Biparametric MRI prior to Radical Radiation Therapy for Prostate Cancer in a Caribbean Population: Implications for Risk Group Stratification and Treatment.

Purpose: To assess risk-group migration and subsequent management change following biparametric MRI using a risk-stratified approach in a group of Caribbean men with prostate adenocarcinoma being offered external beam radiation therapy (EBRT). Materials and Methods: This retrospective study assessed the biparametric MRI findings in men who opted for EBRT from January 2018 to June 2019 (n = 79; mean age, 67.9 years ± 6.2 [standard deviation]). Serum prostate-specific antigen level, digital rectal examination findings, histologic grade group (GG) from transrectal US-guided biopsy, prior androgen deprivation therapy (ADT), and any prior CT results were used to stratify patients into low-, intermediate-, and high-risk groups, according to the National Comprehensive Cancer Network risk categories. Risk-group stratification prior to MRI separated patients into low- (seven of 79 [8.9%]), intermediate- (36 of 79 [45.6%]) and high-risk (36 of 79 [45.6%]) groups. Following MRI, any risk group (low, intermediate, high, nodal involvement, and metastatic disease) or oncologic management changes were recorded. Multivariable binary logistic regression analyses were used to assess predictor of upgrade status, with adjustment for demographic covariates jointly. Results: Following MRI, 30 of 79 (38.0%) patients had risk-group upshifts compared with their original assessment. Patients were recategorized into low risk (one of 79, 1.3%), intermediate risk (19 of 79, 24.1%), high risk (51 of 79, 64.6%), nodal involvement (one of 79, 1.3%), and metastatic disease (seven of 79, 8.9%). From the original groupings, there were six of seven (85.7%) from the low group, 18 of 36 (50.0%) from the intermediate group, and six of 36 (16.7%) from the high group that had risk group upward shifts. There was no association with GG: GG2 versus GG1, P = .53; GG3 versus GG1, P = .98; or prior ADT (P = .37) and the adjusted odds of risk-group upshifts. MRI findings resulted in treatment plan modification for 39 of 79 (49.4%) men overall. Conclusion: Prostate MRI should be considered for patients in high-risk populations prior to EBRT because upstaging from MR image assessment may have implications for modification of treatment.Keywords: MR-Imaging, Prostate, Radiation Therapy© RSNA, 2020See the commentary by Davenport and Shankar in this issue.

A pictorial review of the less commonly encountered patterns of metastatic prostate carcinoma.

Usually late in the course of advanced prostate carcinoma, atypical nodal and distant metastases may be encountered. Accurate characterisation of disease spread and assessment of disease response have significant treatment and prognostic implications. Surveillance imaging, therefore, along with clinical and biochemical parameters, is a key factor in directing appropriate management. Atypical metastases may also require histological re-evaluation, as they may indicate differentiation into aggressive histologic subtypes, which can lead to management alteration. We present a pictorial review of the less common patterns of metastatic prostate carcinoma, to aid in timely recognition and diagnosis.

Imaging features of thalassaemia.

This article highlights the range of osseous findings that can be encountered as well as the imaging features of extramedullary haematopoiesis. As iron overload remains a major cause of morbidity and mortality in these disorders, we also discuss the MRI evaluation of hepatic and cardiac hemosiderosis, to aid in the optimization of iron chelation therapy. Future imaging use will be dictated by evolving clinical needs, such as in screening for emerging morbidities, including hepatic fibrosis and hepatocellular carcinoma.

The steel pan sign of sigmoid volvulus-A case series.

INTRODUCTION: Signs in radiology are usually based on many common objects or patterns that are easily recognizable in everyday life. The objective behind this association is to aid in the understanding and diagnosis of the disease process. These signs can be seen in different imaging modalities such as plain radiograph and computed tomography. PRESENTATION OF CASE: 4 consecutive cases of sigmoid volvulus presented at our tertiary hospital between January 2016 and June 2017. 2 of these cases were managed surgically and others were managed conservatively. The CT scan and abdominal radiographs in these patients were reviewed with consultant radiologist, which bear resemblance to the percussion instrument known as the steel pan. DISCUSSION: The literature has described few radiological signs of sigmoid volvulus in the past. In the following case series, we would like to introduce the "Steel pan Sign", a novel radiological pattern which bears a close resemblance to the percussion instrument known as the steel pan. The Steel pan sign is easier to recognize on CT scan of the abdomen. However, in some cases it can be seen on plain X-Rays. CONCLUSION: The appearance of sigmoid volvulus on CT scans as well as on plain abdominal X-rays bears a significant resemblance to the pattern observed on the face of the Trinidadian steel pan, the recognition of which can aid in the diagnosis of this disease.

Plexiform neurofibroma of the wrist: imaging features and when to suspect malignancy.

Plexiform neurofibromas are essentially pathognomonic for neurofibromatosis type 1 (NF1), occurring when there is diffuse involvement along a nerve segment and its branches. Transformation into a malignant peripheral nerve sheath tumour (MPNST) is a major cause of mortality in NF1 patients. These tumours are highly aggressive and particularly difficult to diagnose in NF1 patients due to the clinical overlap between benign and malignant lesions. We present a case of a plexiform neurofibroma and discuss the typical imaging characteristics on ultrasound, CT, and MRI, including the target sign and continuity with the parent nerve. Certain imaging features should raise suspicion for malignancy however, these modalities may not always reliably differentiate between benign and malignant lesions. Recent studies show a very high negative predictive value for FDG-PET making it quite useful in excluding malignancy. In positive scans, PET/CT aids in guiding biopsy to the most metabolically active area of the tumour.