Six-year experience: long-term disease control outcomes for partial breast irradiation using MammoSite balloon brachytherapy

Background

This report describes estimated 4-year tumor bed and ipsilateral breast recurrence-free intervals, event-free survival, disease-specific survival, and overall survival in a cohort of MammoSite brachytherapy (MBT) patients with mature follow-up treated at a single institution over a 6-year period.

Methods and Materials

An analysis of MBT cases was performed by using a prospectively collected quality-assurance database, departmental chart review, and electronic medical records. Patient-, tumor-, treatment-, and outcome-specific data were extracted and recorded into a research database. Patients were eligible for inclusion in this analysis if they were at least 6 months post-MBT.

Results

From May 2002 through March 2008, 111 MBT patients have been treated and were eligible for the present analysis. With a median follow-up of 46 months, the estimated 4-year outcomes for the entire cohort were tumor bed control 99%, ipsilateral breast control 95%, event-free survival 88%, disease-specific survival 97%, and overall survival 92%.

Conclusions

The present study shows low rates of local and ipsilateral breast disease failure in a well-defined cohort of MBT patients with mature follow-up.     

Descriptions and outcomes of insertion techniques of a breast brachytherapy balloon catheter in 1403 patients enrolled in the American Society of Breast Surgeons MammoSite breast brachytherapy registry trial

BACKGROUND: The use of the MammoSite brachytherapy balloon catheter is 1 option for the delivery of accelerated partial breast irradiation during breast cancer therapy. The device can be inserted into the breast using 3 different techniques. This report describes these methods of insertion and correlates the technique with outcome data collected in a multi-institutional registry trial. METHODS: In the registry trial, MammoSite catheters were inserted either (1) at the time of lumpectomy into an open cavity, (2) after surgery with ultrasound guidance through a separate small lateral incision into a closed cavity, or (3) after surgery by entering directly through the lumpectomy wound (the scar entry technique). Device placement techniques in 1403 patients with early stage breast cancer treated at 87 institutions by 223 different investigators were documented in the registry. Data collected included number of cases of each technique, age of patient, tumor size, skin spacing, catheter pull rates and reasons, infection, radiation recall, cosmesis, and recurrence. RESULTS: Catheter placement at the time of lumpectomy was performed in 619 patients (44%), after surgery with ultrasound guidance in 576 patients (41%), and the scar entry technique technique in 197 patients (14%). The type of technique was not associated with age of patient, tumor size, bra size, catheter size, skin spacing, infection, radiation recall, cosmesis, or recurrence. There was a statistically significant increased incidence of premature catheter removals for pathologically related reasons with the open-cavity technique compared with the 2 postoperative methods secondary to final histology reports disqualifying the patient after MammoSite placement. CONCLUSIONS: These registry data show that the MammoSite catheter can be inserted with any 1 of 3 different techniques. A postoperative placement, after the final pathology report is issued, decreases the incidence of premature removal of the catheter because of disqualifying pathology.     

Four-year clinical update from the American Society of Breast Surgeons MammoSite brachytherapy trial

Background

We present a 4-year update on the efficacy, cosmetic results, and complications of MammoSite breast brachytherapy in patients enrolled in the American Society of Breast Surgeons registry trial.

Methods

A total of 1,449 breasts in 1,440 patients with early stage breast cancer undergoing breast-conserving therapy were treated with adjuvant, accelerated partial breast irradiation (APBI) (34 Gy in 3.4-Gy fractions) delivered with the MammoSite device. The median follow-up period for the entire group was 36.1 months.

Results

The 3-year actuarial rate of ipsilateral breast tumor recurrence was 2.15%. The 3-year actuarial rate of axillary recurrence was .36%. Complication rates were as follows: infection, 9.5%; seroma, 26.8% (symptomatic seroma, 12.7%); and fat necrosis, 2.0%. The percentages of breasts with good or excellent cosmetic results were as follows: 12 months, 95%; 24 months, 94%; 36 months, 94%; and 48 months, 91%.

Conclusions

Locoregional control, complications, and cosmetic outcomes from MammoSite APBI at the 4-year update are acceptable and similar to results seen with other forms of APBI.     

Patient satisfaction and quality of life after MammoSite breast brachytherapy

PURPOSE: To perform a satisfaction/quality-of-life (QOL) survey of patients undergoing MammoSite brachytherapy (MBT; Hologic, Inc, Marlborough, MA). METHODS: We asked patients 15 questions regarding treatment decision-making, and experience on-therapy/post-treatment. RESULTS: A total of 52 patients responded (median follow-up 30 months). Regarding decision-making, 5.8% viewed the avoidance of mastectomy as "not important." If MBT were not available, 55.8% would opt for whole-breast radiotherapy (WBRT) without difficulty, 28.8% would have significant travel/financial difficulty, and 15.4% would refuse radiotherapy/opt for mastectomy. Regarding choice factors, patients selected "focused therapy" (44.2%), "convenience" (36.5%), and "cutting edge" (17.3%). A total of 61.5% patients were not concerned about a second surgical procedure; 90.4% were not/somewhat concerned about infection. During treatment, 73.1% reported no pain/discomfort with catheter, 73.1% no wound difficulty, 51.0% no pain during removal, and 71.2% no pain post-treatment. A total of 98.1% of patients rated the experience good/excellent, 90.4% reported no/minor side effects, 92.3% rated cosmesis good/excellent, 98.1% were very/extremely likely to choose MBT again, and 100% would recommend MBT. CONCLUSIONS: QOL is high during/after MBT. More data are needed from ongoing trials to compare with WBRT.     

Accelerated Partial Breast Irradiation Via the Mammosite® Catheter: Preliminary Reports of a Single-Institution Experience

Abstract: Several studies have shown that the majority of in‐breast recurrences following lumpectomy are at or near the original tumor site while ipsilateral breast recurrences further afield occur rarely. This suggests that the radiation dose could be delivered exclusively to the tumor bed, allowing larger fractions to be used without increasing toxicity and shortening the total treatment time. We investigated the use of the MammoSite irradiation system with a view to analyzing complications, cosmesis and patient comfort. Between 2004 and 2007 intracavity brachytherapy was given to 30 patients using the MammoSite device. The reference isodose was prescribed to the lumpectomy cavity with a 1 cm margin. Geometric parameters and anatomic position of the applicator after implantation were checked via CT, x‐ray and ultrasound. Analysis was done for patient quality of life, cosmesis, early and late complications. Forty‐nine patients received a proposal for MammoSite brachytherapy. Nine declined, 40 enrolled while 10 were excluded for various reasons ( Table 5 ). A total of 30 patients were actually treated to 34 Gy (2 × 3.4 Gy) in 5 days. We observed 3 cases (10%) of infection within 3 months of implantation. Symptomatic seroma was seen in five patients (16.6%) at 6 months, in three (10%) at 12 months, and in just one patient (3.3%) at 18 months. Good to excellent cosmetic results were achieved in 75% by patient and physician ratings. Accelerated partial breast irradiation using the MammoSite catheter produces favorable short‐term outcomes, limited toxic effects on skin, and optimal cosmetic results. Patient tolerance for the treatment is very high. Critical issues may regard the importance of good cavity conformance and adequate balloon‐skin distance in avoiding possible dose excesses to the skin. For a selected patient group, this could be a valid alternative to conventional whole breast irradiation.

Table 5. Causes of Exclusion from the Protocol

Seroma with fibrous capsule formation requiring a surgical resection after a modified radical mastectomy: Report of a case

(Received for publication on Feb. 17, 1997; accepted on July 8, 1997)     

Five-year results: the initial clinical trial of MammoSite balloon brachytherapy for partial breast irradiation in early-stage breast cancer

OBJECTIVE: Patients with early-stage invasive ductal breast cancer were prospectively evaluated using MammoSite RTS balloon brachytherapy (RTS Cytyc Corp, Marlborough, MA) as the sole modality for delivering accelerated partial breast irradiation to the lumpectomy bed with breast-conserving surgery. This report presents the 5-year results of the treated patients. METHODS: From May 2000 to October 2001, 70 patients were enrolled in this prospective study. Forty-three patients completed accelerated partial breast irradiation with MammoSite brachytherapy following lumpectomy and axillary staging. Thirty-six patients have been followed for a median of 5.5 years (mean 65.2 months). Criteria for entry into the study were unifocal invasive ductal carcinoma, tumor size < or = 2 cm, age > or = 45 years, absence of extensive intraductal component, cavity size > or = 3 cm in 1 dimension, node-negative, and final margins negative per National Surgical Adjuvant Breast and Bowel Project definition. A minimum balloon-to-skin surface distance of 5 mm was required. A dose of 34 Gy was delivered in 10 fractions over 5 days prescribed to 1 cm from the applicator surface using iridium-192 high-dose-rate brachytherapy. Data on infection, seromas, cosmetic outcome, and toxicities were collected at 3 and 6 months and at yearly intervals. Local recurrences, both true recurrences in the lumpectomy bed and failures outside the initially treated target volume (elsewhere failures), were recorded. Contralateral breast failure rates were noted. RESULTS: The catheter was not implanted in 16 of the 70 enrolled patients due to cavity size not amenable to balloon placement (n = 10), ineligible by criteria (n = 4), and skin spacing (n = 2). Fifty-four patients were implanted and 43 were successfully treated with MammoSite balloon brachytherapy. Reasons for catheter explantation in 11 patients were poor cavity conformance in 7, inadequate skin spacing in 2, positive node in 1 and age less than 45 years in 1. Of the 43 patients who completed treatment, the infection rate was 9.3%. Seroma formation occurred in 32.6% of patients, of which 12% were symptomatic requiring aspiration. Asymptomatic fat necrosis was identified in 4 of the 43 patients, noted from time of catheter removal at 11, 14, 42, and 63 months. Good-excellent cosmetic outcomes were achieved in 83.3% of the 36 patients with more than 5 years of follow-up. Cosmetic outcomes were improved, with increased skin spacing having statistical significance at skin spacing > or = 7 mm. The only serious adverse events were 2 infections: mastitis and abscess. Seven of the 43 treated patients have been discontinued from follow-up. None had a local recurrence recorded at last visit. Reasons for exit from the study were death from metastatic disease (n = 3), lost to follow-up (n = 2), and placed in hospice for other medical conditions (n = 2). No local recurrences (either at the tumor bed or elsewhere in the breast) or regional recurrences have occurred in the 36 patients who have been followed for a median of 5.5 years. No contralateral cancers have developed. CONCLUSIONS: MammoSite balloon brachytherapy as a sole modality for delivering radiation to the tumor bed has been successful in achieving excellent local control in this initial clinical study of patients with early-stage invasive ductal breast cancer. This has been achieved with minimal toxicities and good-excellent cosmetic outcomes in 83.3%. Accelerated partial breast irradiation using the MammoSite balloon in a carefully selected group of patients has demonstrated 5-year local recurrence results comparable to those achieved with conventional whole breast radiation therapy and interstitial catheter brachytherapy as reported at 5-year data points in studies of these treatment modalities. Poor cavity conformance and inadequate skin distance were the main factors limiting use of the MammoSite device. Extended follow-up will be required to determine the long-term efficacy of this treatment modality.     

American Society of Breast Surgeons MammoSite Radiation Therapy System Registry Trial: ductal carcinoma-in-situ subset analysis—4-year data in 194 treated lesions

Background

A subset analysis of the American Society of Breast Surgeons (ASBS) Registry Trial of patients with ductal carcinoma-in-situ (DCIS) was performed to compare results to patients receiving accelerated partial breast irradiation (APBI) for invasive tumors and to results in patients with DCIS receiving whole breast irradiation.

Methods

One hundred ninety-four cases of DCIS were identified from a total of 1,449 cancers treated on the ASBS Registry Trial. Details of the trial are previously published. Analysis of the entire group of cases was performed in regards to toxicity and local control.

Results

Median age was 62.1 years with 40.1% and 10.9% younger than 60 years and 50 years, respectively. Nuclear grade distribution was 35.6%, 31.4%, 17%, and 16% high, intermediate, low grade, and unknown, respectively. Necrosis was known to be present 42.3% of cases. Comedo/solid architecture was known to be present in 68% of cases. Median tumor size was 8.0 mm (range .1-45 mm, 15.5% unknown). Median margin was 2 mm; 2 cases had positive margins and 56 cases had less than 1-mm margins. The median follow-up time was 46.7 months. Five isolated ipsilateral breast failures occurred. The actuarial isolated ipsilateral breast failure rate was 2.45% at 4 years. The total in-breast 4-year actuarial failure rate was 3.0%. Three of the patients had a failure elsewhere (1.69% 4-year actuarial rate). Three of the failures were true recurrences (1.33% 4-year actuarial rate). Infection occurred in 16 patients for an 8.2% rate. Seroma formation was reported in 31%, with 13% and 12% symptomatic and requiring intervention, respectively. Seroma formation was statistically higher in open versus closed cases for all seromas. Cosmetic outcome was good to excellent in 90.3% of patients with evaluation at 36 months.

Conclusions

The ASBS Registry Trial includes the largest published collection of DCIS treated with APBI. Four-year follow-up shows result similar to those with invasive cancer treated with APBI, as well as DCIS treated with whole breast irradiation.     

Prevention of Seroma Formation after Axillary Dissection—A Comparative Randomized Clinical Trial of Three Methods

Seroma is a frequent complication after breast cancer surgery. Closed suction drainage for several days is the standard procedure to reduce seroma formation. The aim of this study was to compare the efficacy of external compression dressing, suture flap fixation, and the conventional method of closed suction drains in the prevention of seroma formation. A total of 161 patients were prospectively randomized in a three groups × two subgroups design into control (n = 48), compression dressing (n = 53) and suturing groups (n = 49), and two subgroups, conventional drain removal (n = 75) and early drain removal (n = 75). All patients underwent ALND as part of MRM or BCT. The primary end point was the incidence of seroma. Suture flap fixation significantly reduced the incidence of seroma (p = 0.003), total drain output (p = 0.005), and duration of drainage (p = 0.001) without increase in wound complications. Compression dressing reduced duration of drainage significantly (p = 0.03), but not the total drain output (p = 0.15) or seromas (p = 0.58). Early drain removal on postoperative day 7 irrespective of drain output does not significantly increase seroma formation (p = 0.34) or wound complications. On multivariate analysis, BMI ≥ 30 (p = 0.02) and longer duration of drainage (p = 0.04) were identified as independent predictors for seroma formation. Obliteration of the dead space after breast cancer surgery by suture flap fixation is a safe and easy procedure, which significantly reduces postoperative seroma formation and duration of drainage. Compression dressing offers no advantage over normal dressing. Drains can be removed safely on postoperative day 7 irrespective of output without significant increase in complications.     

Preliminary results and evaluation of MammoSite balloon brachytherapy for partial breast irradiation for pure ductal carcinoma in situ: a phase II clinical study

BACKGROUND: This report presents the preliminary results and evaluation of the MammoSite balloon catheter (MammoSite Radiation Therapy System; Cytyc Corporation, Marlboro, MA) as the sole method of delivering partial breast irradiation to the lumpectomy bed with breast-conserving surgery in patients with pure ductal carcinoma in situ (DCIS). METHODS: Twelve institutions are participating in this phase II clinical study. A total of 133 patients have been enrolled and 100 patients have successfully completed the prescribed radiation therapy. A dose of 34 Gy was delivered in 10 fractions over 5 days prescribed to 1 cm from the applicator surface using iridium-192 high-dose rate brachytherapy. Patients who met the following criteria were selected for enrollment into the study: age 45 years or older, unicentric pure DCIS, mammographic lesion of 3 cm or less, negative margins as defined by 1 mm or more, postoperative final gross pathologic size of tumor of 5 cm or less, clinically node negative, and a postlumpectomy mammogram showing the absence of any residual suspicious microcalcifications. The placement of the MammoSite catheter was performed either at the time of the lumpectomy or postlumpectomy. The minimum distance from the balloon surface to the surface of the skin is greater than 5 mm. Data collection points are at time of enrollment, time of implant, 3 months, 6 months, and then yearly at 1- to 5-year follow-up visits. Data collected are local control rates, cosmetic outcome using the Harvard Scale, toxicities, serious adverse events, disease-free survival, cause-specific survival, and contralateral breast failure. The Van Nuys Prognostic Index scores were calculated for each patient. Local recurrence is defined as either invasive or noninvasive recurrence within the target volume. Ipsilateral elsewhere recurrence is defined as either an invasive or noninvasive recurrence occurring outside of the target volume in the previously treated breast. This recurrence is classified as a new primary tumor. RESULTS: The mean follow-up period was 9.5 months (range, 1-24 mo). The MammoSite catheter was explanted for the following reasons: inadequate skin distance (5.1%; 6 of 117), poor cavity conformance (5.1%; 6 of 117), positive margins (2.6%; 3 of 117), final histology (.85%; 1 of 117), and physician decision (.85%; 1 of 117). Of the patients in whom the MammoSite was explanted because of skin spacing or cavity conformance, 50% were at sites of new users (institutions that have placed fewer than 10 Mammosite catheters). Cosmetic results were rated as excellent in 63%, good in 35%, and fair in 2% in the 86 patients with a follow-up visit. Two patients were diagnosed with an ipsilateral local recurrence, 1 outside of the target volume and 1 true recurrence/marginal miss. One patient was diagnosed at 8 months and the other was diagnosed at 11 months. Both of these ipsilateral failures were DCIS. The Van Nuys Prognostic Index of these 2 patients was 9 and 8, respectively. Data collected showed the mean age at placement was 60.8 y, mean tumor size was 10.6 mm, mean actual closest surgical margin was 6.8 mm (range, .1-40 mm), a re-excision rate of 35%, postlumpectomy placement was 71%, and the mean skin-to-balloon surface distance was 13 mm with 89% > or =7 mm. No serious adverse events were reported. The infection rate was 4.0%. CONCLUSIONS: Accelerated partial breast irradiation delivered with the MammoSite balloon was clinically successful in patients entered into a phase II clinical study with pure DCIS, with results comparable with other studies reported in the literature that have evaluated use of the MammoSite balloon brachytherapy for delivery of radiation therapy in early breast cancers. Inadequate skin distance and poor cavity conformance were the main factors limiting the use of the MammoSite device. Cosmetic results were good to excellent in 98%. There have been 2 ipsilateral breast recurrences.     

Secondary angiosarcoma following catheter-based brachytherapy

Secondary angiosarcoma of the breast following catheter-based brachytherapy after lumpectomy is rare. We describe a case of a patient with breast cancer treated with partial mastectomy and sentinel node biopsy followed by accelerated partial breast irradiation (APBI), who developed skin changes 6 years after completion of therapy. Punch biopsy confirmed the diagnosis of secondary angiosarcoma. This case is even more unique in that the location of the skin changes was remote to the lumpectomy site. There is a critical need to recognize secondary angiosarcoma presentation after APBI and determine the rate of occurrence compared with traditional external beam irradiation.     

Surgeon-performed ultrasound reliably predicts skin spacing and may decrease the rate of MammoSite balloon catheter explantation in patients undergoing brachytherapy for breast cancer

OBJECTIVE: The purpose of this study was to determine if the distance from the skin to the seroma cavity, as measured with ultrasound (US) before catheter placement, correlated with the distance from skin to MammoSite balloon catheter as measured on computerized axial tomography (CAT) after catheter placement. METHODS: US was used to measure the distance from the skin to the seroma cavity, and then the MammoSite balloon catheter was inserted. Skin-to-balloon distance was then measured using CAT. Statistical analysis was performed to determine correlation between the 2 measurements. RESULTS: Our cohort consisted of 70 patients. US distance correlated with CAT distance (Pearson correlation coefficient .70). Mean US distance was 10.8 mm (SD 4.5 mm); mean CAT distance was 11.9 mm (SD 7.5 mm); and mean difference between the 2 measurements was -1.1 mm (SD 6.1 mm). A US measurement >/=7.6 mm predicted successful completion of MammoSite brachytherapy in 98% of patients. Patients with skin-to-seroma cavity distance <7.6 mm required explantation before treatment completion 39% of the time. CONCLUSIONS: Office-based US performed before insertion of the MammoSite balloon catheter statistically correlates with measurement by CAT. Patients with >/=7.6 mm skin-to-seroma cavity distance on US had a higher completion rate of MammoSite brachytherapy treatment.     

Postoperative ultrasound-guided percutaneous placement of a new breast brachytherapy balloon catheter

BACKGROUND: The optimal technique and timing for the implantation of a recently developed breast brachytherapy balloon catheter (MammoSite; Proxima Therapeutics, Alpharetta, Georgia) have not been well defined. We hypothesized that placing this postoperatively, utilizing percutaneous ultrasound-guided placement, would be preferable. METHODS: Patients who met eligibility requirements for breast brachytherapy were implanted with the MammoSite device utilizing percutaneous ultrasound-guided technique. Additionally, to study optimal timing, a historical cohort of patients operated upon for breast cancer by two of the authors were analyzed to compare the intraoperative and postoperative candidacy for MammoSite placement. RESULTS: Twenty-one of 23 patients successfully completed brachytherapy after implantation, with only 2 (9%) requiring catheter removal secondary to unfavorable balloon positioning. There were no serious complications. Of 343 historical patients with breast cancer, 137 were intraoperative candidates for brachytherapy, but final postoperative histology disqualified 40 (29%). CONCLUSIONS: Implantation of the MammoSite brachytherapy device is optimally performed postoperatively, after the final pathology is defined, utilizing ultrasound-guided percutaneous technique.     

Large Perigraft Seroma After Aortoiliac Bypass with an Expanded Polytetrafluoroethylene Graft: Report of a Case

A 63-year-old man who had undergone aortoiliac bypass with an expanded polytetrafluoroethylene (PTFE) graft was referred to our hospital for investigation and treatment of a possible pseudoaneurysm of the abdominal aorta. A tender, pulsatile, and bulging mass, about the size of an adult fist, was palpated around the navel. Enhanced computed tomography (CT) showed a large low-density area around the abdominal aorta and PTFE graft, and aortography showed a patent graft with no anastomotic leakage. Operative inspection revealed that the pulsatile mass was a large perigraft seroma, and we replaced the PTFE graft with a new woven Dacron graft. The patient has been well with no sign of recurrence for 1 year, although close long-term follow-up is mandatory.     

Postlumpectomy Insertion of the MammoSite brachytherapy device using the scar entry technique: initial experience and technical considerations

For women undergoing breast-conserving surgery, recent reports suggest that in selected cases accelerated partial breast irradiation may yield results equal to that of whole breast irradiation. Over 31 months, 19 patients underwent accelerated partial breast irradiation using the MammoSite as the sole radiation treatment following breast-conserving surgery. Seventeen patients had the MammoSite inserted postoperatively using the scar entry technique (SET). Treatments were delivered using high dose rate iridium 192 given twice a day for 5 days. Three complications (two minor, one major) occurred. Late radiation morbidity and overall cosmetic results were evaluated. Eighty percent of patients had either no change from baseline or slight change in skin pigment. More than 90% had good or excellent overall cosmetic outcomes. Patients undergoing accelerated partial breast irradiation with the MammoSite inserted using SET had excellent overall cosmetic results. Advantages of the SET over intraoperative placement are presented.     

Accelerated partial breast irradiation: Current status with a focus on clinical practice

Accelerated partial breast irradiation (APBI), a radiation technique in which only the tumor bed is treated, has now become an acceptable radiation modality for selected early‐stage breast cancer patients. Compared to conventional whole breast irradiation (WBI), APBI has some benefits with regard to the reduced total irradiated breast volume and the shorter treatment time. The role of APBI, which can be delivered using diverse techniques, has been evaluated in several prospective randomized phase III trials. These clinical trials demonstrate diverging outcomes relating to local recurrence, while establishing comparable effect in terms of survival between APBI with WBI. The aim of this study was to review the current status of APBI with a focus on clinical practice.     

Breast Cancer Recurrence after Inadvertent Malpositioning of a Partial Breast Radiation Catheter

Abstract: Accelerated partial breast irradiation (APBI) is an alternative to receiving whole breast radiation in carefully selected patients. Because breast cancer local recurrence rates are low and follow‐up has been short‐term, the exact cause of recurrences after APBI has been difficult to evaluate. We report the first case of documented radiation balloon catheter malpositioning that resulted in local recurrence. Patients undergo CT imaging of the breast after radiation balloon catheter placement for radiotherapy treatment planning, which evaluates adequate conformance of the balloon to the surrounding breast parenchyma and confirms a >7 mm distance between the balloon surface and the skin surface. Although true local recurrences are rare in appropriately selected partial breast irradiation candidates, inadvertent malpositioning of the radiation treatment catheter can increase the risk. This case is presented to illustrate the importance of comparing CT radiation planning images, with treatment catheter in place, to the original diagnostic breast imaging studies to confirm proper catheter positioning (in addition to measuring balloon to skin distance and conformance) prior to initiating radiotherapy.     

Shortened Radiation Therapy Schedules for Early‐Stage Breast Cancer: A Review of Hypofractionated Whole‐Breast Irradiation and Accelerated Partial Breast Irradiation

Breast‐conserving therapy consisting of segmental mastectomy followed by whole‐breast irradiation (WBI) has become widely accepted as an alternative to mastectomy as a treatment for women with early‐stage breast cancer. WBI is typically delivered over the course of 5–6 weeks to the whole breast. Hypofractionated whole‐breast irradiation and accelerated partial breast irradiation have developed as alternative radiation techniques for select patients with favorable early‐stage breast cancer. These radiation regimens allow for greater patient convenience and the potential for decreased health care costs. We review here the scientific rationale behind delivering a shorter course of radiation therapy using these distinct treatment regimens in this setting as well as an overview of the published data and pending trials comparing these alternative treatment regimens to WBI.     

Ten daily fractions for partial breast irradiation. Long‐term results of a prospective phase II trial

Partial breast irradiation (PBI) is an effective adjuvant treatment after breast conservative surgery for selected early‐stage breast cancer patients. However, the best fractionation scheme is not well defined. Hereby, we report the 5‐year clinical outcome and toxicity of a phase II prospective study of a novel regimen to deliver PBI, which consists in 40 Gy delivered in 10 daily fractions. Patients with early‐stage (pT1‐pT2, pN0‐pN1a, M0) invasive breast cancer were enrolled after conservative surgery. The minimum age at diagnosis was 60 years old. PBI was delivered with 3D‐conformal radiotherapy technique with a total dose of 40 Gy, fractionated in 10 daily fractions (4 Gy/fraction). Eighty patients were enrolled. The median follow‐up was 67 months. Five‐year local control (LC), disease‐free survival (DFS), and overall survival (OS) were 95%, 91%, and 96%, respectively. Grade I and II subcutaneous fibrosis were documented in 23% and 5% of cases. No grade III late toxicity was observed. PBI delivered in 40 Gy in 10 daily fractions provided good clinical results and was a valid radiotherapy option for early‐stage breast cancer patients.