PET Probe to Improve Skin Cancer Detection


The American Cancer Society estimates approximately 96,000 new cases of melanoma for 2019, and rates have been steadily climbing over the past three decades.  An early diagnosis often means a chance of recovery close to 95%, but this number plummets dramatically the later the disease is found.

Now, an international team of researchers from Stanford University and the Fourth Military Medical University, China, has developed and successfully tested a novel nuclear medicine method for detecting malignant melanoma, one of the most aggressive forms of skin cancer.


The positron emission tomography (PET) tracer N-(2-(diethylamino)-ethyl)-18F-5-fluoropicolinamide (18F-P3BZA) targets melanin pigment, which appears in most melanoma lesions.  It often affects melanoma behavior and as a result the outcome of radiotherapy.  Melanin production shortens overall survival and disease-free survival in patients with metastatic melanoma.

While melanin-targeted PET probes have been studied in small animal models for a long time, this is the first time such a probe has been successfully translated into clinical evaluation”, explained Zhen Cheng, Ph.D.  “Our research shows that 18F-P3BZA is safe and, moreover, it is highly promising for clinical diagnosis and staging of melanoma”.

Initial testing saw six patients receiving injections with 18F-P3BZA and then undergo whole-body PET/CT scans and blood tests to measure biodistribution, pharmacokinetic, and radiation dosimetry at 10 minutes, one hour, two hours, and four hours later.  They concluded that the compound was safe and managed to clearly delineate the melanoma tumors.

Dr.  Cheng also noted that “given its specific melanoma-imaging capability, 18F-P3BZA is expected to be a new probe which may overcome some of the limitations of 18F-FDG, such as the false positive of inflammation and a substantially lower tumor-to-muscle contrast compared with 18F-P3BZA.  Therefore, 18F-P3BZA may improve melanoma and metastasis detection and help guide therapeutic planning for melanoma patients”.

When it comes to any form of cancer, early detection plays an important role in how difficult it is to treat the disease and eventual prognosis.