Secondary ion mass spectrometry (SIMS) microscopy: A new tool for pharmacological studies in humans

The secondary ion mass spectrometry (SIMS) microscope has opened new fields in biological investigation because of its ability to map chemical elements that are either naturally present in tissue or introduced for diagnostic or therapeutic purposes. In this review, we will describe our attempts to localise and quantify antitumor drugs in histological sections to better evaluate successful early cancer treatment. Detection is dependent on the presence of chemical elements in the drug structure, for example halogens (F, Br, I, At) which are imaged and quantified within the nuclei. Our methodological approach combines the results obtained with ionic and photonic microscopes on serial sections. Thus, the different structures in tumor tissue (blood vessels and cells) can be identified and drug localisation visualized. Using embedded samples, we demonstrate that both fluorine (19F) in 5‐Fluorouracil and iodine (127I) in 4′‐iododeoxyrubicin can be mapped in human biopsy material obtained after in vivo chemotherapy. Microsc. Res. Tech. 36:296–300, 1997. © 1997 Wiley‐Liss, Inc.