median follow-up was 53.6 months.

RESULTS

The 5-year actuarial rate of IBTR for unsuitable cases was 5.25% (RNF rate was 0.63%). By comparison, the 5-year actuarial IBTR rates for various subsets of patients were: all 1,449 cases, 3.89% (p = 0.2365); all 1,449 cases excluding unsuitable cases [n =1,273] (3.6%, p =0.1683); invasive only cases [n = 1,255] (3.86%, p = 0.2464); and invasive only cases excluding unsuitable invasive cases [n =1,105] (3.89%, p = 0.2396). On univariate analysis for variables potentially associated with IBTR in all 1,255 cases with invasive cancer (including age, tumor size, nodal status, overall stage, margin status, ER status, presence of an EIC, and ASTRO unsuitable category), only negative ER (-) status was associated with the 5-year rate of IBTR (p = 0002). No other variable (including unsuitable CP designation) was associated with IBTR.

CONCLUSIONS

The ASTRO CP guideline designation of unsuitable did not differentiate a subset of patients with a significantly worse rate of IBTR when treated with the MammoSite® breast brachytherapy catheter to deliver APBI.

Five-year analysis of treatment efficacy and cosmesis by the American Society of Breast Surgeons MammoSite Breast Brachytherapy Registry Trial in patients treated with accelerated partial breast irradiation

PURPOSE

To present 5-year data on treatment efficacy, cosmetic results, and toxicities for patients enrolled on the American Society of Breast Surgeons MammoSite breast brachytherapy registry trial.

METHODS AND MATERIALS

A total of 1440 patients (1449 cases) with early-stage breast cancer receiving breast-conserving therapy were treated with the MammoSite device to deliver accelerated partial-breast irradiation (APBI) (34 Gy in 3.4-Gy fractions). Of 1449 cases, 1255 (87%) had invasive breast cancer (IBC) (median size, 10 mm) and 194 (13%) had ductal carcinoma in situ (DCIS) (median size, 8 mm). Median follow-up was 54 months.

RESULTS

Thirty-seven cases (2.6%) developed an ipsilateral breast tumor recurrence (IBTR), for a 5-year actuarial rate of 3.80% (3.86% for IBC and 3.39% for DCIS). Negative estrogen receptor status (p=0.0011) was the only clinical, pathologic, or treatment-related variable associated with IBTR for patients with IBC and young age (<50 years; p=0.0096) and positive margin status (p=0.0126) in those with DCIS. The percentage of breasts with good/excellent cosmetic results at 60 months (n=371) was 90.6%. Symptomatic breast seromas were reported in 13.0% of cases, and 2.3% developed fat necrosis. A subset analysis of the first 400 consecutive cases enrolled was performed (352 with IBC, 48 DCIS). With a median follow-up of 60.5 months, the 5-year actuarial rate of IBTR was 3.04%.

CONCLUSION

Treatment efficacy, cosmesis, and toxicity 5 years after treatment with APBI using the MammoSite device are good and similar to those reported with other forms of APBI with similar follow-up.

Comparison of organ doses for patients undergoing balloon brachytherapy of the breast with HDR 192Ir or electronic sources using monte carlo simulations in a heterogeneous human phantom

PURPOSE

Accelerated partial breast irradiation via interstitial balloon brachytherapy is a fast and effective treatment method for certain early stage breast cancers. The radiation can be delivered using a conventional high-dose rate (HDR) 192Ir gamma-emitting source or a novel electronic brachytherapy (eBx) source which uses lower energy x rays that do not penetrate as far within the patient. A previous study [A. Dickler, M. C. Kirk, N. Seif, K. Griem, K. Dowlatshahi, D. Francescatti, and R. A. Abrams, "A dosimetric comparison of MammoSite high-dose-rate brachytherapy and Xoft Axxent electronic brachytherapy," Brachytherapy 6, 164-168 (2007)] showed that the target dose is similar for HDR 192Ir and eBx. This study compares these sources based on the dose received by healthy organs and tissues away from the treatment site.

METHODS

A virtual patient with left breast cancer was represented by a whole-body, tissue-heterogeneous female voxel phantom. Monte Carlo methods were used to calculate the dose to healthy organs in a virtual patient undergoing balloon brachytherapy of the left breast with HDR 192Ir or eBx sources. The dose-volume histograms for a few organs which received large doses were also calculated. Additional simulations were performed with all tissues in the phantom defined as water to study the effect of tissue inhomogeneities.

RESULTS

For both HDR 192Ir and eBx, the largest mean organ doses were received by the ribs, thymus gland, left lung, heart, and sternum which were close to the brachytherapy source in the left breast, eBx yielded mean healthy organ doses that were more than a factor of approximately 1.4 smaller than for HDR 192Ir for all organs considered, except for the three closest ribs. Excluding these ribs, the average and median dose-reduction factors were approximately 28 and approximately 11, respectively. The volume distribution of doses in nearby soft tissue organs that were outside the PTV were also improved with eBx. However, the maximum dose to the closest rib with the eBx source was 5.4 times greater than that of the HDR 192Ir source. The ratio of tissue-to-water maximum rib dose for the eBx source was approximately 5.

CONCLUSIONS

The results of this study indicate that eBx may offer lower toxicity to most healthy tissues, except nearby bone. TG-43 methods have a tendency to underestimate dose to bone, especially the ribs. Clinical studies evaluating the negative health effects caused by irradiating healthy organs are needed so that physicians can better understand when HDR 192Ir or eBx might best benefit a patient.