An overview of translational (radio)pharmaceutical research related to certain oncological and non-oncological applications

Figure 8 Difference in accumulation patterns of iodine-123/131 labeled hypericin/hypericin in tumor necrosis over time. Case 1: Ex-vivo analysis of necrotic tumors from rats with hepatic rhabdomyosarcoma (R1) in the first 24 h after the administration of iodine-123 labeled hypericin/hypericin (¹²³I-Hyp/Hyp) in DMSO/PEG 400/propylene glycol/water (25:25:25:25, v/v/v/v) followed by 1% Evans blue solution. At 24 h after ¹²³I-Hyp/Hyp injection, the tumor necrosis is perfectly outlined by the Evans blue as a blue rim, with viable tumor residues and normal liver with almost no staining (A₁). On the autoradiogram, a perfect match was seen between the high levels of ¹²³I-Hyp/Hyp accumulated in the ring (A₂) and the rim of Evans blue previously observed (A₁). Histology analysis confirms the regions of the liver, necrotic and viable tumors (A₃). Case 2: Single-photon emission computed tomography (SPECT), autoradiograms and histology in severe combined immunodeficiency mice bearing bilateral radiation-induced fibrosarcoma-1 subcutaneously having received combretastatin A-4 phosphate (CA4P) to induce tumor necrosis followed 24 h later by ¹³¹I-Hyp/Hyp in DMSO/PEG 400/water (25:60:15, v/v/v). Twelve days after ¹³¹I-Hyp/Hyp administration, SPECT detects a persistent intense high radioactivity mainly inside the tumor necrotic core (arrow). Autoradiography (B₂)¹ and histology (B₃) of the tumor after 30 d of tracer injection correspond well with the hotspot imaging on tumor (B₁). ¹The color code bar indicates the coding scheme for the radioactivity. DMSO: Dimethyl sulfoxide; PEG 400: Polyethylene glycol 400.