Original Title: Avis: utilisation de l’hydrogel SpaceOAR comme espaceur rectal lors de la radiothérapie de la prostate

Authors' objectives: The SpaceOAR™ Hydrogel System (Boston Scientific, USA), approved by Health Canada in 2016, is an option, for men with prostate cancer, for reducing the risk of prostate radiotherapy-induced rectal toxicity. This resorbable polyethylene glycol-based hydrogel injected into the retroprostatic space is designed to temporarily move the anterior rectal wall away from the prostate during radiotherapy. The objective is to reduce the high radiation doses absorbed by the rectal wall and, consequently, the resulting rectal toxicity. The hydrogel rectal spacer maintains the space thus created for about 3 months, after which it is completely absorbed by the body over time. Given the potential benefits of the SpaceOAR™ for patients undergoing prostate radiotherapy, the Programme québécois de cancérologie (PQC) of the Ministère de la Santé et des Services sociaux asked the Institut national d'excellence en santé et en services sociaux (INESSS) to prepare a report on the clinical efficacy and utility, the safety and the efficiency of this new medical device. The purpose of this request to INESSS was to evaluate the use of the SpaceOAR™ Hydrogel System in prostate cancer patients undergoing prostate radiotherapy in Québec’s health-care facilities.

Authors' results and conclusions: RESULTS: The integration of the scientific, experiential and contextual data led to the following findings: There is a need to reduce radiotherapy-induced rectal toxicity, particularly in patients at increased risk for such toxicity, even if other means are used to reduce this toxicity (image guidance, fiducial markers, radiotherapy technique [VMAT, brachytherapy]). SpaceOAR™ hydrogel is a complementary modality. (CLINICAL UTILITY) Hydrogel reduces grade ≥ 2 late rectal toxicity (during IMRT or VMAT [moderate level of evidence] or low-dose SABR [low level of evidence]) and better preserves bowel quality of life (data available for IMRT only [low level of evidence]) Although the clinical impact of reducing rectal toxicity may appear small from a populational perspective, the avoidance of grade ≥ 2 toxicity can have a large impact from an individual perspective. (PROCEDURE) The procedure is quick, is performed under local anesthesia and at the same time as fiducial marker implantation, and does not involve an additional visit for the patient. However, it may be poorly tolerated by some patients. An MRI is necessary for treatment planning after hydrogel implantation. Most of Québec’s radiotherapy centres do not have a MRI scanner dedicated for radiation oncology and will therefore have to go through the hospital's imaging department. (ECONOMIC ASPECT) The efficiency data suggest that the procedure involves significant costs and are accompanied by considerable uncertainty regarding the long-term efficacy and safety data. CONCLUSION: Nevertheless, the experts consulted recognize that this emerging technology is promising. Despite the uncertainty surrounding the selection of appropriate patients and the demonstration of its clinical utility in these patients, some believe that hydrogel could have a certain degree of utility in rigorously selected patients. For example, its use could be considered in those whose medical condition is likely to increase the risk of rectal toxicity very significantly or in those for whom significant deviations in rectal dose constraints are encountered during treatment planning. It would, however, be contraindicated in certain specific situations (e.g., the presence of an active bleeding disorder or a strong likelihood of experiencing difficulty when creating a space for hydrogel implantation).

Authors' recommendations: In light of the analysis of the best available data, and given the significant uncertainty regarding the product’s therapeutic value, the members of INESSS’s Comité d’excellence clinique en services de santé (CEC – santé) consider that public coverage for the SpaceOAR™ is not a fair and reasonable option. Additional data are considered necessary to support the introduction of this technology. Reasons for the unanimous position: The weakness of the data, including the absence of data for groups considered to be at higher risk for rectal toxicity; the risk-benefit ratio, which does not appear to support the use of this technology; the possibility of major complications for patients; the possibility of an increased risk of complications for patients at increased risk for rectal toxicity; the observed dosimetric benefit (sometimes significant) in the data presented, which appears to offer only a small clinical benefit; the contradiction between the positions taken by other organizations; the potential difficulty of access to MRI. Given the considerable uncertainty regarding the therapeutic value of the SpaceOAR™, INESSS considers that this treatment modality should only be offered in an experimental setting. More efficacy and safety data are needed to support the introduction of this technology.

Authors' methods: We conducted a rapid review of the literature data and the data provided by the manufacturer to document the safety, clinical efficacy, clinical utility (impact on toxicity and quality of life) and efficiency of SpaceOAR™ hydrogel. The literature examined was that published up to January 2020 on patients with localized or locally advanced prostate cancer treated with external beam radiotherapy (conformal intensity-modulated radiotherapy [IMRT], volumetric modulated arc therapy [VMAT], stereotactic ablation radiotherapy [SABR]) or brachytherapy combined or not with external beam radiotherapy. The scientific data and experiential and contextual data were integrated into a deliberative process that led to a number of findings and recommendations.  

Project Status: Completed

URL for project: https://www.inesss.qc.ca/publications/repertoire-des-publications/publication/utilisation-de-lhydrogel-spaceoarmd-comme-espaceur-rectal-lors-de-la-radiotherapie-de-la-prostate.html

Year Published: 2021

URL for published report: https://www.inesss.qc.ca/publications/repertoire-des-publications/publication/utilisation-de-lhydrogel-spaceoarmd-comme-espaceur-rectal-lors-de-la-radiotherapie-de-la-prostate.html

Requestor: Programme québécois de cancérologie (PQC)

English language abstract: An English language summary is available

Publication Type: Full HTA

Country: Canada

Province: Quebec

Organisation Name: Institut national d'excellence en sante et en services sociaux

Contact Address: L'Institut national d'excellence en sante et en services sociaux (INESSS) , 2021, avenue Union, bureau 10.083, Montreal, Quebec, Canada, H3A 2S9;Tel: 1+514-873-2563, Fax: 1+514-873-1369

Contact Name: demande@inesss.qc.ca

Contact Email: demande@inesss.qc.ca

Copyright: L'Institut national d'excellence en sante et en services sociaux (INESSS)