The relationship between tumour oxygenation determined by oxygen electrode measurements and magnetic resonance spectroscopy of the fluorinated 2-nitroimidazole SR-4554

Abstract

Summary The relationship between two methods of assessing tumour oxygenation in vivo, namely oxygen electrode measurement and magnetic resonance spectroscopy (MRS) of the fluorinated 2-nitroimidazole SR-4554, was investigated. Using three tumour models (two sites), no linear correlation was observed between 19F retention index and P02 parameters (r < 0.3). Substantial retention of SR-4554 (19F retention index > 0.5) was, however, associated with low tumour P02 (% P02 < 5 mmHg = 60%). Depending on the P02 parameters used, SR-4554 administration was shown to produce either a significant or a non-significant increase in tumour oxygenation. We conclude that measurement of SR-4554-related compound(s) by 19F-MRS has the potential to detect clinically relevant levels of tumour hypoxia.

Molecular Imaging of Hypoxia

“…Introducing several equivalent atoms of 19 F can enhance the signal-to-noise ratio still further. This approach to investigate hypoxia has been reported by several groups as reviewed previously (168)(169)(170)(171)(172)(173). However, the achievable signal-to-noise ratio is typically disappointing, usually requiring long data acquisition times and generally precluding imaging.…”

VatuximabTM: Optimizing Therapeutic Strategies for Prostate Cancer Based on Dynamic MR Tumor Oximetry

“…Aboagye et al [358] found increased retention of SR4554 in hypoxic tumors, but no linear correlation with pO 2 . Lack of correlation with pO 2 measurements [355,358] and pimonidazole uptake [351] suggest that additional factors influence hypoxia marker retention and indeed blood flow/perfusion has been implicated [351].…”

“…Lack of correlation with pO 2 measurements [355,358] and pimonidazole uptake [351] suggest that additional factors influence hypoxia marker retention and indeed blood flow/perfusion has been implicated [351]. Robinson and Griffiths found differential uptake of SR4554 in diverse tumors known to exhibit different levels of hypoxia.…”

Advances in methods for assessing tumor hypoxia in vivo: Implications for treatment planning

“…Some of the markers gaining acceptance in this group are hexafluoromisonidazole (CCI-103F) [77], EF-5 [78], and SR-4554 [79,80]. SR-4554 has shown good results and is now under phase-I trial for in vivo detection of tumor hypoxia [81].…”