distal to iliac bifurcation Lateral pelvic lymph nodes Sciatic nerve Sciatic notch S1/2 nerve roots Piriformis or obturator internus muscles
The second radiological reporting approach utilized by the authors of this chapter provides a roadmap for surgical excision, whereby a highly experienced radiologist reports a detailed and unambiguous roadmap for en‐bloc excision of the locally advanced cancer. Such a roadmap will be complemented by accurate exclusion of extrapelvic metastases and incorporate surgically relevant information such as significant coexisting pathology or findings which may challenge the surgical approach. In the authors’ experience, radiologists who personally review and examine patients and then communicate scan findings in the outpatient clinic, alongside their surgical and nursing colleagues, develop much greater insight into patient management and surgical approaches.
The following principles may help guide radiologists to provide roadmaps for advanced pelvic cancer:
The radiologically derived roadmap for R0 excision is generally tailored to the maximum disease extent identified on sequential MRI, even in the context of downstaging from neoadjuvant treatment. This principle is based on the knowledge that radiologically occult microscopic foci of viable tumor cells may persist beyond the downstaged tumor margins, (e.g. peritumoral scar tissue) which could lead to R1 resection if resection were based on post‐treatment imaging alone [38–43]. Consequently, fibrosis in direct contact with the tumor on post‐treatment imaging should be regarded as potential tumor extension and therefore incorporated in the planned surgical resection [38, 42,44–55].
Each radiological roadmap is created by the radiology team in close co‐operation with the surgical team. The roadmap is tailored to the individual patient based on their anatomy, tumor extent, and comorbidity. The detailed description of excision planes and margins should be based on (distance to) intraoperatively assessable and fixed anatomical landmarks, including sacral promontory, ischial tuberosity, ischial spine, piriformis muscle, sacral foramina and nerve roots, sacral ligaments (sacrotuberous, sacrospinous, and ischiococcygeal), gluteal muscles, bifurcation of aorta/common iliac vessels, and origin of the superior gluteal artery (SGA). In practice, the authors of this chapter use the term SLAM (“sacral ligaments and muscle”) to describe the intimately related sacrotuberous, sacrospinous, and ischiococcygeus complex.
“BONVUE” or “a good view” is a helpful acronym which can be used to remind the team to include a description of bones, organs, nerves, vessels, ureters, and extra (tumor sites).
The key feature of the roadmap approach is that, in contrast to traditional compartment‐based reporting, this system addresses the extent of involvement and resection of individual structures potentially at risk and/or which need to be resected in order to obtain an adequate margin. The structures that are systematically assessed to build the roadmap, with the corresponding surgical considerations, are listed in Table 3.2. For any given patient, a roadmap is constructed based on assessment of the relevant elements in Table 3.2 and their surgical counterparts, which, when combined together, form the definitive surgical strategy.
Case Study
A 32‐year‐old female patient presented to her local hospital with a perforated PR‐bTME and underwent an emergency laparotomy and fashioning of a defunctioning colostomy prior to downsizing with a combination of radiotherapy and systemic chemotherapy. A diagnostic laparoscopy performed after completion of neoadjuvant treatment showed no evidence of peritoneal metastatic disease. T2‐weighted MRI was obtained prior to initiation of neoadjuvant therapy and to evaluate response approximately 12 weeks after completion of neoadjuvant treatment. A compartment‐based report from the referring unit using a published structure [37] is summarized as follows:
Above peritoneal reflection: disease present at the level of the peritoneal reflection with likely compromise of the right ureter
Below peritoneal reflection, anterior: suspected ovarian involvement with involvement of uterus and right adnexal tissuesTable 3.2 The St. Mark’s roadmap approach for assessment of pelvic tumor anatomy and resection margins.CategoryStructures and assessmentSurgical considerationsVisceral structuresRectum Uterus/vagina Prostate/seminal vesicles Bladder Base of penisAPER +/− excision of seminal vesicles +/− penile base excision Posterior/total pelvic exenterationUretersInvolvement relative to ureteric orificePartial ureterectomy +/− reimplantation/reconstructionVesselsCommon/external iliac arteriesVascular resection +/− reconstructionInternal iliac arteries: involvement relative to origin of SGALigation proximal/distal to origin of SGABony/ligamentous pelvisPubic bones + symphysisPubic bone resectionSacrum and presacral fasciaHeight of most proximal involvement relative to sacral promontoryExtent of subperiosteal dissection + level of sacral transectionDepth of cortical involvementSubperiosteal dissection HiSS Full thickness sacrectomyWidth of involvement relative to sacral foraminaWidth of HiSS or asymmetrical sacrectomySacropelvic ligaments and ischial spinesInvolvement of sacrospinous/sacrotuberous/ischiococcygeal ligaments (SLAM) + lateral extent relative to ischial spineResection of SLAM ELSiEDepth of involvement of ischial spineELSiE +/− extension into/toward acetabulumNervesL5/S1 nerve rootsResection of lumbosacral trunk with motor deficitS2/3/4 nerve rootsResection with sensory deficitMain trunk of sciatic nerve in sciatic notchPreservation or partial/total excision (as part of ELSiE)MusclesObturator internusResection as part of sidewall excisionPiriformisMedial aspect resected transabdominally (Sub)total resection requires ELSiEAPER, Abdomino‐perineal excision of the rectum;SLAM, term denoting the complex of sacropelvic ligaments: sacrospinous, sacrotuberous, and ischiococcygeal;SGA, superior gluteal artery;ELSiE, extended lateral sidewall excision;HiSS, high subcortical sacral resection.
Posterior: tumor infiltration of presacral fascia (S1–S5) without cortical invasion; S1/2 nerve roots clear
Lateral: tumor infiltration of pelvic sidewall fascia with sparing of internal and external iliac vessels; sacrotuberous and sacrospinous ligaments spared but right piriformis muscle infiltrated by tumor
Infralevator: tumor involvement of right levator
Anterior urogenital area/perineum/retropubic space: unaffected
In its conclusion, the compartment‐based report states that resection would require removal of the tumor from the anterior compartment above and below the peritoneal reflection, posterior compartment from S1 down, right lateral compartment, and right infralevator compartment.
This compartment‐based approach provides information on tumor extent, provides prognostic information, and helps determine if the local surgical team has the requisite skills to proceed with excision [36, 37].
In the roadmap approach, the relevant components from Table 3.2 were assessed and “translated” into a proposed surgical plan shown in Table 3.3 and Figures 3.1–3.7. Ultimately, the road map constructed by this multidisciplinary approach was for high sacrectomy with right ELSiE and either posterior exenteration (with the patient accepting a non‐functional bladder) and right ureteric
