Digital Breast Tomosynthesis for Upgraded BIRADS Scoring towards the True Pathology of Lesions Detected by Contrast-Enhanced Mammography.

OBJECTIVE: To determine the added value of digital breast tomosynthesis (DBT) in the assessment of lesions detected by contrast-enhanced mammography (CEM). MATERIAL AND METHODS: A retrospective study was conducted in a tertiary university medical center. All CEM studies including DBT performed between January 2016 and December 2020 were included. Lesions were categorized and scored by four dedicated breast radiologists according to the recent CEM and DBT supplements to the Breast Imaging Reporting and Data System (BIRADS) lexicon. Changes in the BIRADS score of CEM-detected lesions with the addition of DBT were evaluated according to the pathology results and 1-year follow-up imaging study. RESULTS: BIRADS scores of CEM-detected lesions were upgraded toward the lesion's pathology with the addition of DBT (p > 0.0001), overall and for each reader. The difference in BIRADS scores before and after the addition of DBT was more significant for readers who were less experienced. The reason for changes in the BIRADS score was better lesion margin visibility. The main BIRADS descriptors applied in the malignant lesions were spiculations, calcifications, architectural distortion, and sharp or obscured margins. CONCLUSIONS: The addition of DBT to CEM provides valuable information on the enhancing lesion, leading to a more accurate BIRADS score.

Screening Mammography for Males With Elevated Breast Cancer Risk, Mutation Carriers, and Gynecomastia.

INTRODUCTION: The recommendations for annual mammography for male carriers with gynecomastia are controversial. This study investigated the potential link between gynecomastia and breast cancer in male carriers. PATIENTS AND METHODS: The database of a tertiary medical center was retrospectively searched for all male patients who underwent at least 1 digital mammography study from 2016 to 2023. Known carriers of a pathogenic variant in a high-risk breast-cancer gene were identified. Patients were stratified by carrier status, diagnosis of breast cancer, and diagnosis of gynecomastia. Data on demographics, hormone profile, and pathology results were compared. RESULTS: The cohort included 446 men of whom 82 were known carriers. Gynecomastia was diagnosed by mammography in 251 patients: 239/364 noncarriers (66%) and 12/82 carriers (15%) (P < .0001). Breast cancer was found in 21/364 noncarriers (6%) and 6/82 carriers (7%) (P < .6), and in 10/251 patients with gynecomastia (4%) and 17/193 (9%) without gynecomastia (P < .05). Among patients without gynecomastia, the number of breast cancer cases was similar in carriers and noncarriers (P = .3). Among patients with gynecomastia, the rate of breast cancer was higher in carriers (P < .08). On logistic regression analysis, the effect of gynecomastia on carriers was significant (P = .02). The odds ratio for a breast cancer diagnosis was 5.8 in the presence of gynecomastia (95% CI, 1.1-31, P < .04) and 0.52 in the absence of gynecomastia (95% CI, 0.2-1.7, P < .3). CONCLUSION: Gynecomastia may be associated with an increased risk of breast cancer in carriers. Larger studies are needed to determine whether and when to screen male carriers.

Incidence and Impact of Preoperative Hiatal Hernia in Patients with Esophageal Carcinoma Undergoing Curative Surgical Resection.

BACKGROUND: Hiatal hernia (HH) and gastroesophageal reflux disease (GERD) are risk factors for esophageal adenocarcinoma. High positive margin rates and poor survival were described among HH patients undergoing esophagectomy. We sought to describe incidence and impact of HH on outcomes following esophagectomy. METHODS: Patients who underwent esophagectomy 2012-2019 for esophago-junctional carcinoma were included. CT studies were blindly reviewed by two radiologists. A third radiologist reviewed cases of disagreement. Hernias ≥ 3 cm were included in the HH group. RESULTS: Overall, 66 patients (33%) had HH ≥ 3 cm. The no hernia group included 12 patients (6%) with < 3 cm HH and 106 (53%) without HH. Preoperative variables were comparable among groups. Location of anastomosis was similar among cohorts and predominantly cervical (n = 97, 82.2% vs 61, 92.4%, p = 0.113). Postoperatively, HH patients had higher incidence of atrial dysrhythmia (n = 11, 16.7% vs n = 6, 5.1% p = 0.015). Rates of R0 resections were similar (n = 62, 93.9%, vs n = 113, 95.8%, p = 0.724). HH patients had higher rates of signet ring cell histology (n = 14, 21.2% vs n = 9, 7.6% p = 0.025); this was confirmed on subgroup analysis including only adenocarcinoma patients (n = 14, 28.6% vs n = 8, 12.3%, p = 0.042). On Cox regression analysis, HH was not associated with disease-free or overall survival (HR 1.308, p = 0.274 and HR .905, p = 0.722). CONCLUSIONS: Patients with preoperative HH had higher rates of postoperative atrial dysrhythmias and signet ring cell features on pathology. In a population with predominant cervical anastomosis, positive margin rates were low and survival comparable among cohorts.

Age-related Changes of the Prostate on Magnetic Resonance Imaging: Quantitative and Qualitative Evaluation in a Screening Cohort of BRCA Mutation Carriers.

BACKGROUND: Age-related changes in multiparametric magnetic resonance imaging (mpMRI) of the prostate have been reported in the general population but not in screening cohorts. OBJECTIVES: To evaluate age-related changes on prostatic mpMRI in a screening cohort of BRCA1/2 mutation carriers. METHODS: Asymptomatic BRCA1/2 mutation carriers underwent mpMRI as part of a screening program. All included patients were followed for 3 years with no evidence of prostate cancer. mpMRIs were retrospectively evaluated by two abdominal radiologists for peripheral zone (PZ) patterns on T2 (homogenous hyperintensity, wedge-shaped hypointensities, patchy hypointensities, or diffuse hypointensity), and transition zone (TZ) pattern on T2 (homogenous, heterogeneous, nodular). Apparent diffusion coefficient (ADC) values of PZ and TZ were measured. Statistical analysis was performed using a predefined age cutoff of 50 years old. RESULTS: Overall, 92 patients were included: 38 in the younger age group (40-49 years) and 54 in the older age group (50-69 years). PZ homogenous hyperintensity and wedge-shaped hypointensities were more common in the older patients, whereas diffuse hypointensity was more common in younger patients (P < 0.001 for both readers) with substantial inter-reader agreement between the readers (kappa=0.643). ADC values were lower in young patients in the PZ (P < 0.001) and TZ (P = 0.003). CONCLUSIONS: Age-related differences in mpMRI were validated in BRCA mutation carriers. As some features overlap with prostatic carcinoma, awareness is crucial, specifically to diffuse T2 hypointensities of the PZ and lower ADC values in the PZ and TZ, which are more common in younger patients.

Selective Intra-Arterial Doxorubicin Eluting Microsphere Embolization for Desmoid Fibromatosis: A Combined Prospective and Retrospective Study.

Desmoid fibromatoses (DFs) are locally aggressive tumors composed of monoclonal fibroblasts within an abundant extracellular matrix. Systemic doxorubicin treatment is effective, but toxic. We investigated arterial doxorubicin eluting embolization (DEE), an approach characterized by high drug concentrations in the tumor alongside limited systemic drug exposure. The primary and secondary endpoints were radiological response using MRI and RECIST 1.1, respectively. The study included 24 patients (median age, 24; interquartile range, 16-34 years). Data were collected prospectively for 9 patients and retrospectively for 15 patients. The most frequent tumor locations were chest/abdomen wall and neck/shoulder/axilla (29% each). Of 24 patients, 7 (24%) were treatment naïve, and 17 (71%) had received one or two prior treatments. Patients underwent a median of two treatments (range, 1-4), with a median of 49 mg (range, 8-75) doxorubicin/treatment. Efficacy outcomes were available for 23 patients. With a median follow-up of 8 months (interquartile range, 3-13), median tumor volumes decreased by 59% (interquartile range, 40-71%) and T2 signal intensity decreased by 36% (interquartile range, 19-55%). Of 23 patients, 9 (39%), 12 (52%), and 2 (9%) had a partial response, stable disease, and progressive disease, respectively. DEE was safe and well tolerated, with one reported grade 3-4 adverse event (cord injury). In conclusion, DEE was safe and achieved rapid clinical/volumetric responses in DFs.

MRI background parenchymal enhancement in patients with invasive lobular carcinoma: Endocrine hormonal treatment effect.

OBJECTIVES: High background parenchymal enhancement (BPE) levels and asymmetric distribution could cause diagnostic uncertainty due to morphological similarity to breast cancer, especially invasive lobular carcinoma (ILC). We investigated BPE in ILC patients, its association with the tumor hormonal profile, and the effect of endocrine treatment (ET). METHODS: The analysis included all MRI examinations performed at our institution between 2010 and 2019 for ILC-diagnosed patients. Baseline study and the first follow-up study were reviewed. Digital medical records were reviewed to retrieve demographics/pathology results/treatment information. BPE and fibroglandular tissue were assessed qualitatively on the contralateral breast according to the criteria of the Breast Imaging Reporting and Data System (BI-RADS). RESULTS: The study included 129 patients. Most (91%) had pure ILC. All received ET; 12% also received chemotherapy; 90% had surgery first; 70% by breast conservation. On the baseline MRI, 70% had mild or moderate BPE; whereas, on the follow-up study, the majority (59%) had minimal BPE. Most BPE reductions were by 2 degrees. In the baseline study, additional biopsies were required in 59% of cases, and in 17%, a short-term follow-up was recommended. In the follow-up study, biopsies were recommended in 10%, and a short-term follow-up was requested in 16%. A correlation between progesterone receptor intensity index and baseline BPE level was observed (r = 0.3, p = 0.004). CONCLUSION: ILC patients usually exhibit high BPE. ET decreases BPE, and therefore may decrease false-positive interpretations. Additional research is needed to explore whether study can be performed on ET without compromising sensitivity. KEY POINTS: ∙ High background parenchymal enhancement levels reduces breast MRI sensitivity, yielding high false positive rates especially when reporting cases of invasive lobular carcinoma [ILC].∙Treatment of ILC with endocrine therapy reduces background parenchymal enhancement and thus could decrease these false-positive interpretations.

Sarcopenia as a Predictor of Survival in Patients with Pancreatic Adenocarcinoma After Pancreatectomy.

OBJECTIVE: To determine whether sarcopenia can potentially predict worse survival after resection of pancreatic ductal adenocarcinoma. BACKGROUND: Sarcopenia is correlated with poor outcomes in hepatopancreatobiliary malignancies, but the relationship of both its qualitative and quantitative features with patient survival after pancreatectomy has not been investigated in a western population. PATIENTS AND METHODS: Preoperative cross-sectional computed tomography scans of consecutive patients who underwent pancreatectomy in 2005-2017 were evaluated for skeletal muscle index (SMI), intramuscular adipose tissue content (IMAC), and visceral-to-subcutaneous adipose tissue area ratio (VSR). Sex-specific categorical cut-offs were determined. Findings were correlated with outcome. RESULTS: The study included 111 patients, 47% of whom were female, with a median age of 67 years (range: 35-87 years), and median body mass index of 23 kg/m2 (range: 16-40 kg/m2); 77% had a Whipple procedure and 66% received adjuvant chemotherapy. Low SMI correlated with poor overall survival (OS) (P = 0.007), disease-specific survival (DSS) (P = 0.006), and recurrence-free survival (RFS) (P = 0.01). High IMAC correlated with poor OS (P = 0.04). Patients with high IMAC tended to have a shorter DSS (P = 0.09), with no correlation with RFS (P = 0.6). VSR was not associated with survival. Multivariable analysis yielded an independent association of low SMI with OS (HR = 1.7, 95%CI: 1.1-2.8, P = 0.02), DSS (HR = 1.8, 95%CI: 1.03-3.2, P = 0.04), and RFS (HR = 1.8, 95%CI: 1.1-2.8, P = 0.01), and of high IMAC with OS (HR = 1.9, 95%CI: 1.1-3.1, P = 0.01). CONCLUSION: Both qualitative and quantitative measures of skeletal muscle were independently associated with impaired survival in patients with resectable PDAC. Sarcopenia might serve as an early radiographic surrogate of aggressive tumor behavior, with potential implications for clinical decision-making and future study.

Machine learning for selecting patients with Crohn's disease for abdominopelvic computed tomography in the emergency department.

BACKGROUND: Patients with Crohn's disease (CD) frequently undergo abdominopelvic computed tomography (APCT) in the emergency department (ED). It's essential to diagnose clinically actionable findings (CAF) as they may need immediate intervention, frequently surgical. However, repeated APCT's includes increased ionizing radiation exposure. Guidance regarding APCT performance is mostly clinical and empiric. AIMS: We used a machine learning (ML) approach for predicting CAF on APCT in the ED. METHODS: We performed a retrospective cohort study of patients with CD who presented to the ED and underwent APCT. CAF were defined as bowel obstruction, perforation, intra-abdominal abscess or complicated fistula. ML was used to predict the probability of having CAF on APCT, using routine clinical variables. RESULTS: Of 101 admissions included, 44 (43.5%) had CAF on APCT. ML successfully identified patients at low (NPV 91.6%, CI-95% 90.6-92.5) and high (PPV 92.8%, CI-95%, 92.3-93.2) risk for CAF (AUROC = 0.774), using beats-per-minute, mean arterial pressure, neutrophil-to-lymphocyte ratio and sex. This allowed the construction of a risk stratification scheme according to patients' probability for CAF on APCT. CONCLUSION: We present a novel artificial intelligence-based approach, utilizing readily available clinical variables to better select patients with CD in the ED for APCT. This might reduce the number of APCTs performed, avoiding related hazards while ensuring high-risk patients undergo APCT.

Diffusion Is Directional: Innovative Diffusion Tensor Imaging to Improve Prostate Cancer Detection.

In the prostate, water diffusion is faster when moving parallel to duct and gland walls than when moving perpendicular to them, but these data are not currently utilized in multiparametric magnetic resonance imaging (mpMRI) for prostate cancer (PCa) detection. Diffusion tensor imaging (DTI) can quantify the directional diffusion of water in tissue and is applied in brain and breast imaging. Our aim was to determine whether DTI may improve PCa detection. We scanned patients undergoing mpMRI for suspected PCa with a DTI sequence. We calculated diffusion metrics from DTI and diffusion weighted imaging (DWI) for suspected lesions and normal-appearing prostate tissue, using specialized software for DTI analysis, and compared predictive values for PCa in targeted biopsies, performed when clinically indicated. DTI scans were performed on 78 patients, 42 underwent biopsy and 16 were diagnosed with PCa. The median age was 62 (IQR 54.4-68.4), and PSA 4.8 (IQR 1.3-10.7) ng/mL. DTI metrics distinguished PCa lesions from normal tissue. The prime diffusion coefficient (λ1) was lower in both peripheral-zone (p < 0.0001) and central-gland (p < 0.0001) cancers, compared to normal tissue. DTI had higher negative and positive predictive values than mpMRI to predict PCa (positive predictive value (PPV) 77.8% (58.6-97.0%), negative predictive value (NPV) 91.7% (80.6-100%) vs. PPV 46.7% (28.8-64.5%), NPV 83.3% (62.3-100%)). We conclude from this pilot study that DTI combined with T2-weighted imaging may have the potential to improve PCa detection without requiring contrast injection.

Association between multitarget tyrosine kinase inhibitors and changes in CT appearance of submucosal fat in the gastrointestinal tract.

INTRODUCTION: Submucosal fat deposition (SMF) in the gastrointestinal tract can be seen in patients treated with vascular endothelial growth factor receptor multitarget tyrosine kinase inhibitors (mtTKIs). We aimed to assess the association between mtTKIs treatment and appearance of SMF on computed tomography (CT). METHODS: We performed retrospective evaluation of patients who started mtTKI treatment between 2016 and 2018, with a comparison patient cohort treated with single-target tyrosine kinase inhibitors (stTKIs). SMF amount for each gastrointestinal tract segment (stomach, duodenum, jejunum, ileum, terminal ileum, right colon, left colon) was scored as follows: 0 = none; 1 = low amount (<2 mm thick); 2 = high amount (>2 mm layer). For each CT, segment scores were aggregated to create an SMF index (SMFI). Maximal increase in SMFI between pretreatment and posttreatment CTs was documented. SMF ⩾3 was defined as positive. RESULTS: Forty patients treated with mtTKIs and 23 patients receiving stTKIs were included. Maximal increase in SMFI during treatment was 0-1 in 56/63 patients (89%) and 3-6 in 7/63 patients (11%). All patients with positive SMFI received mtTKIs compared to 0 patients treated with stTKIs (17.5% vs. 0%; p = 0.04). mtTKI treatment was associated with higher incidence of nausea/vomiting (4/7) and diarrhea (4/7) when positive SMF was noted, as compared to patients with negative SMF (6/33 patients each; p = 0.048). CONCLUSION: Gastrointestinal tract SMF deposition occurs in a considerable proportion of patients treated with mtTKIs with association to abdominal symptoms. This may be unique to mtTKIs and was not found in patients receiving stTKIs.

Timing to imaging and surgery after neoadjuvant therapy for breast cancer.

Neoadjuvant therapy (NAT) is increasingly used in breast cancer (BC), yet, the recommended time interval between NAT completion, preoperative imaging assessment, and breast surgery is not clearly defined. This single-center retrospective study investigated tumor growth between NAT completion and surgery. The analysis included 106 BC patients who received NAT (69% chemotherapy alone, 31% chemotherapy plus anti-HER2 therapy), had post-NAT breast MRI, and definitive surgery between 2012 and 2019. The median time interval between end-of-treatment and surgery was 6 weeks; 90% had surgery within 8 weeks of NAT completion, and 10% had surgery 8-12 weeks after NAT completion. No significant correlation was found between any of the time intervals (i.e., NAT completion-to-surgery, NAT completion-to-MRI, post-NAT MRI to surgery) and the tumor size as captured in the pathology report. The only parameter that was significantly correlated with pathological tumor size was tumor size as measured on the post NAT MRI (P < .0001). The difference in tumor size between post NAT MRI and surgical pathology did not correlate with the time interval between end-of-treatment and surgery. The ratio between residual tumor size on post-NAT MRI and the time interval from the end-of-treatment to surgery, significantly correlated with the tumor size on surgical pathology (P < .0001) suggesting that NAT has a beneficial effect weeks after end-of-treatment. In conclusion, our results suggest that for patients undergoing neoadjuvant chemotherapy, surgery within 4-8 weeks of completing NAT is reasonable, and is unlikely to result in a clinically significant change in residual tumor size.

A noninferiority within-person study comparing the accuracy of transperineal to transrectal MRI-US fusion biopsy for prostate-cancer detection.

BACKGROUND: Magnetic resonance imaging (MRI) and ultrasound (US) fusion prostate-biopsies can be performed in a transrectal (TR-fusion) or transperineal (TP-fusion) approach. Prospective comparative evidence is limited. In this study we compared the detection rate of clinically-significant prostate-cancer (csPCa) within an index lesion between TR and TP-fusion. PATIENTS AND METHODS: This was a prospective, noninferiority, and within-person trial. Men scheduled for MRI-US-fusion with a discrete MRI PI-RRAD ≥ 3 lesion were included. A dominant index lesion was determined for each subject and sampled by TR and TP-fusion during the same session. The order of biopsies was randomized and equipment was reset to avoid chronological and incorporation bias. For each subject, the index lesion was sampled 4-6 times in each approach. All biopsies were performed using Navigo fusion software (UC-Care, Yokneam, Israel). csPCa was defined as: Grade Group ≥ 2 or cancer-core length ≥ 6 mm. We used a noninferiority margin of 10% and a one-sided alpha level of 5%. RESULTS: Seventy-seven patients completed the protocol. Median age was 68.2 years (IQR:64.2-72.2), median PSA was 8.9 ng/ml (IQR:6.18-12.2). Ten patients (13%) were biopsy naive, others (87%) had a previous biopsy. csPCa was detected in 32 patients (42%). All of these cases were detected by TP-fusion, while only 20 (26%) by TR-fusion. Absolute difference for csPCa diagnosis was 15.6 (CI 90% 27.9-3.2%) in favor of TP-fusion (p = 0.029). TP-fusion was noninferior to TR-fusion. The lower boundary of the 90% confidence-interval between TP-fusion and TR-fusion was greater than zero, therefore TP-fusion was also found to be superior. Exploratory subgroup analyses showed TP-fusion was consistently associated with higher detection rates of csPCa compared with TR-fusion in patient and index-lesion derived subgroups (size, location, PI-RADS, PSA, and biopsy history). CONCLUSIONS: In this study, TP-fusion biopsies were found to be noninferior and superior to TR-fusion biopsies in detecting csPCa within MRI-visible index lesion. Centers experienced in both TP and TR-fusion should consider these results when choosing biopsy method.

Computed Tomography Findings Associated With 30-Day Mortality in Patients With Malignant Superior Vena Cava Syndrome.

OBJECTIVE: The objective of this study was to identify radiological and clinical factors associated with early mortality in malignant superior vena cava syndrome (SVCS). MATERIALS AND METHODS: Chest computed tomography studies of 127 patients with malignancy-associated SVCS were retrospectively reviewed. Involvement of SVC and tributaries, pleural and pericardial effusions, pulmonary artery involvement, and ancillary findings were documented. Univariate and multivariate models determined associations between radiological and clinical variables, and 30-day mortality. RESULTS: Thirty-day mortality rate was 16.5% (n = 21). Factors associated with 30-day mortality on univariate analysis included age, cancer stage, SVCS clinical severity, left jugular vein obstruction, number of involved veins, pulmonary arteries involvement, and presence of pleural effusions. Age, SVCS clinical severity, number of veins involved, and pleural effusions were positively associated with 30-day mortality on multivariate analysis. CONCLUSIONS: Selected clinical and radiological variables are associated with early death in malignant SVCS. These factors may identify a subgroup of patients who may benefit from treatment escalation.

[THROMBOCYTOPENIA, LEG EDEMA AND SHORTNESS OF BREATH FOLLOWING CORONARY ARTERY BYPASS SURGERY].

INTRODUCTION: Heparin-induced thrombocytopenia (HIT) is the most important non-hemorrhagic complication of heparin treatment. We report a case of a major thromboembolic event accompanied by thrombocytopenia following heparin exposure during coronary artery bypass graft surgery. Thrombocytopenia was documented one month after the surgery, and a major thromboembolic event which led to the patient's death diagnosed 6 weeks after heparin exposure. We discuss the pathophysiology and clinical aspects of heparin-induced thrombocytopenia, focusing on the unique features of this patient, including late persistent thrombocytopenia.

Thrombosis, anticoagulation and outcomes in malignant superior vena cava syndrome.

Anticoagulation is often used in superior vena cava syndrome (SVCS) associated with cancer (i.e malignant SVCS), even without thrombosis, but its effect on outcomes has not been reported. We aimed to determine factors and outcomes associated with thrombosis and anticoagulation in malignant SVCS. Patients with malignant SVCS diagnosed on computerized tomography (CT) were retrospectively included, indexed at diagnosis and followed for 6 months using medical records. The cohort included 183 patients with malignant SVCS of which 153 (84%) were symptomatic. Thirty of the 127 patients (24%) with a reviewable baseline CT had thrombosis of the SVC or tributaries at diagnosis. Patients with baseline thrombosis more often had symptomatic SVCS (p < 0.01). 70% (21/30) of patients with thrombosis and 52% (49/97) of those without thrombosis at baseline received anticoagulation, most often at therapeutic doses. Thrombosis occurred in 5/39 patients with anticoagulation (13%) compared to 2/18 (11%) of those without, during follow-up (p = 0.85). Anticoagulation was associated with a reduction in risk of SVC stent placement during follow-up that did not reach statistical significance (HR 0.47, 95% CI 0.2-1.13, p = 0.09). Major bleeding occurred in 7 (4%) patients, six of whom received anticoagulation (four therapeutic and two intermediate dose). Neither thrombosis nor anticoagulation affected survival. Anticoagulation is commonly used as primary prevention but its benefit remains to be proven. The role of reduced-dose anticoagulation in non-thrombotic malignant SVCS should be prospectively assessed.

Effect of chemotherapy on the impact of FDG-PET/CT in selection of patients for surgical resection of colorectal liver metastases: single center analysis of PET-CAM randomized trial.

The largest randomized controlled trial (RCT) on the effect of FDG-PET on surgical management for metastatic colorectal adenocarcinoma to liver ("PET-CAM") reported only a modest change in surgical management (8%). PURPOSE: To explore the relationship between prior chemotherapy and detection of metastatic disease on PET in patients from PET-CAM. Secondary aim: to determine whether centralized imaging interpretation could have impacted trial results. METHODS: The study included 120 patients from a single institution. Local PET interpretation (PET-L) was recorded from the original database. Retrospective PET interpretation was performed independently by at least one additional reader (PET-C). The presence of extrahepatic disease (EHD) and significant additional liver metastases (=SALM), defined as metastases not originally planned for resection, was recorded. Patients were stratified to responders to recent chemotherapy (Group R) versus all others (Group O) according to surgical pathology and RECIST criteria. RESULTS: Thirty-seven of 50 patients who received recent chemotherapy (<90 days) were responders (Group R). EHD was present in 30/120 (25%) patients. There was no difference in detection of EHD on PET-L (7/37;18.9%), PET-C (7/37;18.9%), and CT (4/37;10.8%) for Group R (p = 0.375), but in Group O more EHD was detected on both PET-L (15/83;18.1%) and PET-C (22/83;26.5%) than CT (8/83;9.6%); p = 0.039 and p < 0.001, respectively. For the entire cohort, PET-L and PET-C detected EHD and/or SALM not reported on CT in 14 (11.7%) and 22 (18.3%) patients. CONCLUSION: The impact of recent chemotherapy on detection of colorectal metastases with PET suggests that the utility of PET in patient selection for liver resection in the prior PET-CAM-RCT may have been underestimated.