Survey of rectal cancer MRI technique and reporting tumour descriptors in the UK: a multi-centre British Society of Gastrointestinal and Abdominal Radiology (BSGAR) audit

AIM

To evaluate variation in magnetic resonance imaging (MRI) technique and reporting of rectal cancer staging examinations across the UK.

MATERIALS AND METHODS

A retrospective, multi-centre audit was undertaken of imaging protocols and information documented within consecutive MRI rectal cancer reports between March 2020 and August 2021, which were compared against American and European guidelines. Inclusion criteria included histologically proven rectal adenocarcinoma and baseline staging MRI rectum only.

RESULTS

Fully anonymised data from 924 MRI reports by 78 radiologists at 24 centres were evaluated. Thirty-two per cent of radiologists used template reporting, but these reports offered superior documentation of 13 out of 18 key tumour features compared to free-text reports including T-stage, relation to peritoneal reflection and mesorectal fascia (MRF), nodal status, and presence of extramural venous invasion (EMVI; p<0.027 in each). There was no significant differences in the remaining five features. Across all tumour locations, the tumour relationship to the MRF, the presence of EMVI, and the presence of tumour deposits were reported in 79.5%, 85.6%, and 44% of cases, respectively, and tumour, nodal, and distant metastatic stage documented in 94.4%, 97.7%, and 78.3%. In low rectal tumours, the relationship to the anal sphincter complex was reported in only 54.6%.

CONCLUSION

Considerable variation exists in rectal cancer MRI acquisition and reporting in this sample of UK centres. Inclusion of key radiological features in reports must be improved for risk stratification and treatment decisions. Template reporting is superior to free-text reporting. Routine adoption of standardised radiology practices should now be considered to improve standards to facilitate personalised precision treatment for patients to improve outcomes.

The impact of endoscopic ultrasound on the management and outcome of patients with oesophageal cancer: an update of a systematic review

AIM

To provide an updated systematic review concerning the impact of endoscopic ultrasound (EUS) in the modern era of oesophageal cancer staging.

MATERIALS AND METHODS

To update the previous systematic review, databases including MEDLINE and EMBASE were searched and studies published from 2005 onwards were selected. Studies reporting primary data in patients with oesophageal or gastro-oesophageal junction cancer who underwent radiological staging and treatment, regardless of intent, were included. The primary outcome was the reported change in management after EUS. Secondary outcomes were recurrence rate and overall survival. Two reviewers extracted data from included articles. This study was registered with PROSPERO (CRD42021231852).

RESULTS

Eighteen studies with 11,836 patients were included comprising 2,805 patients (23.7%) who underwent EUS compared to 9,031 (76.3%) without EUS examination. Reported change of management varied widely from 0% to 56%. When used, EUS fine-needle aspiration precluded curative treatment in 37.5%-71.4%. Overall survival improvements ranged between 121 and 639 days following EUS intervention compared to patients without EUS. Smaller effect sizes were observed in a randomised controlled trial, compared to larger differences reported in observational studies.

CONCLUSION

Current evidence for the effectiveness of EUS in oesophageal cancer pathways is conflicting and of limited quality. In particular, the extent to which EUS adds value to contemporary cross-sectional imaging techniques is unclear and requires formal re-evaluation.

A national cross-sectional survey investigating the use of endoscopic ultrasound in the diagnosis and treatment of oesophageal cancer in the UK

AIM

To evaluate variation in the pre-pandemic use of endoscopic ultrasound (EUS) for oesophageal cancer diagnosis and treatment planning up to 2019, and which factors contributed to this.

MATERIALS AND METHODS

A UK-wide online survey of oesophagogastric multidisciplinary team lead clinicians was undertaken to determine perceptions towards, and the use of, EUS to aid staging and treatment planning in oesophageal cancer.

RESULTS

Thirty-five responses were received, representing 97 UK National Health Service Trusts/Health Boards. A majority of centres (n=21, 60%) did not have formal written guidance for EUS use. Although all respondents had access to EUS, a perceived lack of utility (n=7) and concerns about delaying treatment start dates (n=8) each restricted EUS use for a fifth of respondents. For most centres (n=24, 68.6%), EUS use is case-specific, whereas for 10 (28.6%) EUS is used for all patients with potentially curable disease. A majority of centres use diagnostic positron-emission tomography for radiotherapy target volume delineation (TVD), whereas 22 (62.9%) use EUS. The factors contributing to decisions to use EUS for staging, TVD and surgical planning varied between centres. The proportion of centre respondents who would request EUS in each of six clinical scenarios varied considerably.

CONCLUSION

There were substantial differences in the patient and disease characteristics that are perceived to be indications for EUS use for both staging and treatment planning. Research to clarify in which patients with oesophageal cancer EUS affords benefit is required, as is urgent standardisation of its role in the diagnostic pathway.

Opportunities in cancer imaging: a review of oesophageal, gastric and colorectal malignancies

The incidence of gastrointestinal (GI) malignancy is increasing worldwide. In particular, there is a concerning rise in incidence of GI cancer in younger adults. Direct endoscopic visualisation of luminal tumour sites requires invasive procedures, which are associated with certain risks, but remain necessary because of limitations in current imaging techniques and the continuing need to obtain tissue for diagnosis and genetic analysis; however, management of GI cancer is increasingly reliant on non-invasive, radiological imaging to diagnose, stage, and treat these malignancies. Oesophageal, gastric, and colorectal malignancies require specialist investigation and treatment due to the complex nature of the anatomy, biology, and subsequent treatment strategies. As cancer imaging techniques develop, many opportunities to improve tumour detection, diagnostic accuracy and treatment monitoring present themselves. This review article aims to report current imaging practice, advances in various radiological modalities in relation to GI luminal tumour sites and describes opportunities for GI radiologists to improve patient outcomes.

Radiological prediction of positive circumferential resection margin in oesophageal cancer

PURPOSE

A positive circumferential resection margin (CRM) is regarded as a poor prognostic indicator in oesophageal cancer (OC) but its prediction can be challenging. MRI is used to predict a threatened CRM in rectal cancer but is not commonly performed in OC unlike PET/CT, which is now routinely used. Therefore, this study assessed the additional predictive value of PET-defined tumour variables compared with EUS and CT T-stage. The prognostic significance of CRM status was also assessed.

MATERIALS AND METHODS

This retrospective study included 117 consecutive patients [median age 64.0 (range 24-78), 102 males, 110 adenocarcinomas, 6 squamous cell carcinoma (SCC), 1 neuro-endocrine] treated between 1st March 2012 and 31st July 2015. A binary logistic regression model tested 5 staging variables; EUS T-stage (≤T2 vs ≥ T3), CT T-stage (≤T2 vs ≥ T3), PET metabolic tumour length (MTL), PET metabolic tumour width (MTW) and the maximum standardised uptake value (SUV_max).

RESULTS

The CRM was positive in 43.6%. Sixty-seven (57.3%) patients received neo-adjuvant chemotherapy (NACT), 31 patients (26.5%) underwent surgery alone and 19 patients (16.2%) had neo-adjuvant chemo-radiotherapy (NACRT). Median overall survival (OS) was 36.0 months (95% confidence interval (CI) 24.1-47.9) and the 2-year OS was 55.4%. A binary logistic regression model showed EUS ≥ T3 tumours were independently and significantly more likely to have a positive CRM than EUS ≤ T2 tumours (HR 5.188, 95% CI 1.265-21.273, p = 0.022). CT T-stage, PET MTL, PET MTW and SUV_max were not significantly associated with CRM status (p = 0.783, 0.852, 0.605 and 0.413, respectively). There was a significant difference in OS between CRM positive and negative groups (X² 4.920, df 1, p = 0.027).

CONCLUSION

Advanced EUS T-stage is associated with a positive CRM, but PET-defined tumour variables are unlikely to provide additional predictive information. This study demonstrates the continued benefit of EUS as part of a multi-modality OC staging pathway.

Accuracy of contemporary oesophageal cancer lymph node staging with radiological-pathological correlation

AIM

To evaluate the accuracy of contemporary N-staging and provide radiological-pathological correlation in patients with lymph node metastases (LNMs) that were radiologically staged N0.

MATERIALS AND METHODS

One hundred and twelve patients were included who underwent surgery alone (n=41) or neoadjuvant therapy (n=71) between October 2010 and December 2015. Contrast-enhanced computed tomography (CECT), endoscopic ultrasound (EUS), and combined positron-emission tomography (PET) and CT N-stage were compared to pathological N-stage [node-negative (N0) versus node-positive (N+) groups]. Fifty LNMs from 15 patients preoperatively staged as N0 were measured and the maximum size recorded.

RESULTS

Accuracy, sensitivity, and specificity of N0 versus N+ disease with CECT, EUS, and PET/CT was 54.5%, 39.7% and 77.3%, 55.4%, 42.6% and 75%, and 57.1% 35.3%, and 90.9%, respectively. All techniques were more likely to under-stage nodal disease; CECT (X² 32.890, df=1, p<0.001), EUS (X² 28.471, df=1, p<0.001), and PET/CT (X² 50.790, df=1, p<0.001). PET/CT was more likely to under-stage nodal disease than EUS (p=0.031). Median LNM size was 3 mm, with 41 (82%) of LNMs measuring <6 mm and 22 (44%) classified as micro-metastases (≤2 mm).

CONCLUSION

This study has demonstrated poor N-staging accuracy in the modern era of radiological staging. Eighty-two percent of LNMs measured <6 mm, making direct identification extremely challenging on medical imaging. Future research should focus on investigating and developing alternative surrogate markers to predict the likelihood of LNMs.