Given the more widespread use of conventional imaging techniques such as magnetic resonance imaging or computed tomography, recent years have witnessed an increased rate of incidental findings in the adrenal gland and those adrenal masses can be either of benign or malignant origin. In this regard, routinely conducted morphological imaging cannot always reliably distinguish between cancerous and noncancerous lesions. As such, those incidental adrenal masses trigger further diagnostic work-up, including molecular functional imaging providing a non-invasive read-out on a sub-cellular level. For instance, [¹⁸F]FDG positron emission tomography (PET) as a marker of glucose consumption has been widely utilized to distinguish between malignant vs benign adrenal lesions. In addition, more adrenal cortex-targeted radiotracers for PET or single photon emission computed tomography have entered the clinical arena, e.g., Iodometomidate or IMAZA, which are targeting CYP11B enzymes, or Pentixafor identifying CXCR4 in adrenal tissue. All these tracers are used for diagnosing tumors deriving from the adrenal cortex. Furthermore, radiolabeled MIBG, DOPA, and DOTATOC/-TATE are radiotracers that are quite helpful in detecting pheochromocytomas originating from the adrenal medulla. Of note, after having quantified the retention capacities of the target in-vivo, such radiotracers have the potential to be used as anti-cancer therapeutics by using their therapeutic equivalents in a theranostic setting. The present review will summarize the current advent of established and recently introduced molecular image biomarkers for investigating adrenal masses and highlight its transformation beyond providing functional status towards image-guided therapeutic approaches, in particular in patients afflicted with adrenocortical carcinoma.

2014-06-01·Molecular Imaging and Biology3区 · 医学

Radiosynthesis of [124I]Iodometomidate and Biological Evaluation Using Small-Animal PET

3区 · 医学

Article

作者: Claudia Kuntner ; Friedrich Hammerschmidt ; Ilse Zolle ; Reingard Aigner ; Thomas Wanek ; Herbert Kvaternik

PURPOSEThe application of radiolabelled inhibitors of cytochrome P450 enzymes is a novel approach for molecular imaging of adrenocortical masses to detect adrenal tumours. One potential tracer is radiolabelled iodometomidate (IMTO) with a common option for scintigraphic diagnosis and therapeutic applications. The aim of this study was to radiolabel iodometomidate with the positron-emitting radionuclide iodine-124 ((124)I) for the investigation of the biological behaviour and pharmacokinetics with positron emission tomography (PET).PROCEDURES[(124)I]IMTO has been synthesized by oxidative radioiodo-destannylation, purified via semi-preparative HPLC and formulated in acetate-buffered saline, which contained ascorbic acid and ethanol to avoid radiolytic decomposition. Biological evaluation was performed in rats which received 5.5 ± 0.7 MBq [(124)I]IMTO in vivo. The radioactivity distribution (n = 3) has been dynamically imaged from 0-120 min after intravenous (i.v.) injection by small-animal PET. Regions of interest have been defined manually in the reconstructed PET images, and the activity concentration was expressed as percent injected dose per gram tissue (%ID/g).RESULTS[(124)I]IMTO was prepared with a radiochemical yield of 83 ± 5 % (n = 3) and a radiochemical purity of >97 %. The final formulation of [(124)I]IMTO was stable for up to 48 h at room temperature. Two hours after i.v. administration in rats, radioactivity concentration in the adrenal glands were 2.1 ± 0.3 %ID/g, which was sufficient to achieve highest-contrast adrenal PET images.CONCLUSIONSIn the present study, the biological characteristics of radioiodinated metomidate were evaluated. [(124)I]IMTO appears as an attractive PET tracer for imaging of adrenals.

2012-03-01·The Journal of Clinical Endocrinology & Metabolism2区 · 医学

[131I]Iodometomidate for Targeted Radionuclide Therapy of Advanced Adrenocortical Carcinoma

2区 · 医学

Article

作者: Haenscheid, Heribert ; Reiners, Christoph ; Kreissl, Michael C. ; Lang, Katharina ; Allolio, Bruno ; Hahner, Stefanie ; Buck, Andreas K. ; Knoedler, Pascal ; Schirbel, Andreas ; Fassnacht, Martin

CONTEXTIn advanced adrenocortical carcinoma (ACC), many patients have progressive disease despite standard treatment, indicating a need for new treatment options. We have shown high and specific retention of [123I]metomidate ([123I]IMTO) in ACC lesions, suggesting that labeling of metomidate with 131I offers targeted radionuclide therapy for advanced ACC.OBJECTIVESafety and efficacy of radionuclide therapy with [131I]IMTO in advanced ACC.DESIGN/SETTINGThis monocentric case series comprised 19 treatments in 11 patients with nonresectable ACC.PATIENTS AND INTERVENTIONBetween 2007 and 2010, patients with advanced ACC not amenable to radical surgery and exhibiting high uptake of [123I]IMTO in their tumor lesions were offered treatment with [131I]IMTO (1.6-20 GBq in one to three cycles of [131I]IMTO).MAIN OUTCOME MEASURETumor response was assessed according to response evaluation criteria in solid tumors (RECIST version 1.1) criteria, and side effects were assessed by Common Toxicity Criteria (version 4.0).RESULTSBest response was classified as partial response in one case with a change in target lesions of -51% from baseline, as stable disease in five patients, and as progressive disease in four patients. One patient died 11 d after treatment with [131I]IMTO unrelated to radionuclide therapy. In patients responding to treatment, median progression-free survival was 14 months (range, 5-33) with ongoing disease stabilization in three patients at last follow-up. Treatment was well tolerated, but transient bone marrow depression was observed. Adrenal insufficiency developed in two patients.CONCLUSIONSRadionuclide therapy with [131I]IMTO is a promising treatment option for selected patients with ACC, deserving evaluation in prospective clinical trials.

100 项与 131I-iodometomidate 相关的药物交易

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