Radiation Dosimetry of 99mTc-Labeled C225 in Patients with Squamous Cell Carcinoma of the Head and Neck

• Published in: The Journal of nuclear medicine (1978) Vol. 45; no. 10; p. 1683
• Main Authors: Schechter, Naomi R, Wendt, Richard E., III, Yang, David J, Azhdarinia, Ali, Erwin, William D, Stachowiak, Anne M, Broemeling, Lyle D, Kim, E. Edmund, Cox, James D, Podoloff, Donald A, Ang, K. Kian
• Format: Journal Article
• Language: English
• Published: United States Soc Nuclear Med 01-10-2004
• Subjects: Antibodies, Monoclonal - pharmacokinetics; Antibodies, Monoclonal - therapeutic use; Antibodies, Monoclonal, Humanized; Body Burden; Carcinoma, Squamous Cell - diagnostic imaging; Carcinoma, Squamous Cell - metabolism; Carcinoma, Squamous Cell - radiotherapy; Cetuximab; Head and Neck Neoplasms - diagnostic imaging; Head and Neck Neoplasms - metabolism; Head and Neck Neoplasms - radiotherapy; Humans; Organ Specificity; Positron-Emission Tomography - methods; Radiation Dosage; Radiometry - methods; Radiopharmaceuticals - pharmacokinetics; Sensitivity and Specificity; Technetium - pharmacokinetics; Technetium - therapeutic use; Tissue Distribution
• ISSN: 0161-5505; 1535-5667

This study assessed the radiation dosimetry of 99mTc-labeled ethylene dicysteine (EC) C225 (EC-C225), a promising radioligand for functional tumor imaging.
Whole-body scanning was performed on 6 patients with head and neck squamous cell carcinoma up to 24 h after administration of 99mTc-EC-C225. Alternate patients who had been randomized to receive C225 in a phase III trial received 99mTc-EC-C225 before their 20-mg test dose or after their 400 mg/m2 loading dose of unlabeled C225 (patients 1/3/5 and 2/4/6, respectively). Radiation dosimetry was assessed using the MIRD method.
The critical organ was the kidney, with an average radiation-absorbed dose for all 6 patients of 0.0274 mGy/MBq. The average total-body absorbed dose was 0.0022 mGy/MBq (0.243 cGy/1,110 MBq).
The new radiopharmaceutical 99mTc-EC-C225 appears to have reasonable dosimetric properties for a diagnostic nuclear medicine agent. Correlation of the imaging results with clinical findings is the next step.