Breakthrough in diagnosis using PET could affect future standard of care for deadliest skin cancer

A new study using positron emission tomography (PET) determined PET is a more accurate way to diagnose recurrent melanoma than the present, standard procedures.

Published in the August issue of The Journal of Nuclear Medicine, the research conducted by David Fuster, MD, and his team at the University of Pennsylvania (PENN), Division of Nuclear Medicine, found that, by using PET as a routine clinical tool in diagnosing recurrent melanoma, significant changes in patient care can, and will, occur. In fact, in this study alone, results from PET scans led to changes in clinical management in 36% of patients studied.

Although melanoma accounts for only 4% of skin cancers, it is, by far, the most lethal of the three forms of skin cancer. But despite its deadliness, melanoma is also highly curable if it is detected and treated before the cancer has a chance to metastasize. PET results from this study show an improvement in detecting distant metastases over standard procedures, with an accuracy of 85% for PET compared to only 55% for current standard diagnostics.

Dr. Fuster and his team also determined the accuracy for PET in diagnosing locoregional (i.e., restricted to a localized region of the body) disease was 91%, far superior to current practice, which is about 67% accurate. Dr. Abass Alavi, one of the study’s coauthors and chief of the Nuclear Medicine Division at PENN stated, “Our study is successful because of the large number of patients we used. We felt that the more data we could produce—184 PET scans were taken for 156 patients with confirmed melanoma and suspected recurrence—then the more accurate our findings would be. Thus, we feel the results are irrefutable, and PET will soon change the standard of patient care.”

The current method of diagnosing primary melanoma is clinical; a biopsy of the region is taken and determined to be either benign or malignant. This will remain the standard, as biopsy is more accurate than PET in diagnosing primary melanoma. However, it is in the follow-up—after successful treatment of melanoma—that PET will play a significant role.

The recurrence of melanoma after successful treatment is high, and it is difficult to detect using standard procedures. In this study, PET proved to be more accurate in detecting both local recurrence and the spread of the cancer to lymph nodes, bone, liver and abdomen.

According to Dr. Alavi, “PET is the future of diagnosis for recurrent melanoma simply because it will lead to earlier detection of recurrence of disease and, therefore, better and less invasive treatment options.”