Accuracy of apparent diffusion coefficient in differentiating pancreatic neuroendocrine tumour from intrapancreatic accessory spleen.

OBJECTIVES: To evaluate and compare the accuracy of absolute apparent diffusion coefficient (ADC) and normalised ADC (lesion-to-spleen ADC ratio) in differentiating pancreatic neuroendocrine tumour (NET) from intrapancreatic accessory spleen (IPAS). METHODS: Study included 62 patients with the diagnosis of pancreatic NET (n=51) or IPAS (n=11). Two independent reviewers measured ADC on all lesions and spleen. Receiver operating characteristics (ROC) analysis to differentiate NET from IPAS was performed and compared for absolute and normalised ADC. Inter-reader reliability for the two methods was assessed. RESULTS: Pancreatic NET had significantly higher absolute ADC (1.431x10-3 vs 0.967x10-3 mm2/s; P<0.0001) and normalised ADC (1.59 vs 1.09; P<0.0001) compared to IPAS. An ADC value of ≥1.206x10-3 mm2/s was 70.6% sensitive and 90.9% specific for the diagnosis of NET vs. IPAS. Lesion to spleen ADC ratio of ≥1.25 was 80.4% sensitive, and 81.8% specific while ratio of ≥1.29 was 74.5% sensitive and 100% specific in the differentiation. The area under the curve (AUCs) for two methods were similar (88.2% vs. 88.8%; P=0.899). Both methods demonstrated excellent inter-reader reliability with ICCs for absolute ADC and ADC ratio being 0.957 and 0.927, respectively. CONCLUSION: Both absolute and normalised ADC allow clinically relevant differentiation of pancreatic NET and IPAS. KEY POINTS: • Imaging overlaps between IPASs and pancreatic-NETs lead to unnecessary procedures including pancreatectomy. • Uniquely low ADC of spleen allows differentiating IPASs from pancreatic NETs. • Both absolute-ADC and normalised-ADC (lesion-to-spleen ADC-ratio) demonstrate high accuracy in differentiating IPASs from NETs. • Both methods demonstrate excellent inter-reader reliability.

Preoperative bevacizumab and volumetric recovery after resection of colorectal liver metastases.

BACKGROUND AND OBJECTIVES: While preoperative treatment is frequently administered to CRLM patients, the impact of chemotherapy, with or without bevacizumab, on liver regeneration remains controversial. METHODS: The early and late regeneration indexes were defined as the relative increase in liver volume (RLV) within 2 and 9 months from surgery. Regeneration rates of the preoperative treatment groups were compared. RESULTS: Preoperative chemotherapy details and volumetric data were available for 185 patients; 78 (42.2%) received preoperative chemotherapy with bevacizumab (Bev+), 46 (24.8%) received chemotherapy only (Bev-), and 61 (33%) received no chemotherapy. Patients in the Bev+ and Bev- groups received similar chemotherapy cycles (4 [3-6] vs 4 [4-6]; P = 0.499). Despite the comparable clinicopathological characteristics and Resected Volume/Total Liver Volume (TLV) at surgery (P = 0.944) of both groups, Bev+ group had higher early and late regeneration (17.2% vs 4.3%; P = 0.035 and 14.0% vs 9.4%; P = 0.091, respectively). Of note, early and late regeneration rates (3.7% and 10.9% vs 6.6% and 5.5%, respectively) were comparable between the no chemotherapy and Bev- groups (all P > 0.05). In multivariable analysis -adjusted for gender, age, portal vein embolization, preoperative chemotherapy, resected liver volume, tumor number, postoperative chemotherapy, fibrosis, steatosis- bevacizumab independently predicted early liver regeneration (P = 0.019). CONCLUSION: Our findings suggest that preoperative bevacizumab administered along with chemotherapy was associated with enhanced volumetric restoration. Interestingly, this effect was more pronounced among patients who received oxaliplatin-based regimens and bevacizumab compared to those treated with irinotecan-based regimens and bevacizumab.

Increased kinetic growth rate during late phase liver regeneration impacts the risk of tumor recurrence after colorectal liver metastases resection.

BACKGROUND: Although experimental data strongly support the pro-tumorigenic role of postoperative liver regeneration, this hypothesis has not been clinically investigated. We aimed to examine the impact of liver regeneration determined by volumetric imaging on recurrence following resection of colorectal liver metastasis (CRLM). METHODS: Resected liver volume was subtracted from total liver volume (TLV) to define postoperative remnant liver volume (RLVp). Early and late kinetic growth rates (KGR) were defined as the postoperative increases in liver volume within 2-3 and 8-10 months from surgery, respectively, divided by the corresponding time interval. RESULTS: Median early and late KGR was 2.6%/month (IQR: -0.9 to 12.3) and 1.0%/month (IQR: -0.64 to 2.91), respectively. Late KGR predicted intrahepatic recurrence after 1 year from surgery (AUC 0.677, P = 0.011). Specifically, patients with a late KGR ≥1% had a higher cumulative risk of recurrence compared with patients with a KGR <1% (P = 0.038). In multivariate analysis, KGR ≥1% independently predicted recurrence (P = 0.027). DISCUSSION: A KGR ≥1% during the late regeneration phase was associated with increased risk of intrahepatic recurrence. These data may inform the timing of adjuvant therapy administration and focus surveillance strategies for high-risk patients.

Transcatheter stent implantation for the treatment of abdominal aortic coarctation and right renal artery stenosis in takayasu's arteritis: a case with a 4-year follow up.

We describe a Takayasu arteritis patient who was admitted because of an abdominal aortic stenosis, further complicated by the presence of a stenotic right renal artery located in the area of the aortic stenosis. After treatment of the renal stenosis with a 4 × 15 mm Driver stent, a 16 × 60 self-expandable nitinol stent (OptiMed) was deployed through the stenosis of the abdominal aorta. Even though the right renal artery was initially compromised after stent deployment through the aortic stenosis, the patient was successfully treated with renal artery re-dilation by a balloon passed through open cells of the aortic stent. During follow up, the patient suffered no procedure-related complications.