24 A new study has found that a specialised imaging technique using the radiotracer 18F-FDG shows strong uptake in renal medullary carcinoma, a rare and highly aggressive form of kidney cancer. This distinguishes it from other types of kidney cancer, which often display more variable uptake of the tracer. The research, published in the September issue of The Journal of Nuclear Medicine, showed that 18F-FDG PET/CT imaging remained highly effective even after patients had received systemic treatment, and it detected additional metastases that conventional anatomic imaging had missed. Renal medullary carcinoma, or RMC, is a rare subtype of non-clear cell renal cell carcinoma. It predominantly affects adolescents and young adults and occurs more often in males. At the time of diagnosis, patients frequently already have metastatic disease. Median overall survival stands at approximately 14.5 months. Accurate staging is especially critical in this cancer. Simone Krebs, MD, nuclear medicine physician and scientist at the University of Texas MD Anderson Cancer Center in Houston, explained the importance. “In RMC, the value of accurate staging cannot be overstated,” she said. “Upstaging a patient from localised to metastatic disease spares them from non-curative, high-morbidity surgeries that delay the initiation of essential systemic therapy. Identifying metastatic disease may also provide opportunities for more effective therapies.” The utility of 18F-FDG PET/CT for detecting kidney cancer lesions varies by tumour subtype. Researchers therefore set out to evaluate how well the technique assesses disease burden and informs treatment planning specifically in patients with RMC. The single-centre retrospective review examined 49 patients with RMC who underwent 18F-FDG PET/CT between 2016 and 2025. The team assessed 18F-FDG uptake levels and quantitative PET/CT metrics. They also recorded every case in which the imaging findings led to a change in treatment. 18F-FDG uptake was present in 98% of patients, or 48 out of 49. The single patient who showed no uptake had no other evidence of active disease on anatomic imaging either. Additional cancer lesions were identified in 65% of patients, and these new findings prompted a change in the treatment plan for 21% of patients who had active disease. Krebs highlighted the clinical implications. “Our work demonstrates that PET/CT can provide clinically meaningful information beyond conventional imaging, helping doctors to better assess the extent of disease and choose the most appropriate treatment strategy,” she said. “On a larger scale, this research supports including 18F-FDG PET/CT in future clinical guidelines for RMC so that it can be more widely used in patient care.” The study was conducted entirely at the University of Texas MD Anderson. While the findings come from a single centre and a relatively small cohort, reflecting the rarity of the disease, they provide the strongest evidence to date that 18F-FDG PET/CT should be considered earlier and more routinely in the management of RMC. Clinicians treating young patients with this uncommon cancer may now have clearer grounds to request PET/CT scans both at diagnosis and during follow-up after systemic therapy.