Role of Dedicated Subspecialized Radiologists in Multidisciplinary Team Discussions on Lower Gastrointestinal Tract Cancers

Abstract

Objective: To determine the impact of dedicated subspecialized radiologists in multidisciplinary team (MDT) discussions on the management of lower gastrointestinal (GI) tract malignancies.

Materials and methods: We retrospectively analyzed the data of 244 patients (mean age ± standard deviation, 61.7 ± 11.9 years) referred to MDT discussions 249 times (i.e., 249 cases, as five patients were discussed twice for different issues) for lower GI tract malignancy including colorectal cancer, small bowel cancer, GI stromal tumor, and GI neuroendocrine tumor between April 2018 and June 2021 in a prospective database. Before the MDT discussions, dedicated GI radiologists reviewed all imaging studies again besides routine clinical reading. The referring clinician's initial diagnosis, initial treatment plan, change in radiologic interpretation compared with the initial radiology report, and the MDT's consensus recommendations for treatment were collected and compared. Factors associated with changes in treatment plans and the implementation of MDT decisions were analyzed.

Results: Of the 249 cases, radiologic interpretation was changed in 73 cases (29.3%) after a review by dedicated GI radiologists, with 78.1% (57/73) resulting in changes in the treatment plan. The treatment plan was changed in 92 cases (36.9%), and the rate of change in the treatment plan was significantly higher in cases with changes in radiologic interpretation than in those without (78.1% [57/73] vs. 19.9% [35/176], p < 0.001). Follow-up records of patients showed that 91.2% (227/249) of MDT recommendations for treatment were implemented. Multiple logistic regression analysis revealed that the nonsurgical approach (vs. surgical approach) decided through MDT discussion was a significant factor for patients being managed differently than the MDT recommendations (Odds ratio, 4.48; p = 0.017).

Conclusion: MDT discussion involving additional review of radiology examinations by dedicated GI radiologists resulted in a change in the treatment plan in 36.9% of cases. Changes in treatment plans were significantly associated with changes in radiologic interpretation.

Keywords: Disease management; Multidisciplinary care team; Neoplasms; Patient care team; Radiologists.

Fig. 1. A 79-year-old male with rectal cancer.

A. Initial contrast-enhanced CT shows eccentric enhancing wall thickening with perirectal fat infiltration in the distal rectum (arrow). Incidentally, a lateral spreading tumor was also found in the transverse colon during preoperative colonoscopy (not shown). After concurrent chemoradiation therapy, subsequent ultra-low anterior resection and left hemicolectomy were performed, and the patient was finally diagnosed with ypT2N1c-stage rectal cancer and a low-grade tubular adenoma in the transverse colon. B. On a follow-up contrast-enhanced CT taken 15 months after the surgery, an 8-mm enhancing nodule (arrow) was noted at the greater omentum. C-E. On fully integrated ¹⁸F-FDG PET/MRI, the peritoneal lesion (arrows) shows intermediate-high signal intensity on a T2-weighted image (C), diffusion restriction on a diffusion-weighted image (D), and hot uptake on an FDG PET image (E). The initial radiologic diagnosis was peritoneal seeding. F. During a thorough review of CT images by a dedicated gastrointestinal radiologist prior to the MDT discussion, intralesional fat density and perilesional infiltration (arrows) were found; therefore, the radiologic diagnosis for the lesion was changed to fat necrosis. After MDT discussion, the patient’s management plan was changed from palliative chemotherapy to observation. G. A follow-up CT image obtained 5 months later reveals that the lesion (arrow) had shrunk in size without any treatment. FDG = fluorodeoxyglucose, MDT = multidisciplinary team

Fig. 2. A 71-year-old female with cecal cancer.

A, B. Initial contrast-enhanced CT depicted an enhancing wall thickening with pericolic fat infiltration at the cecum (arrowhead on A), with no evidence of a focal lesion except a simple cyst in the liver (arrow on B). The patient underwent right hemicolectomy and was finally diagnosed with T3bN2b-stage cecal adenocarcinoma. C. On a follow-up CT obtained 5 months after surgery, a 7-mm low attenuated lesion (arrow) was newly found in segment III of the liver. The initial radiologic diagnosis was liver metastasis. After an image review prior to a MDT meeting, a dedicated gastrointestinal radiologist suggested the possibility of a benign lesion, such as a hepatic cyst because of the low HU value (25 HU). During MDT meeting, the radiologist recommended liver MRI to precisely characterize the lesion. D. On axial T2-weighted MRI of the liver, the lesion (arrows) shows bright high signal intensity suggesting a benign lesion such as a hepatic hemangioma or cyst. E. On contrast-enhanced T1-weighted MRI images obtained in the arterial (left) and portal (right) phases, no enhancement is observed in the lesion (arrows). Therefore, a hepatic cyst was diagnosed. Accordingly, the patient’s management plan was changed from palliative chemotherapy to observation. HU = Hounsfield unit, MDT = multidisciplinary team

Fig. 3. A 74-year-old female with ascending colon cancer.

The patient had undergone right hemicolectomy 2 years previously. A. Follow-up contrast-enhanced CT after surgery shows a 7-mm low attenuated lesion (arrow) at segment III of the liver. The lesion was confirmed as liver metastasis through ultrasound-guided percutaneous biopsy. For this lesion, RFA was performed. B. A 3-cm dark attenuated RFA defect (*) is observed on follow-up CT after RFA. Note mild dilatation of the adjacent BDs (arrowheads) due to RFA-related biliary stricture. C. On follow-up CT obtained at 9 months after RFA, a low attenuated lesion (arrow) with adjacent BD dilatation (arrowheads) is still noted. At that time, a radiologist reported this lesion as an RFA defect with secondary BD dilatation. However, after a thorough image review by a dedicated gastrointestinal radiologist during a MDT discussion, the possibility of tumor recurrence with intraductal tumor extension was suggested because the attenuation within the treated lesion was increased compared to that in the previous CT, and slight progression of ductal dilatation was noted. Therefore, further imaging was recommended with PET/MRI. D-F. On ¹⁸F-fluorodeoxyglucose PET/MRI, the lesion (arrows) shows intermediate high signal intensity on T2-weighted imaging (D), restricted diffusion on diffusion-weighted imaging (E), and strongly hot uptake on fusion PET/MRI (F). Tumor recurrence with intraductal tumor extension was strongly suggested during an MDT discussion. Therefore, the patient’s management plan was changed from observation to surgery. The patient underwent left hemihepatectomy. G. Photo of a gross specimen shows a 5.5-cm yellowish mass (arrows) at segment III of the liver and intraductal soft tissue lesions (arrowheads). Microscopic examination finally confirmed liver metastasis with intraductal tumor extension. BD = bile duct, MDT = multidisciplinary team, RFA = radiofrequency ablation

Fig. 4. A 73-year-old female with rectosigmoid junction cancer.

A. A 5-cm ulceroinfiltrative mass (arrows) is seen at the rectosigmoid junction on a colonoscopic image. Colonoscopic biopsy confirmed well-differentiated adenocarcinoma (not shown). B, C. Axial (B) and coronal (C) contrast-enhanced CT images show well-enhanced wall thickening in the rectosigmoid junction colon (white arrows) and adjacent pericolic LN enlargement (arrowheads). The left distal ureter is encased by the enlarged LN, leading to left hydronephrosis (red arrows). D. On a ¹⁸F-FDG PET/CT image, colon wall thickening (arrow) and an adjacent enlarged LN (arrowhead) show strong FDG uptake suggesting rectosigmoid junction cancer with a pericolic metastatic LN. E. On an FDG PET/CT image at the thoracic level, a few FDG-avid LNs (arrows) are observed at the left axillary area. The nuclear medicine doctor interpreted these LNs as metastatic LNs. Therefore, palliative chemotherapy was planned. However, after a thorough image review by a dedicated gastrointestinal radiologist during a MDT discussion, the radiologist circumspectly noticed that there was an FDG-avid lesion at the left deltoid area (arrowhead) and therefore suggested the possibility of reactive FDG uptake after COVID-19 vaccination. After an MDT conference, clinicians confirmed that the patient received a COVID-19 vaccination 18 days before FDG PET imaging. Therefore, the management plan for the patient was changed to radical surgery. COVID = coronavirus disease, FDG = flurodeoxyglucose, LN = lymph node, MDT = multidisciplinary team