Immune checkpoint blockade induced sarcoid-like reaction mimicking progression of disease in a patient with microsatellite instable colorectal cancer: case report and review of the literature.

Background: Oncologists are prescribing checkpoint inhibitors with greater frequency, and an awareness of and ability to recognize immune-related adverse events (irAEs) is a key part of the safe administration of these drugs. Case Description: Herein, we report the case of a 26-year-old male diagnosed with de novo metastatic right-sided colon cancer to the liver, with tumor immunohistochemistry demonstrating loss of MSH2 and MSH6, and a pathogenic mutation in MSH2 identified on germline testing, consistent with Lynch Syndrome. The patient received first-line treatment with pembrolizumab. Following 7 months of immune checkpoint blockade (ICB), new pulmonary findings on routine imaging were felt to be concerning for disease progression, despite ongoing excellent clinical status, disease control in the liver, and stable tumor markers. An endobronchial biopsy of one of the mediastinal lymph nodes demonstrated granulomatous inflammation consistent histologically with sarcoidosis, and a diagnosis of sarcoid-like reaction (SLR) secondary to immunotherapy was established. Pembrolizumab was discontinued, and the patient continued active monitoring off of active therapy, with durable cancer control. After 8 months of watchful waiting, new hepatic lesions and increasing abdomino-pelvic lymphadenopathy were identified on imaging, concerning for progression of disease. Inguinal lymph node biopsy demonstrated findings consistent with ongoing SLR. The patient remains with durable cancer control, now 24 months since receipt of ICB. In addition, he remains asymptomatic of the SLR. Conclusions: This case highlights the propensity of SLRs to imitate progression of disease, and the importance of awareness of this adverse effect, to prompt appropriate investigation and management.

GRASPNET: Fast spatiotemporal deep learning reconstruction of golden-angle radial data for free-breathing dynamic contrast-enhanced magnetic resonance imaging.

The purpose of the current study was to develop a deep learning technique called Golden-angle RAdial Sparse Parallel Network (GRASPnet) for fast reconstruction of dynamic contrast-enhanced 4D MRI acquired with golden-angle radial k-space trajectories. GRASPnet operates in the image-time space and does not use explicit data consistency to minimize the reconstruction time. Three different network architectures were developed: (1) GRASPnet-2D: 2D convolutional kernels (x,y) and coil and contrast dimensions collapsed into a single combined dimension; (2) GRASPnet-3D: 3D kernels (x,y,t); and (3) GRASPnet-2D + time: two 3D kernels to first exploit spatial correlations (x,y,1) followed by temporal correlations (1,1,t). The networks were trained using iterative GRASP reconstruction as the reference. Free-breathing 3D abdominal imaging with contrast injection was performed on 33 patients with liver lesions using a T1-weighted golden-angle stack-of-stars pulse sequence. Ten datasets were used for testing. The three GRASPnet architectures were compared with iterative GRASP results using quantitative and qualitative analysis, including impressions from two body radiologists. The three GRASPnet techniques reduced the reconstruction time to about 13 s with similar results with respect to iterative GRASP. Among the GRASPnet techniques, GRASPnet-2D + time compared favorably in the quantitative analysis. Spatiotemporal deep learning enables reconstruction of dynamic 4D contrast-enhanced images in a few seconds, which would facilitate translation to clinical practice of compressed sensing methods that are currently limited by long reconstruction times.

Factors Associated With Premature Ovarian Insufficiency in Young Women With Locally Advanced Rectal Cancer Treated With Pelvic Radiation Therapy.

PURPOSE: Pelvic radiation therapy (RT) is standard of care for patients with locally advanced rectal cancer (LARC). Premature ovarian insufficiency (POI) in premenopausal women is a possible side effect. The purpose of our study was to evaluate factors associated with POI in women younger than 50 years, treated with pelvic RT for LARC, including those who underwent ovarian transposition (OT). METHODS AND MATERIALS: We retrospectively reviewed the records of women younger than 50 years treated with pelvic RT for LARC at our institution between 2001 and 2019. Clinical and hormonal data were used to determine ovarian function. The ovaries and uterus were contoured and dose volume histograms were generated. Association of clinical and dosimetric factors with POI within 12 months of RT was evaluated using Wilcoxon-rank sum test and Fisher's exact test. RESULTS: We identified 76 premenopausal women at time of RT with median age of 43 years (range, 20-49). Twenty-six women (34%) underwent OT. Neoadjuvant, concurrent, and adjuvant chemotherapy was administered in 56 (74%), 69 (91%), and 26 (34%) women, respectively. Median RT dose was 50 Gy/25 fractions. Among 75 women with 12 months of follow-up, 25% had preservation of ovarian function, all in the OT group. Ovarian function was preserved in 19 (76%) women who underwent OT. The median of ovarian mean dose was 1.7 Gy in the OT group versus 44.8 Gy in the non-OT group (P < .001). OT and age at RT were significantly associated with POI (P < .001). No patient with ovarian mean dose less than 1.36 Gy developed POI. CONCLUSIONS: OT was significantly associated with reduced risk of POI by enabling lower radiation doses to the ovaries. OT should be considered in young patients undergoing pelvic RT. Although there appears to be a significant association between ovarian mean dose and POI, larger studies are needed to find a dosimetric threshold. Our results suggest keeping the dose to the ovaries as low as reasonably achievable in patients who undergo OT and pelvic RT.

Post-treatment CT LI-RADS categories: predictors of overall survival in hepatocellular carcinoma post bland transarterial embolization.

PURPOSE: The LI-RADS Treatment Response (LR-TR) algorithm was introduced in 2017 to assist radiologists in assessing hepatocellular carcinoma (HCC) response following locoregional therapy. The objective of this study was to evaluate the associations between pre-treatment LI-RADS diagnostic categories, post-treatment LR-TR categories, and mRECIST response categories with overall survival (OS) of patients with HCC. METHODS: This retrospective study included untreated patients with one or two lesions who underwent transarterial embolization with or without concomitant ablation from December 2003 to December 2017. Two radiologists (R1 and R2) reviewed pre- and post-treatment CT imaging. Associations between pre- and post-treatment variables, including post-treatment LR-TR categories (Viable, Equivocal, Nonviable), with OS were assessed using the Kaplan-Meier method and Cox proportional hazards regression. RESULTS: Eighty-five patients were included (median age = 71 years, range 50-87; 17 women). The median OS from first embolization was 43.92 months. Pre- and post-treatment tumor size, pre-treatment LR-TIV (compared with LR-5), and post-treatment LR-TR Viable (compared with LR-TR Nonviable) were associated with OS (p < 0.05 for all). Median OS was shorter for LR-TR Viable patients (R1, 25.64 months, 95% CI 18.58-35.70; R2, 26.43 months 95% CI 20.68-43.92) than for LR-TR Nonviable patients (64.21 months R1 and R2, 95% CI 42.71-92.45 and 36.30-94.09, respectively). mRECIST categories showed similar associations with OS. Inter-reader agreement was moderate for LI-RADS categories (κ = 0.57, 95% CI 0.35-0.78) and substantial for LR-TR categories (κ = 0.68, 95% CI 0.55-0.81). CONCLUSIONS: LR-TR categories show a strong association with OS in HCC patients treated with transarterial embolization.

Imaging for pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers worldwide due to its aggressiveness and the challenge to early diagnosis. Complete surgical resection is the only curative option, but fewer than 20% of patients have potentially resectable disease at the time of the diagnosis. Radiologists can assess whether PDAC is resectable, borderline resectable, locally advanced or metastatic based on current imaging tests. This review will outline the role of imaging in both the diagnosis and staging of PDAC, with the goal of assisting the multidisciplinary team in tailoring the best treatment for patients.

PET-avid hepatocellular adenomas: incidental findings associated with HNF1-α mutated lesions.

BACKGROUND: Hepatocellular adenoma (HCA) is the second most common benign liver neoplasm and occurs predominantly in women in their reproductive years. Positron emission tomography (PET) using [18F] fluorodeoxyglucose (FDG) is commonly used in cancer staging, surveillance and evaluation of treatment response. PET-avid HCA are rare and can be falsely interpreted as malignancies. METHODS: A retrospective review of four institutions' database was performed to identify the PET-avid HCAs with clinico-pathological correlation. RESULTS: Nine patients with histological proven PET-avid HCA was identified. Eight out of 9 patients were female with a median age at diagnosis of 44 years. All patients' tumors with available histological subtyping (8/8) were HNF1-α mutated and had no inflammatory changes; 6 out the 9 lesions had prominent (>50%) steatotic changes. CONCLUSION: Hepatocellular adenomas, specifically the HNF1-α subtype, can cause false-positive PET findings when seeking to identify malignancy. Concomitantly, PET-CT may have the potential to identify the HCA histopathologic variant with the lowest malignant and hemorrhagic potential.

PET-avid hepatocellular adenomas: incidental findings associated with HNF1-α mutated lesions.

BACKGROUND: Hepatocellular adenoma (HCA) is the second most common benign liver neoplasm and occurs predominantly in women in their reproductive years. Positron-emission tomography (PET) using [18F] fluorodeoxyglucose (FDG) is commonly used in cancer staging, surveillance and evaluation of the treatment response. PET-avid HCA is rare and can be falsely interpreted as malignancies. METHODS: A retrospective review of four institutions' database was performed to identify the PET-avid HCAs with clinico-pathological correlation. RESULTS: Nine patients with histological proven PET-avid HCA was identified. Eight out of nine patients were female with a median age at diagnosis of 44 years. All patients' tumours with available histological subtyping (8/8) were HNF1-α mutated and had no inflammatory changes; six out the nine lesions had prominent (>50%) steatotic changes. CONCLUSION: Hepatocellular adenomas, specifically the HNF1-α subtype, can cause false-positive PET findings when seeking to identify malignancy. Concomitantly, PET-CT may have the potential to identify the HCA histopathological variant with the lowest malignant and haemorrhagic potential.

Three-dimensional CT volumetry predicts outcome of laparoscopic splenectomy for splenomegaly: retrospective clinical study.

BACKGROUND: The aim of this study was to determine the predictive value of the preoperative three-dimensional reconstructed volume (3D volumetry) for outcomes of laparoscopic splenectomy. The impact of splenomegaly on the feasibility of laparoscopic splenectomy is still debated. We hypothesized that splenic volumetry may accurately estimate splenic volume preoperatively and be used by surgeons to select patients for laparoscopic splenectomy. METHODS: We performed a retrospective review of 88 patients seen at a tertiary referral center undergoing laparoscopic or open splenectomy between 2001 and 2010. Patients included in the study underwent elective splenectomy without associated procedures and had preoperative imaging available at our institution. We evaluated clinical, demographic characteristics and perioperative imaging as predictors of outcome. Study endpoints included conversion to open splenectomy, operating time, estimated blood loss (EBL), length of stay (LOS), postoperative complications, and mortality. RESULTS: In all, 53 procedures were started laparoscopically. Among them, 7 (13.2 %) were converted to open splenectomy and 7 (13.2 %) to hand-assisted laparoscopic splenectomy. The conversion group was matched with 35 patients who underwent open splenectomy to determine differences in outcomes between these groups. There were no conversions in spleens measuring <1100 cc, whereas spleens of 1100 to 2700 cc had a conversion rate of 41 %. Spleen volume >2700 cc was associated with an 87.5 % conversion rate. Spleen 3D volumetry >2700 cc was the only independent predictor of surgical conversion on multivariate analysis (odds ratio 38.0, confidence interval 4.02-358.75, p = 0.001). Patients who underwent open splenectomy had shorter operating times (160.3 vs. 253.0 min, p = 0.001) than those converted from laparoscopic to open splenectomy. CONCLUSIONS: A 3D reconstructed splenic volume of >2700 cc is a predictor of conversion from laparoscopic to open splenectomy. For spleens measuring <2700 cc, laparoscopic splenectomy may be performed by experienced surgeons with low to moderate rates of conversion. For spleens with a 3D reconstructed volume >2700 cc, laparoscopic splenectomy is associated with high rates of conversion to open surgery.