Germany: Amino Acid PET Study

Amino acid PET has good accuracy in the differential diagnosis of recurrent brain metastases, a recently published meta-analysis in The Journal of Nuclear Medicine has shown.

A specificity of 84% indicates that amino acid PET may reduce the number of invasive procedures and overtreatment in patients with treatment-related changes. This study provides class IIa evidence on using amino acid PET in the differential diagnosis of recurrent brain metastases.

Brain metastases occur in 20 to 40 percent of all cancer patients. They are most likely to occur in those with lung, breast and renal cancer, melanoma, and gastrointestinal tract cancers. Management of patients with brain metastases usually includes:

• Surgery
• Radiation
• Chemotherapy

Some patients develop treatment-related changes such as radiation necrosis or pseudoprogression.

“A differentiation between recurrent or progressive brain metastases and treatment-related changes is challenging,” said Igor Yakushev, senior physician in the nuclear medicine department at the Technical University of Munich in Germany. “As the management of patients with recurrent or progressive brain metastases and treatment-related changes is fairly different, accurate and early differential diagnosis is essential.”

The meta-analysis included 12 studies with amino acid PET radiotracers. The studies included a total of 397 patients with 547 lesions. 269 lesions (49 percent) were recurrent or progressive brain metastases. Using a histologic examination and radiological and clinical follow-up as reference, the pooled sensitivity and specificity of amino acid PET were 82 and 84 percent, respectively.

“This study provides IIa class evidence on the diagnostic utility of amino acid PET in the differential diagnosis of recurrent or progressive brain metastases,” stated Yakushev. “These findings align with an increasing role of molecular imaging in the management of patients with brain tumors, yet the results also point to the potential for further improvement of diagnostic accuracy.”

Reference:

Timo Schlürmann, Birgit Waschulzik, Stephanie Combs, Jens Gempt, Benedikt Wiestler, Wolfgang Weber and Igor Yakushev, Journal of Nuclear Medicine May 2023, 64 (5) 816-821; DOI: https://doi.org/10.2967/jnumed.122.264803.