From the Guidelines
Ultrasound is the most effective non-radiation, non-MRI diagnostic tool for detecting kidney cancer recurrence. This imaging technique uses sound waves to create pictures of the kidneys and surrounding tissues, making it particularly useful for identifying solid masses that could indicate recurrent renal cell carcinoma. According to the most recent study 1, ultrasound is considered an appropriate alternative for patients with contraindications to CT or MRI, although it may be less sensitive than CT or MRI for detecting small recurrences or distant visceral and nodal metastases in the abdomen.
Some key points to consider when using ultrasound for kidney cancer recurrence surveillance include:
- Ultrasound examinations are typically performed every 3-6 months during the first two years after initial treatment, then annually thereafter, though frequency may vary based on individual risk factors 1.
- The procedure is non-invasive, widely available, relatively inexpensive, and can be performed quickly without exposure to radiation or contrast agents.
- Ultrasound works by detecting differences in tissue density and can identify masses as small as 1-2 cm, though its effectiveness depends on the patient's body habitus and the skill of the technician.
- Blood tests measuring kidney function (creatinine, BUN) and urinalysis checking for blood in urine should complement ultrasound monitoring, as these can provide additional indicators of possible recurrence 1.
- While ultrasound may not detect all recurrences, particularly small lesions or those in certain locations, it remains the best radiation-free, non-MRI option for routine surveillance.
It's worth noting that individual follow-up plans should be developed taking into account the size of the primary tumor, extent of extrarenal spread, tumor histology, and relative risk of relapse 1. Additionally, alternate surveillance programs, such as the University of California Los Angeles (UCLA) Integrated Scoring System (UISS), can enable selective use of imaging and appropriate targeting of patients most in need of intensive surveillance 1.
From the Research
Diagnostic Tools for Kidney Cancer Recurrence
Excluding MRI and radiation diagnostics, the most effective diagnostic tools for detecting kidney cancer recurrence are:
- Ultrasound: a non-invasive and non-radiative method that can provide anatomic and functional information about the kidney 2
- Dynamic renal scintigraphy: can be used to assess the function of each kidney and detect any abnormalities 2
Limitations of Other Diagnostic Tools
- FDG PET/CT: although useful in some cases, its application is limited in renal cell carcinoma due to physiological excretion of FDG from the kidneys, which can decrease contrast between renal lesions and normal tissue 3, 4
- CT scan: can be used for renal imaging, but may not be suitable for patients with severe renal failure or those who require contrast agents 2, 5