Impact of a Novel Bioabsorbable Implant on Radiation Treatment Planning for Breast Cancer

Combining a Chest Wall Perforator Flap and Bioabsorbable Implant to Facilitate Oncoplastic Breast-conserving Surgery

Oncoplastic breast conservation is classically divided into two approaches: volume displacement and volume replacement (VR). These approaches are important to use when more than 20% of the breast is removed to avoid deformity. Smaller, nonptotic breasts require VR strategies from flaps based off of local chest wall perforators. When larger volumes are required, a flap based off the thoracodorsal artery can be used. Although this flap can replace larger volumes, it usually requires a position change with increased operative time, patient morbidity, and longer recovery while also exhausting a major reconstructive modality. In an effort to avoid this increased operative complexity, we have found that combining a local chest wall perforator flap and bioabsorbable implant, which has been previously shown to be safe and effective in reconstructing partial mastectomy defects, allows for a simpler VR strategy in patients who might otherwise require a more extensive thoracodorsal artery-based flap surgery or a mastectomy. Here, we present 10 cases where we combined flaps based off the lateral, anterior or medial intercostal artery perforators or lateral thoracic artery perforator with a bioabsorbable implant to successfully perform oncoplastic breast conservation in patients who might otherwise be marginal candidates for VR using a local chest wall perforator flap.

Maintaining Contour with a Three-dimensional Interstitial Tissue Marker in 134 Lumpectomies

Breast-conserving surgery (BCS) is meant to preserve the natural appearance of the breast; however, tissue volume deficits cannot always be compensated by soft tissue mobilization. A three-dimensional (3D) interstitial tissue marker (BioZorb) was designed to delineate the lumpectomy cavity for targeting boost irradiation, but an unexpected secondary benefit may be in guiding wound contraction and restoring contour to the lumpectomy bed. We analyze tissue volume excised at the time of lumpectomy as a function of device size selected.

Methods

In total, 134 consecutive lumpectomy patients implanted with BioZorb between May 2015 and February 2020 were retrospectively analyzed for tissue volume excised, device size used, location, and re-operation rates, including explantation of the device.

Results

An estimated 113 patients underwent device implantation at initial lumpectomy, and 21 at margin re-excision. Twenty-seven patients underwent re-excision, while 14 elected mastectomy for positive margins following insertion; 22 had the same device reimplanted. Mean lumpectomy volume was 79.0 cm³ (range 10.3-275.8 cm³) during the first implant procedure. Large-volume lumpectomies, averaging 136.5 cm³, were associated with selection of larger devices, which aided in restoring volume and maintaining breast contour. Three (2.2%) patients requested removal of the device.

Conclusions

BioZorb implantation can be a safe and useful oncoplastic technique for restoring volume with BCS. Large-volume lumpectomies can be performed without contouring defects using the device. An unexpected secondary benefit of the device may be scaffolding for wound contraction.

Post-operative imaging surveillance of breast cancer patients status post lumpectomy with BioZorb implant placement

The evolving nature of newer surgical techniques and devices adds to the challenge of interpreting breast imaging in the post lumpectomy setting. The BioZorb surgical marker placed at lumpectomy sites for post-operative radiation targeting has its own distinct imaging appearance on each modality. Determining the expected follow-up imaging findings unique to this relatively new device is an ongoing endeavor with minimal literature on this topic. The following series of cases of post BioZorb breast surveillance are one of the first reported in the literature to provide examples of developing asymmetries and new or enlarging masses adjacent to the BioZorb site along with the final pathologic diagnosis for each case. Pathology findings range from fat necrosis and foreign body reaction to recurrent disease.

Use of a Bioabsorbable Implant-Acellular Dermal Matrix Construct to Facilitate Oncoplastic Breast-conserving Surgery

Supplemental Digital Content is available in the text.

Deformity after partial mastectomy for breast cancer is not uncommon. The immediate replacement of breast volume by a bioabsorbable implant has been shown to facilitate tissue ingrowth, maintain breast contour, reduce scarring and fibrosis, and preserve cosmesis. Soft tissue coverage is critical to minimize palpability and to prevent infection and extrusion of this device, especially after radiotherapy. This coverage is often not possible after significant oncological resection or in leaner patients. Here, we describe the use of a bioabsorbable implant-acellular dermal matrix construct in patients with insufficient soft tissue coverage after wide local excision.

A Three-Dimensional Bioabsorbable Tissue Marker for Volume Replacement and Radiation Planning: A Multicenter Study of Surgical and Patient-Reported Outcomes for 818 Patients with Breast Cancer

Background

Accurate identification of the tumor bed after breast-conserving surgery (BCS) ensures appropriate radiation to the tumor bed while minimizing normal tissue exposure. The BioZorb^® three-dimensional (3D) bioabsorbable tissue marker provides a reliable target for radiation therapy (RT) planning and follow-up evaluation while serving as a scaffold to maintain breast contour.

Methods

After informed consent, 818 patients (826 breasts) implanted with the BioZorb^® at 14 U.S. sites were enrolled in a national registry. All the patients were prospectively followed with the BioZorb^® implant after BCS. The data collected at 3, 6, 12, and 24 months included all demographics, treatment parameters, and provider/patient-assessed cosmesis.

Results

The median follow-up period was 18.2 months (range, 0.2–53.4 months). The 30-day breast infection rate was 0.5 % of the patients (n = 4), and re-excision was performed for 8.1 % of the patients (n = 66), whereas 2.6 % of the patients (n = 21) underwent mastectomy. Two patients (0.2 %) had local recurrence. The patient-reported cosmetic outcomes at 6, 12, and 24 months were rated as good-to-excellent by 92.4 %, 90.6 %, and 87.3 % of the patients, respectively and similarly by the surgeons. The radiation oncologists reported planning of target volume (PTV) reduction for 46.2 % of the patients receiving radiation boost, with PTV reduction most commonly estimated at 30 %.

Conclusions

This report describes the first large multicenter study of 818 patients implanted with the BioZorb^® tissue marker during BCS. Radiation oncologists found that the device yielded reduced PTVs and that both the patients and the surgeons reported good-to-excellent long-term cosmetic outcomes, with low adverse effects. The BioZorb^® 3D tissue marker is a safe adjunct to BCS and may add benefits for both surgeons and radiation oncologists.

Electronic supplementary material

The online version of this article (10.1245/s10434-020-09271-2) contains supplementary material, which is available to authorized users.

Postoperative Imaging Appearance of an Implantable Three-dimensional Bioabsorbable Tissue Marker After Breast Surgery: Initial Experience at a Single Institution

OBJECTIVE

Three-dimensional bioabsorbable tissue marker (BTM) placement during breast surgery is performed for the purpose of improved surgical cavity delineation for radiotherapy and improved cosmetic outcome. The purpose of this study is to evaluate the postsurgical imaging findings of BTM.

METHODS

This Institutional Review Board-approved retrospective review included all patients implanted with BTM at breast surgery from January 2017 to September 2018. Demographics, tumor characteristics, imaging, and histologic findings were evaluated. Medical records were reviewed during a three-year period to evaluate for tumor recurrence.

RESULTS

Ninety-seven patients had BTM implanted, of which 76 patients had imaging follow-up of at least 1 year. Of the 76 patients who had mammographic follow-up, 3 (3.9%) developed suspicious microcalcifications requiring biopsy, yielding ductal carcinoma in-situ in 2 patients and benign calcifications in 1 patient. Of 61 patients who had sonographic follow-up, 44 (72.1%) patients had complex fluid collections containing avascular, heterogeneously hyperechoic solid components, which remained stable or decreased in size over time; no recurrent tumors were found in this group. One patient (1.6%) had a vascular solid mass, which yielded recurrent papilloma. Four (6.6%) patients developed irregular hypoechoic masses at the surgical site, one of which corresponded with a developing asymmetry mammographically; biopsy yielded fibromatosis. Tissue sampling of the remaining three cases yielded invasive ductal carcinoma, fat necrosis, and radiation changes, respectively.

CONCLUSION

Accurate identification of the expected postoperative imaging appearance of BTM may prevent unnecessary biopsy. Suspicious findings necessitating biopsy are pleomorphic calcifications, developing asymmetry and vascular and irregular hypoechoic masses.

A Bioresorbable Fiducial for Head and Neck Cancer

We aim to evaluate a novel bioresorbable fiducial for marking tumor bed margins in head and neck cancers (HNCs) to improve upon current use of nonresorbable materials. A feasibility test was done placing the marker (L-lactide and ε-caprolactone) in an orange for computed tomography (CT) and applesauce for T1-, T2-, and PD-weighted magnetic resonance imaging (MRI) image acquisition, using routine clinical parameters. The resulting CT and MRI images showed excellent delineation of the marker with all of its margins well seen without adjacent artifact. The marker appeared similar to air on CT and MRI, surrounded by fluid-like appearance of the medium. Surgical bed appearance when radiotherapy is planned should not produce any artifact near the marker, and there should be no inherent marker-related artifact. These pilot CT and MR images show clinical utility for intraoperative marking of positive margins in the skull base or neck to guide future treatment and monitoring.

Increasing Role of Oncoplastic Surgery for Breast Cancer

PURPOSE OF REVIEW

The goals of surgery for breast cancer have remained the same over the years, to eliminate breast cancer from the breast with the least degree of deformity. With the current expectation of long-term survival after breast cancer treatment, more attention has turned to the cosmetic result of the surgical treatment. Whether lumpectomy or mastectomy, the need for aesthetic improvement was recognized by surgeons both in and outside the USA.

RECENT FINDINGS

Oncoplastic surgery combines the skills of the cancer surgeon with those of the plastic surgeon. Sometimes, this means a team approach with a breast surgeon and a plastic surgeon both performing their mutual skills for the patient. Other times, the properly trained breast surgeon may perform some of the plastic techniques at the time of cancer surgery. Breast surgeons are rapidly gaining the ability to improve the post-cancer treatment appearance. To simplify the classification of oncoplastic techniques, we have used lower level, upper level, and highest level. The assignment of techniques to levels is based on both the technique and the surgeon's training and experience. Much data has accumulated demonstrating the safety and efficacy of the "aesthetic cancer cure." We describe the development of oncoplastic surgery, the techniques available, matching the right candidate with the right technique, and some comments about the future. It is clear from both clinical benefit and patient satisfaction that oncoplastic breast cancer procedures are here to stay. Plastic surgeons will likely focus on the upper- and highest-level procedures while breast/general surgeons will learn lower-level procedures and some of upper-level procedures as needed by their locale. Opportunities to educate breast/general surgeons in these techniques will continue to increase over the next several years. Formal education in oncoplastic surgery during breast fellowships will be necessary to catch up with the rest of the surgical world outside the USA.