Development of a novel CT-based index for predicting the number of extracorporeal shockwave lithotripsy (ESWL) sessions required for successful fragmentation of obstructing pancreatic duct stones

Nikhil Bush, Praneeth Chandragiri, Nitish Ashok Gaurav, Sneh Sonaiya, Ila Lahooti, Anmol Singh, Abhinav Gupta, Elham Afghani, Georgios Papachristou, Mouen A. Khashab, Peter J. Lee, Rupjyoti Talukdar, Sundeep Lakhtakia, Vikesh K. Singh, Samuel Han, Manu Tandan, Venkata S. Akshintala

Research output: Contribution to journalArticlepeer-review


Background & aim: Extracorporeal shock wave lithotripsy (ESWL) is used for the treatment of pancreatic duct stones (PDS) in patients with chronic pancreatitis (CP). We aimed to develop a CT based index to predict the required number of ESWL sessions for technical success. Methods: We retrospectively evaluated patients with PDS secondary to CP who underwent ESWL. Technical success was defined as the complete fragmentation of stones to <3 mm. CT features including PDS size, number, location, and density in Hounsfield units (HU) were noted. We analyzed the relationship between PDS characteristics and the number of ESWL sessions required for technical success. A multiple linear regression model was used to combine size and density into the pancreatic duct stone (PDS) index that was translated into a web-based calculator. Results: There were 206 subjects (mean age 38.6 ± 13.7 years, 59.2% male) who underwent ESWL. PDS size showed a moderate correlation with the number of ESWL sessions (r = 0.42, p < 0.01). PDS in the head required a fewer number of sessions in comparison to those in the body (1.4 ± 0.6 vs. 1.6 ± 0.7, p = 0.01). There was a strong correlation between PDS density and the number of ESWL sessions (r = 0.617, p-value <0.01). The PDS index {0.3793 + [0.0009755 x PDS density (HU)] + [0.02549 x PDS size (mm)]} could accurately predict the required number of ESWL sessions with an AUC of 0.872 (p < 0.01). Conclusion: The PDS index is a useful predictor of the number of ESWL sessions needed for technical success that can help in planning and patient counseling.

Original languageEnglish (US)
Pages (from-to)643-648
Number of pages6
Issue number4
StatePublished - Jun 2024


  • Density
  • Extracorporeal shock wave lithotripsy (ESWL)
  • Fragmentation
  • PDS index
  • Pancreatic duct stone (PDS)
  • Size

ASJC Scopus subject areas

  • Endocrinology
  • Endocrinology, Diabetes and Metabolism
  • Hepatology

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