The role of DWI MRI for differential diagnostic of solid renal tumors

Introduction. Currently, CT and MRI do not reliably differentiate oncocytoma, angiomyolipoma with minimal fat and renal cell carcinoma, and therefore most patients with localized solid renal tumors undergo surgical treatment. Identification of differential signs of benign formations according to imaging methods would make it possible to change the therapeutic tactics in more than a third of cases in patients with newly diagnosed small renal masses (less than 4 cm).
Purpose. The aim of the study was to evaluate the diagnostic efficacy of diffusion-weighted MRI (DWI) in the differential diagnosis of solid renal masses.
Materials and methods. А prospective study, which included 90 patients aged 34 to 79 years with primary solid renal masses who were examined and treated at the Hertsen Moscow Oncology Research Institute – Branch of the National Medical Research Radiological Centre of the Ministry of Health of the Russian Federation was conducted in the period from February 2019 to October 2021. Before surgery, all patients underwent MRI of the retroperitoneal organs using DWI with b-factors of 0–800 s/mm2 and 0–1000 s/mm2. The diffusion coefficient was quantified on two ADC maps for renal masses of various histological types and the obtained values were compared with each other.
Results. According to the results of the statistical analysis, the values of the diffusion coefficient for benign tumors were significantly higher than for RCC (p < 0.05). There was no statistically significant difference between clear cell, chromophobe and papillary types of RCC in terms of diffusion coefficient both at b-factors of 0–800 s/mm2 and at 0–1000 s/mm2.
Conclusion. Using DWI we can suggest a benign genesis of a solid renal mass. Differential signs for RCC of various histological types according to diffusion-weighted images were not identified.

1. Renal carcinoma, 2021. Russian clinical guidelines (Russian National Union “Association of Oncologists of Russia”, Russian Public Organization “Russian Society of Urological Oncology”, Russian Public Organization “Russian Society of Clinical Oncology”, Russian Public Organization “Russian Society of Urologists”) (In Russian)

2. The state of cancer care in Russia in 2020 / Eds of Каprin А.D., Starinskiy V.V., Shakhzadova A.O. М.: Moscow Research Oncological Institute named after P.A. Herzen, 2021. 239 p. (In Russian)

3. Urology. Russian clinical guidelines / Eds Alyaev Yu.G., Glybochko P.V., Pushkar D. Yu. M.: Medforum, 2017: 293–357. (In Russian)

4. Sasaguri K., Takahashi N. CT and MR imaging for solid renal mass characterization. Eur. J. Radiol. 2018; 99: 40–54. https://doi.org/10.1016/j.ejrad.2017.12.008

5. Kay F.U., Pedrosa I. Imaging of solid renal masses. Radiol. Clin. N. Am. 2016; 55 (2): 243–258. https://doi.org/10.1016/j.rcl.2016.10.003

6. EAU Guidelines. Renal cell carcinoma. Edn. presented at the EAU Annual Congress Amsterdam 2022. ISBN 978-94-92671-16-5

7. Macklin P.S., Sullivan M.E., Tapping C.R. et al. Tumour Seeding in the Tract of Percutaneous Renal Tumour Biopsy: A Report on Seven Cases from a UK Tertiary Referral Centre. Eur. Urol. 2019. 75 (5): 861–867. https://doi.org/10.1016/j.eururo.2018.12.011

8. Patel H.D., Druskin S.C., Rowe S.P. et al. Surgical histopathology for suspected oncocytoma on renal mass biopsy: a systematic review and meta-analysis. BJU Int. 2017; 119 (5): 661–666. https://doi.org/10.1111/bju.13763

9. Liu S., Lee S., Rashid P. et al. Active surveillance is suitable for intermediate term follow-up of renal oncocytoma diagnosed by percutaneous core biopsy. BJU Int. 2016; 118, Suppl. 3: 30–34. https://doi.org/10.1111/bju.13538

10. Rubtsova N.A., Kryaneva E.V., Golbits A.B. et al. The R.E.N.A.L. nephrometry score in radiologist’s practice. Onkourologiya = Cancer Urology. 2020; 16 (4): 17–31. https://doi.org/10.17650/1726-9776-2020-16-4-17-31 (In Russian)

11. Crestani A., Rossanese M., Calandriello M. et al. Introduc tion to small renal tumours and prognostic indicators. Int. J. Surg. 2016; 36: 495–503. http://dx.doi.org/10.1016/j.ijsu.2016.03.038

12. Sebastià C., Corominas D., Musquera M. et al. Active surveillance of small renal masses. Insights into Imaging. 2020; 11 (1): 63. https://doi.org/10.1186/s13244-020-00853-y

13. Tordjman M., Mali R., Madelin G. et al. Diagnostic test accuracy of ADC values for identification of clear cell renal cell carcinoma: systematic review and meta-analysis Eur. Radiol. 2020; 30: 4023–4038. https://doi.org/10.1007/s00330-020-06740-w

14. Kay F.U., Canvasser N.E., Xi Y. et al. Diagnostic Performance and Interreader Agreement of a Standardized MR Imaging Approach in the Prediction of Small Renal Mass Histology. Radiology. 2018; 287 (2): 543–553. https://doi.org/10.1148/radiol.2018171557

15. Lopes Vendrami C., Parada Villavicencio C., DeJulio T.J. et al. Differentiation of solid renal tumors with multiparametric MR Imaging. RadioGraphics. 2017; 37: 2026–2042. https://doi.org/10.1148/rg.2017170039

16. Woo S., Cho J.Y. Imaging Findings of Common Benign Renal Tumors in the Era of Small Renal Masses: Differential Diagnosis from Small Renal Cell Carcinoma – Current Status and Future Perspectives. Korean J. Radiol. 2015; 16 (1): 99–113. http://dx.doi.org/10.3348/kjr.2015.16.1.99

17. Zhong Y., Wang H., Shen Y. et al. Diffusion-weighted imaging versus contrast-enhanced MR imaging for the differentiation of renal oncocytomas and chromophobe renal cell carcinomas. Eur. Radiol. 2017; 27: 4913–4922. https://doi.org/10.1007/s00330-017-4906-9

18. Sevcenco S., Heinz-Peer G., Ponhold L. et al. Utility and limitations of 3-tesla diffusion-weighted magnetic resonance imaging for differentiation of renal tumors. Eur. J. Radiol. 2014; 83: 909–913. https://doi.org/10.1016/j.ejrad.2014.02.026

19. Cornelis F., Tricaud E., Lasserre A.S. et al. Routinely performed multiparametric magnetic resonance imaging helps to differentiate common subtypes of renal tumours. Eur. Radiol. 2014; 24: 1068–1080. https://doi.org/10.1007/s00330-014-3107-z

20. Mytsik Yu.O. The role of diffuse-weighted imaging of magnetic resonance imaging in the differential diagnosis of malignant renal masses. Nauka molodih (ERUDITIO JUVENIUM) 2014; 4: 121–127 (In Russian)