Rectum-spacer related acute toxicity – endoscopy results of 403 prostate cancer patients after implantation of gel or balloon spacers

Abstract

BackgroundRectal spacers are used to limit dose to the anterior rectal wall in high dose external beam radiation therapy of the prostate and have been shown to reduce radiation induced toxicity. Here we report the complication rate and toxicity of the implantation procedure in a large cohort of patients who have either received a gel- or balloon-type spacer.MethodsIn total, 403 patients received rectal spacing, 264 with balloon, 139 with gel. Allocation was non-randomized. Two hundred seventy-six patients were treated with normofractionated regimen, the remaining 125 patients in moderate hypofractionation. Spacer related acute and late rectal toxicity was prospectively assessed by endoscopy using a mucosa scoring system (Vienna Rectoscopy Score) as well as CTCAE V.4. For the balloon subgroup, position and rotation of balloon spacers were additionally correlated to incidence and grade of rectal reactions in a post-hoc analysis of post-implant planning MRIs.ResultsOverall rectal toxicity was very low with average VRS scores of 0.06 at the day after implantation, 0.10 at the end of RT, 0.31 at 6 months and 0.42 at 12 months follow up. Acute Grade 3 toxicity (rectum perforation and urethral damage) directly related to the implantation procedure occurred in 1.49% (n = 6) and was seen exclusively in patients who had received the spacer balloon. Analysis of post implant MR imaging did not identify abnormal or mal-rotated positions of this spacer to be a predictive factors for the occurrence of spacer related G3 toxicities.ConclusionsSpacer technology is an effective means to minimize dose to the anterior rectal wall. However, the benefits in terms of dose sparing need to be weighed against the low, but possible risks of complications such as rectum perforation.

What is the quality of hydrogel spacer insertions? and which patients will benefit? A literature review

“…The inclusion criteria included a range of HS trials. [9][10][11][12][13][14][15][16][17] Table 3 provides the details of these trials, showing a range of use of radiotherapy techniques and patient staging. The use of ADT was not always mentioned.…”

“…The authors mentioned that the misplacement of spacers was not due to an initial learning curve as the first perforation was not detected until the 59 th balloon spacer patient. 14 The CTCAE toxicity scores were also very low with grade 1-2 GI toxicity average of TP1: 2•0% and TP2: 10•9%, TP3: 6•2% and TP4: 6•0%. Acute grade 3 GI toxicity was limited to the five patients who had insertion-related rectal perforations.…”

Application of rectal retractor for postprostatectomy salvage radiotherapy of prostate cancer: A case report and literature review

“…Moreover, the ERB position is not reproducible between treatment sessions that can cause deformations in the prostate . As reported by studies, the implantation of prostate‐rectum spacers can lead to rectal ulceration, and perforation, perineal abscess, etc . Of note, rate of these complications is very low.…”

An abdominal spacer that does not require surgical removal and allows drainage of abdominal fluids in patients undergoing carbon ion radiotherapy

“…Long-term installation of spacers for radiation therapy causes several adverse events, including intestinal perforation and abdominal infection [6,7]. The spacer should be removed after finishing radiation therapy as soon as possible to prevent spacer-induced adverse events.…”

“…To avoid surgery for removing the spacer, spacer gels with the absorptive properties have been used [1]. However, surgical intervention to remove spacers or to drain infectious fluid collections from the abdominal cavity is necessary for radiation-treated patients with abdominal infections caused by long-term spacer placement [7]. Spacers that do not need to be surgically removed and yet effectively drain the abdomen are urgently needed.…”