The 2023 Stone-Free CT Mandate: Addressing the Two Sides of the Debate - Beyond the Abstract

Introduction: Starting in 2023, the editors of the Journal of Endourology have mandated that any manuscript reporting stone-free rates must be based on results of non-contrast CT scans with ≤3mm cuts. While the spirit of more rigorous academic merit should be applauded, this bold new requirement will have far-reaching effects on the future of urolithiasis research. As is the case with any such decision, there are two camps of clinicians: those who are in favor and those who are opposed to such a change. A summary of the two sides is outlined below.

An argument in favor of the mandate: We were excited when the editors of the Journal of Endourology implemented the mandate. Establishing guidelines and adherence to them is necessary to achieve consistency in research and improve our field of endourology. Simply, outcomes need to be comparable. Stone-free status is an important outcome in evaluating treatment success, but its determination varies widely in the literature, leading to selection bias and hindered comparisons. We understand that in the real world, it is not practical or cost effective to get CT scans on every post-operative patient nor do we recommend it. However, in the context of research, where one is trying to answer a specific question, comparing one technique or device with another, standardization is crucial to compare innovations in endourology effectively. Although CTs are more expensive than other imaging modalities, the benefits of accurate assessment and comparison justify the costs.

An argument against the mandate: The argument against can be simplified into a) the detriment to the patient and b) the detriment of “real world” databases which are largely populated with results of x-ray and ultrasound postoperative imaging.

Patient perspective: A low-dose stone-search CT has <4 mSv of radiation dose, <8% of patients undergoing CT for stone disease received a low dose protocol, and thus received many times the radiation dose.1 While a single non-low dose CT is unlikely to have long-term consequences, the cumulative radiation dose of the multiple CT scans performed for chronic stone formers could result in an increased risk of malignancy. Cost must also be considered, as CT ($1160) is significantly more expensive than renal ultrasound ($571) or abdominal x-ray ($384).2

Real world data: Undoubtedly, in the race of diagnostic superiority for detecting kidney stones CT wins by a wide margin. However, when it comes to the actual implementation of post-surgical imaging, the majority of patients don’t get any imaging at all, and those that do largely get ultrasound or x-ray over CT.3,4 With the Journal of Endourology mandating CT for reporting stone-free rates, the data available from “real world” databases and registries (such as the MUSIC database) would be severely restricted.

Conclusion: In conclusion, while supporting the editors' efforts to enhance research quality, it is essential to acknowledge that there may be unintended consequences of widespread CT imaging. We both agree on the use of CT as the gold standard for assessing new technologies. However, we must not forget the patient experience. Does the 1 mm residual fragment matter to the patient if they no longer have pain and never have another stone episode? Incorporating patient-reported outcomes can contribute to a more comprehensive and meaningful understanding of surgical efficacy and patient outcomes. As the leading authority in the field, we hope the Journal of Endourology will continue to promote impactful research while keeping patient well-being at the forefront.

Written by:

Co-first authors: Andrew M. Higgins,1 Vishnuvardhan Ganesan2
Other authors: Khurshid R. Ghani,1 Deepak Agarwal,2 Casey Dauw,1 and Michael S. Borofsky2

  1. Department of Urology, University of Michigan, Ann Arbor, MI, USA
  2. Department of Urology, University of Minnesota, Minneapolis, MN, USA

References:

  1. Smith-Bindman R, Moghadassi M, Giffrey RT, Camargo CA, Bailitz J, Beland M, et al. Computed Tomography Radiation Dose in Patients With Suspected Urolithiasis. JAMA Intern Med. 2015;175(8):1413–6.
  2. HonorHealth Average Pricing Information 2022 [Internet]. [cited 2022 Aug 27]. Available from: https://www.honorhealth.com/patients-visitors/average-pricing
  3. DiBianco JM, Daignault-newton S, Conrado B, Jafri SM, Korman H, Johnson J, et al. Variation and Correlation in Postoperative Imaging After Shockwave Lithotripsy and Ureteroscopy by Treatment Modality: Results of a Statewide Clinical Registry. Urology [Internet]. 2022;Article in:1–7. Available from: https://doi.org/10.1016/j.urology.2022.06.029
  4. Ahn JS, Holt SK, May PC, Harper JD. National Imaging Trends after Ureteroscopic or Shock Wave Lithotripsy for Nephrolithiasis. J Urol [Internet]. 2018;199(2):500–7. Available from: https://doi.org/10.1016/j.juro.2017.09.079 
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