Clara Santos-Cuevas1, Jenny Davanzo2, Guillermina Ferro-Flores3, Francisco O García-Pérez2, Blanca Ocampo-García1, Eleazar Ignacio-Alvarez4, Edgar Gómez-Argumosa2, Martha Pedraza-López5. 1. Departamento de Materiales Radiactivos, Instituto Nacional de Investigaciones Nucleares (ININ), Ocoyoacac, 52750, Estado de México, Mexico. 2. Departamento de Medicina Nuclear, Instituto Nacional de Cancerología, Ciudad de México 14000, Mexico. 3. Departamento de Materiales Radiactivos, Instituto Nacional de Investigaciones Nucleares (ININ), Ocoyoacac, 52750, Estado de México, Mexico. Electronic address: ferro_flores@yahoo.com.mx. 4. Departamento de Medicina Nuclear, Instituto Nacional de Cancerología, Ciudad de México 14000, Mexico; Departamento de Medicina Nuclear, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Ciudad de México 14000, Mexico. 5. Departamento de Medicina Nuclear, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Ciudad de México 14000, Mexico.
Abstract
The prostate-specific membrane antigen (PSMA) is expressed in epithelial cells of the prostate and highly overexpressed in 95% of advanced prostate cancers. The aims of this study was to estimate the biokinetics and dosimetry of 99mTc-EDDA/HYNIC-iPSMA (99mTc-labeled PSMA inhibitor) in eight healthy subjects and evaluate its usefulness as a tumor-imaging agent in eight prostate cancer patients. METHODS: 99mTc-EDDA/HYNIC-iPSMA was obtained from a lyophilized formulation with radiochemical purities >98%, determined by reversed-phase HPLC and ITLC-SG analyses. Whole-body images from eight healthy subjects were acquired at 20min, and at 2, 6 and 24h after 99mTc-EDDA/HYNIC-iPSMA administration. Regions of interest (ROIs) were drawn around the source organs on each time frame. Each ROI was corrected by background, attenuation, scattered radiation and physical decay. The image sequence was used to extrapolate the 99mTc-EDDA/HYNIC-iPSMA time-activity curves of each organ to adjust the biokinetic model and calculate the total number of disintegrations (N) that occurred in the source regions. N data were the input for the OLINDA/EXM code to calculate internal radiation doses. In eight prostate cancer patients with histologically confirmed cancer, whole-body SPECT/CT images were obtained at 3h. RESULTS: The blood activity showed a half-life value of 4.98min for the fast component (T1/2α=ln2/8.34), 2.49h for the first slow component (T1/2β=ln2/0.278), and 9.24h for the second slow component (T1/2γ=ln2/0.076). Images from patients showed an average tumor/background ratio of 8.99±3.27 at 3h. The average equivalent doses calculated for a study using 740MBq were 3.80, 7.06, 9.69, 10.70, and 28.80mSv for the breast, spleen, salivary glands, liver, and kidneys respectively, with an effective dose of 3.42±0.78mSv. CONCLUSIONS: All the absorbed doses were comparable to those known for most of the 99mTc studies. 99mTc-EDDA/HYNIC-iPSMA obtained from kit formulations showed high tumor uptake in patients with malignant lesions, making it a promising imaging radiopharmaceutical to target site-specific prostate cancer.
The prostate-specific membrane antigen (PSMA) is expressed in epithelial cells of the prostate and highly overexpressed in 95% of advanced prostate cancers. The aims of this study was to estimate the biokinetics and dosimetry of 99mTc-EDDA/HYNIC-iPSMA (99mTc-labeled PSMA inhibitor) in eight healthy subjects and evaluate its usefulness as a tumor-imaging agent in eight prostate cancerpatients. METHODS:99mTc-EDDA/HYNIC-iPSMA was obtained from a lyophilized formulation with radiochemical purities >98%, determined by reversed-phase HPLC and ITLC-SG analyses. Whole-body images from eight healthy subjects were acquired at 20min, and at 2, 6 and 24h after 99mTc-EDDA/HYNIC-iPSMA administration. Regions of interest (ROIs) were drawn around the source organs on each time frame. Each ROI was corrected by background, attenuation, scattered radiation and physical decay. The image sequence was used to extrapolate the 99mTc-EDDA/HYNIC-iPSMA time-activity curves of each organ to adjust the biokinetic model and calculate the total number of disintegrations (N) that occurred in the source regions. N data were the input for the OLINDA/EXM code to calculate internal radiation doses. In eight prostate cancerpatients with histologically confirmed cancer, whole-body SPECT/CT images were obtained at 3h. RESULTS: The blood activity showed a half-life value of 4.98min for the fast component (T1/2α=ln2/8.34), 2.49h for the first slow component (T1/2β=ln2/0.278), and 9.24h for the second slow component (T1/2γ=ln2/0.076). Images from patients showed an average tumor/background ratio of 8.99±3.27 at 3h. The average equivalent doses calculated for a study using 740MBq were 3.80, 7.06, 9.69, 10.70, and 28.80mSv for the breast, spleen, salivary glands, liver, and kidneys respectively, with an effective dose of 3.42±0.78mSv. CONCLUSIONS: All the absorbed doses were comparable to those known for most of the 99mTc studies. 99mTc-EDDA/HYNIC-iPSMA obtained from kit formulations showed high tumor uptake in patients with malignant lesions, making it a promising imaging radiopharmaceutical to target site-specific prostate cancer.
Authors: George Crișan; Nastasia Sanda Moldovean-Cioroianu; Diana-Gabriela Timaru; Gabriel Andrieș; Călin Căinap; Vasile Chiș Journal: Int J Mol Sci Date: 2022-04-30 Impact factor: 6.208
Authors: Ora Israel; O Pellet; L Biassoni; D De Palma; E Estrada-Lobato; G Gnanasegaran; T Kuwert; C la Fougère; G Mariani; S Massalha; D Paez; F Giammarile Journal: Eur J Nucl Med Mol Imaging Date: 2019-07-04 Impact factor: 9.236
Authors: Paola Vallejo-Armenta; Clara Santos-Cuevas; Juan Soto-Andonaegui; Rosa M Villanueva-Pérez; Jorge I González-Díaz; Francisco O García-Pérez; Angélica Arrellano-Zarate; Myrna Luna-Gutiérrez; Erika Azorín-Vega; Blanca Ocampo-García; Guillermina Ferro-Flores Journal: Contrast Media Mol Imaging Date: 2020-04-27 Impact factor: 3.161