Patient Reported Quality of Life Outcomes After Definitive Radiation Therapy With Absorbable Spacer Hydrogel for Prostate Cancer

Rectal toxicity of 3-dimensional conformal radiation therapy following hydrogel spacer (Space OAR) injection for men with prostate cancer

Purpose

To evaluate whether hydrogel spacer injection, which increases the distance between the prostate and rectum, prior to local radiation therapy for prostate cancer reduces rectal and bladder toxicity.

Patients and methods

With institutional review board approval (05-004), we retrospectively reviewed rectal and bladder toxicity after local radiation therapy in patients with prostate cancer who were followed up for more than 1 year.

Results

We included 156 patients who had received local radiation therapy. Their ages ranged from 63 to 86 years, with an average of 75 years. Most patients were treated only on the prostate and seminal vesicles. All prostate sites were irradiated as follows: whole pelvis with prostate in 10 patients, whole pelvis with prostate and metastatic sites in six, and prostate and metastatic sites in eight. Radiation therapy (70-74 Gy) was performed for the prostate. Irradiation of 45-46.8 Gy was applied to whole pelvic and para-aortic lymph nodes, with 54-60 Gy applied to bone metastatic sites. In one case, stereotactic body radiation therapy (36 Gy) was performed for a sacral bone metastatic site. The hydrogel spacer was injected in 39 patients. Rectal toxicity was reported in 21 patients without (17.9%) and 3 patients with (7.7%) the hydrogel spacer. Bladder toxicity was reported in five patients without and only one patient with the hydrogel spacer.

Conclusion

Hydrogel spacer injection prior to local radiation therapy for prostate cancer reduces rectal radiation exposure, lowers the risk of rectal complications, and may be a promising method for boosting the irradiation dose in the future.

Expanding access to rectal spacers in the United Kingdom: an examination of current evidence and an early review of data from a single institution

Background:

Prostate cancer is a common malignancy with rising incidence in Western countries such as the United Kingdom. In localised disease there are a variety of curative treatment modalities. Patients can be referred for surgery, or for a combination of hormonal therapies and radiotherapy (external beam radiotherapy or brachytherapy). Each treatment option comes with side effects and in the case of radiotherapy one potential complication is bowel toxicity from radiation exposure. New technologies are being developed to try and mitigate the side effects and long term morbidity of this treatment, and to expand access to radiotherapy for patients who may previously have been excluded (i.e those with inflammatory bowel disease). Rectal Spacers are absorbable polyethylene glycol hydrogels injected into the perirectal space. These position the anterior rectal wall away from the prostate, subsequently minimising radiation dose to the rectum. Rectal Spacers have been introduced to National Healthcare Service (NHS) practice as part of the Innovation and Technology Payment (ITP) programme, however, their use is now under review.

Methodology and Results:

In this editorial we conduct a narrative review of some of the available evidence for Rectal Spacers, discuss their utilization within the NHS and the barriers to their wider use. We also explore preliminary dosimetry and quality of life data for use of Rectal Spacers in our centre where we have been part of the NHS ITP programme. Dosimetry data and Quality of life questionnaires were gathered from 22 treated patients and 11 matched controls. This indicated lower radiation doses to the prostate in those treated with Rectal Spacers.

Conclusion:

Rectal Spacers are an effective method to reduce radiation dose to the prostate in men treated for localised prostate cancer, however, their use remains under review in the NHS and there are a variety of barriers to upscaling their use.