Strut-based Brachytherapy Research Articles

Strut-based accelerated partial breast irradiation: Report of treatment results for 250 consecutive patients at 5 years from a multicenter retrospective study

PurposeThis registry trial studied the long-term outcomes of women receiving accelerated partial breast irradiation (APBI) using strut-based applicators and reports on the local control, toxicity, and survival for the first 250 patients treated with this device. Methods and MaterialsPatients were treated using the strut-based brachytherapy device with conventional dose and fractionation of 34 Gy in 10 twice-daily fractions. Planning goals for the planning target volume were V90 > 90%, V150 < 50 cc, and V200 < 20 cc. Toxicity was graded based on the Common Terminology Criteria for Adverse Events v3.0. Recurrence rates were also calculated. ResultsMedian followup was 59.5 months for the 250 patients. Grade 2 or higher adverse events at any time for hyperpigmentation, induration, erythema, telangiectasia, breast pain, seroma, and fat necrosis were 0.4%, 3.0%, 3.0%, 3.0%, 3.9%, 4.8%, and 1.3%, respectively. The median V90 was 97%, V95 was 95.1%, V150 was 28.7 cc, and V200 was 14.2 cc. For those patients with a less than a 5-mm or 3-mm-skin bridge, the median skin max doses were 272 and 289 cGy, respectively. The 4-year actuarial recurrence rates for true recurrence/marginal miss and ipsilateral breast tumor recurrence were 2.3% and 3.6%, respectively. The 4-year actuarial rates for overall survival, cause-specific survival, and disease-free survival were 97%, 98%, and 92%, respectively. ConclusionsThe strut-based applicator was designed to simplify APBI compared to interstitial brachytherapy. This report confirms excellent tumor control and survival with low toxicity and supports the evidence that brachytherapy has less normal tissue toxicity than APBI with external beam irradiation.

Abstract P3-13-10: Minimally-invasive (percutaneous) stereotactic and ultrasound-guided lumpectomy for DCIS and small breast cancers

Abstract Background In spite of advances characterizing the biology of individual breast cancers, current analytics cannot adequately identify truly indolent lesions. As a result many indolent breast cancers and DCIS are over-treated in order to avoid under-treatment of truly life-threatening cancers. Reducing over-treatment for DCIS and small cancers is a current priority for breast cancer management, to optimize both patient care and resource utilization. Intact minimally-invasive excision (percutaneous lumpectomy) with radiofrequency basket capture can eliminate the need for open excision of many atypical ductal hyperplasia (ADH) breast lesions (Whitworth, et al, Ann Surg Oncol, 2011). Percutaneous lumpectomy provides standard margin and lesion analysis of the specimen, accomplishing the same goals as open excision. Here we report results of the IPEX study, a prospective phase 4 trial evaluating the same minimally-invasive strategy when employed to manage small breast cancers and DCIS. Methods 94 women age 31-86 had minimally-invasive (percutaneous) removal of DCIS or small breast cancers using a 20 mm radiofrequency basket capture technique with stereotactic or ultrasound guidance. Tissue elasticity permitted removal through a small incision (less than 10 mm). A second 20 mm basket capture was used to shave and further evaluate margins. Procedures were conducted with adequate local anesthesia and P.O. sedation in the imaging department. Patient tolerance scores were recorded. Standard radiologic evaluation (specimen and breast) and histologic criteria were applied in all cases. Standard open sentinel node biopsy was offered to patients with invasive breast cancers. All patients provided informed consent for the study. Results Final histologic lesion size was 1-20 mm. Of 40 DCIS and 54 invasive lesions, 18 (19%) had positive margins and/or open re-excision, including one patient who had re-excision in spite of negative margins because of inadequate shaved-margin quality (no residual disease on pathology). 58 patients completed APBI (balloon or strut-based brachytherapy) and 16 had whole breast radiation. Of 54 patients with invasive cancers, 34 (age 66-86) had no sentinel node biopsy based on patient preference and low risk features. Patient pain scores averaged 1.9 out of 10 (range 0-7). Conclusions Minimally-invasive (percutaneous) lumpectomy provides satisfactory management of DCIS and small breast cancers, accomplishing the same goals as open surgery. The specimen is intact so the pathologist can conduct standard histologic analysis of the lesion, distinguishing DCIS, ADH and invasive cancer. Margin analysis is standard. Compared to open surgery, less tissue can be removed because of small lesion size with more precise targeting and resection. Minimally-invasive (percutaneous) lumpectomy reduces morbidity, distress, discomfort and expense associated with overtreatment of small breast cancers. Citation Format: Whitworth PW, Graham C, Schonholz S, Manahan E, Phillips R, Robertson Y, Hardwick MK. Minimally-invasive (percutaneous) stereotactic and ultrasound-guided lumpectomy for DCIS and small breast cancers. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-13-10.

Outcomes for APBI with strut-based brachytherapy: First 100 accrued patients (5-year median follow-up).

114 Background: The SAVI Collaborative Research Group (SCRG), was created to study the long-term outcomes of women receiving accelerated partial breast irradiation (APBI) using strut-based applicators. The outcomes for the first 100 accrued patients in the study are reported. Methods: Patients for this subset analysis weretaken as the initial 100 treated across all participating sites. Median follow-up of this cohort was 56.3 months at the time of the abstract. Patients were treated with APBI using the strut-based brachytherapy device with conventional dose and fractionation (3.4 Gy x 10 fx, BID). Treatment planning goals for the planning target volume were a V90&gt;90%, V150&lt;50 cc, and V200&lt;20 cc. Patients were followed regularly by their radiation oncologist and outcomes were graded based on the CTCAE v3.0 (common terminology criteria for adverse events, version 3.0). Recurrence (raw and actuarial) rates were also calculated based on the follow up. Cosmesis was graded using the Harvard Scale. Results: 75 patients had invasive disease and 25 had ductal carcinoma in situ. The median age was 60.5 yrs (range 40-85 yrs), with 84% post-menopausal. Median tumor size was 10.0 mm (range 0.7-35 mm) with 92% being estrogen receptor positive. 65% of patients had at least one round of hormone therapy and 7% had chemotherapy. All patients completed APBI as planned with no serious adverse events. All patients met the dosimetric criteria. Good/excellent cosmesis was seen in &gt;94% of subjects at all times of follow up (6-60 months). The 5-yr actuarial rates for TR/MM were 2.2%, 1.5% and 4.2% for all subjects, invasive and DCIS subgroups, respectively. The 5-yr actuarial rates for IBTR were 3.3%, 3.0% and 4.2% for all subjects, invasive and DCIS subgroups, respectively. Conclusions: For these initially treated 100 patients with a median 5 years of follow up, strut-based brachytherapy appears to be a well-tolerated, effective treatment with low rates of toxicities and local control as good as other brachytherapy APBI methods.

Outcomes for APBI With Strut-Based Brachytherapy: 596 Patients With 39-Month Median Follow-Up

(grade 0 vs grade 1 vs grade 2/3) compared to a V105 > 10% (p Z 0.09 and 0.03, respectively). The mean DoS was 22 cm (range 16-30 cm), with 22% and 3% of patients having a DoS greater than 25 cm and 28 cm, respectively. The mean BV was 1523 cc (range 299-3279 cc), with 19% and 5% having a BV greater than 2000 cc and 2500 cc, respectively. Neither a larger DoS nor a larger BV correlated with an inability to achieve a V105 10% (p Z 0.37 and p Z 0.13, respectively). Neither DoS nor BV predicted for worse acute toxicity, chronic toxicity, or cosmesis. Conclusions: Minimizing the V110 and V115 and limiting the V105 to 10% are useful dosimetric objectives to achieve excellent or good cosmesis following H-WBI. Acceptable toxicity and excellent cosmesis is achievable in women with large DoS or BV, provided techniques to maximize dose homogeneity are employed. Author Disclosure: R.V. Hymas: None. M.S. Jawad: None. V.S. Mangona: None. L. Zamdborg: None. J.L. Wobb: None. A. Pietron: None. M. Wallace: None. P.Y. Chen: None. I.S. Grills: None. D.S. Brabbins: None. J.T. Dilworth: None.

Outcomes for APBI With Strut-Based Brachytherapy: First 200 Accrued Patients (52-Month Median Follow-Up)

Outcomes for APBI With Strut-Based Brachytherapy: First 200 Accrued Patients (52-Month Median Follow-Up)

Recurrence Rates by Age Stratification for Accelerated Partial Breast Irradiation Using Strut-Based Brachytherapy in Ductal Carcinoma In Situ Patients: A Report on 284 Patients

Recurrence Rates by Age Stratification for Accelerated Partial Breast Irradiation Using Strut-Based Brachytherapy in Ductal Carcinoma In Situ Patients: A Report on 284 Patients

Abstract P5-14-06: Outcomes in 500 patients from a large, retrospective study of APBI with a strut-based breast brachytherapy applicator

Abstract Purpose/Objectives: The SAVI Collaborative Research Group (SCRG) is a coalition of 14 institutions who have retrospectively compiled a large database of APBI patients treated with a strut-based brachytherapy device (SAVI). This report details the findings of statistical correlations between numerous dosimetric variables and cosmetic outcome. Materials/Methods: The SCRG study enrolled 1005 patients. A subset of patients with complete dosimetry and more than 1 year of follow-up by a radiation oncologist were analyzed for toxicity, cosmesis and recurrence/survival. Dosimetric parameters were tabulated for patients, including: V90, V95, V100, V150, V200, skin spacing (skin-bridge), maximum skin dose, tumor size, PTV-Eval volume and applicator size (model). Toxicity (e.g., telangiectasia, fibrosis, fat necrosis, seroma) were graded by physicians for patients with at least 1 year of follow-up (up to 6 years) using the CTCAE v3 Scale and fat necrosis using a simplified CTCAE scale (Grade 1 asymptomatic but seen on imaging, grade 2 symptomatic without intervention, &amp; grade 3 required intervention). Results: Median follow up in this cohort was 29.2 months (range 2.4 to 72.2 months). Follow up was &amp;gt;2 yr and &amp;gt;3 yr for 323 and 191 subjects, respectively. Overall, in 500 subjects the late toxicity (grade ≥2) rates were less than 5% during follow up: telangiectasia 1.0%, fibrosis 4.1%, seroma 2.9% and fat necrosis 0.6%. Cosmesis was reported at various post-APBI follow-up visits following treatment completion (6, 12, 24, 36, 48 &amp; 60+ months). For the 6 and 12 month intervals, 98% (n = 122) and 97% (n = 262) were reported excellent or good (E/G), respectively. At 24, 36, 48 and 60 month intervals, the E/G rates were 93% (n = 184), 90% (n = 98), 100% (n = 41) and 94% (n = 15), respectively. The raw rates of ipsilateral breast tumor recurrence (IBTR) and TR/MM were 1.6% (n = 8) and 1.2% (n = 6), respectively, in 500 patients with &amp;gt;1 year of follow up. The 1- and 2-year actuarial rates of overall survival and disease-free survival were: 1-year, 99.6% &amp; 99.4%, resp. and 2-year, 99.2% &amp; 96.7%. Conclusions: APBI treatment with the strut-based applicators was well-tolerated, demonstrated low toxicity rates, favorable cosmetic outcomes and excellent local control over the follow-up to date. Patients with challenging breast anatomy were successfully treated with strut-based devices. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-14-06.

Outcomes for APBI With Strut-Based Brachytherapy: 101 Patients at 4.5 Years Median Follow-up

The SAVI Collaborative Research Group (SCRG), was created to study the long-term outcomes of women receiving accelerated partial breast irradiation (APBI) using strut-based applicators. The outcomes for the most mature subgroup of this study's patients (n = 101), accrued 3.5 to 6 years ago at 3 institutions, is presented. All patients were treated at least 42 months prior to abstract submission. Median follow-up of this cohort was 54 months. Patients were treated with APBI using the strut-based brachytherapy device with conventional dose and fractionation (3.4 Gy x 10 fx, BID). Treatment planning goals for the planning target volume were a V90 >90%, V150 <50 cc, and V200 <20 cc. Patients were followed regularly and outcome was graded based on the CTCAE v3.0 (common terminology criteria for adverse events, version 3.0). Seventy-one patients had invasive disease and 29 had ductal carcinoma in situ. The median age was 62 years (range, 40-82 years), with 82% post-menopausal. Median tumor size was 12.5 mm (range, 2-35 mm) with 92% being estrogen receptor positive. All patients completed APBI as planned with no serious adverse events. All patients met the dosimetric criteria with median V90 of 96%, V150 of 29 cc and V200 of 14 cc. Late toxicity (grade ≥2) rates were low; hyperpigmentation (0%), telangiectasias (2%), seroma (2%), fat necrosis (0%) and breast asymmetry secondary to radiation effects (3%). Statistically, tumor size had a weak association with fibrosis (21.7 cc vs 12.5 cc, p = 0.049) and surgical breast asymmetry (22 cc vs 12.7 cc, p = 0.089). There were no statistical associations (p < 0.05) between treatment parameters and toxicity, possibly due to the low event rates (≤3%). Local control was excellent with a true recurrence/marginal miss rate of 2% and an ipsilateral/elsewhere recurrence rate of 2%. These data will be updated and presented for 5 year median follow-up in October 2013. For these 101 patients with a median 4.5 years of follow-up (all with >3.5 years), strut-based brachytherapy appears to be a well-tolerated, effective treatment with low rates (<5%) of toxicities. With APBI an acceptable treatment for many women with early-stage breast cancer, strut-based brachytherapy continues on longer follow-up to be versatile, safe and effective.

Outcomes for APBI With the Strut-Based Brachytherapy Applicator in 430 Patients

The SAVI Collaborative Research Group (SCRG) was created to study the long-term outcomes of women receiving accelerated partial breast irradiation (APBI) using strut-based applicators. The outcomes for a large cohort of this study's patients (n = 430 w/follow-up >12 months, 236 w/follow-up >24 months) is presented.

Accelerated partial-breast irradiation using strut-based brachytherapy in ductal carcinoma in situ patients: A report on 321 patients with median 25-month follow-up.

92 Background: Limited data are available on the treatment of ductal carcinoma in situ (DCIS) with accelerated partial breast irradiation (APBI). The American Society for Radiation Oncology (ASTRO) consensus guidelines on APBI classify patients with DCIS as “cautionary”. We present the largest series of DCIS patients reported to date treated with APBI using strut-based brachytherapy. Methods: The SAVI Collaborative Research Group (SCRG) database was used to identify APBI patients with DCIS at 15 institutions treated with strut-based brachytherapy. All patients had a histologic diagnosis of DCIS and received monotherapy APBI (34 Gy in 10 fractions). Data on patient age and margin status, implant dosimetry, device size, disease status and toxicity in this population were analyzed. Results: From 2007-2011, 321 patients (322 breasts) with DCIS received APBI using strut-based brachytherapy. Patient ages ranged from 40-88 with a median age of 62. 51 patients were under 50 years of age. Detailed dosimetry data were reported on 245 patients. Long-term follow up was available on 221 breasts (median F/U = 25 months). Sixty patients have been followed for &gt;3 years. Skin spacing was a challenge in a significant number of patients including 52 with skin spacing ≤ 5mm and 20 with skin spacing ≤ 3mm. Median maximum skin dose in those patient groups were 87% and 84% of prescription dose (PD), respectively. Overall reported dosimetry (n=245) was excellent: median percent of target volume receiving 90% PD was 96.9%, median maximum skin dose was 83.2%, V150% and V200% (volume at 150% and 200% PD) were 25.2 cc and 12.7 cc respectively. The ipsilateral recurrence rate was 2.2% (1.1% TR/MM). Late toxicity (grade ≥ 2) was low: hyperpigmentation = 0.0%, telangiectasias =1.4%, seroma = 3.2%, and fat necrosis in 1.8%. Conclusions: APBI using strut-based brachytherapy appears to be an effective treatment for patients with DCIS with acceptably low ipsilateral breast recurrence rates and low rates of late toxicity. 52 patients in our series had skin spacing 5 mm or less. APBI using brachytherapy may not have been possible for these women with other single-entry devices.

SU-D-108-06: Dosimetry of 108 Strut-Based Accelerated Partial Breast Irradiation (APBI) Treatments With Applicator Distance Less Than 7 Mm From Both the Skin and Ribs

Purpose: To report on the dosimetry of 108 strut-based APBI treatments where the applicators were less than 7 mm from both the skin and the ribs Methods: Data from 108 patients whose applicators were sandwiched between the skin and ribs were analyzed. The patients were divided into three cohorts: those where the applicator was less than 7 mm from the skin and ribs (n=67), those where the distance was less than 5 mm (n=33), and those with less than 3 mm between both the skin and ribs (n=8). Dosimetric parameters analyzed include PTVEVAL volume (cm3), V90 (%), V95 (%), V100 (%), V150 (cm3), V200 (cm3), and the maximum doses to the skin and ribs. Results: Over all three cohorts the PTV_EVAL volumes ranged from 20.5 cm3 to 125.7 cm3 with a median value of 55.5 cm3. In each of the three groups, the V90 averaged between 94% and 95%, the V95 averaged between 90% and 92%, and the V100 averaged between 85% and 87%. The average V150 ranged between 21.8 cm3 and 26.6 cm3, and the average V200 ranged from 10.9 cm3 to 13.1 cm3. Across the three cohorts, the maximum skin dose ranged from 8.4% of the prescription dose to 117% of the prescription dose (median values were between 85% and 87%) and the maximum rib dose fell between 1.8% of the prescription dose and 198% of the prescription dose with the median values falling between 100% and 107%. Conclusion: This study demonstrates the dosimetric versatility of the strut-based brachytherapy device. It has been used in patients where the proximity of the skin and chest wall precludes the use of other types of single-entry brachytherapy devices. It allows for optimized dose coverage of the target while providing dose sparing to the adjacent critical structures. This project was partially funded by Cianna Medical, Inc.

Outcomes for Accelerated Partial Breast Irradiation with the Strut-Based Brachytherapy Applicator: 101 Patients at Four-Year Median Followup

Outcomes for Accelerated Partial Breast Irradiation with the Strut-Based Brachytherapy Applicator: 101 Patients at Four-Year Median Followup

Outcomes for Accelerated Partial Breast Irradiation with a Strut-Based Brachytherapy Applicator: 320 Patients with at least 24-Month Followup

Outcomes for Accelerated Partial Breast Irradiation with a Strut-Based Brachytherapy Applicator: 320 Patients with at least 24-Month Followup

Results of the SAVI Research Collaborative Group Registry: Correlating Clinical Toxicity With Dosimetric Parameters in Patients Treated With APBI Using Strut-based Brachytherapy

Results of the SAVI Research Collaborative Group Registry: Correlating Clinical Toxicity With Dosimetric Parameters in Patients Treated With APBI Using Strut-based Brachytherapy

Dosimetric Variables Correlating With Excellent and Good Cosmetic Outcomes in a Large, Retrospective Study of APBI With a Strut-based Breast Brachytherapy Applicator

Dosimetric Variables Correlating With Excellent and Good Cosmetic Outcomes in a Large, Retrospective Study of APBI With a Strut-based Breast Brachytherapy Applicator

Accelerated partial breast irradiation using a strut-based brachytherapy device: A multi-institutional initial report on acute and late toxicity with greater than 24-month follow-up.

149 Background: Accelerated partial breast irradiation (APBI) is commonly used in early-stage breast cancer. The SAVI Collaborative Research Group is a multi-institutional group created to study outcomes in patients who received APBI utilizing strut-based brachytherapy. This analysis reports the acute and late toxicities for patients with greater than 2-year follow-up (F/U) from this study. Methods: 904 APBI patients (ductal carcinoma in situ [n=267] or invasive breast cancer [n=637]), received HDR brachytherapy (34 Gy in 10 fractions) using the SAVI device (Cianna Medical). Patients with dosimetry and documented follow-up were evaluated within 6 weeks of treatment for early adverse events (AEs), and at 1 year, 2 years, and beyond for late AEs. Dosimetric parameters were evaluated with respect to toxicity and will be presented. Results: In 212 patients (median age 62.9 years, range 40-88) all with follow-up greater than 24 months, the median tumor size was 12mm. As of last follow-up (&gt;24 months) cumulative rates of erythema and hyperpigmentation of grade 2 or higher were 1.4% and 0.5%. The incidence of grade 2 or higher telangiectasia, seroma and fat necrosis were 2.8%, 2.8%, and 0.5% respectively. Conclusions: Adverse events for APBI with SAVI are low in incidence, low in grade and compare favorably to other HDR APBI methods.