Abstract P3-13-20: Use of a 3-D bioabsorbable tissue marker in 61 patients over two years
Authors: Kaufman CS , Hall W , Behrndt V , Wolgamot G , Hill L , Zacharias K , Rogers A , Nix S , Schnell N 
Published: March 2017

Background: Breast conservation surgery (BCS) may preserve the breast but many women have less than optimal cosmetic outcomes. Increasingly, this has been addressed by the use of oncoplastic reconstruction.Now, targeting radiation treatment for boost or partial breast irradiation (PBI) using the seroma has become more difficult due to the adjacent tissue rearrangement and resultant “benign” seromas. Since the radiation dose generated increases by the third power of the radius (r3), there is a need to accurately focus radiation therapy to avoid chronic radiation side effects.We have used a 3-dimensional bioabsorbable tissue marker to accurately target the tumor bed while excluding inadvertent seromas caused by oncoplastic procedures. We report on tissue marker implantation on 61 consecutive breast conservation patients in regards to targeting, impact on cosmesis, imaging followup, ease of re-excision, as well as side effects and patient satisfaction.

METHODS: Consecutive lumpectomy patients who were candidates for targeted radiation therapy were considered for implantation with the 3-D bioabsorbable marker from May 2014 to June 2016. The tissue marker has a fixed array of 6 titanium clips and was sutured to the site of the excised breast cancer during lumpectomy.The framework of the implant resorbs slowly over time, while the clips remain permanently. All patients had oncoplastic reconstruction with total implant coverage. The marker was utilized for boost or partial breast irradiation (PBI) planning or treatment targeting. Data includes patient demographics, breast size, tumor characteristics, surgical and radiotherapy techniques, follow-up imaging, cosmesis and patient satisfaction.

Results:Data on 61 patients with median follow-up 12.7 months was analyzed (range 1.5–25.5). Median age was 62.4 years (range 33-74), 5 of women were postmenopausal and 15% had comorbidities. Cancer histology was in-situ (13%), invasive ductal (84%), invasive lobular (3%) of sizes T0 (13%), T1 (59%), T2 (25%), T3-4 (3%). Laterality and tumor location within the breast were typical. Re-excisions occurred in 11% of patients. No infections occurred in the postoperative period. One infection occurred with chemotherapy and another with repeated aspirations of oncoplastic area.No device was removed for infection, misplacement or patient-generated concerns. No cancer recurrences have been reported. Size of device used reflected size of the tumor; 2X2cm (44%), 2X3cm (34%) and 3X3cm (20%). The device was utilized by radiation oncologists for boost or PBI planning and treatment. Data on ease of setup and boost planning is being collected. Mammography at one year demonstrated marker clips coalescing as the bioabsorbable device dissolves. Evaluation of cosmetic appearance has shown good to excellent cosmesis as judged separately by both physicians and patients (92% and 94%).

Conclusions: Initial experience with 61 patients implanted with a novel 3-D absorbable device prospectively followed for an average of 12 months can be used in an array of breast cancer patients without device specific morbidity. Good to excellent cosmesis may be related to the addition of volume to the lumpectomy bed not seen with rearrangement of existing tissues.

Citation Format: Kaufman CS, Hall W, Behrndt V, Wolgamot G, Hill L, Zacharias K, Rogers A, Nix S, Schnell N. Use of a 3-D bioabsorbable tissue marker in 61 patients over two years [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-13-20.