Liu R. et al., 2019: Quantitative factors of unenhanced CT for predicting fragmenting efficacy of extracorporeal shock wave lithotripsy on pancreatic duct stones
Liu R, Su W, Wang J, Gong J, Lu J.
Department of Radiology,Department of Nuclear Medicine, Changhai Hospital Affiliated to the Second Military Medical University, Changhai Road 168, Yangpu District, Shanghai, 200433 PR China.
AIM: To find potential predictors at unenhanced computed tomography (CT) to evaluate the stone clearance rate (SCR) of pancreatic duct stones (PDS) by extracorporeal shock wave lithotripsy (ESWL). MATERIALS AND METHODS: A total of 106 consecutive patients with multiple stones of maximal transverse length (MTL) 0.3-3.6 cm in pancreatic head region were enrolled. Unenhanced CT was performed both before and after ESWL therapy. All patients underwent ESWL therapy using an electromagnetic lithotripter, and were divided into three groups with threshold values of >90%, 50-90% and <50% of SCR. Factors including sex, age, MTL, mean stone density (MSD), standard deviation of stone density (SDSD), variation coefficient of stone density (VCSD), attenuation density (AD), pancreatic duct diameter (PDD), skin-to-stone distance (SSD), and number of ESWL sessions were analysed, and their impact on SCR was evaluated by univariate and multivariate analyses. The diagnostic threshold of the independent predicting index was further calculated, and its relationship with SCR and ESWL was analysed by drawing a trend line. RESULTS: The only significant predictor of SCR by ESWL was MSD (p<0.05). More courses of ESWL therapy are required in PDS patients with an MSD higher than the cut-off value of 375.4 HU (mean, 2.6 versus 1.8), but with a relatively lower SCR (mean, 43.96 versus 88.68%) .CONCLUSION: MSD on pre-treatment unenhanced CT is an independent predictor for SCR of PDS patients treated with ESWL. Using a cut-off value of 375.4 HU, patients with low MSD are good candidates for ESWL therapy.
Clin Radiol. 2019 Feb 23. pii: S0009-9260(19)30080-7. doi: 10.1016/j.crad.2019.01.018. [Epub ahead of print]
The ease with which Gastroenterologists treat pancreatic duct stones with several ESWL sessions always impressed me. At the same time, Urologist did experimental and clinical studies to find out about the side effects of ESWL to kidney stones, like pancreatitis and diabetes. Thinking outside the box can help to understand the world better.
Gastroenterologists now detect the CT to predict success of ESWL for pancreatic stones.
They deal with Calcium-carbonate stones and very low HUs. Up to 8 sessions of ESWL are not unusual.