Читать книгу Surgical Management of Advanced Pelvic Cancer - Группа авторов - Страница 34

Advanced pelvic cancers including locally advanced primary rectal cancers extending beyond the normal anatomical planes (beyond the total mesorectal excision (TME) plane or primary rectal beyond TME (PR‐bTME)), pelvic recurrences of previously treated cancer including recurrent rectal cancer (RRC), and recurrent squamous cell cancer (SCC) of the anus with or without colorectal peritoneal metastasis (CPM) need specialist management [1, 2].

Various exenterative techniques have evolved to address the specific anatomical and surgical challenges posed by advanced pelvic cancers [3–5]. These techniques combine visceral soft‐tissue resection with bony excision to achieve a complete pathological (R0) resection of the cancer surrounded by a rim of uninvolved tissue [2]. Disease threatening or involving the sacrum can be excised utilizing either a subperiosteal approach, partial sacrectomy, or, in selected cases with superficial involvement of the anterior cortex of the proximal sacrum, high subcortical sacral resection (HiSS) [6–8]. Cancer involvement of the lateral compartment structures including the greater sciatic notch and piriformis muscle was traditionally considered unresectable. However, in recent years surgical techniques have been refined to optimize R0 resection, including lateral pelvic compartment excision using approaches from both inside and outside the true pelvis; laterally extended endopelvic resection (LEER); and extended lateral pelvic sidewall excision (ELSiE) [9–14]. Disease extending anteriorly into the retropubic space can also be excised by penile base excision with partial pubic bone resection when involved [15, 16].

The goal of exenterative surgery is achieving microscopically complete tumor clearance (≥ 1 mm microscopically clear resection margins), termed R0 resection. Five‐year survival rates of up to 65% are achievable in patients undergoing R0 resection [17–20], while survival rates after R1 or R2 resections are significantly lower [21–23]. Consequently, R0 resection is currently considered the primary determinant of surgical outcome for advanced pelvic cancer. Furthermore, for curative intent surgery, only R0 resection will confer sufficient overall patient benefit to meaningfully outweigh the risk and morbidity of attempted resection.

To help achieve R0 resection, radiological assessment of advanced pelvic cancer should first accurately delineate the cancer margins, distinguishing viable tumor from scar tissue resulting from previous surgery or (chemo)radiotherapy, and “healthy” (uninvolved) adjacent structures. The radiologist must then create and communicate a clear roadmap for resection using surgically relevant planes to ensure R0 resection while preserving uninvolved organs. Finally, radiologists must ensure accurate and timely identification of extrapelvic metastases which could influence decision‐making on whether (and when) to offer surgery. This chapter provides a more detailed review of current practice for preoperative assessment of tumor anatomy and resectability.