Implantation of tissue expander prior to irradiation in the era of intensity modulated radiotherapy: impact on the management of patients with pelvic digestive cancers

Purpose: Before the introduction of intensity-modulated radiation therapy (IMRT), few teams used to implant a pelvic tissue expander to keep the bowel away from the radiation field, so as to reduce the risk of acute and late enteritis. However, this unexpected surgery could impact patient's overall treatment and may be no more necessary in the era of modern radiotherapy.

Material and methods: This is a retrospective cross-sectional study including 13 patients who underwent tissue expander implantation before radiotherapy or chemoradiotherapy for rectal or anal carcinoma between November 2008 and March 2019. First, we aim to show that IMRT could sometimes be insufficient to respect dosimetric constraints, and then we aim to report the impact of tissue expander implantation on the global strategy of care of patients with anal and rectal cancers.

Results: Seventy-seven percent of the included patients were treated for anal neoplasms, while the remaining 23% had locally advanced rectal cancer. The median follow-up since implantation of the expander was 51 months [3.7-115]. Three patients recurred. One patient developed grade III toxicity related to the implantation of a tissue expander. The delay between diagnosis and the start of irradiation was significantly prolonged (median of 3 months), requiring unusual induction chemotherapy.

Conclusion: Implantation of tissue expander prior to chemoradiotherapy should be considered, even in the era of IMRT, when irradiated peritoneal cavity volume (V15Gy-V45Gy) far exceeds usual dose constraints. However, it impacts the global strategy of care by delaying the start of irradiation, by introducing induction chemotherapy, and rarely by causing post-operative complications.