You need JavaScript to view this

Locoregional injection of F-18 radiopharmaceuticals suppresses tumor xenograft growth in rats

Conference:

Abstract

The energetic positrons (0.633 Mev) from F-18 dissipate kinetic energies before annihilation to produce two 0.511 Mev photons which also contribute to the radiation absorbed dose to the surroundings. In living organism, the contribution from the positron itself to the surrounding tissues (up to 2 mm) is larger than from the 2 photons. Apoptosis has been reported in rat tumors after systemic injection of F-18 FDG although no growth retardation was noted. This study is designed to exploit the pharmacokinetic advantages of locoregional injection of positron emitters in the suppression of tumor growth in rats. Methods: Groups of Fisher 344 adult female rats were inoculated with rat mammary tumors (100,000 cells) intramuscularly (IM) in the thigh. Locoregional injection with F-18 NaF or F-18 FDG was accomplished in days 3 or 7 with single doses of increasing strengths (0.2 to 3 mCi). Tumor growth rates were noted and compared to control (sham injection with saline). The locoregional distribution and clearance of F-18 were estimated from serial tomograms using a Concord MicroPET (R4) after intramuscular injection of 0.1-0.2 mCi of F-18 NaF or F-18 FDG in groups of triplicate rats. Results: A dose-related pattern of tumor suppression is noted with F-18 FDG,  More>>
Authors:
Wong, C -L [1] 
  1. The Univ. of Texas M.D. Anderson Cancer Center, Texas (United States)
Publication Date:
Jul 01, 2004
Product Type:
Conference
Resource Relation:
Conference: 8. Asia oceania congress of nuclear medicine and biology, Beijing (China), 9-13 Oct 2004; Related Information: In: 8th Asia oceania congress of nuclear medicine and biology final program abstracts| 246 p.
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; ANNIHILATION; APOPTOSIS; CLEARANCE; DISTRIBUTION; DOSES; DOSIMETRY; EMISSION; FLUORINE 18; FLUORODEOXYGLUCOSE; GROWTH; INHIBITION; INTRAMUSCULAR INJECTION; NEOPLASMS; PHOTONS; POSITRONS; RADIOPHARMACEUTICALS; RATS; SODIUM FLUORIDES; THERAPY
OSTI ID:
22083975
Research Organizations:
Asia and Oceania Federation of Nuclear Medicine and Biology, Beijing (China)
Country of Origin:
China
Language:
English
Other Identifying Numbers:
TRN: CN1300971042387
Availability:
Available from China Nuclear Information Centre (China Institute of Nuclear Information and Economics)
Submitting Site:
INIS
Size:
page(s) 99
Announcement Date:
Apr 18, 2013

Conference:

Citation Formats

Wong, C -L. Locoregional injection of F-18 radiopharmaceuticals suppresses tumor xenograft growth in rats. China: N. p., 2004. Web.
Wong, C -L. Locoregional injection of F-18 radiopharmaceuticals suppresses tumor xenograft growth in rats. China.
Wong, C -L. 2004. "Locoregional injection of F-18 radiopharmaceuticals suppresses tumor xenograft growth in rats." China.
@misc{etde_22083975,
title = {Locoregional injection of F-18 radiopharmaceuticals suppresses tumor xenograft growth in rats}
author = {Wong, C -L}
abstractNote = {The energetic positrons (0.633 Mev) from F-18 dissipate kinetic energies before annihilation to produce two 0.511 Mev photons which also contribute to the radiation absorbed dose to the surroundings. In living organism, the contribution from the positron itself to the surrounding tissues (up to 2 mm) is larger than from the 2 photons. Apoptosis has been reported in rat tumors after systemic injection of F-18 FDG although no growth retardation was noted. This study is designed to exploit the pharmacokinetic advantages of locoregional injection of positron emitters in the suppression of tumor growth in rats. Methods: Groups of Fisher 344 adult female rats were inoculated with rat mammary tumors (100,000 cells) intramuscularly (IM) in the thigh. Locoregional injection with F-18 NaF or F-18 FDG was accomplished in days 3 or 7 with single doses of increasing strengths (0.2 to 3 mCi). Tumor growth rates were noted and compared to control (sham injection with saline). The locoregional distribution and clearance of F-18 were estimated from serial tomograms using a Concord MicroPET (R4) after intramuscular injection of 0.1-0.2 mCi of F-18 NaF or F-18 FDG in groups of triplicate rats. Results: A dose-related pattern of tumor suppression is noted with F-18 FDG, whether treatment occurs in day 3 or 7 after inoculation. Additional experiment of injection of 5 mci of F-18 FDG at day 14 also suppressed the growth of a well-formed tumor. Tumor suppression by F-18 NaF is less obvious and only occurs with high dose (2 mCi). MicroPET images demonstrate that F-18 FDG is retained in the injection site while F-18 NaF dissipates rapidly. Conclusion: Locoregional injection of positron-emitters may be sufficient to suppress tumor growth. The mechanism is likely related to the pharmacokinetic profile of the compound within the tissue. Discussion: Locoregional application of radionuclides may provide feasible alternatives to slow tumor growth or prevent tumor recurrence. The use of clinically available positron-emiting radiopharmaceutical also confers the logistic advantages that there are established safety profiles from systemic dosages which may serve as guidelines for the locoregional dosages. More detailed radiation dosimetry, whether local or whole-body, will be needed to establish this scheme of locoregional positron emission therapy (LPET). This approach may also be extended to the use of beta emitters. (authors)}
place = {China}
year = {2004}
month = {Jul}
}