Does the Use of BioZorb (R) Result in Smaller Breast Seroma Volume?

Y Aim: To evaluate the impact of BioZorb (R), a 3D-bioabsorbable marker, on the tumor-bed boost volume and dosimetric parameters in adaptive boost planning for breast cancer. Patients and Methods: Records were reviewed for 51 breast-cancer patients who underwent breast-conserving surgery and adjuvant whole-breast irradiation between January 2017 and October 2018. Changes in lumpectomy boost volume (LBV), doses to organs at risk, toxicity and cosmesis were compared between patients with and without BioZorb (R). Chi-square test and paired and independent t-tests were used for comparisons of variables. Results: Median follow-up was 35.5 months. Mean LBV on initial CT (LBV1; 32.2 vs. 33.8 cc, p=0.74) and on boost computed tomography (CT) (LBV2; 25.3 vs. 24.8 cc, p=0.87) were similar with and without BioZorb (R). The mean decrease from LBV1 to LBV2 was 9.0 cc and 6.8 cc with and without BioZorb (R), respectively (p=0.42). LBV1 was significantly positively correlated with a 20% reduction in LBV (p=0.02). Mean heart and lung doses on adaptive boost planning CT were slightly lower compared to initial planning CT in both groups. Acute breast pain was reported in 18/51 patients, 9 of whom had BioZorb (R) (p=0.24). Grade-2 pain was reported in 5/51 patients, 3 of whom had BioZorb (R) (p=0.11). Excellent or good cosmesis was reported in 36/41 patients. Fair cosmesis was reported in 5/41 patients, of whom 2 had BioZorb (R) (p=0.64). Conclusion: BioZorb (R) placement does not impact the tumor-bed boost volume nor the variation of seroma volume within the period of treatment. More data and longer follow-up are needed to identify a measurable clinical impact of BioZorb (R) placement.