Lifetime Radiation Exposure in Patients with Recurrent Nephrolithiasis

Patients presenting with nephrolithiasis often undergo repeated imaging studies before, during, and after management. Considering the significant risk of stone recurrence in primary stone-formers, repeated imaging studies are not uncommon. Cumulative effects of ionizing radiation exposure from various imaging studies could potentially increase the risk for developing cataracts and solid malignancies in urolithiasis patients. Therefore, practitioners planning or performing imaging studies with ionizing radiation are compelled to keep radiation exposure to humans and the environment as low as possible, thus strictly adhering to the ALARA (As Low as Reasonably Achievable) principles. This chapter will review the latest literature on lifetime radiation exposure of nephrolithiasis patients and present the latest recommendations in minimizing radiation exposure to them pre-, intra-, and postoperatively. For patients presenting with acute renal colic, especially those with body mass index of < 30, low-dose noncontrast computed tomography is the current gold standard of imaging. Patients with opaque stones are followed with ultrasonography (US) and plain radiography (kidney, ureter, and bladder or KUB). Intraoperatively, pulsed fluoroscopy could be used to significantly reduce radiation during ureteroscopy and percutaneous nephrolithotomy. Immediately postoperatively and in the long term, US and KUB could be used to follow up patients with nephrolithiasis. Only symptomatic patients suspected of ureteral stricture should obtain tri-phasic CT urography. Following these latest imaging guidelines from the American Urological Association will dramatically reduce lifetime radiation exposure to patients with nephrolithiasis.