Outcomes with Partial Breast Irradiation vs. Whole Breast Irradiation: a Meta-Analysis.

BACKGROUND: Several randomized trials have been performed comparing partial breast irradiation (PBI) and whole breast irradiation (WBI) though controversy remains, including regarding differences by PBI technique. We performed a meta-analysis to compare results between WBI versus PBI and between PBI techniques. METHODS: A systematic review was performed to identify modern randomized studies listed in MEDLINE from 2005 to 2020. PBI trials were divided into external beam radiation and brachytherapy techniques, with intraoperative radiation excluded. A Bayesian logistic regression model evaluated the risk of ipsilateral breast tumor recurrence (IBTR) and acute and chronic toxicities. The primary outcome was IBTR at 5 years with WBI compared with PBI. RESULTS: A total of 9758 patients from 7 studies were included (4840-WBI, 4918-PBI). At 5 years, no statistically significant difference in the rate of IBTR was noted between PBI (1.8%, 95% HPD 0.68-3.2%) and WBI (1.7%, 95% HPD 0.92-2.4%). By PBI technique, the 5-year rate of IBTR rate for external beam was 1.7% and 2.2% for brachytherapy. Rates of grade 2 + acute toxicity were 7.1% with PBI versus 47.5% with WBI. For late toxicities, grade 2/3 rates were 0%/0% with PBI compared with 1.0%/0% with WBI. CONCLUSIONS: IBTR rates were similar between PBI and WBI with no significant differences noted by PBI technique; PBI had reduced acute toxicities compared to WBI. Because studies did not provide toxicity data in a consistent fashion, definitive conclusions cannot be made with additional data from randomized trials needed to compare toxicity profiles between PBI techniques.

Early complications of high-dose-rate brachytherapy in soft tissue sarcoma: a comparison with traditional external-beam radiotherapy.

BACKGROUND: Radiotherapy and surgery are routinely utilized to treat extremity soft tissue sarcoma. Multiple radiation modalities have been described, each with advantages and disadvantages, without one modality demonstrating clear superiority over the others. QUESTIONS/PURPOSES: We determined the overall initial complication rate in patients receiving surgery and radiotherapy, which specific complications were found when comparing different modalities, and whether combination therapy increased the overall rate of complications compared with surgery and single-modality radiotherapy. PATIENTS AND METHODS: We retrospectively reviewed the records of 190 patients who received external-beam radiotherapy (141 patients), high-dose-rate brachytherapy (37 patients), or both (12 patients). We evaluated 100 men and 90 women (mean age, 57 years; range, 18-94 years) for tumor size and subtype, comorbidities, stage, grade, margin of resection, type of adjuvant treatment, and complications. Minimum followup was 3 months (mean, 40 months; range, 3-155 months). RESULTS: The most frequent early complications in the high-dose-rate brachytherapy cohort were infection, cellulitis, and seroma and/or hematoma. In the external-beam radiotherapy cohort, chronic edema, fibrosis, and chronic radiation dermatitis were more frequently encountered. The total number of early complications and overall incidence of major complications requiring further surgery were similar among the three cohorts, but a larger number of patients in the high-dose-rate brachytherapy group required subsequent surgery for infection compared with the external-beam radiotherapy group. CONCLUSIONS: High-dose-rate brachytherapy decreases radiation exposure and allows shorter duration of treatment compared with traditional external-beam radiotherapy but has a higher perioperative wound complication rate. LEVEL OF EVIDENCE: Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Imaging findings after breast brachytherapy.

OBJECTIVE: The purpose of this study was to determine whether there are imaging changes specific to partial breast radiation therapy with interstitial catheters or a single balloon. MATERIALS AND METHODS: The records of 43 of 83 patients treated with partial breast irradiation at our institution from June 1996 to October 2003 were retrospectively reviewed. The images of 27 patients who had received radiation by interstitial catheters and 16 who had received radiation by a single balloon were reviewed. Patients were examined for the presence of skin thickening, diffuse and focal increased density, mass, lucency, and calcifications. Fifteen initial sonograms were ordered to evaluate pain or focal findings on mammograms. In addition, two patients underwent one and one patient underwent three follow-up sonographic examinations. RESULTS: Mild to moderate skin thickening was present in 26 (60%) and no skin thickening in 17 (40%) of the 43 patients. Forty-one (95%) of the 43 patients had focal increased density. Diffuse increased density was seen in only one (2%) of the patients. There was no change in overall density in 2 (5%) of the patients. Fifteen (35%) of the 43 patients had mass or seroma at the first follow-up examination. Central lucency was present in 35 (81%) of 43 patients on at least one follow-up study. Calcification was present in 8 (19%) of 43 cases. CONCLUSION: Imaging findings after breast brachytherapy include the spectrum of findings seen with external beam radiation but are more focal. The focal findings may be alarming both clinically and radiographically, but biopsy can be avoided in most instances if information from the history is correlated with findings from continued follow-up of the patient's case.

Accelerated partial breast irradiation: the case for current use.

The treatment of early stage breast cancer is evolving from traditional breast conservation techniques, employing conventionally fractionated whole breast irradiation, to techniques in which partial breast irradiation is used in an accelerated fractionation scheme. A growing body of evidence exists, including favorable findings. Additional studies are under way that may ultimately prove equivalence. The logic behind this approach is reviewed, and the currently available data are presented to support the current use of carefully applied partial breast irradiation techniques in appropriately selected and informed patients.

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.