Mandatory medical device diagnostics.
- Sonography (ultrasonography) of the abdomen or renal ultrasonography – as a basic diagnostic test.
- [Renal tumors can be detected from about 5 mm; T1a: tumor 4 cm or less in greatest extent;
- 5-7% of all renal cell carcinomas are completely cystic; 4-15% of all solid renal cell carcinomas have cystic portions]
- Differential diagnoses of cystic renal space involvement include: Abscesses (encapsulated collection of pus), aneurysm (circumscribed pathologic (abnormal) bulge in the arterial wall), arteriovenous malformations (congenital malformation of blood vessels in which arteries are directly connected to veins without intervening capillaries), or rare congenital malformations.
- Note: If the mass is <1 cm, sonomorphologic examination should be performed to determine whether an angiomyolipoma (AML) is present. Contrast sonography may be performed for this purpose. This procedure reliably depicts the vasculature of a tumor (better than CT).
- Sonography (ultrasound examination) of the pelvis – as a basic diagnostic.
- Computed tomography (CT) of the abdomen (abdominal CT); native from liver dome to symphysis as well as with early arterial (kidneys to pelvic inlet) and venous phase from liver dome to symphysis (sensitivity: approx. 90%) – for staging and resection planning.
- Magnetic resonance imaging of the abdomen (abdominal MRI); better contrast and soft tissue resolution than CT (probably becoming the gold standard) – patients with suspected renal cell carcinoma and venous or caval involvement.
Optional medical device diagnostics – depending on the results of the history, physical examination, laboratory diagnostics and obligatory medical device diagnostics – for differential diagnostic clarification.
- X-ray of the chest (X-ray thorax/chest), in two planes – if pulmonary metastases are suspected.
- Computed tomography of the thorax (thoracic CT).
- In suspected pulmonary metastases or asymptomatic patients with malignant tumors larger than 3 cm.
- For follow-up after local therapy of non-metastatic renal cell carcinoma (including the bone window).
- Magnetic resonance imaging of the skull (cranial MRI, cranial MRI or cMRI; contrast-enhanced) – if brain metastases are suspected.
- Whole-body CT (low-dose) or MRI (preference over skeletal scintigraphy) if bone metastases are suspected.
- Bone scintigraphy or positron emission tomography (PET; procedure of nuclear medicine, with which the creation of cross-sectional images of living organisms / organs by visualizing the distribution patterns of weak radioactive substances is made possible) or FDG-PET (FDG: 18F-fluorodeoxyglucose = correlate of glucose metabolism) – if bone metastases are suspected.
Further notes
- Actively monitor small localized space-occupying renal lesions (active surveillance, AS) ! This applies to patients with comorbidities (concomitant diseases) that make surgery risky or are associated with a low survival expectancy. In 1,245 patients (mean age 71 years) with 1,364 indeterminate renal tumors <4 cm, follow-up averaged 33 months:
- Increase in tumor diameter of a mean of 0.26 cm per year
- Biopsy in 22% of tumors
- Definitive surgery in 34% (between 4 and 70%).
- Disease progression to metastatic renal cell carcinoma in 1.1% of all patients
- In the first three years after renal (partial) resection (surgical removal) for low-risk renal cell carcinoma, an average of 1,000 imaging studies are performed to detect recurrence requiring treatment.Of 21 recurrences, 11 were detected only after three years.
- S3 guideline of 2015 gives the following recommendations for imaging in follow-up of renal cancer patients with low risk of recurrence: abdominal ultrasonography (ultrasound of abdominal organs) at 3, 6, 12, 18, 36, and 60 months; CT thorax (chest) at 12, 24, and 48 months; and CT abdomen at 24 and 48 months.
