Imaging in pelvic exenteration-a multidisciplinary practice guide from the ESGAR-SAR-ESUR-PelvEx collaborative group

Abstract

Pelvic exenteration (PE) is a radical surgical approach designed for the curative treatment of advanced pelvic malignancies, requiring en-bloc resection of multiple pelvic organs. While the procedure is radical, it has shown promise in enhancing long-term survival and is now comparable in surgical mortality to elective resections for primary pelvic cancers. Imaging plays a crucial role in preoperative planning, with MRI, CT, and PET/CT being pivotal in assessing the extent of cancer and formulating a surgical roadmap. This paper presents clinical practice guidelines for imaging in the context of PE, developed jointly by ESGAR, SAR, ESUR, and the PelvEx Collaborative. These guidelines aim to standardize imaging protocols and reporting to improve the preoperative assessment and facilitate decision-making in the multidisciplinary treatment of pelvic cancers. Our recommendations underscore the importance of a multidisciplinary approach and the need for clear and precise imaging reports to optimize patient care. CLINICAL RELEVANCE STATEMENT: Our recommendations underscore the importance of a multidisciplinary approach and the need for clear and precise imaging reports to optimize patient care. KEY POINTS: MRI is mandatory for local staging in pelvic exenteration. Structured reporting (using the template provided in this guide) is recommended. Multidisciplinary review of imaging is critical for surgical planning.

Keywords: CT; Cancer; MRI; PET/CT; Pelvic exenteration.

Fig. 1

Reporting template

Fig. 2

Compartment approach to describing pelvic patterns of disease in sagittal (a) and axial (b). The central or axial compartment (yellow) includes the rectum—incl. anastomosis if present, mesorectum, pouch of Douglas, internal & external sphincter, and levator ani. The anterior compartment (pink) includes the genitourinary tract, pubic symphysis, and superior & inferior rami of the pubic bone. The posterior compartment (blue) includes the piriformis muscles, presacral fascia, sacrum, coccyx, sacrospinus & sacrotuberous ligaments, sciatic nerve & branches, and coccygeus muscles. The lateral compartment (green) includes the ureters, obturator muscles, ischial spine, ischium, sacral nerves/roots, lateral pelvic lymph nodes, and iliac arteries & veins

Fig. 3

Illustration highlighting the different important structures to evaluate on imaging during preoperative assessment for pelvic exenteration using the BONVUE acronym (Bones, Organs, Nerves, Vessels, Ureters, Extra tumor sites)

Fig. 4

Axial T2-weighted MR image (a without annotations, b with annotations) at the level of the S2 highlighting the position of the nerves and vessels. EIA, external iliac artery; EIV, external iliac vein; IIA, internal iliac artery; IIV, internal iliac vein

Fig. 5

Axial T2-weighted MR image (a without annotations, b with annotations) at the level of the S5, pointing out the position of the obturator nerve which is a very good surgical landmark, especially for lymphadenectomy. SSL, sacrospinous ligament; IGA&V, inferior gluteal artery and vein; OA&V, obturator artery and vein, ON, obturator nerve; EIA, external iliac artery; EIV, external iliac vein

Fig. 6

a Template report for a recurrent rectal tumor involving the right lateral and central pelvic compartments following prior abdominoperineal resection. b Template report including surgical planning ‘roadmap’ discussion for a large recurrent rectal tumor involving the central and left lateral pelvic compartments following prior abdominoperineal resection