Long-term results of multicatheter interstitial high-dose-rate brachytherapy for accelerated partial-breast irradiation

Purpose

The purpose of this study was to report the long-term results of women treated in one center with accelerated partial-breast irradiation (APBI) with interstitial high-dose-rate (HDR) brachytherapy.

Long-term outcome and toxicity in a Phase I/II trial using high-dose-rate multicatheter interstitial brachytherapy for T1/T2 breast cancer

PURPOSE: To present an updated analysis of survival, recurrence rate, and toxicity for a cohort of women with early-stage breast cancer treated with high-dose-rate interstitial brachytherapy for accelerated partial breast irradiation. METHODS AND MATERIALS: From August 1997 to July 2001, a total of 32 women with 33 breast cancers were treated with interstitial high-dose-rate brachytherapy after breast-conserving surgery as part of a Phase I/II protocol. All patients had T1-2 tumors with < or b=3 axillary nodes positive, nonlobular histology, negative surgical margins, and no evidence of extracapsular lymph node extension. Multiple brachytherapy catheters were used and radiation was delivered with a high activity (3-10Ci) (192)Ir source placed via remote after loader. Dose was prescribed to the tumor bed plus a 2 cm margin. A total of 3400 cGy was delivered in 10 fractions of 340 cGy each given twice daily over 5 days. Toxicities (skin, subcutaneous tissue, pain, fat necrosis) were evaluated by Radiation Therapy Oncology Group criteria; cosmesis was assessed using a previously published scale. Toxicity scores were separated into four followup intervals: < or =6 months, >6 months and < or =2 years, >2 and < or =5 years, and >5 years. RESULTS: The actuarial local recurrence rate was 6.1% at 5 years with the last measured event at 70.5 months. A total of three treatment failures were observed at 25.8, 39.9, and 70.5 months of followup. All three were elsewhere failures within the treated breast. One patient died after 90.0 months of followup secondary to a subsequently diagnosed small-cell lung cancer. For the purpose of analysis, toxicity scores were assigned to each of four followup intervals: < or =6 months, >6 but < or =24 months, >24 but < or =60 months, and >60 months. Fat necrosis was not seen in the first 6 months after treatment, then appeared in 27.3% of patients from 6 to 24 months, 28.1% from 24 to 60 months, and 17.9% beyond 60 months. Skin toxicity appeared to stabilize with longer followup: the percentage of patients showing any degree of skin toxicity was 69.7%, 33.3%, 40.6%, and 28.6% at each successive time interval. Subcutaneous toxicity increased beyond 60 months: moderate to severe subcutaneous toxicity was seen in 15.2%, 18.2%, 18.8%, and 35.7% of patients successively. The percentage of patients with less than excellent cosmetic outcome improved beyond 60 months (21.2%, 21.2%, 21.9%, and 11.1% successively). Only 1 patient experienced more than mild pain at any time. The percentage of patients experiencing any degree of pain improved over time (30.3%, 33.3%, 18.8%, 17.9%). CONCLUSIONS: Our series showed a local recurrence rate of 6.1% at 5 years, which is comparable to that seen in conventional whole breast series. Fat necrosis was found in more than half the cohort. Fat necrosis, pain, and cosmesis appeared to improve with longer followup, whereas subcutaneous toxicity worsened and skin toxicity stabilized.     

Multi-institutional registry study evaluating the feasibility and toxicity of accelerated partial breast irradiation using noninvasive image-guided breast brachytherapy

PurposeThe noninvasive image-guided breast brachytherapy (NIBB) technique is a novel noninvasive yet targeted method for accelerated partial breast irradiation. We established a multi-institutional registry to evaluate the toxicity and efficacy of this technique across various practice settings.Methods and MaterialsInstitutions using the NIBB technique were invited to participate. Data for acute/late toxicity, cosmetic outcome, and tumor recurrence were collected. Toxicity and cosmetic outcome were graded based on the Common Terminology Criteria for Adverse Events version 3.0 and NRG/Radiation Therapy Oncology Group scale, respectively. Treatment variables were analyzed for association with outcomes.ResultsA total of 252 patients from eight institutions were analyzed. The median age was 69 years. The mean tumor size was 1.1 cm (0.1–4.0 cm). Treatment was delivered 10 fractions (34–36 Gy) in 75% and five fractions (28.5 Gy) in 22%. B.i.d. fractionation was used in 9%. Acute radiation dermatitis was Grade 0–1, 2, and 3 in 77%, 19%, and 4%, respectively. One hundred ninety-one patients with a median followup of 18 months (4–72 months) were evaluable for late outcomes. Late toxicity Grades 2 and 3 were observed in 8.8% and 1%, respectively. Cosmetic outcome was excellent, good, and fair/poor in 62%, 36%, and 2%, respectively. B.i.d. fractionation was associated with higher acute and late toxicity. Second-generation applicators were associated with lower late toxicity and better cosmetic outcome. Actuarial freedom from ipsilateral breast tumor recurrence and true recurrence were 98.3% and 98.3% at 2 years and 90.9% and 95.4% at 5 years, respectively.ConclusionsAccelerated partial breast irradiation using NIBB was well tolerated with a low rate of acute and late toxicity across various practice settings. Ipsilateral breast tumor recurrence and cosmetic outcomes were favorable. b.i.d. fractionation was associated with higher toxicity. Longer followup is needed to confirm late endpoints.     

Is oncoplastic surgery a contraindication for accelerated partial breast radiation using the interstitial multicatheter brachytherapy method?

PurposeTo evaluate accelerated partial breast irradiation (APBI) in patients after oncoplastic surgery for early breast cancer.Methods and MaterialsA retrospective analysis of 136 breasts of 134 patients, who received breast-conserving oncoplastic surgery for low-risk breast cancer between 2002 and 2010 in the Universities of Vienna and Luebeck followed by adjuvant APBI applying total doses of pulse dose rate of 50.4 Gy or high-dose rate (HDR) of 32 Gy over 4 days. Target volume definition was performed by the use of surgical-free margin data, related to intraoperatively fixed clip positions, pre- and postoperative imaging, and palpation.ResultsAt the time of data acquisition, 131 of 134 patients were alive. The median follow-up time was 39 months (range, 4–106 months). After high-dose rate treatment, 3 of 89 patients showed systemic progress after a mean follow-up of 47 months (range, 19–75 months) and 2 patients had a different quadrant in-breast tumor after 27 and 35 months. One patient died 7 months after treatment of unknown causes. After pulse dose rate treatment, 1 of 45 patients had a local recurrence after 42 months and 1 patient died because of another cause after 13 months. We observed mild fibrosis in 27 breasts, telangiectasia in 6, hyperpigmentation in 14 cases, and keloid formation in 1.ConclusionsThese preliminary results suggest the feasibility of multicatheter APBI after oncoplastic breast-conserving surgery in selected low-risk breast cancer patients; however, special attention to target volume definition is needed. Further prospective investigations with long follow-up are needed to define the real value of the procedure.     

Accelerated partial breast irradiation via brachytherapy: a patterns-of-care analysis with ASTRO consensus statement groupings

Purpose

The 2002 Food and Drug Administration approval of the MammoSite catheter (Hologic, Inc., Beford, MA) led to a surge of interest in accelerated partial breast irradiation (APBI). Until recently, guidelines as to the optimal candidates for this treatment were unavailable. We performed a patterns-of-care analysis for patients undergoing breast brachytherapy and compared these results with the American Society for Radiation Oncology (ASTRO) consensus statement.

Methods and Materials

The Surveillance, Epidemiology, and End Results database was used to examine female breast cancer patients treated with brachytherapy between 2002 and 2007. The patients were then categorized into suitable, cautionary, and unsuitable groups based on the ASTRO guidelines.

Results

We identified 4172 female breast cancer patients treated within the stated years. The number of brachytherapy cases increased nearly 10-fold over the time period studied from 163 in 2002 to 1427 in 2007 (p < 0.0001). Patients with data missing were excluded, leaving a total of 3593 patients available for analysis. The mean patient age was 64 years. Most patients had small (<2 cm in 80.9%) estrogen receptor-positive (86.7%) invasive (88.6%) tumors. The percentage of patients treated for ductal carcinoma in situ increased with time (p < 0.001), whereas the percentage of patients treated with positive lymph nodes decreased with time (p < 0.001). Using the data available, 1369 (38.1%), 1563 (43.5%), and 661 (18.3%) patients were characterized as suitable, cautionary, and unsuitable, respectively.

Conclusions

More than 60% of patients who received APBI via brachytherapy would fall into the ASTRO cautionary or unsuitable groupings. This is the largest patterns-of-care analysis for APBI patients and serves as a baseline for future comparison.     

Management of ductal carcinoma in situ with accelerated partial breast irradiation brachytherapy: Implications for guideline expansion

PurposeAccelerated partial breast irradiation (APBI) for patients with ductal carcinoma in situ (DCIS) is controversial, and the suitability criteria from the American Brachytherapy Society (ABS), American Society of Therapeutic Radiology and Oncology (ASTRO), and the European Society for Radiotherapy and Oncology (GEC-ESTRO) have important differences.Methods and MaterialsThis is a single-institution retrospective review of 169 consecutive patients with DCIS who underwent lumpectomy followed by APBI intracavitary brachytherapy from 2003 to 2018. Outcomes, including overall survival, recurrence-free survival (RFS), ipsilateral breast tumor recurrence, and distant metastasis, were estimated with the Kaplan–Meier method.ResultsThe median followup time was 62.5 months. Median age was 66 years (47–89 years). The majority of patients had estrogen receptor–positive disease (89%). Fifty patients (30%) had Grade 3 disease. Of the 142 patients with adequate pathology interpretation, 91 and 108 cases had margins ≥ 3 mm and ≥2 mm, respectively. Most patients (72%) were prescribed and started endocrine therapy. Of the patients evaluable for ABS criteria (N = 130), 97 met the suitability criteria. Of the patients evaluable for ASTRO criteria (N = 129), 42 were deemed cautionary and 33 were deemed unsuitable. Of the patients evaluable for GEC-ESTRO criteria (N = 143), 141 cases were at intermediate risk and two were at high risk. Five-year ipsilateral breast tumor recurrence, RFS, and overall survival were 0.6%, 97.7%, and 97.2%, respectively. The ABS, ASTRO, and GEC-ESTRO criteria failed to significantly predict for RFS.ConclusionsThese results, although limited by short-term followup, indicate that expansion of the eligibility criteria of APBI for patients with DCIS should be considered.     

Results of accelerated partial breast irradiation in patients not suitable for external beam irradiation stratified by GEC-ESTRO,ASTRO, and ABS guidelines

PurposeThis study aims to review the outcome of an institution in multicatheter/interstitial accelerated partial breast irradiation (MC-APBI) for treatment of patients with breast cancer, either with strong criteria for APBI or unable to be treated with whole-breast irradiation. The outcomes were also stratified by the American Society for Radiation Oncology, American Brachytherapy Society, and Groupe Européen de Curiethérapie-European Society for Therapeutic Radiology and Oncology patient selection criteria.MethodsThe study includes 118 patients and 120 MC-APBI treatments, treated in a single tertiary center, between November 2003 and August 2016. The analysis is focused on the clinical baseline characteristics, local control, relapse-free survival, disease-specific survival (DSS), and overall survival.ResultsIn accordance to the American Society for Radiation Oncology, American Brachytherapy Society, and Groupe Européen de Curiethérapie-European Society for Therapeutic Radiology and Oncology, 17.1% were “unsuitable,” 19.2% were “unacceptable,” and 19.5% were “high risk,” respectively. The main reasons why high-risk patients were submitted to MC-APBI were as follows: cardiopathy (n = 7), social difficulties (n = 4), and mobility limitations (n = 4). At the median followup period of 86.5 months, ipsilateral breast tumor recurrence was observed in one (0.8%) patient. The 3-year and 5-year relapse-free survival were 100% and 99.1%, respectively. DSS was 100%.ConclusionsThis study demonstrated excellent control rates, DFS, and DSS of MC-APBI, rendering APBI as an excellent treatment for patients with breast cancer, even those who are not necessarily eligible for this treatment approach. The selection criteria for ABPI diverge according to different guidelines and are based on studies with discrepancies, making extremely possible that these recommendations could be changed.     

Accelerated partial breast irradiation for suitable elderly women using a single fraction of multicatheter interstitial high-dose-rate brachytherapy: Early results of the Single-Fraction Elderly Breast Irradiation (SiFEBI) Phase I/II trial

Purpose/ObjectiveTo evaluate feasibility and early clinical outcomes of a single fraction of multi-catheter interstitial high-dose rate brachytherapy for accelerated partial breast irradiation (APBI) in the elderly.Material/MethodsFrom November 2012 to September 2014, 26 patients (≥70) with early breast cancer were enrolled in a prospective phase II trial (NCT01727011). After lumpectomy, intra-operative catheter implant was performed for post-operative APBI (single fraction 16 Gy). Surveillance was achieved at 1, 3 and 6 months after APBI, then twice a year. Acute toxicity was investigated. Early cosmetic outcome was analyzed (patient, radiation oncologist, 2 observers). Local and regional relapse-free survival, cancer specific survival and overall survival were analyzed.ResultsMedian age was 77 years [69–89]. Median CTV was 41 cc [22-95]. Acute toxicity was observed in 18 pts (70%) with a total of 44 events: G1: 75.7%; G2: 22.8%; G3: 4.5%. Breast fibrosis (31.8%), puncture site inflammation (13.6%) and skin hyperpigmentation (11.4%) were the most frequent side effects. Cosmetic evaluation at 6 months was excellent/good in 88%, 92%, 85% and 88% for patient, radiation oncologist, observer #1 and #2 respectively. With a median follow-up of 37.2 months [35.6-42.3], side effects were G1: 4 pts (15%) and G2: 1 pt (4%). Three-year Local and regional relapse-free survival, cancer specific survival and overall survival rates were 100%, 100%, 100% and 95.2% respectively.ConclusionsFor elderly early breast cancer, a post-operative multi-catheter interstitial high-dose rate brachytherapy single dose (16 Gy) appears feasible. Acute toxicity is acceptable as well as early cosmetic outcome. Oncologic outcome seems encouraging and allows going forward with new clinical trials focusing on single fraction APBI.     

Predicting adherence of dose–volume constraints for personalized partial-breast irradiation technique

PurposeMulticatheter interstitial brachytherapy (MIB) and external-beam (EB) radiotherapy are established partial-breast irradiation (PBI) techniques. Although EB-PBI is widely available, it requires extra irradiated margins for target uncertainties. We examined the impact of EB-PBI on dose–volume constraints as compared to MIB-PBI.Methods and MaterialsAmong 653 patients receiving MIB-PBI between October 2008 and April 2020, consequent 159 patients after September 2018 were examined. Clinical target volume (CTV) included the lumpectomy cavity plus 1.0 cm. Planning target volume (PTV) for EB-PBI was defined as CTV with 1.0-cm expansion. Because the ratio of PTV to breast volume (RPB) was related to cosmesis, <25% of RPB was defined as suitable for the ipsilateral breast constraints. Preoperative breast size was classified as very small (<350 cm³), small (350–699 cm³), and medium or large (≥700 cm³). According to each category, the dose–volume constraints of the organs at risk were compared between the two PBI techniques.ResultsPatients including 84 very small, 59 small, and 16 moderate to large breasts were examined. Although RPB was suitable in all patients receiving MIB-PBI, it was achieved in 74 patients (46.5%) receiving EB-PBI (p < 0.0001). The suitable RPB in patients with very small, small, and moderate to large breast was 32.1%, 55.9%, and 100%, respectively (p < 0.0001). Normal-tissue constraints for the other organs could be satisfied in patients with moderate to large breasts.ConclusionAlthough EB-PBI may be an appropriate option for patients with moderate to large breasts, MIB-PBI could still be a crucial technique, especially for patients with small breasts.     

Five fraction accelerated partial breast irradiation using noninvasive image-guided breast brachytherapy: Feasibility and acute toxicity

PurposeTo improve efficiency, convenience, and cost, a prospective phase II trial was initiated to evaluate accelerated partial breast irradiation delivered with noninvasive image-guided breast brachytherapy (NIBB) via five once-daily fractions.Methods and MaterialsWomen ≥50 years old with early-stage breast cancer undergoing breast conserving surgery were enrolled. Eligibility criteria included invasive carcinoma ≤2.0 cm or ductal carcinoma in situ ≤3.0 cm, ER positive (if invasive), lymph node negative, LVI absent, and margins negative by 2 mm. Patients received a total dose of 28.5 Gy in five daily fractions. NIBB was delivered using two orthogonal axes for each fraction. Applicators were selected to encompass the lumpectomy cavity with a 1.0 cm clinical target volume margin and 0 to 0.5 cm planning target volume margin. Acute and late toxicity was assessed based on CTCAE v3.0.ResultsForty patients with a mean age of 67 years underwent protocol treatment. Mean tumor size was 1.0 cm (0.3–2.0 cm). Eighty percent had invasive carcinoma and the remainder had ductal carcinoma in situ. Mean tumor bed volume was 21 cc (5–79 cc) and mean breast volume was 1319 cc (499–3044 cc). Mean breast separation with compression was 6.7 cm (3.5–8.9 cm). All patients tolerated well. Median discomfort with compression was 1 (range: 0–7) on a 10-point pain scale. Acute skin reaction was Grade 0–1 in 70%, Grade 2 in 28%, and Grade 3 in 3%. Acute skin toxicity was not associated with breast size but was associated with larger breast separation with compression (p < 0.01) and larger applicator size (p < 0.01). No Grade 3+ late toxicity or local recurrences have been observed at a median followup of 14 months.ConclusionsAccelerated partial breast irradiation delivered using NIBB over five daily fractions is a convenient treatment option that is feasible and well tolerated.     

The rationale,technique, and feasibility of partial breast irradiation using noninvasive image-guided breast brachytherapy

PurposeNoninvasive image-guided breast brachytherapy (NIBB) is a novel approach to deliver accelerated partial breast irradiation (APBI). NIBB is noninvasive, yet maintains a high degree of precision by using breast immobilization and image guidance. This makes NIBB an attractive alternative to existing APBI techniques.Methods and MaterialsForty patients were enrolled to an institutional review board-approved prospective clinical trial evaluating APBI using NIBB. The NIBB technique is described in detail. Briefly, patients were treated with the breast compressed and immobilized sequentially in two orthogonal axes for each fraction. Radiation was delivered using collimated emissions from a high-dose-rate iridium-192 source via specialized applicators. The prescribed dose was 34.0 Gy in 10 fractions. Feasibility and tolerability of treatment were assessed.ResultsAll patients completed protocol treatment. The median age was 68 years. Sixty-three percent of patients had invasive carcinoma, and 37% had ductal carcinoma in situ. All were node negative. Ninety-three percent of patients were postmenopausal. Mean tumor size, tumor bed volume, and breast volume were 1.1 cm, 22.4 cc, and 1591 cc, respectively. NIBB treatment was well tolerated. Median patient-reported discomfort was 1 on a 10-point pain scale. Treatment delivery times were reasonable. The average treatment time per axis was 14 min (5–20 min), and the average time from start of first treatment axis to completion of orthogonal axis was 43 min (30–63 min). Acute skin toxicity was Grade 0, 1, and 2 in 20%, 53%, and 28% of patients, respectively. There were no Grade 3 or greater acute toxicities observed.ConclusionsNIBB holds promise as an alternative method to deliver APBI. NIBB is feasible and well tolerated by patients. Further investigation of NIBB to deliver APBI is warranted.     

Five-year results of accelerated partial breast irradiation: A single-institution retrospective review of 289 cases

PurposeThe purpose of the study was to describe our institutional experience with accelerated partial breast irradiation (APBI) using multicatheter brachytherapy with high-dose-rate. We report 5-year survival outcomes, cosmesis, and treatment-related toxicity.Methods and MaterialsThis included a retrospective review of patients who underwent breast-conserving surgery followed by APBI at our institution from 2004 to 2017.ResultsA total of 289 patients were evaluated. Median followup was 72 months. Median age was 70 years. APBI was the only primary treatment in 86.2% of cases with early-stage breast cancer and a second conservative treatment in 13.8%. The implant was performed postoperatively in 213 patients (73.7%) and intraoperatively in 76 (26.3%). The most common radiation schemes were 10 fractions of 3.4 Gy and eight fractions of 4 Gy. Elderly or frail patients (10%) received a single 16 Gy dose. Of the 289 patients, 215 met Groupe Européen de Curiethérapie-European Society for Radiotherapy and Oncology criteria for APBI; in this group, late side effects included Grade 2 (G2) fibrosis (14.8%), skin discoloration at the catheter points (8.8%), and telangiectasia (0.5%). The cosmetic result was considered excellent or good in 88.3% of cases. Five-year local control, disease-free, cancer-specific, and overall survival rates were 98.9%, 96.7%, 99.1%, and 95.6%, respectively.ConclusionsLocal control and survival outcomes at 5 years of followup in this group of well-selected patients were excellent, with low rates of treatment-related toxicity. These findings confirm the safety and effectiveness of APBI, even in elderly and frail patients. These results provide further support for the clinical use of APBI in suitable patients.     

Accelerated partial breast irradiation in the elderly: 8-year oncological outcomes and prognostic factors

PurposeThe purpose of the study is to evaluate long-term clinical outcomes and prognostic factors after accelerated partial breast irradiation (APBI) in the elderly using high-dose-rate interstitial multicatheter brachytherapy (HIBT).Methods and MaterialsBetween 2005 and 2018, 109 patients underwent APBI using HIBT (34 Gy/10f/5d or 32 Gy/8f/4d). Based on a prospective database, outcomes were retrospectively analyzed (local relapse-free survival, metastatic-free survival, specific survival (SS), and overall survival (OS)). Prognostic factors were investigated. Late toxicity and cosmetic evaluation were reported.ResultsWith a median followup of 97 months [7–159], median age was 81.7 years [58–89]. In accordance with the GEC-ESTRO APBI classification, 72.5%, 11.9%, and 15.6% were classified as low, intermediate, and high risk, respectively. The histological type was mainly invasive ductal carcinoma (87.1%). The median tumor size was 10 mm [range 1–35]. Eight-year local relapse-free survival, SS, and OS were 96.7% [95% confidence interval (CI) [0.923; 1]), 96.7% [95% CI [0.924; 1], and 72% [95% CI [0.616; 0.837], respectively. In univariate analysis, APBI classification was not considered as prognostic factor, whereas molecular classification was prognostic factor for OS (p < 0.0001), SS (p = 0.007), and metastatic-free survival (p = 0.009) but not for local recurrence (p = 0.586). No Grade ≥3 late toxicity was observed, whereas 61 patients (88.4%) and 8 patients (11.6%) presented Grade 1 and 2 toxicities, respectively. The cosmetic outcome was excellent/good for 96.4%.ConclusionsLong-term followup confirms that HIBT is safe and effective for elderly early breast cancer. Our results suggest that selected elderly women presenting with high-risk breast cancer could be also considered for APBI.     

Radiation recall reaction with docetaxel administration after accelerated partial breast irradiation with electronic brachytherapy

PurposeAccelerated partial breast irradiation (APBI) offers several advantages over whole breast irradiation. Electronic brachytherapy may further reduce barriers to breast conserving therapy by making APBI more available. However, its toxicity profile is not well characterized.Methods and MaterialsA 60-year-old woman was treated with APBI using Axxent (Xoft, Sunnyvale, CA) electronic brachytherapy. One month after APBI, a cycle of docetaxel and cyclophosphamide was given. Within 3 weeks, the patient developed an ulcerative radiation recall reaction in the skin overlying the lumpectomy cavity. To investigate this toxicity, the skin dose from electronic brachytherapy was compared with the dose that would have been delivered by an iridium-192 (¹⁹²Ir) source. Additionally, a dose equivalent was estimated by adjusting for the increased relative biologic effectiveness (RBE) of low energy photons generated by the electronic source.ResultsUsing electronic brachytherapy, the skin dose was 537 cGy per fraction compared with 470 cGy for an ¹⁹²Ir source. Given an RBE for a 40 kV source of 1.28 compared with ¹⁹²Ir, the equivalent dose at the skin for an electronic source was 687 cGy-equivalents, a 46% increase.ConclusionsWe present a case of an ulcerative radiation recall reaction in a patient receiving APBI with electronic brachytherapy followed by chemotherapy. Our analysis shows that the use of electronic brachytherapy resulted in the deposition of significantly higher equivalent dose at the skin compared with ¹⁹²Ir. These findings suggest that standard guidelines (e.g., surface-to-skin distance) that apply to ¹⁹²Ir-based balloon brachytherapy may not be applicable to electronic brachytherapy.     

Long-term followup of breast preservation by re-excision and balloon brachytherapy after ipsilateral breast tumor recurrence

PurposeTo report our long-term experience with balloon brachytherapy in retreatment of the breast after ipsilateral breast tumor recurrence.Methods and MaterialsBetween March 2004 and June 2012, 18 patients previously treated with external beam radiotherapy were retreated using either the MammoSite (Hologic Corporation, Marlborough, MA), MammoSite ML (Hologic Corporation), or the Contura (Bard Peripheral Vascular, Inc., Tempe, AZ) brachytherapy devices. Sixteen patients were treated for an ipsilateral breast tumor recurrence after breast conservation surgery and postoperative irradiation (11 with infiltrating ductal carcinoma [IDC] and 6 with ductal carcinoma in situ [DCIS]), whereas 2 patients developed an in-field breast cancer likely associated with Hodgkin disease mantle irradiation (27 and 17 years prior, respectively). The recurrent histology of seven was IDC, with seven others recurring as DCIS, three as a combination of IDC/DCIS, and one as infiltrating lobular carcinoma. All patients received a twice-daily tumor dose of 3400 cGy at 340 cGy per fraction. Acute and chronic side effects were graded by the Common Terminology Criteria for Adverse Events, version 4.0. Cosmesis was graded by both the Harvard Cosmesis Scale and the Allegheny General Modification of the Harvard Scale.ResultsWith a mean of followup of 39.6 months, only 2 patients developed a local recurrence. One patient developed an inflammatory recurrence from what was identified as a moderately differentiated T1N0M0 estrogen receptor–positive recurrence, and the second developed a recurrence immediately adjacent to the implant site. Both patients were treated locally by salvage mastectomy. The patient who developed an inflammatory recurrence rapidly developed visceral metastases including brain lesions and succumbed to her progressive disease. The second patient was successfully salvaged with uncomplicated mastectomy, and she survives to this date. One patient developed a chronic abscess in the sinus tract of the balloon, which required mastectomy, and one developed a post-treatment infection in the catheter tract, which was successfully treated with oral antibiotics. Cosmesis as graded by the Harvard cosmesis criteria and the Allegheny General Modification Score diminished one grade in only 2 patients. All other patients had stable cosmetic scores.ConclusionsUse of balloon brachytherapy devices in the treatment of the previously irradiated breast is feasible and may provide adequate local control and acceptable cosmesis in carefully selected patients. Further study and refinement of this therapy is required for more definitive results.     

Impact of Increasing Margin Around the Lumpectomy Cavity to Define the Planning Target Volume for 3D Conformal External Beam Accelerated Partial Breast Irradiation

The purpose of this study was to evaluate the dose to normal tissues as a function of increasing margins around the lumpectomy cavity in accelerated partial breast irradiation (APBI) using 3D-conformal radiotherapy (3DCRT). Eight patients with Stage 0-I breast cancer underwent treatment planning for 3DCRT APBI. The clinical target volume (CTV) was defined as a 15-mm expansion around the cavity limited by the chest wall and skin. Three planning target volumes (PTV1, PTV2, PTV3) were generated for each patient using a 0, 5-, and 10-mm expansion around the CTV, for a total margin of 15, 20, and 25 mm. Three treatment plans were generated for every patient using the 3 PTVs, and dose-volume analysis was performed for each plan. For each 5-mm increase in margin, the mean PTV:total breast volume ratio increased 10% and the relative increase in the mean ipsilateral breast dose was 15%. The mean volume of ipsilateral breast tissue receiving 75%, 50%, and 25% of the prescribed dose increased 6% to 7% for every 5 mm increase in PTV margin. Compared to lesions located in the upper outer quadrant, plans for medially located tumors revealed higher mean ipsilateral breast doses and 20% to 22% more ipsilateral breast tissue encompassed by the 25% IDL. The use of 3DCRT for APBI delivers higher doses to normal breast tissue as the PTV increases around the lumpectomy cavity. Efforts should be made to minimize the overall PTV when this technique is used. Ongoing studies will be necessary to determine the clinical relevance of these findings.     

Second breast-conserving surgery and interstitial brachytherapy vs. salvage mastectomy for the treatment of local recurrences: 5-year results

PurposeThe purpose of this study was to report the clinical outcomes of a second breast-conserving therapy (2nd BCT) with perioperative interstitial brachytherapy (iBT) vs. those of salvage mastectomy (sMT) in the treatment of ipsilateral breast tumor recurrences (IBTRs).Methods and MaterialsBetween 1999 and 2015, 195 patients with IBTR after a previous breast-conserving treatment were salvaged either with reexcision and perioperative high-dose-rate iBT (n = 39), or with sMT (n = 156). In the 2nd BCT group, a total dose of 22 Gy in five fractions of 4.4 Gy was delivered to the tumor bed with intraoperatively implanted catheters for 3 consecutive days.ResultsThe median followup time was 59 months (1–189) in the 2nd BCT, and 56 months (3–189) in the sMT group. The mean size of IBTR was 16 mm (2–70) vs. 24 mm (2–90), respectively (p = 0.0005), but there were no other significant differences in patient- or IBTR-related parameters between the two groups. During the followup period, 4 of 39 (10.2%) and 28 of 156 (17.9%) second local recurrences (2nd LR) occurred in the 2nd BCT and the sMT group, respectively. The 5-year actuarial rate of 2nd LR was 6% vs. 18% (p = 0.22), the 5-year probability of disease-free, cancer-specific and overall survival was 69% vs. 65% (p = 0.13), 85% vs. 78% (p = 0.32), and 81% vs. 66% (p = 0.15), respectively. In the 2nd BCT group, the rate of good to excellent cosmesis was 70%.Conclusions2nd BCT with perioperative high-dose-rate iBT is a safe and feasible option for the management of IBTR, resulting in similar 5-year oncological outcomes and better cosmetic results compared with sMT.     

Impact of Increasing Margin Around the Lumpectomy Cavity to Define the Planning Target Volume for 3D Conformal External Beam Accelerated Partial Breast Irradiation

The purpose of this study was to evaluate the dose to normal tissues as a function of increasing margins around the lumpectomy cavity in accelerated partial breast irradiation (APBI) using 3D-conformal radiotherapy (3DCRT). Eight patients with Stage 0-I breast cancer underwent treatment planning for 3DCRT APBI. The clinical target volume (CTV) was defined as a 15-mm expansion around the cavity limited by the chest wall and skin. Three planning target volumes (PTV1, PTV2, PTV3) were generated for each patient using a 0, 5-, and 10-mm expansion around the CTV, for a total margin of 15, 20, and 25 mm. Three treatment plans were generated for every patient using the 3 PTVs, and dose-volume analysis was performed for each plan. For each 5-mm increase in margin, the mean PTV:total breast volume ratio increased 10% and the relative increase in the mean ipsilateral breast dose was 15%. The mean volume of ipsilateral breast tissue receiving 75%, 50%, and 25% of the prescribed dose increased 6% to 7% for every 5 mm increase in PTV margin. Compared to lesions located in the upper outer quadrant, plans for medially located tumors revealed higher mean ipsilateral breast doses and 20% to 22% more ipsilateral breast tissue encompassed by the 25% IDL. The use of 3DCRT for APBI delivers higher doses to normal breast tissue as the PTV increases around the lumpectomy cavity. Efforts should be made to minimize the overall PTV when this technique is used. Ongoing studies will be necessary to determine the clinical relevance of these findings.     

Uterine perforation during brachytherapy for cervical cancer: Complications,outcomes, and best practices for forward treatment planning and management

PurposeThe purpose of the study was to determine the incidence of uterine perforations, review the associated complications, and propose guidelines for management of perforations after brachytherapy.Methods and MaterialsA retrospective chart review was conducted for all patients with cervical cancer who received single or multiple high-dose-rate brachytherapy implants between April 2006 and May 2017 at a single academic institution. CT and MRI images were retrospectively evaluated to record incidences of uterine perforation of tandem during brachytherapy. Acute and long-term complications during and after treatment were scored using the Common Terminology Criteria for Adverse Events, Version 4.0, of the National Cancer Institute.ResultsA total of 123 patients were included in the study. Perforations were observed in 22 patients (17.9%) with 31 (6.4%) of the 482 total implants. Of the different categories of adverse events, only the rate of acute infectious complications among those with perforations (n = 3, 13.6%) versus those without perforations (n = 3, 3.0%) was significant (p = 0.040). Two of the three perforated patients with acute infections had mild urinary tract infections, and all resolved without complications or treatment delays. The remaining one patient had a frank perforation of the anterior uterine wall with a subsequent Grade 3 pyometra infection despite administration of prophylactic antibiotics and 1-week treatment delay. This case was eventually resolved with cervical dilation and evacuation of fluid. Long-term complications were not different between the two arms.ConclusionsPatients with cervical cancer with uterine perforations may be able to safely proceed with brachytherapy treatment without delay or need for prophylactic antibiotics in the acute setting. Further validating data would be able to assist in establishing a new standard of care and help prevent unnecessary and harmful breaks during treatment.     

An evaluation of our experience in position verification of catheters used for interstitial high-dose-rate brachytherapy of solitary bladder tumors

PurposeThe goal of this study was to verify the position of catheters used over 4 days for brachytherapy of solitary bladder tumors.Methods and MaterialsThe study covered three phases. Shifting of catheters was studied using daily position verification CT scans of 20 patients. The possibility to omit the CT scan on Day 2 by adding a loading margin of 4 mm on each side was studied using data of 5 patients. Whether the Day 4 verification CT scan could be omitted if this margin was used, was studied for another group of 10 patients, comparing the Day 3 treatment plan to the Day 4 CT scan.ResultsAn average catheter shift on Days 2, 3, and 4 of, respectively, −0.3 mm (−8 to 10 mm), −0.5 mm (−14 to 10 mm), and −0.1 mm (−16 to 28 mm) was found over the measurements at both sites of the catheter. Including only shifts causing underdosing of the clinical target volume (CTV), the average shift on Days 2, 3, and 4 was, respectively, −3.6 mm (−1 to −8 mm), −5.4 mm (−1 to −14 mm), and −5.3 mm (−1 to −16 mm). After adding a loading margin, the CTV was covered on Day 2; however, the margin was not sufficient for Days 3 and 4. On Day 4, in 2/10 patients, the CTV was not completely covered. In 5/10 patients, an increased 200% isodose volume was found.ConclusionsPosition verification is necessary in bladder brachytherapy. If a 4-mm margin on each side of the loading pattern was added, position verification on Day 2 could be omitted. The verification CT scan of Days 3 and 4 is still necessary.