Evaluation of hyaluronic acid gel dissolution with hyaluronidase in an in-vitro prostate cancer model. (March 2022)

• Record Type: Journal Article
• Authors: Vanneste, Ben G.L.; Lutgens, Ludy; Van Limbergen, Evert J.
• Is Part Of: Clinical and translational radiation oncology. Volume 33(2022)
• Page Start: 53
• Page End: 56
• Publication Date: 2022-03
• Subjects: Rectum spacer -- Hyaluronic acid -- Hyaluronidase -- In-vitro -- Prostate cancer radiotherapy; Cancer -- Radiotherapy -- Periodicals; Oncology -- Periodicals; Cancer -- Radiotherapy; Oncology; Radiation Oncology; Neoplasms -- radiotherapy; Translational Medical Research; Periodicals; Electronic journals; Periodicals; 616.9940642
• DOI: 10.1016/j.ctro.2021.12.009
• Languages: English
• ISSNs: 2405-6308

Abstract

Highlights: Hyaluronic acid (HA) is an implantable rectum spacer used to decrease rectal radiation dose in prostate cancer radiotherapy. Hyaluronidase (HAS) is an enzyme that degrades HA, when wrongly positioned. A ratio of HA:HAS of 1:2 has already a decrease of half of volume on the 2nd day. Abstract: Aim: To determine a dose response relationship of disintegration of a hyaluronic acid (HA) and hyaluronidase (HAS) used in prostate cancer radiotherapy. Materials and methods: Five in-vitro models are applicated with 3 ml (ml) HA. For dissolution varying doses of HAS were used: 6 ml, 3 ml, 1.5 ml, and 0 ml. One ml contains 150 International Units (IU). Each HAS was added with saline till the complementary amount of 6 ml. One phantom was solely implanted with a HA 3 ml acting as a control. Length, width and height were measured on different time points: 1st day 4 times, 2nd day 3 times, third day 2 times, and then once daily during one week, with a final measurement 2 weeks after implantation. The experiments were performed in duplicate to exclude variations and confirm the results. Results: The fastest dissolution was observed with the highest concentration of HAS, already observed at the first time point 2 h after implantation, with volume decrease of 50% on the second day, and less than 1 ml residue (33%) on day 4. The 2 other concentrations of HAS also showed a volume decrease, with less than 2 ml (66%) on day 4. All the applied quantities of HAS are observed with a residue of less than 1 ml after 7 days. After 14 days the control phantom and the saline filled one remains on steady state volume (3 ml). Conclusions: A dose response was observed by HAS injection: highest volumes of HAS dissolute most swiftly. Using a ratio of HA:HAS of 1:2 results in a decrease to half of initial volume within 24 h. This is of special interest when used in clinical practice following erroneous positioning, and dissolution is urgently needed.