Subcutaneous spacer injection to reduce skin toxicity in breast brachytherapy: A pilot study on mastectomy specimens.

Autor: Struik GM; Department of Surgery, Franciscus Gasthuis and Vlietland, Rotterdam, The Netherlands; Department of Radiation Oncology, Erasmus MC Cancer Institute, Rotterdam, The Netherlands. Electronic address: g.struik@franciscus.nl., Pignol JP; Department of Radiation Oncology, Erasmus MC Cancer Institute, Rotterdam, The Netherlands; Department of Radiation Oncology, Dalhousie University, Halifax, Nova Scotia, Canada., Kolkman-Deurloo IK; Department of Radiation Oncology, Erasmus MC Cancer Institute, Rotterdam, The Netherlands., Godart J; Department of Radiation Oncology, Erasmus MC Cancer Institute, Rotterdam, The Netherlands., Verduijn GM; Department of Radiation Oncology, Erasmus MC Cancer Institute, Rotterdam, The Netherlands., Koppert LB; Department of Surgery, Erasmus MC Cancer Institute, Rotterdam, The Netherlands., Birnie E; Department of Statistics and Education, Franciscus Gasthuis and Vlietland, Rotterdam, The Netherlands; Division of Woman and Baby, Department of Obstetrics and Gynecology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands., Ghandi A; Department of Radiology, Franciscus Gasthuis and Vlietland, Rotterdam, The Netherlands., Klem TM; Department of Surgery, Franciscus Gasthuis and Vlietland, Rotterdam, The Netherlands.
Jazyk: angličtina
Zdroj: Brachytherapy [Brachytherapy] 2019 Mar - Apr; Vol. 18 (2), pp. 204-210. Date of Electronic Publication: 2018 Dec 05.
DOI: 10.1016/j.brachy.2018.11.003
Abstrakt: Purpose: Accelerated partial breast irradiation is a treatment option for selected patients with early-stage breast cancer. Some accelerated partial breast irradiation techniques lead to skin toxicity with the skin dose as a main risk factor. Biodegradable spacers are effective and safe in prostate brachytherapy to protect the rectum. We hypothesize that a subcutaneous spacer injection reduces the skin dose in breast brachytherapy.
Methods and Materials: Ultrasound-guided spacer injections, either hyaluronic acid (HA) or iodined polyethylene glycol (PEG), were performed on fresh mastectomy specimens. Success was defined as a spacer thickness of ≥5 mm in the high-dose skin area. Usability was scored using the system usability scale. Pre and postinjection CT scans were used to generate low-dose-rate seed brachytherapy treatment plans after defining a clinical target volume. Maximum dose to small skin volumes (D 0.2cc ) and existence of hotspots (isodose ≥90% on 1 cm 2 of skin) were calculated as skin toxicity indicators.
Results: We collected 22 mastectomy specimens; half had HA and half had PEG injection. Intervention success was 100% for HA and 90.9% for PEG (p = NS). Hydrodissection was feasible in 81.8% with HA and 63.6% with PEG. Median system usability scale score was 97.5 for HA and 82.5 for PEG (p < 0.001). Mean D 0.2cc was 80.8 Gy without spacer and 53.7 Gy with spacer (p < 0.001). Skin hotspots were present in 40.9% without spacer but none with spacer (p < 0.001).
Conclusions: A spacer injection in mastectomy specimens is feasible. An extra 5 mm space is always achieved, thereby potentially reducing the skin dose dramatically in low-dose-rate seed breast brachytherapy.
(Copyright © 2018 American Brachytherapy Society. All rights reserved.)
Databáze: MEDLINE
Externí odkaz: