Presented at the Southern Section Meeting of the Triological Society, January 10, 2008, Naples, Florida, U.S.A. Editor's Note: This Manuscript was accepted for publication January 3, 2008. This work was supported by a grant from the American Cancer Society (RSG-06-1006-01-CCE).
Fluorescent Detection of Rat Parathyroid Glands via 5-Aminolevulinic Acid†
Article first published online: 2 JAN 2009
Copyright © 2008 The Triological Society
Volume 118, Issue 6, pages 1014–1018, June 2008
How to Cite
Asher, S. A., Peters, G. E., Pehler, S. F., Zinn, K., Newman, J. R. and Rosenthal, E. L. (2008), Fluorescent Detection of Rat Parathyroid Glands via 5-Aminolevulinic Acid. The Laryngoscope, 118: 1014–1018. doi: 10.1097/MLG.0b013e3181671b61
- Issue published online: 2 JAN 2009
- Article first published online: 2 JAN 2009
- 5-aminolevulinic acid;
- protoporphyrin IX;
- fluorescent detection;
- parathyroid glands
Objective: Anatomic identification of parathyroid glands during surgery is challenging and time consuming. We sought to determine whether 5-aminolevulinic acid (5-ALA) could produce parathyroid gland fluorescence to improve their detection in a preclinical model.
Methods: Thirty-two rats were administered 0 to 700 mg/kg of 5-ALA by intraperitoneal injection prior to neck exploration under the illumination of a blue light (380–440 nm). Tissue fluorescence was assessed at 1, 2, or 4 hours postinjection and then removed for histologic confirmation of parathyroid tissue.
Results: Rat parathyroid glands could not be visualized under ambient light. At dosages of 300 mg/kg or greater, bilateral parathyroid glands were visualized in 18 of 19 rats using blue light illumination. At dosages less than 300 mg/kg, parathyroid gland fluorescence was detected in only 1 of 13 rats. At 2 hours after 5-ALA administration, the net mean intensity of parathyroid gland fluorescence was optimal with a dose of 500 mg/kg. At both 1 and 4 hours after 5-ALA injection, the net mean intensity of parathyroid gland fluorescence was optimal at the highest dose (700 mg/kg) and positively correlated with dosage increases.
Conclusion: 5-ALA can be used to selectively detect parathyroid tissue from surrounding tissue in a preclinical model. Our data support the use of this technique in the clinical setting.