Objectives:
To give the precise dosage of radiation, molecule targeting keloid techniques are necessary. Due to higher uptake of F-18-FDG in keloids, PET scans provide insights into the activity of keloids. TSPO (Translocator protein,18 kDa) increased during the inflammation process. F-18-FEPPA, a ligand of TSPO, may be a more sensitive agent than FDG to detect keloid. We aimed to study if F-18- FEPPA could be a more sensitivity agent and find out its correlation with clinical performance.
Materials and Method: We retrospectively reviewed 51 patients with keloids for more than 1 year in Cathay General Hospital. Their follow-up information was collected and we compared the patients with recurrent keloids to those without recurrence.
Result: Among the participants, 4 patients had recurrence of keloid. The recurrence rate was around 7.8 %. Two of them are at the ear lobe, while one of them is at the helix and the other is at the chest. Under the IHC and HE stains, the recurrent keloids of patients had higher expression of the TSPO stain in comparison to the normal cell. In comparison to normal cell, both FDG and F-18-FEPPA had significantly higher ratio of cell bound in keloid cell. Under PET scan, keloid cells with F-18-FEPPA showed higher expression than those with FDG.
Conclusion: In our cases, ear lobe had a high recurrence rate of keloid in comparison to other sites. As TSPO expression increased in keloid tissue, FEPPA PET scan is a useful tool in diagnosing and monitoring keloids activity.