The Rectal Spacer segmentation by type distinguishes three primary product families: hydrogel, balloon, and collagen spacers. Hydrogel spacers, exemplified by the SpaceOAR system, dominate the market due to their minimally invasive injection technique, rapid polymerisation, and favorable safety profile, accounting for roughly 65 % of total unit sales. Balloon spacers, such as the ProSpace device, offer a reusable, adjustable volume but require trans‑perineal placement and are limited by higher procedural complexity, contributing approximately 20 % of the market. Collagen‑based spacers, derived from animal tissue, present a niche solution for patients with contraindications to synthetic materials; their limited adoption reflects a 10‑15 % share, driven by higher cost and regulatory constraints. A residual 5 % comprises emerging hybrid technologies still in clinical validation. Each type’s contribution is measured not only by volume but also by reimbursement pathways and physician preference, collectively shaping the overall Rectal Spacer market size.