Validation of an alternative radiochemical purity method for [99mTc]pentetate ([99mTc]DTPA).

[(99m)Tc]pentetate ([(99m)Tc]DTPA) is the most commonly used radiopharmaceutical renography agent. The aim of this work was to validate an alternative method for assessing [(99m)Tc]DTPA radiochemical purity (RCP), according to the ICH Q2(R1) guidance: "Validation of Analytical Procedures". The proposed method is composed of two chromatographic systems. System A is a miniaturized system of thin layer chromatography (TLC) silica gel impregnated aluminum strips as stationary phase (SP) and distilled water as mobile phase (MP). System B consists of Whatman 1 paper strips as SP and methyl ethyl ketone as MP. Results indicate that the proposed RCP method has been validated, as it is specific, precise, accurate, linear and robust. Therefore, it can be used as an alternative method for RCP quality control purposes and as stability indicator as well.

Special safety considerations in preparation of technetium Tc-99m DTPA for cerebrospinal fluid-related imaging procedures.

OBJECTIVE: To review special safety considerations in the preparation of technetium 99m (Tc-99m) diethylenetriaminepentaacetic acid (DTPA; generic name, pentetate) for cerebrospinal fluid (CSF)-related imaging procedures. DATA SOURCES: Review of practices and results at one institution supplemented with findings and recommendations from the literature. Literature searches were conducted via Medline/PubMed using the following terms: Tc-99m DTPA/pentetate, CSF, cisternography, intrathecal, and adverse reactions. The author's own files were also searched for articles (e.g., in newsletters) not indexed by Medline/PubMed. STUDY SELECTION: Articles considered appropriate for review included all human research studies, reviews, case reports, abstracts, and letters published in English on Tc-99m DTPA use in CSF-related imaging procedures, especially with regard to safety or adverse reactions. DATA EXTRACTION: All information related to safety precautions and adverse reactions associated with Tc-99m DTPA injected intrathecally or otherwise used for CSF-related imaging procedures were considered. DATA SYNTHESIS: 18 years' experience in one institution was reviewed with the added perspective of literature findings and recommendations. CONCLUSION: With proper attention to safety considerations, Tc-99m DTPA can be safely used in CSF-related imaging procedures.

[Usefulness of 99mTc-DTPA-HSA scintigraphy in the diagnosis of protein losing enteropathy--comparison with 99mTc-HSA].

We evaluated the usefulness of 99mTc-diethylene-triamine-pentaacetic acid human serum albumin scintigraphy (FTPA-HSA) in the diagnosis of protein losing enteropathy in 3 cases of inflammatory bowel diseases in comparison with 99mTc-human serum albumin scintigraphy (HSA). The results were as follows: 1. DTPA-HSA demonstrated the colonic accumulation earlier than that of HSA. 2. Hepatic flexure and splenic flexure are not observed clearly, because of marked renal uptake in HSA. On the other hand, they are observed in DTPA-HSA. Hepatic uptake is rather stronger in DTPA-HSA. In conclusion, DTPA-HSA is one of the easiest and most useful methods in the diagnosis of protein losing enteropathy.

[Evaluation of clinical usefulness of 99mTc-GSA, a functional hepatic imaging agent--correlation with per-rectal portal scintigraphy].

Liver scintigraphy using 99mTc-GSA, which binds specifically to the asialoglycoprotein receptors on the surface of the hepatocytes, was performed in 41 patients with chronic liver disease (11 chronic hepatitis cases and 30 liver cirrhosis) to investigate the correlations between the images and the various liver function tests. Two liver functional indexes, HH15 for plasma clearance of 99mTc-GSA and LHL15 for liver accumulation of 99mTc-GSA, showed significant differences between the chronic hepatitis group and the decompensated liver cirrhosis group. These indexes also showed significant correlations with the liver function tests such as serum albumin level and prothrombin time. HH15 and LHL15 correlated with the per-rectal portal shunt index obtained in 10 patients by 99mTcO4- per-rectal portal scintigraphy. These results suggest that HH15 and LHL15 have value as new liver functional indexes.