Stabilised Hyaluronic Acid (sHA) gel as a novel marker for breast cancer tumour bed cavity: Surgical feasibility

Introduction

Consistent delineation of the breast conserving surgery (BCS) tumour bed (TB) for breast cancer remains a challenge for radiation oncologists. Accurate delineation allows for better local control and reduces toxicity when planning partial breast or TB boost radiation therapy (RT).

Methods

In the operating theatre (OT) breast surgeons inserted stabilised hyaluronic acid (sHA) gel as small drops approximately one cm into the walls surrounding the resection cavity. Surgical feasibility was determined by the rate of successful sHA gel insertion procedure, the ease of insertion as rated by surgeons, the time required for insertion procedure, the quantity used, and any adverse events (AE) relating to sHA gel insertion.

Results

Thirty-five patients were enrolled. All patients underwent sHA gel insertion successfully. The procedure added a median of 2.8 min to the OT time and was rated as 'easy' in 89 % of patients. There were no immediate AE in OT. Five (14 %) patients experienced a grade 2 or higher AE. Three of the five patients were prescribed oral antibiotics for breast infection. Two of the five patients experienced a grade 3 AE - haematoma which required evacuation in OT day 1 post-BCS, and infected seroma which required drainage and washout in OT 2 months post-BCS. All five patients recovered and underwent the planned adjuvant therapies for their BC. The AE data reflects common risks with standard BCS and are not clearly attributed to sHA gel insertion alone.

Conclusion

We show that sHA gel is surgically feasible as a marker to help define the TB cavity for post-BCS adjuvant MRI-based RT planning.

Comparison of Tumor Bed Delineation Using a Novel Radiopaque Filament Marker Versus Surgical Clips for Targeting Breast Cancer Radiotherapy

BACKGROUND

Accuracy of tumor bed (TB) delineation is essential for targeting boost doses or partial breast irradiation. Multiple studies have shown high interobserver variability with standardly used surgical clip markers (CMs). We hypothesize that a radiopaque filament marker (FM) woven along the TB will improve TB delineation consistency.

METHODS

An FDA-approved FM was intraoperatively used to outline the TB of patients undergoing lumpectomy. Between January 2020 and January 2022, consecutive patients with FM placed after either (1) lumpectomy or (2) lumpectomy with oncoplastic reconstruction were identified and compared with those with CM. Six "experts" (radiation oncologists specializing in breast cancer) across 2 institutions independently defined all TBs. Three metrics (volume variance, dice coefficient, and center of mass [COM] deviation). Two-tailed paired samples t tests were performed to compare FM and CM cohorts.

RESULTS

Twenty-eight total patients were evaluated (14 FM and 14 CM). In aggregate, differences in volume between expert contours were 29.7% (SD ± 58.8%) with FM and 55.4% (SD ± 105.9%) with CM ( P < 0.001). The average dice coefficient in patients with FM was 0.54 (SD ± 0.15), and with CM was 0.44 (SD ± 0.22) ( P < 0.001). The average COM deviation was 0.63 cm (SD ± 0.53 cm) for FM and 1.05 cm (SD ± 0.93 cm) for CM; ( P < 0.001). In the subset of patients who underwent lumpectomy with oncoplastic reconstruction, the difference in average volume was 21.8% (SD ± 20.4%) with FM and 52.2% (SD ± 64.5%) with CM ( P <0.001). The average dice coefficient was 0.53 (SD ± 0.12) for FM versus 0.39 (SD ± 0.24) for CM ( P < 0.001). The average COM difference was 0.53 cm (SD ± 0.29 cm) with FM versus 1.25 cm (SD ± 1.08 cm) with CM ( P < 0.001).

CONCLUSION

FM consistently outperformed CM in the setting of both standard lumpectomy and complex oncoplastic reconstruction. These data suggest the superiority of FM in TB delineation.

Stereotactic partial breast irradiation in primary breast cancer: A comprehensive review of the current status and future directions

In selected low-risk breast cancer patients, accelerated partial breast irradiation (APBI) may represent an alternative option to the whole breast irradiation to reduce the volume of irradiated breast and total treatment duration. In the last few years, preliminary data from clinical trials showed that stereotactic partial breast radiotherapy may have the advantage to be less invasive compared to other APBI techniques, with preliminary good results in terms of local toxicity and cosmesis: the use of magnetic resonance, fiducial markers in the tumor bed, and new breast devices support both a precise definition of the target and radiation planning.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021257856, identifier CRD42021257856.

Feasibility and Short-Term Toxicity of a Consecutively Delivered Five Fraction Stereotactic Body Radiation Therapy Regimen in Early-Stage Breast Cancer Patients Receiving Partial Breast Irradiation

Background

For appropriately selected patients with early-stage breast cancer (ESBC), accelerated partial breast irradiation (APBI) yields equivalent rates of ipsilateral breast tumor recurrence with mixed results in patient-rated cosmesis compared with whole-breast radiotherapy depending on the technique utilized. When utilizing external beam radiotherapy for APBI, techniques to reduce target margins and overall treatment volume are potentially important to decrease rates of long-term adverse cosmesis. Stereotactic body radiotherapy (SBRT) is a promising technique to deliver APBI because of its increased accuracy and sparing of uninvolved breast tissue. We report the initial results of a prospective clinical trial investigating feasibility, safety, and cosmetic outcomes of a daily five-fraction SBRT regimen for APBI.

Methods

Twenty-three patients with ESBC after lumpectomy who met APBI suitability were enrolled. During lumpectomy, a bioabsorbable three-dimensional fixed array tissue marker (BioZorb™, Hologic, Marlborough, MA) was placed for enhanced visualization of the cavity boundaries. Clinical target volume (CTV) was defined as the delineable cavity plus a 1-cm isotropic expansion followed by a 3-mm isotropic planning target volume (PTV) expansion. Patients received 30 Gy delivered in five planned consecutive daily fractions in either prone or supine positioning depending on individual anatomy. Two patients completed the five-fraction treatments in 9-day interval and 11-day interval due to external circumstances. A maximum PTV of 124cc was allowed to minimize incidence of fat necrosis. Plans utilized 10-MV flattening filter–free beams delivered on a Varian Edge linear accelerator. Local control, toxicity, and nurse/patient-scored cosmesis at pre-treatment baseline, 1 month post-treatment, and at subsequent 6-month intervals were recorded.

Results

Twenty-three patients were accrued at the time of submission with median follow-up of 6 months. No patients experienced grade ≥3 acute toxicity. Of the 10 events reported probably related to SBRT, nine were grade 1 (n = 9/10, 90%). There was no evidence of difference, deterioration, or change in patient or nurse-scored cosmesis from baseline to 1 and 6 months post-treatment. One patient developed nodal failure shortly after APBI.

Conclusions

Although longer follow-up is needed to assess long-term toxicity and local control, this study demonstrated a five-fraction SBRT regimen delivered over consecutive days is a safe, efficient, well-tolerated, and cosmetically favorable means of delivering APBI in suitable women.

Clinical Trial Registration

https://www.clinicaltrials.gov/ct2/show/NCT03643861, NCT03643861.

Review of Current Accepted Practices in Identification of the Breast Lumpectomy Tumor Bed

Purpose

Of the 260,000 women diagnosed with breast cancer annually in the United States, more than 60% are treated with breast-conserving surgery or lumpectomy, followed by radiation to decrease the chance of local recurrence. More than 70% of breast cancer recurrences are localized to the original tumor cavity. Hence, targeted radiation therapy after lumpectomy is critical for recurrence prevention. With 30,000 patients annually opting for oncoplastic reconstruction of the breast after lumpectomy to improve cosmesis, the resulting tissue rearrangement increases the difficulty for radiation oncologists to accurately delineate the cavity when planning radiation therapy. Owing to the absence of a standardized protocol, it is important to assess the efficacy of various methods used to mark the tumor cavity for improved delineation.

Methods and Materials

A keyword search and analysis was used to compile relevant articles on PubMed (National Center for Biotechnology Information).

Results

Currently, a common practice for tumor cavity localization is applying titanium surgical clips to the borders of lumpectomy cavity. Tissue movement and seroma formation both impact the positioning of surgical clips within the tumor cavity and lead to significant interobserver variability. Furthermore, the main application of surgical clips is to control the small vessels during surgery, and that can create confusion when the same clips are used for tumor bed localization. All alternative solutions present more precise tumor bed delineation but possess individual concerns with workflow integration, patient comfort, and accuracy. Though liquid-based fiducials were found to be the most effective for delineating tumor cavities, there are still drawbacks for clinical use.

Conclusions

These findings should encourage medical innovators to develop novel techniques for tumor cavity marking to increase delineation accuracy and effectively target at-risk tissue. Future solutions in this space should consider the properties of liquid-based fiducial markers to improve radiation oncologists' ability to precisely delineate the tumor cavity.

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.

Improved Overall Well-Being After Breast Conserving Therapy Using Three-Dimensional Bioabsorbable Markers and Tissue Rearrangement, a Single Institution's Preliminary Experience

Tissue rearrangement (TR) is a basic oncoplastic technique to reshape the breast after breast conserving therapy (BCT). Tissue rearrangement can be combined with three-dimensional bioabsorbable markers (3DBM) as an easily adaptable technique to provide volume replacement and focused radiation. Since 3DBM can take time for absorption and symptoms related to its use have not been fully assessed, we evaluate patient's overall satisfaction and well-being after TR with 3DBM is performed. We surveyed patients receiving BCT with adjuvant radiotherapy using BREAST-QTM BCT satisfaction and physical well-being surveys comparing patients receiving BCT alone to BCT with TR and/or 3DBM. Of 68 patients, 56 underwent BCT alone, 10 had BCT with TR + 3DBM, and 2 had BCT with TR. No significant difference was seen in physical well-being (P = .39), while overall satisfaction was significantly improved following TR + 3DBM (P = .0088). In summary, TR with use of 3DBM provides basic oncoplastic options to improve patient satisfaction without significantly changing symptoms.

Dosimetric Effect of Biozorb Markers for Accelerated Partial Breast Irradiation in Proton Therapy

Purpose

To investigate dosimetric implications of biodegradable Biozorb (BZ) markers for proton accelerated partial breast irradiation (APBI) plans.

Materials and Methods

Six different BZs were placed within in-house breast phantoms to acquire computed tomography (CT) images. A contour correction method with proper mass density overriding for BZ titanium clip and surrounding tissue was applied to minimize inaccuracies found in the CT images in the RayStation planning system. Each breast phantom was irradiated by a monoenergetic proton beam (103.23 MeV and 8×8 cm²) using a pencil-beam scanning proton therapy system. For a range perturbation study, doses were measured at 5 depths below the breast phantoms by using an ionization chamber and compared to the RayStation calculations with 3 scenarios for the clip density: the density correction method (S1: 1.6 g/cm³), raw CT (S2), and titanium density (S3: 4.54 g/cm³). For the local dose perturbation study, the radiographic EDR2 film was placed at 0 and 2 cm below the phantoms and compared to the RayStation calculations. Clinical effects of the perturbations were retrospectively examined with 10 APBI plans for the 3 scenarios (approved by our institutional review board).

Results

In the range perturbation study, the S1 simulation showed a good agreement with the chamber measurements, while excess pullbacks of 1∼2 mm were found in the S2 and S3 simulations. The film study showed local dose shadowing and perturbation by the clips that RayStation could not predict. In the plan study, no significant differences in the plan quality were found among the 3 scenarios. However, substantial range pullbacks were observed for S3.

Conclusion

The density correction method could minimize the dose and range difference between measurement and RayStation prediction. It should be avoided to simply override the known physical density of the BZ clips for treatment planning owing to overestimation of the range pullback.

Regenerative tissue filler for breast conserving surgery and other soft tissue restoration and reconstruction needs

Complete removal of cancerous tissue and preservation of breast cosmesis with a single breast conserving surgery (BCS) is essential for surgeons. New and better options would allow them to more consistently achieve this goal and expand the number of women that receive this preferred therapy, while minimizing the need for re-excision and revision procedures or more aggressive surgical approaches (i.e., mastectomy). We have developed and evaluated a regenerative tissue filler that is applied as a liquid to defects during BCS prior to transitioning to a fibrillar collagen scaffold with soft tissue consistency. Using a porcine simulated BCS model, the collagen filler was shown to induce a regenerative healing response, characterized by rapid cellularization, vascularization, and progressive breast tissue neogenesis, including adipose tissue and mammary glands and ducts. Unlike conventional biomaterials, no foreign body response or inflammatory-mediated "active" biodegradation was observed. The collagen filler also did not compromise simulated surgical re-excision, radiography, or ultrasonography procedures, features that are important for clinical translation. When post-BCS radiation was applied, the collagen filler and its associated tissue response were largely similar to non-irradiated conditions; however, as expected, healing was modestly slower. This in situ scaffold-forming collagen is easy to apply, conforms to patient-specific defects, and regenerates complex soft tissues in the absence of inflammation. It has significant translational potential as the first regenerative tissue filler for BCS as well as other soft tissue restoration and reconstruction needs.

Surgical excision of BioZorb device eroding through the nipple-areolar complex one year postoperatively: A case report

The recent use of placing a BioZorb device during breast conservation surgery has been shown to improve targeting of adjuvant radiation therapy by significantly reducing target volume to the breast. However, the risks of surgical and/or infectious complications related to a BioZorb placement are largely unknown. In this case report, we describe a patient who underwent BioZorb placement after breast lumpectomy for ductal carcinoma in situ (DCIS), who presented with repeated infections and eventual erosion of the BioZorb through her nipple-areolar complex (NAC), requiring surgical debridement and excision of her NAC and BioZorb 1 year postoperatively.

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.