Pelvic colorectal recurrence: crucial role of radiologists in oncologic and surgical treatment options

[Postoperative Imaging Findings of Colorectal Surgery: A Pictorial Essay]

Postoperative colorectal imaging studies play an important role in the detection of surgical complications and disease recurrence. In this pictorial essay, we briefly describe methods of surgery, imaging findings of their early and late complications, and postsurgical recurrence of cancer and inflammatory bowel disease.

Dentate line invasion as a predictive factor of poor distant relapse-free survival in locally advanced lower rectal cancer with anal sphincter involvement

Background

While an important surgical landmark of the dentate line has been established for locally advanced lower rectal cancer (LALRC), the prognostic significance of dentate line invasion (DLI) has not been well defined. This study aimed to explore the impact of DLI on prognosis in LALRC patients with anal sphincter involvement after neoadjuvant chemoradiotherapy followed by surgery.

Methods

We analyzed 210 LALRC patients and classified them into DLI group (n = 45) or non-DLI group (n = 165). The exact role of DLI in survival and failure patterns was assessed before and after propensity-score matching(PSM). Finally, 50 patients were matched.

Results

Before matching, patients in the DLI group had poorer 5-year distant relapse-free survival (DRFS) (P < 0.001), disease-free survival (DFS) (P < 0.001), and overall survival (OS) (P = 0.022) than those in the non-DLI group, with the exception of local recurrence-free survival (LRFS) (P = 0.114). After PSM, the 5-year DRFS, DFS, OS, and LRFS were 51.7% vs. 79.8%(P = 0.026), 51.7% vs. 79.8%(P = 0.029), 71.6% vs. 85.4%(P = 0.126), and 85.7% vs. 92.0%(P = 0.253), respectively, between the two groups. DLI was also an independent prognostic factor for poor DRFS with (Hazard ratio [HR] 3.843, P = 0.020) or without matching (HR 2.567, P = 0.001). The DLI group exhibited a higher rate of distant metastasis before (44.4% vs. 19.4%, P < 0.001) and after matching (48.0% vs. 20.0%, P = 0.037) and similar rates of locoregional recurrence before (13.3% vs.7.9%, P = 0.729) and after matching (16.0% vs.12.0%, P = 1.000).

Conclusions

DLI may portend worse DRFS and distant metastasis in LALRC patients with anal sphincter involvement, and this may be an important variable to guide clinicians.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-10299-8.

Locally Recurrent Rectal Cancer According to a Standardized MRI Classification System: A Systematic Review of the Literature

(1) Background: The classification of locally recurrent rectal cancer (LRRC) is not currently standardized. The aim of this review was to evaluate pelvic LRRC according to the Beyond TME (BTME) classification system and to consider commonly associated primary tumour characteristics. (2) Methods: A systematic review of the literature prior to April 2020 was performed through electronic searches of the Science Citation Index Expanded, EMBASE, MEDLINE, and CENTRAL databases. The primary outcome was to assess the location and frequency of previously classified pelvic LRRC and translate this information into the BTME system. Secondary outcomes were assessing primary tumour characteristics. (3) Results: A total of 58 eligible studies classified 4558 sites of LRRC, most commonly found in the central compartment (18%), following anterior resection (44%), in patients with an 'advanced' primary tumour (63%) and following neoadjuvant radiotherapy (29%). Most patients also classified had a low rectal primary tumour. The lymph node status of the primary tumour leading to LRRC was comparable, with 52% node positive versus 48% node negative tumours. (4) Conclusions: This review evaluates the largest number of LRRCs to date using a single classification system. It has also highlighted the need for standardized reporting in order to optimise perioperative treatment planning.

The use of radiomic analysis of magnetic resonance imaging in predicting distant metastases of rectal carcinoma following surgical resection: A systematic review and meta-analysis

AIM

Estimating prognosis in rectal carcinoma (RC) is challenging, with distant recurrence (DR) occurring in up to 30% of cases. Radiomics is a novel field using diagnostic imaging to investigate the tumour heterogeneity of cancers and may have the potential to predict DR. The aim of the study was to perform a systematic review of the current literature evaluating the use of radiomics in predicting DR in patients with resected RC.

METHODS

A systematic review was performed as per PRISMA guidelines to identify studies reporting radiomic analysis of magnetic resonance imaging (MRI) to predict DR in patients diagnosed with RC. Sensitivity and specificity of radiomic analyses were included for meta-analysis.

RESULTS

A total of seven studies including 1497 patients (998 males) were included, seven, five and one of whom reported radiomics, respectively. The overall pooled rate of DR from all included studies was 17.1% (256/1497), with 15.6% (236/1497), 1.3% (19/1497) and 0.2% (3/1497) of patients having hepatic, pulmonary and peritoneal metastases. Meta-analysis demonstrated that radiomics correctly predicted DR with pooled sensitivities and specificities of MRI 0.76 (95% CI: 0.73, 0.78) and 0.85 (95% CI: 0.83, 0.88), respectively.

CONCLUSION

This systematic review suggests the benefit of radiomic analysis of preoperative MRI in identifying patients with resected RC at an increased risk of DR. Our findings warrant validation in larger prospective studies as modalities to predict DR is a significant unmet need in RC. Radiomics may allow for tailored therapeutic strategies for high-risk groups.

Diagnostic performance of 18F-fluorodeoxyglucose-PET/MRI versus MRI alone in the diagnosis of pelvic recurrence of rectal cancer

Purpose

To compare the diagnostic performance of ¹⁸F-fluorodeoxyglucose-PET/MRI and MRI in the diagnosis of pelvic recurrence of rectal cancer.

Methods

All PET/MRIs of patients in the follow-up of rectal cancer performed between 2011 and 2018 at our institution were retrospectively reviewed. Recurrence was confirmed/excluded either by histopathology or imaging follow-up (> 4 months). Four groups of readers (groups 1/2: one radiologist each, groups 3/4: one radiologist/one nuclear medicine physician) independently interpreted MRI and PET/MRI. The likelihood of recurrence was scored on a 5-point-scale. Inter-reader agreement, sensitivity, specificity, PPV/NPV and accuracy were assessed. ROC curve analyses were performed.

Results

Fourty-one PET/MRIs of 40 patients (mean 61 years ± 10.9; 11 women, 29 men) were included. Sensitivity of PET/MRI in detecting recurrence was 94%, specificity 88%, PPV/NPV 97% and 78%, accuracy 93%. Sensitivity of MRI was 88%, specificity 75%, PPV/NPV 94% and 60%, accuracy 85%. ROC curve analyses showed an AUC of 0.97 for PET/MRI and 0.92 for MRI, but the difference was not statistically significant (p = 0.116). On MRI more cases were scored as equivocal (12% versus 5%). Inter-reader agreement was substantial for PET/MRI and MRI (0.723 and 0.656, respectively).

Conclusion

¹⁸F-FDG-PET/MRI and MRI are accurate in the diagnosis of locally recurrent rectal cancer. Sensitivity, specificity, PPV, NPV and accuracy are comparable for both modalities, but PET/MRI increases readers’ confidence levels and reduces the number of equivocal cases.

Graphic abstract

Patterns of failure and implications for clinical target volume definition of locally advanced T4b rectal cancer identified with magnetic resonance imaging and treated using neoadjuvant chemoradiotherapy and surgery

BACKGROUND AND PURPOSE

Elective irradiation of the external iliac lymph nodes (EIN) has always been advocated for T4b rectal cancer with anterior organ invasion without convincing evidence. This study aimed to explore the patterns of treatment failure for locally advanced T4b rectal cancer treated using neoadjuvant chemoradiotherapy (NCRT) and surgery. This information may help to clarify whether the current definition of the clinical target volume (CTV) is still appropriate.

MATERIALS AND METHODS

We retrospectively analyzed data from 126 patients with locally advanced T4b rectal cancer who received NCRT, without elective EIN irradiation, followed by surgery between January 2010 and October 2018. Pretreatment magnetic resonance imaging was used to identify the T4b disease in all cases. The locoregional recurrence (LRR) rate and EIN failure rate were evaluated, and the LRR locations were identified using a three-dimensional model.

RESULTS

After a median follow-up of 53.9 months, LRR occurred in 11.1% of patients (14/126). All LRRs were located in the previously irradiated fields and below the S2-S3 junction. The EIN failure rate was 0.8% (1/126) among all patients and 1.8% (1/56) in the group with anterior genitourinary organ invasion. The estimated 4-year distant relapse-free survival, disease-free survival and overall survival were 79.3%, 73.2% and 86.9%, respectively.

CONCLUSIONS

It may be feasible to exclude the external iliac region from the CTV during NCRT for locally advanced T4b rectal cancer. However, further studies are needed to clarify whether the cranial border of the CTV can be lowered.

Sciatic and Femoral Nerve Resection During Extended Radical Surgery for Advanced Pelvic Tumours: Long-term Survival, Functional, and Quality-of-life Outcomes

OBJECTIVE

To report survival, functional, and quality-of-life (QoL) outcomes after extended radical resection for advanced pelvic tumors with en bloc sciatic or femoral nerve resection.

BACKGROUND

Advanced pelvic tumors involving the sciatic or femoral nerve have traditionally been considered inoperable. Small studies have suggested acceptable functional outcomes can be achieved after pelvic exenteration with en bloc sciatic nerve resection.

METHOD

Consecutive patients who underwent extended radical pelvic surgery with en bloc resection of the sciatic or femoral nerves at a single center were included.

RESULTS

Of 713 radical pelvic resections, 68 patients (9.5%) had en bloc sciatic or femoral nerve resection. Complete sciatic, partial sciatic, and complete femoral nerve resection was performed in 26 (38%), 38 (56%), and 4 patients (6%), respectively. Overall and major postoperative complication rates were 63% and 40%, respectively. R0 resection was achieved in 65% of patients, which translated to 55% and 76% overall and local recurrence-free 5-year survival in those with colorectal cancer. Twenty-two (96%) and 25 (92%) patients could mobilize independently after complete and partial sciatic nerve resection, respectively. Physical QoL was significantly lower at 6 months after surgery compared with baseline (P = 0.041), but returned to baseline at 12 months (P = 0.163). There was no difference in mental or overall QoL at 6 or 12 months compared with baseline.

CONCLUSION

En bloc sciatic and femoral nerve resection can be performed during extended radical pelvic resections with morbidity and survival outcomes comparable with existing exenteration literature, including in patients with recurrent rectal cancer. Physical QoL may be impaired after surgery, but returns to baseline by 12 months.

Systematic review of classification systems for locally recurrent rectal cancer

Background

Classification of pelvic local recurrence (LR) after surgery for primary rectal cancer is not currently standardized and optimal imaging is required to categorize anatomical site and plan treatment in patients with LR. The aim of this review was to evaluate the systems used to classify locally recurrent rectal cancer (LRRC) and the relevant published outcomes.

Methods

A systematic review of the literature prior to April 2020 was performed through electronic searches of the Science Citation Index Expanded, EMBASE, MEDLINE and CENTRAL databases. The primary outcome was to review the classifications currently in use; the secondary outcome was the extraction of relevant information provided by these classification systems including prognosis, anatomy and prediction of R0 after surgery.

Results

A total of 21 out of 58 eligible studies, classifying LR in 2086 patients, were reviewed. Studies used at least one of the following eight classification systems proposed by institutions or institutional groups (Mayo Clinic, Memorial Sloan-Kettering – original and modified, Royal Marsden and Leeds) or authors (Yamada, Hruby and Kusters). Negative survival outcomes were associated with increased pelvic fixity, associated symptoms of LR, lateral compared with central LR and involvement of three or more pelvic compartments. A total of seven studies used MRI with specifically defined anatomical compartments to classify LR.

Conclusion

This review highlights the various imaging systems in use to classify LRRC and some of the prognostic indicators for survival and oncological clearance based on these systems. Implementation of an agreed classification system to document pelvic LR consistently should provide more detailed information on anatomical site of recurrence, burden of disease and standards for comparative outcome assessment.

[Resection of recurrent rectal cancer]

A curative treatment of locally recurrent rectal cancer (LRRC) can only be achieved with a complete resection and microscopically tumor-free surgical margins (R0). Imaging techniques are the most important investigations for the preoperative staging of local and systemic diseases. Due to substantial improvements in surgical strategies and techniques, previously unresectable tumors can now be excised. Several publications have demonstrated the oncological benefits of high sacral resection for LRRC. High subcortical sacrectomy (HiSS), extended lateral resection and extended lateral pelvic sidewall excision (ELSiE) belong to the newer surgical options. Biological meshes, various myocutaneous flaps, titanium and bone allografts can be used for reconstruction. Specialized centers provide an efficient management of complications and postoperative treatment.

Benchmarking trial between France and Australia comparing management of primary rectal cancer beyond TME and locally recurrent rectal cancer (PelviCare Trial): rationale and design

BACKGROUND

Among patients with rectal cancer, 5-10% have a primary rectal cancer beyond the total mesorectal excision plane (PRC-bTME) and 10% recur locally following primary surgery (LRRC). In both cases, patients 'care remains challenging with a significant worldwide variation in practice regarding overall management and criteria for operative intervention. These variations in practice can be explained by structural and organizational differences, as well as cultural dissimilarities. However, surgical resection of PRC-bTME and LRRC provides the best chance of long-term survival after complete resection (R0). With regards to the organization of the healthcare system and the operative criteria for these patients, France and Australia seem to be highly different. A benchmarking-type analysis between French and Australian clinical practice, with regards to the care and management of PRC-bTME and LRRC, would allow understanding of patients' care and management structures as well as individual and collective mechanisms of operative decision-making in order to ensure equitable practice and improve survival for these patients.

METHODS/DESIGN

The current study is an international Benchmarking trial comparing two cohorts of 120 consecutive patients with non-metastatic PRC-bTME and LRRC. Patients with curative and palliative treatment intent are included. The study design has three main parts: (1) French and Australian cohorts including clinical, radiological and surgical data, quality of life (MOS SF36, FACT-C) and distress level (Distress thermometer) at the inclusion, 6 and 12 months; (2) experimental analyses consisting of a blinded inter-country reading of pelvic MRI to assess operatory decisions; (3) qualitative analyses based on MDT meeting observation, semi-structured interviews and focus groups of health professional attendees and conducted by a research psychologist in both countries using the same guides. The primary endpoint will be the clinical resection rate. Secondary end points will be concordance rate between French and Australian operative decisions based on the inter-country reading MRI, post-operative mortality and morbidity rates, oncological outcomes based on resection status and one-year overall and disease-free survival, patients' quality of life and distress level. Qualitative analysis will compare obstacles and facilitators of operative decision-making between both countries.

DISCUSSION

Benchmarking can be defined as a comparison and learning process which will allow, in the context of PRC-bTME and LRRC, to understand and to share the whole process management of these patientsbetween Farnce and Australia.

TRIAL REGISTRATION

NCT02551471 . (date of registration: 09/14/2015).

Factors associated with the location of local rectal cancer recurrence and predictors of survival

PURPOSE

The location of locally recurrent rectal cancer (LRRC) may influence survival. This study examines factors affecting the location of LRRC, the effect of LRRC location on survival, and predictive factors for survival in patients with LRRC.

METHODS

Patients undergoing initial proctectomy and subsequent management of LRRC at the Cleveland Clinic (1980-2011) were included. Data regarding index surgery, LRRC, and survival were obtained from a prospectively maintained database.

RESULTS

One hundred and fifty-seven patients were identified with a mean follow-up 59.8 ± 50.1 months and time to LRRC of 31.7 ± 30.1 months. Sixty patients underwent surgery with curative intent. Anastomotic leak and retrieving less than 12 lymph nodes at index proctectomy were associated with posterior (P = 0.019) and lateral (P = 0.036) recurrences, respectively. Having an axial relative to an anterior, posterior, or lateral recurrence was associated with improved overall survival (P = 0.001). On multivariable analysis, undergoing primarily palliative treatment (OR, 5.2; 95 % confidence interval (CI), 3.2-8.4; P < 0.001), age at LRRC >60 years (OR, 1.9; 95 % CI, 1.3-2.7, P < 0.001), advanced primary tumour stage (OR, 1.5; 95 % CI, 1.1-2.1; P = 0.021), and anastomotic leak at index surgery (OR, 1.8; 95 % CI, 1.2-2.7; P = 0.008) were associated with reduced LRRC 5-year survival.

CONCLUSIONS

The current study suggests that features of the primary tumour and technical factors at the time of index proctectomy influence both the location of LRRC and survival.

Rectal cancer staging: focus on the prognostic significance of the findings described by high-resolution magnetic resonance imaging

High-resolution (HR) magnetic resonance imaging (MRI) has become an indispensable tool for multidisciplinary teams (MDTs) addressing rectal cancer. It provides anatomic information for surgical planning and allows patients to be stratified into different groups according to the risk of local and distant recurrence. One of the objectives of the MDT is the preoperative identification of high-risk patients who will benefit from neoadjuvant treatment. For this reason, the correct evaluation of the circumferential resection margin (CRM), the depth of tumor spread beyond the muscularis propria, extramural vascular invasion and nodal status is of the utmost importance. Low rectal tumors represent a special challenge for the MDT, because decisions seek a balance between oncologic safety, in the pursuit of free resection margins, and the patient's quality of life, in order to preserve sphincter function. At present, the exchange of information between the different specialties involved in dealing with patients with rectal cancer can rank the contribution of colleagues, auditing their work and incorporating knowledge that will lead to a better understanding of the pathology. Thus, beyond the anatomic description of the images, the radiologist's role in the MDT makes it necessary to know the prognostic value of the findings that we describe, in terms of recurrence and survival, because these findings affect decision making and, therefore, the patients' life. In this review, the usefulness of HR MRI in the initial staging of rectal cancer and in the evaluation of neoadjuvant treatment, with a focus on the prognostic value of the findings, is described as well as the contribution of HR MRI in assessing patients with suspected or confirmed recurrence of rectal cancer.