Evaluation of an Objective MRI-Based Tumor Regression Grade (mrTRG) Score and a Subjective Likert Score for Assessing Treatment Response in Locally Advanced Rectal Cancers-A Retrospective Study

Purpose:  Magnetic resonance imaging (MRI) with the help of MRI-based tumor regression grade (mrTRG) score has been used as a tool to predict pathological tumor regression grade (pTRG) in patients of rectal cancer post-neoadjuvant chemoradiation. Our study aims to evaluate the ability of MRI in assessing treatment response comparing an objective mrTRG score and a subjective Likert score, with a focus on the ability to predict pathologic complete response (pCR). Methods:  Post-treatment MRI studies were retrospectively reviewed for 170 consecutive cases of histopathologically proven rectal cancer after receiving neoadjuvant chemoradiation and prior to surgery by two oncoradiologists blinded to the eventual postoperative histopathology findings. An objective (mrTRG) and a subjective Likert score were assigned to all the cases. Receiver operating characteristic curves were constructed to determine the ability of Likert scale and mrTRG to predict pCR, with postoperative histopathology being the gold standard. The optimal cutoff points on the scale of 1 to 5 were obtained for mrTRG and Likert scale with the greatest sum of sensitivity and specificity using the Youden Index. Results:  The most accurate cutoff point for the mrTRG to predict complete response was 2.5 (using Youden index), with a sensitivity of 69.2%, specificity of 69.6%, positive predictive value (PPV) of 85.6%, negative predictive value (NPV) of 46.4%, and accuracy of 69.3%. The most accurate cutoff for the Likert scale to predict complete response was 3.5, with a sensitivity of 47.5%, specificity of 89.1%, PPV of 91.9%, NPV of 39.4%, and accuracy of 59%. mrTRG had a lower cutoff and was more accurate in predicting pCR compared to Likert score. Conclusion:  An objective mrTRG was more accurate than a subjective Likert scale to predict complete response in our study.

MRI in rectal cancer patients on 'watch and wait': patterns of response and their evolution

PURPOSE

Evaluate MR patterns of response and their evolution in rectal cancer patients on watch and wait (WW).

METHODS

We retrospectively reviewed 337 MRIs of 60 patients (median follow-up: 12 months; range: 6-49 months). Baseline MRIs (available in 34/60 patients) were evaluated for tumor morphology, location, thickness, circumferential involvement, nodal status and EMVI. First post-treatment MRIs (in all patients) were additionally evaluated for pattern of response on T2 and DWI. Change in post-treatment scar thickness and scar depth angle between the first and second post-treatment scans was also evaluated. Evolution of the response pattern/recurrence were evaluated till the last available scan.

RESULTS

On the baseline scans, 20/34 (59%) patients had polypoidal tumor with 12/20 having ≤ 25% circumferential wall involvement. We saw five patterns of response-normalized rectal wall (2/60-3%), minimal fibrosis (23/60-38%), full thickness fibrosis (16/60-27%), irregular fibrosis (11/60-18%) and split scar (6/60-10%), with 2/60 (3%) showing possible residual disease. On the first post-treatment scans, 12/60 (20%) had restricted diffusion, with 3/12 having persistent restriction till last follow-up. Post-treatment fibrosis/split scar remained stable in 44/60 (73%) cases and improved further in the rest. 9/60 (15%) patients developed regrowth/recurrence. Patients with recurrence had < 10 mm scar thickness and < 21° change in scar angle between the first and second post-treatment MRIs.

CONCLUSION

Most patients on WW protocol developed minimal or full thickness fibrosis, majority of which remained stable on follow-up.

Rectal cancer lexicon 2023 revised and updated consensus statement from the Society of Abdominal Radiology Colorectal and Anal Cancer Disease-Focused Panel

The Society of Abdominal Radiology's Colorectal and Anal Cancer Disease-Focused Panel (DFP) first published a rectal cancer lexicon paper in 2019. Since that time, the DFP has published revised initial staging and restaging reporting templates, and a new SAR user guide to accompany the rectal MRI synoptic report (primary staging). This lexicon update summarizes interval developments, while conforming to the original lexicon 2019 format. Emphasis is placed on primary staging, treatment response, anatomic terminology, nodal staging, and the utility of specific sequences in the MRI protocol. A discussion of primary tumor staging reviews updates on tumor morphology and its clinical significance, T1 and T3 subclassifications and their clinical implications, T4a and T4b imaging findings/definitions, terminology updates on the use of MRF over CRM, and the conundrum of the external sphincter. A parallel section on treatment response reviews the clinical significance of near-complete response and introduces the lexicon of "regrowth" versus "recurrence". A review of relevant anatomy incorporates updated definitions and expert consensus of anatomic landmarks, including the NCCN's new definition of rectal upper margin and sigmoid take-off. A detailed review of nodal staging is also included, with attention to tumor location relative to the dentate line and locoregional lymph node designation, a new suggested size threshold for lateral lymph nodes and their indications for use, and imaging criteria used to differentiate tumor deposits from lymph nodes. Finally, new treatment terminologies such as organ preservation, TNT, TAMIS and watch-and-wait management are introduced. This 2023 version aims to serve as a concise set of up-to-date recommendations for radiologists, and discusses terminology, classification systems, MRI and clinical staging, and the evolving concepts in diagnosis and treatment of rectal cancer.

Treatment outcomes and prognostic factors in children with hepatoblastoma using a risk-stratified approach

BACKGROUND

Not all the significant progress made in the management of children with hepatoblastoma (HB) has translated into improved outcomes in limited-resource settings. There are limited data on outcomes in children with HB from India.

METHODS

All patients diagnosed with HB between July 2013 and December 2020 were risk-stratified and treated as per International Liver Tumor Strategy Group (SIOPEL). Patients with standard-risk HB received cisplatin monotherapy and those with high-risk HB received alternating cycles of cisplatin and the combination of carboplatin plus doxorubicin. Data regarding demographic details, chemotherapy, surgery, liver transplantation, outcomes, prognostic factors, and toxicity were collected.

RESULTS

Of 157 patients with HB, 117 (74%) were high risk, 31 (20%) were standard risk, and nine (6%) unknown. Patients with standard-risk disease had excellent outcomes, with 3-year event-free survival (EFS) and overall survival (OS) of 96% and 100%, respectively. Among high-risk HB, six underwent orthotopic liver transplantation of which four were alive at last follow-up. The 3-year EFS and OS of patients with high-risk disease was 56% and 66%, respectively. Outcomes of patients with PRETEXT IV (3-year EFS: 42%, 3-year OS: 50%) and metastatic disease (3-year EFS: 30%, 3-year OS: 50%) were dismal. Patients with serum alpha-fetoprotein (AFP) reduction greater than 90% following two courses of chemotherapy had favorable outcomes; 3-year EFS: 80% versus 58% (p = .013) and 3-year OS: 95% vs. 68% (p < .01). Only two (6%) of 31 patients with relapse/refractory HB were alive at a median follow-up of 36 months, and both had received salvage chemotherapy and surgery.

CONCLUSIONS

While children with standard-risk HB had excellent outcomes, those with high-risk disease continue to do poorly. Serial monitoring of serum AFP values is a cost-effective and reliable predictor of outcomes. Orthotopic liver transplantation remains a viable option for inoperable disease in resource-limited settings as well.

Imaging Recommendations for Diagnosis, Staging, and Management of Small Bowel and Colorectal Malignancies

Small bowel malignancies are rare, though colorectal cancers are common. This article reviews the current imaging recommendations for small bowel and colorectal malignancies. Contrast-enhanced computed tomography (CT) is the imaging modality of choice for diagnosis/staging/response evaluation/follow-up of the small bowel and colonic tumors. Magnetic resonance imaging of the pelvis with high-resolution T2-weighted images in sagittal, oblique axial, and coronal planes is the imaging modality of choice for staging/response evaluation of anorectal tumors. CT colonography may be utilized as a tumor screening modality, alternative to colonoscopy.

Imaging Recommendations for Diagnosis, Staging, and Management of Pediatric Solid Tumors

Paediatric extra-cranial solid tumours are one of the common causes for paediatric malignancies. Lack of appropriate imaging at presentation, staging and for follow-up is a major challenge for paediatric solid tumours. We have reviewed the paediatric solid tumour imaging protocols suggested by the major oncological societies/groups around the world (mainly the SIOP – Society International Pediatric Oncology, and the COG – Children's Oncology Group). We have adapted some of those protocols to develop imaging recommendations for the diagnosis, staging and management of extra-cranial solid tumours based on the treatment protocols followed in India.

A Radiologist's Perspective on Treatment-Related Pseudoprogression: Clues and Hues

Pseudoprogression refers to the initial apparent increase in tumor burden observed on imaging after cancer therapy, with subsequent delayed response to the same treatment, thus giving a false initial appearance of disease progression. It is essential to differentiate pseudoprogression from true progression to prevent the patients from getting deprived of the benefits of their ongoing cancer therapy owing to their early withdrawal. It also affects their recruitment for clinical trials. Pseudoprogression, albeit uncommon, has been observed after various types of cancer therapy; however, this phenomenon has gained momentum of late due to the emergence of immunotherapy for the treatment of various malignancies. Besides immunotherapy, pseudoprogression has predominantly been of concern in a few patients after radiation therapy for brain tumors and metastasis, after molecular targeted therapy for a variety of tumors, and after chemotherapy in metastatic bone lesions. This article reviews the available data on imaging of pseudoprogression from various types of cancer therapies, highlighting ways to suspect or identify it on imaging.

Prognostic Significance of EMVI in Rectal Cancer in a Tertiary Cancer Hospital in India

Background  Presence of extramural venous invasion (EMVI) is a poor prognostic factor for rectal cancer as per literature. However, India-specific data are lacking.

Aim  The aim of the study is to determine the prognostic significance of EMVI in locally advanced rectal cancer on baseline MRI.

Materials and Methods  We retrospectively reviewed 117 MRIs of operable non-metastatic locally advanced rectal cancers in a tertiary cancer institute. Three dedicated oncoradiologists determined presence or absence of EMVI, and its length and thickness, in consensus. These patients were treated as per standard institutional protocols and followed up for a median period of 37 months (range: 2–71 months). Kaplan-Meier curves (95% CI) were used to determine disease-free survival (DFS), distant-metastases free survival (DMFS), and overall survival (OS). Univariate analysis was performed by comparing groups with log-rank test.

Results  EMVI positive cases were 34/114 (29%). More EMVI-positive cases developed distant metastasis compared with EMVI-negative cases (14/34–41% vs. 22/83–26%). The difference, however, was not statistically significant ( p  = 0.146). After excluding signet-ring cell cancers ( n  = 14), EMVI showed significant correlation with DMFS ( p  = 0.046), but not with DFS or OS. The median thickness and length of EMVI was 6 and 14 mm, respectively in patients who developed distant metastasis, as compared with 5 and 11 mm in those who did not, although this difference was not statistically significant.

Conclusion  EMVI is a predictor of distant metastasis in locally advanced non-metastatic, non-signet ring cell rectal cancers. EMVI can be considered another high-risk feature to predict distant metastasis.

Dedifferentiated liposarcoma with heterologous spindle cell rhabdomyoblastic de-differentiation: An unusual pattern expanding the morphological spectrum

Dedifferentiated liposarcoma (DDLS) is characterized by a wide histopathological spectrum. Spindle cell type of rhabdomyoblastic dedifferentiation has been rarely described in case of DDLS. A 39-year-old male presented with a recurrent retroperitoneal tumor mass, diagnosed as well-differentiated liposarcoma, for which he underwent surgical excisions on two occasions, followed by adjuvant radiation therapy previously. Computed tomogram scan his of abdomen revealed a large-sized, fat-containing recurrent, retroperitoneal mass, measuring 18.1 cm in the largest dimension. Histopathologic examination of the resected tumor revealed distinct areas of well- and dedifferentiated liposarcoma, including areas reminiscent of a myxofibrosarcoma, further progressing into a high-grade spindle cell sarcoma with fascicular and "Herringbone-like" growth patterns (fibrosarcoma-like). Immunohistochemically, high-grade spindle cell sarcomatous (dedifferentiated) component displayed distinct positivity for desmin and MyoD1, along with focal tumor nuclei, showing nuclear positivity for myogenin. Both well-differentiated liposarcomatous and dedifferentiated components displayed diffuse, intense nuclear positivity for MDM2 (overexpression) and p16INK4A. Furthermore, upon testing tumor sections displaying spindly sarcomatous areas for MDM2 amplification, by FISH technique, nearly all tumor cells displayed MDM2 gene amplification. This case constitutes one of the rare cases of DDLS displaying spindle cell rhabdomyoblastic dedifferentiation. Its diagnostic and treatment implications are discussed herewith.

Is There a Difference Between LI-RADS 3 to LI-RADS 5 Progression Assessment Using CT Versus MR? A Retrospective, Single-Center, Longitudinal Study of Patients Who Underwent 5082 Radiologic Examinations for Surveillance of Hepatocellular Carcinoma Over a 43-Month Period

OBJECTIVE

The Liver Imaging Reporting and Data System (LI-RADS) has been widely applied to CT and MR liver observations in patients at high-risk for hepatocellular carcinoma (HCC). We investigated the impact of CT vs MR in upgrading LI-RADS 3 to LI-RADS 5 observations using a large cohort of high-risk patients.

METHODS

We performed a retrospective, longitudinal study of CT and MR radiographic reports (June 2013 - February 2017) with an assigned LI-RADS category. A final population of 757 individual scans and 212 high-risk patients had at least one LI-RADS 3 observation. Differences in observation time to progression between modalities were determined using uni- and multivariable analysis.

RESULTS

Of the 212 patients with a LI-RADS 3 observation, 52 (25%) had progression to LI-RADS 5. Tp ranged from 64 - 818 days (median: 196 days). One hundred and three patients (49%) had MR and 109 patients (51%) had CT as their index study. Twenty-four patients with an MR index exam progressed to LI-RADS 5 during the follow-up interval, with progression rates of 22% (CI:13%-30%) at 1 year and 29% (CI:17%-40%) at 2 years. Twenty-eight patients with a CT index exam progressed to LI-RADS 5 during follow-up, with progression rates of 26% (CI:16%-35%) at 1 year and 31% (CI:19%-41%) at 2 years. Progression rates were not significantly different between patients whose LI-RADS 3 observation was initially diagnosed on MR vs CT (HR: 0.81, P = 0.44).

DISCUSSION

MR and CT modalities are comparable for demonstrating progression from LI-RADS 3 to 5 for high risk patients.

Accuracy of MRI for nodal restaging in rectal cancer: a retrospective study of 166 cases

AIM

Assessing metastatic mesorectal nodal involvement is a challenge in rectal cancer, especially in the post chemoradiation setting. We aim to assess the accuracy of MRI for nodal restaging and the validity of SAR criteria (≥ 5 mm size being metastatic).

MATERIALS AND METHODS

This was an IRB-approved retrospective study of 166 patients with locally advanced rectal cancers, operated after neoadjuvant treatment. Two dedicated oncoradiologists reviewed the 166 post-chemoradiation presurgical MRIs in consensus. Nodal size and morphology (shape, margins, and signal intensity) were noted. The most accurate cut-off for size for predicting positive pN status was determined using the Youden index.

RESULTS

MRI understaged 30/166 (18%) and overstaged 40/166 (24%) patients using the SAR criteria. The most accurate cut-off for node size was 5.5 mm, with a sensitivity of 75%, specificity of 60.2%, PPV of 40.7%, NPV of 86.9% (95% CI:78-92.5%), accuracy of 64.2%, and area under the curve (AUC) 0.657 (95% CI-0.524-0.79). Morphological characteristics were not significant to determine involvement, with positive nodes including 42% of round and 31% of oval nodes, 40% of heterogeneous and 45% of homogeneous nodes, and 31% irregularly marginated and 46% nodes with regular margins being positive on pathology. MRI was accurate in predicting pathology for mucinous nodes in 9/29 (31%) cases. Seven cases which were yN2 on MRI and yN0 on pathology demonstrated mucinous changes on MRI and had acellular mucin on histopathology.

CONCLUSIONS

MRI has good negative predictive value, poor positive predictive value and moderate accuracy in nodal restaging. The cut-off of 5.5 mm demonstrated in our study is close to the SAR cut-off of 5 mm in the post-treatment setting. MRI accuracy is lower in patients with mucinous nodes.

Can Post-Treatment MRI Features Predict Pathological Circumferential Resection Margin (pCRM) Involvement in Low Rectal Tumors

The MERCURY II study demonstrated the use of MRI-based risk factors such as extramural venous invasion (EMVI), tumor location, and circumferential resection margin (CRM) involvement to preoperatively predict pCRM (pathological CRM) outcomes for lower rectal tumors in a mixed group of upfront operated patients and patients who received neoadjuvant treatment. We aim to study the applicability of results of MERCURY II study in a homogeneous cohort of patients who received neoadjuvant chemoradiation (NACTRT) prior to surgery. After Institutional Review Board approval, post NACTRT restaging MRI of 132 patients operated for low rectal cancer between 2014 and 2018 were retrospectively reviewed by two radiologists for site of tumor, EMVI status, distance from anal verge (< 4 or > 4 cm), and mrCRM positivity. Findings were compared with post surgery pCRM outcomes using Fisher's exact test. Only 9/132(7%) patients showed pCRM involvement on histopathology, 8 of them being CRM positive on MRI (p = 0.01). The positive predictive value (PPV) of mrCRM positive status and pCRM status was 12.7% (95% CI: 9.7-16.5%), while the negative predictive value was 98.5% (95% CI: 91.4-99.8%) (p = 0.01). EMVI positive and anteriorly located tumors showed higher incidence of pCRM positivity but were not found to be significant (15% vs 5.2% and p = 0.13 and 8.6% vs 2.1% and p = 0.28, respectively). Unsafe mrCRM was the only factor significantly associated with pCRM positivity on post neoadjuvant restaging MRI. Tumors less than 4 cm from anal verge, anterior tumor location, and mrEMVI positivity did not show statistically significant results to predict pCRM involvement.

Rare Pancreatic Tumors

Pancreatic ductal adenocarcinoma, neuroendocrine tumor, and cystic pancreatic neoplasms are the common pancreatic tumors most radiologists are familiar with. In this article we review the clinical presentation, pathophysiology, and radiology of rare pancreatic neoplasms. While the imaging features are usually nonspecific and diagnosis is based on pathology, the radiology along with patient demographics, history, and laboratory parameters can often help indicate the diagnosis of an uncommon pancreatic neoplasm and guide appropriate management in these cases.

Impact of a standardized reporting format on the quality of MRI reports for rectal cancer staging

BACKGROUND AND AIMS

Besides providing a surgical roadmap, rectal MRI plays a major role in treatment planning. We recently started using a structured template for reporting rectal cancer via MRI. We study the impact of using this template at our hospital in terms of number of essential imaging parameters described in the reports as compared to the pre-template free-text reports.

METHODS

A structured rectal MRI reporting template was created in consensus with members of the colorectal tumour board and was introduced in the department, which included 14 essential parameters to be mentioned in the reports. We conducted a retrospective analysis of rectal MRI reports of 100 cases with histologically proven rectal cancer, comprising 50 consecutive free-text reports before the template was introduced and 50 consecutive structured reports after its introduction, checking for the presence or absence of inclusion of the 14 parameters. An anonymous online feedback survey was conducted as well after the introduction of the template for the members of the colorectal tumour board.

RESULTS

Overall, the total number of parameters reported increased from a median value of 10 (range 6-13) to 14 (range 12-14). The common unreported parameters prior to template introduction included T staging, presence or absence of restricted diffusion, anterior peritoneal reflection (APR) involvement, and presence or absence of extramural vascular invasion; these were reported in 16%, 22%, 30% and 50% respectively. These improved to 98-100% reporting after template introduction. Maximum improvement was in T staging (16% to 98%) (P < 0.0001), restricted diffusion on DWI (from 22% to 100%) (P < 0.0001) and APR involvement (from 30% to 100%) (P < 0.0001). The most common unreported parameter after template introduction was the "tumoral T2 signal intensity" (unreported in 4% cases). The results of the survey were as follows: 100% felt a decreased need to talk to the radiologist to clarify the report, 81.8% felt an improvement in the quality of reporting as compared to free style reports, and 91% felt that the new template is easier to interpret.

CONCLUSION

The introduction of a structured template for rectal cancer significantly improved the quality of rectal MRI reports, along with the satisfaction of referring providers.

Tumor Response Criteria in Oncoimaging: RECIST Criteria and beyond—Part 1

The rapid recent advances in oncology have made the dream of precision oncology a reality, with targeted therapy available for various tumors depending on the molecular genotype. This has led to the corresponding development of personalized radiology as well, with various tumor response criteria used to characterize disease response/progression depending on chemotherapy used. In these two review articles, we review the various tumor response criteria widely applied in both research and clinical settings. These include the classic size-based criteria such as RECIST (Response Evaluation Criteria in Solid Tumors) 1.1 and the WHO (World Health Organization) criteria, as also various other criteria such as Choi and modified Choi criteria for tumors treated by targeted therapy, EASL and modified RECIST (mRECIST) criteria for hepatocellular carcinomas, and immune-related response criteria (irRC) and immune RECIST (iRECIST) for patients on immunotherapy. Other clinically important criteria such as PERCIST (PET Response Criteria In Solid Tumors) for positron emission tomography–computed tomography (PET-CT) and the MD Anderson criteria for evaluating bone metastases are also highlighted.

Tumor Response Criteria in Oncoimaging: RECIST Criteria and beyond—Part 2

The rapid recent advances in oncology have made the dream of precision oncology a reality, with targeted therapy available for various tumors depending on the molecular genotype. This has led to the corresponding development of personalized radiology as well, with various tumor response criteria used to characterize disease response/progression depending on chemotherapy used. In these two review articles, we review the various tumor response criteria widely applied in both research and clinical settings. These include the classic size-based criteria such as RECIST (Response Evaluation Criteria In Solid Tumors) 1.1 and the WHO (World Health Organization) criteria, as also various other criteria such as Choi and modified Choi criteria for tumors treated by targeted therapy, EASL (European Association for the Study of the Liver) and modified RECIST (mRECIST) criteria for hepatocellular carcinomas, immune-related response criteria (irRC) and immune RECIST (iRECIST) for patients on immunotherapy. Other clinically important criteria such as PERCIST (PET Response Criteria In Solid Tumors) for positron emission tomography–computed tomography (PET-CT), and the MD Anderson criteria for evaluating bone metastases are also highlighted.

Ambiguous Findings on Radiographs

Findings with uncertain clinical significance are frequently encountered on radiographs. A structure or opacity visible on radiographs could be due to several causes ranging from artifact or external structure to malignancy or a life-threatening process. The approach that a radiologist chooses to address ambiguous findings can have a significant impact on a patient's health. In this article we discuss the causes and impact of ambiguous findings on radiographs. We also discuss the various strategies radiologists can adopt to maximize clinical value and, when needed, reach a definite diagnosis.

Non-radiation occupational hazards and health issues faced by radiologists – A cross-sectional study of Indian radiologists

Context: Radiologists as a group face unique occupational health hazards among which musculoskeletal injuries, chronic eye strain, and others are yet to receive adequate attention. Constant mental strain due to demanding turnaround times and work pressures may lead to burnout and depression. These combine to decrease overall work satisfaction and productivity. Aims: To study the prevalence of various health issues faced by radiologists in India and to assess whether specific demographic and occupational factors are associated with an increased risk. Settings and Design: Cross-sectional observational study conducted as a voluntary anonymous electronic survey. Methods and Materials: A 36-item survey was sent to radiologists through email and social media. All respondents who completed survey were included in the study. Questions regarding workload, repetitive stress injuries, eye strain, burnout, and so on were asked. Statistical Analysis Used: Chi-square test was used to test significance of correlation (P < 0.05). Results: In all, 383 radiologists completed the survey. A high prevalence of repetitive stress injuries, chronic eye strain, depression, and burnout was found. Significant correlation was found between repetitive stress injuries and burnout. Pre-Conception and Pre-Natal Diagnostic Techniques Act (PCPNDT) related issues and work overload were the most common causes of high stress levels. Radiologists whose practices followed ergonomic design showed significantly less prevalence of neck pain. Conclusion: Radiologists in India have a high prevalence of repetitive stress injuries, chronic eye strain, and burnout, along with unique mental stressors such as PCPNDT-related issues.

Role of Ultrasonography in the Surveillance of Disease-Free Patients with Colorectal Cancer: a Retrospective Audit

Close surveillance of colorectal cancer (CRC) patients is helpful as early detection of resectable metastasis has a survival benefit. Ultrasonography (USG) is a frequently used modality to detect liver recurrence, although international guidelines do not include it. To evaluate the potential added role of USG in early detection of CRC recurrence. We performed a retrospective analysis of 230 patients of colorectal cancer treated at our institute in 2013-2014 who underwent abdominal USG for surveillance. 77/230 (33%) developed recurrence, with liver being the second most common site (22/230). 5/230 (2%) patients had recurrent disease first detected on USG, four of which also had raised serum CEA (carcinoembryonic antigen) levels. There were three false positive and four false-negative cases on USG. There was no added advantage of USG for early detection of CRC recurrence.

Imaging characterization of adnexal lesions: Do CT findings correlate with US?

OBJECTIVE

To compare contrast-enhanced CT and US agreement in characterizing adnexal lesions in late post-menopausal women.

MATERIALS AND METHODS

This was a HIPAA-compliant IRB-approved retrospective review of the contrast-enhanced CTs of 130 late post-menopausal women (> 55 years). The lesions were classified as simple cystic, minimally complex cystic, complex cystic, solid-cystic, or solid based on CT and US morphology. Findings were analyzed to evaluate agreement between CT and US on adnexal lesion characterization.

RESULTS

One forty-one adnexal lesions were assessed by both contrast-enhanced CT and US. Overall, there was good agreement between CT and US, which agreed on the lesion morphology in 114 (81%) cases with an unweighted kappa value of 0.68 (95% CI 0.56-0.78). By CT, 83 (59%) were classified as simple cystic, of which 73/83 (88%) were confirmed as simple cystic by US. Of the remaining 10 CT simple cysts, 9 were reclassified by US as minimally complex cystic and one as complex cystic. Eight of these lesions were benign based on pathology or follow-up imaging, while two lesions remained indeterminate. By CT, 27 lesions (19%) were classified as minimally complex, while US reclassified 13 (48%) of the lesions (eight to simple cystic and five as complex or solid-cystic). Among the 31 remaining lesions, there were 4 (13%) discordances between CT and US.

CONCLUSION

There is good agreement between CT and US in characterizing adnexal lesion morphology, particularly simple cysts. However, there was significant discordance seen with characterization of minimally complex cysts, indicating that these lesions need US follow-up.

Prophylactic hydration to protect renal function from intravascular iodinated contrast material

Nijssen EC, Rennenberg RJ, Nelemans PJ, Essers BA, Janssen MM, Vermeeren MA, van Ommen V, Wildberger JE. (Departments of Radiology and Nuclear Medicine, Internal Medicine, Epidemiology, Clinical Epidemiology and Medical Technology Assessment, and Cardiology, Maastricht University Medical Centre, Maastricht, The Netherlands.) Prophylactic hydration to protect renal function from intravascular iodinated contrast material in patients at high risk of contrast-induced nephropathy (AMACING): A prospective, randomised, phase 3, controlled, open-label, non-inferiority trial. Lancet 2017;389:1312-22.

Tricky Findings in Liver Transplant Imaging: A Review of Pitfalls With Solutions

Orthotopic liver transplantation is the preferred treatment for end-stage liver disease. Imaging plays an important role in the follow-up of transplant recipients by identifying a variety of complications. Posttransplant liver imaging can be challenging with altered vascular and nonvascular postoperative findings closely mimicking pathologies. A thorough knowledge of these common imaging findings in a posttransplant liver is essential for the radiologist to avoid erroneous diagnoses and unnecessary workup. We focus on such imaging findings and provide tips to avoid misinterpretation.

Contrast-enhanced CT features of hepatoblastoma: Can we predict histopathology?

BACKGROUND

Hepatoblastoma is the most common hepatic malignancy occurring in the pediatric population. Intratumoral cellular behavior varies, and the small-cell undifferentiated histopathology carries a poorer prognosis than other tissue subtypes. Neoadjuvant chemotherapy is recommended for this tumor subtype prior to surgical resection in most cases. Early identification of tumors with poor prognosis could have a significant clinical impact. Objective The aim of this work was to identify imaging features of small-cell undifferentiated subtype hepatoblastoma that can help distinguish this subtype from more favorable tumors and potentially guide the clinical management. We also sought to characterize contrast-enhanced CT (CECT) features of hepatoblastoma that correlate with metastatic disease and patient outcome.

MATERIALS AND METHODS

Our study included 34 patients (24 males, 10 females) with a mean age of 16months (range: 0-46months) with surgically confirmed hepatoblastoma and available baseline abdominal imaging by CECT. Clinical data and CT abdominal images were retrospectively analyzed.

RESULTS

Five tumors with small-cell undifferentiated components were identified. All of these tumors demonstrated irregular margins on CT imaging. Advanced PRETEXT stage, vascular invasion and irregular margins were associated with metastatic disease and decreased survival. Capsular retraction was also significantly associated with decreased survival. Irregular tumor margins demonstrated statistically significant association with the presence of small-cell undifferentiated components. No other imaging feature showed statistically significant association.

CONCLUSION

Tumor margin irregularity, vascular invasion, capsular retraction, and PRETEXT stage correlate with worse patient outcomes. Irregular tumor margin was the only imaging feature significantly associated with more aggressive tumor subtype.

Current Concepts in Non-Gastrointestinal Stromal Tumor Soft Tissue Sarcomas: A Primer for Radiologists

Non-gastrointestinal stromal tumor (GIST) soft tissue sarcomas (STSs) are a heterogeneous group of neoplasms whose classification and management continues to evolve with better understanding of their biologic behavior. The 2013 World Health Organization (WHO) has revised their classification based on new immunohistochemical and cytogenetic data. In this article, we will provide a brief overview of the revised WHO classification of soft tissue tumors, discuss in detail the radiology and management of the two most common adult non-GIST STS, namely liposarcoma and leiomyosarcoma, and review some of the emerging histology-driven targeted therapies in non-GIST STS, focusing on the role of the radiologist.

Update on Gastrointestinal Stromal Tumors for Radiologists

The management of gastrointestinal stromal tumors (GISTs) has evolved significantly in the last two decades due to better understanding of their biologic behavior as well as development of molecular targeted therapies. GISTs with exon 11 mutation respond to imatinib whereas GISTs with exon 9 or succinate dehydrogenase subunit mutations do not. Risk stratification models have enabled stratifying GISTs according to risk of recurrence and choosing patients who may benefit from adjuvant therapy. Assessing response to targeted therapies in GIST using conventional response criteria has several potential pitfalls leading to search for alternate response criteria based on changes in tumor attenuation, volume, metabolic and functional parameters. Surveillance of patients with GIST in the adjuvant setting is important for timely detection of recurrences.

A hairy situation: trichobezoar presenting with intussusception, and intestinal and biliary perforation in a child

Trichobezoars are an uncommon cause of acute abdominal pain. We present a case of a 12-year-old girl with a history of a trichobezoar who presented to the emergency department with acute abdominal pain. Abdominal sonography was performed which suggested portal venous gas and showed complex peritoneal fluid. Subsequent computed tomography demonstrated both gastric and small bowel bezoars, with a jejunojejunal intussusception, and confirmed portal venous gas and complex ascites. At the time of surgery, there was evidence of intestinal and biliary perforation. Our case illustrates a constellation of complications in association with a long-standing trichobezoar.

Clinical implications for imaging of vascular invasion in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the second largest cause of cancer mortality in the world, with vascular invasion being one of the most important prognostic factors. HCC with tumor thrombus was traditionally considered to have very limited treatment options. However, multiple promising treatment strategies have emerged in recent years, with diagnostic and interventional radiologists playing a major role in patient management. We provide a comprehensive update on the diagnosis and management of HCC with vascular invasion and the role of the radiologist in this condition.

"Children are not small adults": avoiding common pitfalls of normal developmental variants in pediatric imaging

Imaging of children is complicated with a vast array of normal variants, congenital or developmental disorders, and age-dependent differential considerations. We present imaging findings of several common anatomic variants as well as physiological and maturational processes that occur in children. We compare and contrast them with pathological entities so that the reader can successfully distinguish them when interpreting pediatric imaging examinations. The content has been accrued from the authors' collective experience at a tertiary-care pediatric hospital, teaching and consulting with radiology trainees and clinicians, as well as a comprehensive review of the literature, and is intended to represent a useful error prevention tool for radiologists interpreting pediatric studies.

Assessment of metastatic risk of gastric GIST based on treatment-naïve CT features

OBJECTIVE

To study whether the CT features of treatment-naïve gastric GIST may be used to assess metastatic risk.

METHODS

In this IRB approved retrospective study, with informed consent waived, contrast enhanced CT images of 143 patients with pathologically confirmed treatment-naïve gastric GIST (74 men, 69 women; mean age 61 years, SD ± 14) were reviewed in consensus by two oncoradiologists blinded to clinicopathologic features and clinical outcome and morphologic features were recorded. The metastatic spread was recorded using available imaging studies and electronic medical records (median follow up 40 months, interquartile range, IQR, 21-61). The association of maximum size in any plane (≤10 cm or >10 cm), outline (smooth or irregular/lobulated), cystic areas (≤50% or >50%), exophytic component (≤50% or >50%), and enhancing solid component (present or absent) with metastatic disease were analyzed using univariate (Fisher's exact test) and multivariate (logistic regression) analysis.

RESULTS

Metastatic disease developed in 42 (29%) patients (28 at presentation, 14 during follow-up); 23 (16%) patients died. On multivariate analysis, tumor size >10 cm (p = 0.0001, OR 9.9), irregular/lobulated outline (p = 0.001, OR 5.6) and presence of a enhancing solid component (p < 0.0001, OR 9.1) were independent predictors of metastatic disease. On subgroup analysis, an irregular/lobulated outline and an enhancing solid component were more frequently associated with metastases in tumors ≤5 cm and >5-≤10 cm (p < 0.05).

CONCLUSION

CT morphologic features can be used to assess the metastatic risk of treatment-naïve gastric GIST. Risk assessment based on pretreatment CT is especially useful for patients receiving neoadjuvant tyrosine kinase inhibitors and those with tumors <5 cm in size.

Magnetic Resonance Imaging of Abdominal and Pelvic Pain in the Pregnant Patient

The utility of MR imaging in evaluating abdominal and pelvic pain in the pregnant patient is discussed. Details regarding the indications, technical aspects, and imaging findings of various common abdominal and pelvic abnormalities in pregnancy are reviewed.

Malignant Transformation of Hepatic Adenoma in Glycogen Storage Disease Type-1a: Report of an Exceptional Case Diagnosed on Surveillance Imaging

Hepatocellular adenoma is a heterogeneous group of benign neoplasms arising from hepatocellular cells and can be subclassified into four major groups based on genotypic and phenotypic characteristics. These four subtypes are hepatocyte nuclear factor (HNF) 1α-inactivated, β-catenin–activated, inflammatory, and unclassified adenomas. Immunohistochemistry studies have demonstrated that since β-catenin–activated adenomas have a higher risk of malignant transformation, the identification of the subtype of adenoma remains crucial in patient management. However, malignant transformation of hepatic adenoma without β-catenin overexpression can be seen in 30–65% cases. We report a case of malignant transformation of hepatic adenoma without overexpression of β-catenin in a 31-year-old man with a known glycogen storage disease (GSD) Type-1a, which was diagnosed on surveillance magnetic resonance imaging (MRI). The MRI showed a mild interval increase in one lesion with relative stability of the other adenomas. The lesion was presumed to be suspicious for a hepatocellular carcinoma (HCC) and was confirmed on pathology.

MDCT of extranodal mantle cell lymphoma: a single institute experience

OBJECTIVE

To study the pattern of extranodal and particularly gastrointestinal (GI) involvement of mantle cell lymphoma (MCL) on MDCT MATERIALS AND METHODS: In this IRB-approved, HIPAA compliant retrospective study, MDCT features of 78 patients (62 males and 16 females, mean age 57 years) with MCL including 28 patients at presentation were reviewed. Clinical and histopathological (blastoid vs. non-blastoid) data were noted from medical records.

RESULTS

Extranodal involvement was present in overall 51/78 patients on CT (65%), 18/28 (64%) patients at presentation. Spleen (21/78-27%) and bowel (19/78-24%) were the most common sites of extranodal involvement by MCL on imaging, followed by lungs (10/78-13%) and skin/subcutaneous tissue (9/78-12%). Bowel involvement was either in the form of endophytic polypoidal lesions (n = 11, mean size 3.1 cm), as focal mild bowel wall thickening (n = 5, mean thickness 1.4 cm), or as combination of the two (n = 3). Blastoid histology was present in 14/78 (24%) patients and was statistically associated with skin/subcutaneous involvement (p < 0.05; Fisher's exact t test). Median follow-up was 72 months during which 21 patients died with median survival of 48 months (26 months for blastoid histology vs. 47 months for non-blastoid histology). There was no statistical correlation between sites of involvement and survival.

CONCLUSIONS

MCL has a predilection for extranodal disease, predominantly involving the spleen, bowel, lungs, and subcutaneous tissue. GI involvement on CT is in the form of endoluminal polypoidal lesions and mild bowel wall thickening. Skin/subcutaneous involvement was statistically more common with blastoid histology in our study.

Correlation of CT patterns of primary intrahepatic cholangiocarcinoma at the time of presentation with the metastatic spread and clinical outcomes: retrospective study of 92 patients

OBJECTIVE

To study the CT appearance and histopathology of mass-forming intrahepatic cholangiocarcinoma (IHCC) at presentation and correlate these features with metastatic disease and patient survival.

MATERIALS AND METHODS

In this IRB-approved, HIPAA compliant retrospective study, we reviewed pathology database of 459 patients with cholangiocarcinoma seen from 2004 through 2013 to identify 92 patients with IHCC (48 women, 44 men, mean age 61 years) who had CT scans of primary tumor available for review. All baseline and follow-up CT's were reviewed by two radiologists in consensus to record imaging characteristics and metastatic patterns. Clinical and histopathology data were obtained from electronic medical records. Imaging patterns and histopathology were analyzed for associations with metastatic spread and survival.

RESULTS

Three distinct CT patterns of IHCC at presentation were identified: solitary dominant mass (type I IHCC, n = 34), dominant mass with satellite nodules in same segment (type II IHCC, n = 19), and multiple scattered hepatic lesions (type III IHCC, n = 39). Distant metastases developed in 49/92 patients (53%); 39 (42%) of which were present at diagnosis. Lungs (22/92; 24%), peritoneum (17/92; 18%), and bones (13/92; 14%) were most common metastatic sites. Type I IHCC had smaller size, lowest incidence of metastases at presentation, and best overall survival, while type III IHCC had shortest survival (p < 0.017). Poorly differentiated IHCC had higher proportion of osseous metastases (p = 0.042) and worse survival (p = 0.027).

CONCLUSION

IHCC has three distinct CT patterns at presentation with different prognoses. Knowledge of these patterns can help radiologists to detect the extrahepatic disease and predict prognosis.

MDCT and clinicopathological features of small bowel gastrointestinal stromal tumours in 102 patients: a single institute experience

OBJECTIVE

Small bowel (SB) is the second most common site of gastrointestinal stromal tumours (GISTs). We evaluated clinical presentation, pathology, imaging features and metastatic pattern of SB GIST.

METHODS

Imaging and clinicopathological data of 102 patients with jejunal/ileal GIST treated at Dana-Farber Cancer Institute and Brigham and Women's Hospital (Boston, MA) between 2002 and 2013 were evaluated. Imaging of treatment-naive primary tumour (41 patients) and follow-up imaging in all patients was reviewed.

RESULTS

90/102 patients were symptomatic at presentation, abdominal pain and lower gastrointestinal blood loss being the most common symptoms. On pathology, 21 GISTs were low risk, 17 were intermediate and 64 were high risk. The mean tumour size was 8.5 cm. On baseline CT (n = 41), tumours were predominantly well circumscribed, exophytic and smooth/mildly lobulated in contour. Of 41 tumours, 16 (39%) were homogeneous, whereas 25 (61%) were heterogeneous. Of the 41 tumours, cystic/necrotic areas (Hounsfield units < 20) were seen in 16 (39%) and calcifications in 9 (22%). CT demonstrated complications in 13/41 (32%) patients in the form of tumour-bowel fistula (TBF) (7/41), bowel obstruction (4/41) and intraperitoneal rupture (2/41). Amongst 102 total patients, metastases developed in 51 (50%) patients (27 at presentation), predominantly involving peritoneum (40/102) and liver (32/102). 7/8 (87%) patients having intraperitoneal rupture at presentation developed metastases. Metastases elsewhere were always associated with hepatic/peritoneal metastases. At last follow-up, 28 patients were deceased (median survival, 65 months).

CONCLUSION

SB GISTs were predominantly large, well-circumscribed, exophytic tumours with or without cystic/necrotic areas. Complications such as TBF, bowel obstruction and intraperitoneal perforation were visualized at presentation, with patients with perforation demonstrating a high risk of metastatic disease. Exophytic eccentric bowel wall involvement and lack of associated adenopathy are useful indicators to help differentiate GISTs from other SB neoplasms.

ADVANCES IN KNOWLEDGE

SB GISTs are predominantly large, well-circumscribed, exophytic tumours, and may present with complications. They often are symptomatic at presentation, are high risk on pathology and metastasize to the peritoneum more commonly than the liver.

Imaging features of primary and metastatic extremity synovial sarcoma: a single institute experience of 78 patients

OBJECTIVE

To study the appearance of primary and metastatic extremity synovial sarcoma (SS) on cross-sectional imaging.

METHODS

In this institutional review board-approved, Health Insurance Portability and Accountability Act-compliant retrospective study, the imaging features of 78 patients (42 males and 36 females; mean age, 40 years) with primary and metastatic extremity SS on MRI and multidetector CT were reviewed, with baseline MRI of the primary available in 31 patients.

RESULTS

Primary SSs were predominantly well-circumscribed (27/31) and heterogeneously enhancing solid (18/31) or solid-cystic (13/31) tumours. Imaging features visualized included the presence of perilesional oedema (14/31), interfascial (15/31) and intercompartmental extension (7/31), triple sign (11/31), intratumoral haemorrhage (10/31), calcification (6/31), bowl of grapes appearance (5/31) and bone involvement (3/31). Smaller T1 stage tumours (8/31) appeared as heterogeneously enhancing lesions, with some lesions demonstrating interfascial and intercompartmental extension and perilesional oedema. Recurrent/metastatic disease developed in 49/78 (63%) patients. Of these, 20/78 (26%) had metastasis at presentation, while the remaining developed metastatic disease at a median interval of 27 months (range, 3-161 months). Pleuropulmonary metastases (46/78) were the most common sites, with most of the metastases being pleural based. On univariate analysis, larger tumour size, the presence of perilesional oedema, intercompartmental extension, the presence of intralesional haemorrhage and bowl of grapes appearance on MRI were associated with a significantly higher incidence of metastatic disease.

CONCLUSION

Certain imaging features of primary SS predict the risk of development of metastatic disease. Imaging features of T1 stage tumours included heterogeneous enhancement, interfascial extension and perilesional oedema. Pleural-based metastases are commonly seen in SSs.

ADVANCES IN KNOWLEDGE

Imaging features of primary SS correlate with metastatic disease. Pleural-based metastases are often present in SSs.

Diagnosis and management of intrahepatic cholangiocarcinoma: a comprehensive update for the radiologist

There is increasing focus on intrahepatic cholangiocarcinoma (IHCC) due to its rising incidence worldwide and relatively poor prognosis, with the revised TNM classification (2009) introducing a separate staging system for IHCC for the first time. In this article, we comprehensively review the current role of the radiologist in the diagnosis and management of patients with IHCC.

Imaging features of primary and metastatic alveolar soft part sarcoma: single institute experience in 25 patients

OBJECTIVE

To describe imaging features of primary and metastatic alveolar soft part sarcoma (ASPS).

METHODS

In this institutional review board-approved and Health Insurance Portability and Accountability Act-compliant retrospective study, 25 patients (14 males; mean age, 25 years; range, 18-40 years) with pathologically proven ASPS seen at our institute between 1995 and 2013 were included. Imaging of primary tumours in 5 patients and follow-up imaging in 25 patients were reviewed by 2 radiologists in consensus. Clinical information was obtained from electronic medical records.

RESULTS

The most common sites for the primary tumour were extremities (17/25, 68%) and torso (6/25, 24%). Primary tumours (n = 5) were well circumscribed, compared with skeletal muscle, were isodense on CT, hyperintense on T1 and T2 weighted images with intense post-contrast enhancement, prominent feeders on CT and flow voids on MRI. Metastases developed in 23/25 (92%) patients, 18 at presentation. The most common sites of metastases were the lungs (100%), lymph nodes (74%), bones (57%) and brain (43%). Visceral and nodal metastases were hypervascular. At the time of reporting the results, 15 patients have died, 6 are alive and 4 were lost to follow-up. Median survival was 74 months for those without brain metastases (n = 8) and 60 months for those with brain metastases (n = 7). Median survival was shorter for patients with metastases at presentation.

CONCLUSION

ASPS most commonly involves the lower extremities of young adults, is hypervascular on imaging, often metastasizes at presentation, frequently to lung, nodes, bones and brain, and has an indolent course despite metastases. Brain metastases and high tumour burden (number of metastatic sites) at presentation decreased survival in our study.

ADVANCES IN KNOWLEDGE

ASPS has an unusual pattern of metastases to the brain and nodes in addition to lung and bones. It has an indolent course despite metastases.