Novel Imaging Techniques May Eliminate Need for Renal Mass Biopsy for Locally-advanced RCC

MIAMI—Nuclear or molecular imaging offers a promising non-invasive means of determining renal tumor histology for the purpose pretreatment risk stratification, according to a presentation at the 14^th International Kidney Cancer Symposium (IKCS).¹

Because the cT1 renal mass is a diverse clinical entity that includes a variety of benign and malignant tumor histologies, patients presenting with cT1 renal mass should ideally be managed with a risk-stratified approach.

However, current available anatomical imaging techniques are unable to reliably differentiate between the various tumor types or kidney tumors and renal mass biopsy has numerous significant shortcomings.

“There are a number of limitations of renal mass biopsy,” said Michael Gorin, MD, of the Johns Hopkins University James Buchanan Brady Urological Institute in Baltimore, MD.

Renal mass biopsy requires sedation or anesthesia, is associated with pain and discomfort, has a non-diagnostic rate of 10% to 20%, results in major complications in 1% of patients, and cannot accurately determine tumor grade.

Fortunately, novel imaging techniques are being researched to help differentiate renal tumor histologies. One example is ¹²⁴I-girentuximab, which was studied in the REDECT trial.² Results showed that ¹²⁴I-girentuximab PET/CT imaging has a sensitivity of 86.2% and a specificity of 85.9%; however, the U.S. Food and Drug Administration required more data on the imaging technique. The REDECT 2 trial is in the early stages of development.³

Another novel imaging technique is ^99mTc-sestamibi SPECT/CT for the diagnosis of renal oncocytoma or hybrid oncocytic tumors, which correctly identified 5 of 6 oncocytomas and 2 of 2 hybrid oncocytic tumors, resulting in overall sensitivity of 87.5% and a specificity of 95.2%.⁴

Dr. Gorin envisions a future approach where cross-sectional imaging and nuclear imaging are used when a patient present with indeterminate cT1 renal mass, followed by risk stratification.

“We feel we could eliminate the need for renal mass biopsy,” Dr. Gorin concluded.

References

1. Gorin M. Novel imaging techniques in RCC [Oral presentation at 14th International Kidney Cancer Symposium].
2. Divgi CR1, Uzzo RG, Gatsonis C, et al. Positron emission tomography/computed tomography identification of clear cell renal cell carcinoma: results from the REDECT trial. J Clin Oncol. 2013;31(2):187-194.
3. REDECT 2: REnal Masses: Pivotal Trial to DEteCT Clear Cell Renal Cell Carcinoma With PET/CT. U.S. National Institutes of Health Clinical Trials website. https://clinicaltrials.gov/ct2/show/NCT01762592. Accessed November 6, 2015.
4. Gorin MA, Rowe SP, Baras AS, et al. Prospective Evaluation of 99mTc-sestamibi SPECT/CT for the Diagnosis of Renal Oncocytomas and Hybrid Oncocytic/Chromophobe Tumors [published online ahead of print September 16, 2015]. Eur Urol. doi: 10.1016/j.eururo.2015.08.056.