Incidental findings on staging rectal MRI: clinical significance and outcomes.

BACKGROUND: Incidental findings (IFs) are commonly seen in staging rectal magnetic resonance imaging (MRI) scans. Their prevalence and clinical significance have not been previously documented. PURPOSE: To assess the prevalence, clinical significance, and outcomes of incidental findings in MRI scans performed for the staging of rectal cancer. MATERIAL AND METHODS: A retrospective study was performed at a tertiary colorectal imaging institution. Consecutive MRI rectal staging scans with correlative pathology confirmed primary rectal cancer between March 2014 and March 2021 were identified. The respective imaging reports were reviewed for IFs, which were classified as high, moderate, and low, according to their clinical significance. Medical records were reviewed to assess the outcomes of the highly significant IFs. RESULTS: There were 266 eligible patients (97 women; mean age = 64.2 years) during the study period. A total of 120 (45%) patients did not have any IFs. A total of 238 IFs in 146 (55%) patients were found. There were 21 (9%) IFs of high clinical significance, 122 (51%) of moderate clinical significance, and 95 (40%) of low clinical significance. The prostate and uterus had the most IFs of high clinical significance, two of which were subsequently pathology confirmed as prostate adenocarcinomas. CONCLUSION: IFs were seen in more than half of the staging MRI scans in rectal cancer but less than 10% of these were of high clinical significance. The results of this study highlight the range of potential IFs and can guide future research assessing the potential impact of these IFs on patients and the healthcare system.

Incidental findings on staging CT for rectal cancer: Frequency, clinical significance and outcomes.

AIM: To assess the prevalence, clinical significance, and outcomes of incidental findings in CT studies performed for rectal cancer staging. METHOD: This retrospective study was performed at a tertiary colorectal imaging institution. Institutional review board approval was obtained. Consecutive patients who had a CT of the chest, abdomen and pelvis for rectal cancer staging between March 2014 and March 2021 were identified. Patients with a pathologically confirmed primary rectal cancer were included. The imaging reports were reviewed for incidental findings (IFs), which were classified into high, moderate, and low categories, according to their clinical significance. Medical records were reviewed to assess the clinical outcomes of the highly significant IFs. RESULTS: There were 241 eligible patients with a mean age of 67 years (92 females). A total of 942 IFs were found in 235 patients (97.5 %). There were 91 IFs (10 %) of high clinical significance, 371 (39 %) of moderate clinical significance, and 480 (51 %) of low clinical significance. There were 8 synchronous malignancies, all of which were highly clinically significant IFs. There were 4 lung adenocarcinomas, 1 bladder urothelial carcinoma, and 3 renal cell carcinomas. Six patients did not have any IFs (2.5 %). CONCLUSION: IFs were seen in 97.5 % of staging CT scans for rectal cancer, 10 % of which were of high clinical significance. Importantly, these included 8 synchronous malignancies. The results highlight the wide range of potential IFs, which can be encountered in staging rectal cancer scans, and raise awareness as to their potential clinical relevance and impact on the healthcare system.

The Impact of Slice Thickness on Diagnostic Accuracy in Digital Breast Tomosynthesis.

Purpose: To evaluate the effect of slice thickness on diagnostic accuracy in Digital Breast Tomosynthesis (DBT). Method: Two readers retrospectively interpreted 150 DBT (125 normal and 25 pathology-proven cancer) cases scanned between October 2017-November 2020. The DBT studies were randomised and reviewed independently by the two readers. DBT studies were reviewed using a standard protocol (1 mm slices, no overlap and synthetic 2D-mammography (SM)) and an experimental protocol (10 mm slabs, 5 mm overlap and SM). Any abnormality and BIRADS scores were recorded by each reader. Sensitivity, specificity, interobserver and intraobserver agreement were calculated (Cohen's Kappa κ). For diagnostic accuracy, the reference standard was histopathology or a normal mammogram at 2 years. Results: The sensitivity and specificity for reader 1 and 2 for cancer detection was reader 1 (97% and 79% for the standard protocol, 97% and 76% for the experimental protocol) and reader 2 (97% and 74% for both protocols). Reader 1 had 97.6% intraobserver agreement (κ .95) and reader 2 had 96.4% intraobserver agreement (κ .92) when assessing the standard and experimental protocols. There was 90.5% agreement between the readers for the standard protocol (κ .80). There was 90.9% agreement between the readers for the experimental protocol (κ .81). Of the 25 DBT studies with pathology-proven cancer, one cancer was missed by both readers using both protocols. Conclusion: The diagnostic accuracy was similar between the standard and experimental DBT protocols, demonstrating excellent interobserver and intraobserver agreement. This suggests 10-mm thick slabs can potentially replace 1-mm thin slices in the interpretation of DBT.

Single-centre Experience of Patients with Metastatic Urothelial Cancer Treated with Chemotherapy Following Immune Checkpoint Inhibition.

There are few data on outcomes for patients with metastatic urothelial carcinoma (MUC) who receive chemotherapy (CT) after progression on immune checkpoint inhibitors (ICIs). We carried out a retrospective single-centre analysis of MUC patients who progressed after ICI and then received CT. Patients fell into two groups: CT-naive (no prior-CT) and CT-pretreated (platinum-based CT followed by ICI on progression). The response rate (RR), progression-free survival (PFS), and duration of response (DOR) were assessed. A total of 29 patients received CT following progression on ICI. The median follow-up was 17.0mo (interquartile range 9.1-20.5mo). In the CT-naive group (n=17), 53% had a partial response, 18% had stable disease, and 29% had progressive disease. In the CT-pretreated group (n=12) 17% had a partial response, 67% had stable disease, and 16% had progressive disease. The median PFS was 6.4mo (95% confidence interval [CI] 3.8-9.1) in the CT-naive and 4.4mo (95% CI 1.5-7.3) in the CT-pretreated group. The median DOR was 8.1mo (range 5.1-11.1) among the ten patients with a response to CT after ICI in both groups. Some 38% of patients in the CT-naive and 17% in the CT-pretreated group had dose reductions on post-ICI CT. CT and ICI can be sequenced after previous chemotherapy exposure, although this does not induce long-term durable remissions in most patients. PATIENT SUMMARY: We looked at outcomes for patients with metastatic bladder cancer who received chemotherapy after the cancer got worse while on immunotherapy. We found that patients can be safely treated with further chemotherapy. However, the positive effects of chemotherapy will not be durable in the majority of patients.

Adverse effects and radiological manifestations of new immunotherapy agents.

Immunotherapy has had increasing use in Medical Oncology for a diverse range of primary malignancies. There are various types of immunotherapy which are grouped based on mechanism of action. In recent decades, the immune checkpoint inhibitors (ICI) immunotherapies have been at the forefront of Medical Oncology, sparked by very encouraging results. Some patients with metastatic cancer who were previously deemed palliative were seeing durable response rates and significant increased survival with ICIs. The mechanism of action of ICIs vary wildly compared to the conventional, cytotoxic chemotherapy, upon which traditional radiology response criteria were based and validated upon. Novel responses such as pseudo progression, disease response in the context of new metastases and prolonged stable disease were observed and correlated with improved patient survival with ICI. New radiology response criteria were proposed to better capture disease response to ICI; however, the criteria have been applied heterogeneously and there is continued work in this sector. In addition to the novel responses, ICIs have been linked to numerous, diverse immune-related adverse events (irAE) affecting multiple systems. A large majority of these are mild, but some irAEs are life threatening. Only some of the irAEs have radiological manifestations. It is important that the reporting radiologist recognises potential irAE so clinical teams can be alerted, ICI treatment paused or cessated and steroid treatment initiated. This review will discuss the evolution of the radiology response criteria in ICI and the varied radiological appearances of irAE.

Response Rate to Chemotherapy After Immune Checkpoint Inhibition in Metastatic Urothelial Cancer.

Immune checkpoint inhibitors (ICIs) are active in metastatic urothelial carcinoma (MUC). They have joined chemotherapy (CT) as a standard of care. Here, we investigate the activity of CT after progression on ICIs. Two cohorts of sequential patients with MUC were described (n=28). Cohort A received first-line ICIs followed by CT after progression. Cohort B received CT after failure of first-line platinum-based CT followed by ICIs. Response rate (RR) to CT was assessed using Response Evaluation Criteria in Solid Tumors (RECIST v1.1) by a designated radiologist. Best RR for cohort A was 64%. Two patients experienced clinical progression and died before the first radiographic assessment. RR for cohort B was 21%, which was significantly lower than that for cohort A. Progression of disease occurred in 43% of cohort B patients by the end of CT. These data suggest a lack of cross resistance between CT and ICIs in MUC. Therefore, the sequencing of these drugs is likely to be important to maximise outcomes. This is particularly true after first-line ICIs as subsequent CT has significant activity. PATIENT SUMMARY: In this report, we studied the effect of chemotherapy in metastatic bladder cancer, which relapsed after immune checkpoint inhibitors. We found that the activity of chemotherapy was maintained despite previous exposure to immune therapy. This underlines the importance of sequencing these agents to maximise outcomes.

Preprocedural MRI and MRA in planning fibroid embolization.

This pictorial review aims to discuss and illustrate the up-to-date use of preprocedural magnetic resonance imaging (MRI) in selecting patients and planning uterine artery embolization (UAE). The merits of magnetic resonance angiography (MRA) in demonstrating the pelvic vasculature to guide UAE are highlighted. MRI features of fibroids and their main differential diagnoses are presented. Fibroid characteristics, such as location, size, and enhancement, which may impact patient selection and outcome, are presented based on recent literature. Pelvic arterial anatomy relevant to UAE, including vascular variants are illustrated, with conventional angiography and MRA imaging correlation. MRA preprocedural determination of the optimal projection angles for uterine artery catheterization is straightforward and constitutes an important strategy to minimize ionizing radiation exposure during UAE. A reporting template for MRI/MRA preassessement of UAE for fibroid treatment is provided.

Heterogeneous response and progression patterns reveal phenotypic heterogeneity of tyrosine kinase inhibitor response in metastatic renal cell carcinoma.

BACKGROUND: Molecular intratumour heterogeneity (ITH) is common in clear cell renal carcinomas (ccRCCs). However, it remains unknown whether this is mirrored by heterogeneity of drug responses between metastases in the same patient. METHODS: We performed a retrospective central radiological analysis of patients with treatment-naïve metastatic ccRCC receiving anti-angiogenic tyrosine kinase inhibitors (TKIs) (sunitinib or pazopanib) within three similar phase II trials. Treatment was briefly interrupted for cytoreductive nephrectomy. All patients had multiple metastases that were measured by regular computed tomography scans from baseline until Response Evaluation Criteria In Solid Tumours (RECIST)-defined progression. Each metastasis was categorised as responding, stable or progressing. Patients were classed as having a homogeneous response if all lesions were of the same response category and a heterogeneous response if they differed. RESULTS: A total of 115 metastases were assessed longitudinally in 27 patients. Of these patients, 56% had a heterogeneous response. Progression occurred through the appearance of new metastases in 67%, through progression of existing lesions in 11% and by both in 22% of patients. Despite RECIST-defined progression, 57% of existing metastases remained controlled. The sum of controlled lesions was greater than that of uncontrolled lesions in 47% of patients who progressed only with measurable new lesions. CONCLUSIONS: We identified frequent ITH of anti-angiogenic TKI responses, with subsets of metastases responding and progressing within individual patients. This mirrors molecular ITH and may indicate that anti-angiogenic drug resistance is confined to subclones and not encoded on the trunk of the tumours' phylogenetic trees. This is clinically important, as patients with small-volume progression may benefit from drug continuation. Predominant progression with new rather than in existing metastases supports a change in disease biology through anti-angiogenics. The results highlight limitations of RECIST in heterogeneous cancers, which may influence clinical trial data validity. This analysis requires prospective confirmation. TRIAL REGISTRATION: European Clinical Trials Database(EudraCT): 2009-016675-29 , registered 17 March 2010; EudraCT: 2006-004511-21 , registered 09 March 2007; EudraCT: 2006-006491-38 , registered 22 December 2006.

The MRI features of histologically proven ovarian cystadenofibromas-an assessment of the morphological and enhancement patterns.

OBJECTIVES: To assess the morphological and enhancement features of histologically proven cystadenofibromas (CAFs) on magnetic resonance imaging (MRI). METHODS: Forty-seven histologically proven CAFs (42 benign, five borderline) were retrospectively reviewed. One benign CAF had a synchronous adenocarcinoma in the same ovary. The morphological, signal and enhancement characteristics on MRI were recorded. RESULTS: The mean long axis diameter of the CAFs was 80 mm. The contralateral ovary was abnormal in 45 % of cases. A solid component was seen in 85 %, which returned low T2-weighted signal in 75 % of CAFs. Septa were seen in 74 % and one CAF was purely cystic. The majority of solid components and septa demonstrated enhancement that was less than the myometrium. Wash-in rates (WIR) of the solid tissue were available for measurement in nine patients with an average WIR of 3.2 l/s. CONCLUSION: This is the largest series describing MRI appearances of histologically proven CAFs. They are typically complex adnexal lesions containing septa, cystic components and solid tissue. The majority of solid components demonstrate low T2 signal and minimal enhancement. Almost half of the cases have an abnormal contralateral ovary.