A bioabsorbable 3D marker implanted into a tumor bed during breast-conserving surgery (BCS) was shown to improve outcomes and follow-up care in results of 2 separate studies presented at the 2017 Annual Meeting of the American Society of Breast Surgeons.

The marker (BioZorb; Focal Therapeutics, Aliso Viejo, California) has a 3D framework made of a bioabsorbable material that holds 6 titanium clips. It is approximately the size of a walnut and is implanted in the tumor bed after lumpectomy. The framework slowly dissolves leaving the clips to mark the tumor site for adjuvant radiotherapy and long-term monitoring.

In addition, the marker provides a scaffold for oncoplastic tissue rearrangement. Research has indicated this can improve cosmetic outcomes after surgery.

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Tumor Bed

The implant provides a more precise marker of the surgical site, offering the potential for better targeted radiation therapy that limits exposure to healthy tissue. Therefore, a team led by Kara-Lynn Leonard, MD, a radiation oncologist at Rhode Island Hospital, in Providence, sought to determine whether use of the marker reduced the size of the irradiated tumor bed.

For the study, Dr Leonard’s team conducted a retrospective assessment of 117 women who underwent breast radiation at Rhode Island Hospital for breast cancer diagnosed between May 2015 and April 2016. The women, identified from an institutional database, were classified into 2 groups: those in whom the marker was placed and those who did not have the marker placed.1

Surgical pathology reports were reviewed to determine the total specimen volume excised during BCS. Lumpectomy specimen size was reported in 3 dimensions, and volume was calculated as a cube.

Results of the study indicated that the women who received the marker (n=42) had smaller tumor bed volume than the women who did not (n=75). Average tumor bed volumes were 27.5 cc and 43.2 cc, respectively, and average surgical specimen volume was 102.7 cc and 104.2 cc, respectively. Linear regression analysis revealed a linear relationship existed between excised surgical specimen volume and tumor bed volume in both study groups. A t-test to assess differences in the slopes of these lines between the group with the marker and the group without the marker revealed a significant difference (t =.001).

The outcome most affected by implanting the marker in the tumor bed is the irradiated volume. This study shows that the marker reduces the volume of tissue irradiated as part of the boost, Dr Leonard explained in an interview with Oncology Nurse Advisor.

“The obstacles with BioZorb [3D marker] are clearly defining patients most likely to have benefit without side effects from the device,” concluded Dr Leonard.