Application of a hydrogel spacer for postoperative salvage radiotherapy of prostate cancer - Abstract

BACKGROUND: In contrast to primary radiotherapy, no reports are available for a hydrogel spacer application in postoperative salvage radiotherapy for prostate cancer.

CASE REPORT: A 77-year-old patient presented 20 years after radical prostatectomy with a digitally palpable local recurrence at the urethrovesical anastomosis (PSA 5.5 ng/ml). The hydrogel spacer (10 ml, SpaceOARTM) was injected between the local recurrence and rectal wall under transrectal ultrasound guidance. Treatment planning was performed with an intensity-modulated technique up to a total dose of 76 Gy in 2-Gy fractions. The same planning was performed based on computed tomography before spacer injection for comparison.

RESULTS: The local recurrence, initially directly on the rectal wall, could be displaced more than  1 cm from the rectal wall after hydrogel injection. With a mean total dose of 76 Gy to the planning target volume, rectal wall volumes included in the 70 Gy, 60 Gy, 50 Gy isodoses were 0 cm3, 0 cm3, and 0.4 cm3 with a spacer and 2.9 cm3, 4.5 cm3, and 6.2 cm3 without a spacer, respectively. The patient reported rectal urgency during radiotherapy, completely resolving after the end of treatment. The PSA level was 5.4 ng/ml a week before the end of radiotherapy and dropped to 0.9 ng/ml 5 months after radiotherapy.

CONCLUSION: A hydrogel spacer was successfully applied for dose-escalated radiotherapy in a patient with macroscopic local prostate cancer recurrence at the urethrovesical anastomosis to decrease the dose at the rectal wall. This option can be considered in specifically selected patients.

Written by:
Pinkawa M, Schubert C, Escobar-Corral N, Holy R, Eble MJ.   Are you the author?
Department of Radiation Oncology, RWTH Aachen University, Pauwelsstrasse 30, 52057, Aachen, Germany.  

Reference: Strahlenther Onkol. 2014 Oct 23. Epub ahead of print.
doi: 10.1007/s00066-014-0769-z

PubMed Abstract
PMID: 25339311

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