Program Information
PET Radiopharmaceuticals for Prostate Cancer Imaging: A Review
F Fernandes1;2*, D da Silva1 , L Rodrigues2 , (1) Delfin Farmacos e Derivados Ltda, Lauro De Freitas, Bahia, (2) Escola Bahiana de Medicina e Saude Publica, Salvador, Bahia
Presentations
SU-E-I-82 (Sunday, July 12, 2015) 3:00 PM - 6:00 PM Room: Exhibit Hall
Purpose: The aim of this work was to review new and clinical practice PET radiopharmaceuticals for prostate cancer imaging.
Methods: PET radiopharmaceuticals were reviewed on the main databases. Availability, dosimetry, accuracy and limitations were considered.
Results: The following radioisotopes with respective physical half-life and mean positron energy were found: ¹⁸F (109,7 min, 249,8 keV), ⁸⁹Zr (78,4 hs, 395,5 keV), ¹¹C (20,4 min, 385,7 keV) and ⁶⁸Ga (67,8 min, 836 keV). ⁶⁸Ga was the only one not produced by cyclotron. Radiopharmaceuticals uptake by glucose metabolism (¹⁸F-FDG), lipogenesis (¹¹C-Choline and ¹¹C-Acetate), amino acid transport (Anti-¹⁸F-FACBC), bone matrix (¹⁸F-NaF), prostate-specific membrane antigen (⁶⁸Ga-PSMA and ⁸⁹Zr-J591), CXCR receptors (⁶⁸Ga-Pentixafor), adrenal receptors (¹⁸F-FDHT) and gastrin release peptide receptor (bombesin analogue). Most of radiopharmaceuticals are urinary excretion, so bladder is the critical organ. ¹¹C-choline (pancreas), Anti-¹⁸F-FACBC (liver) and ¹⁸F-FBDC (stomach wall) are the exception. Higher effective dose was seen ¹⁸F-NaF (27 μSv/MBq) while the lowest was ¹¹C-Acetate (3,5 μSv/MBq).
Conclusion: Even though ¹⁸F-FDG has a large availability its high urinary excretion and poor uptake to slow growing disease offers weak results for prostate cancer. Better accuracy is obtained when ¹⁸F-NaF is used for bone metastatic investigation although physicians tend to choose bone scintigraphy probably due to its cost and practice. Many guidelines in oncology consider ¹¹C or ¹⁸F labeled with Choline the gold standard for biochemical relapse after radical treatment. Local, lymph node and distant metastatic relapse can be evaluated at same time with this radiopharmaceutical. There is no consensus over bigger urinary excretion for ¹⁸F labeling. Anti-¹⁸F-FACBC, ⁶⁸Ga-PSMA and ⁶⁸Ga-Pentixafor are demonstrating good results but more researches are needed. While PSMA imaging seems to be independent of PSA level, one choline limitation, anti-¹⁸F-FACBC adds value because imaging any disease stage. ⁶⁸Ga-Petixafor is being tested as theranostics marker integrating molecular image and therapy.
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