Phase I study of 131I-chimeric(ch) TNT-1/B monoclonal antibody for the treatment of advanced colon cancer.

PURPOSE: The primary aim of this study was to evaluate the biodistribution and toxicity of 131I-chimeric(ch) TNT-1/B monoclonal antibody (MAB), which binds to intracellular antigens of necrotic regions within tumors, in patients with advanced colon or colorectal cancer. The rationale for targeting areas of tumor necrosis is the observation that necrotic lesions are more abundant in cancer lesions than in surrounding tissues. PATIENTS AND METHODS: Cohorts of patients with advanced colon or colorectal cancer were administered a one-time 30-60-minute intravenous (i.v.) infusion of 131I-chTNT-1/B at doses ranging from 12.95 to 66.23 MBq/kg (0.35-1.79 mCi/kg). RESULTS: The dose-limiting toxicity, experienced at 66.23 MBq/kg (1.79 mCi/kg) 131I-chTNT-1/B MAB, was myelosuppression. Two (2) patients at the 66.23-MBq/kg (1.79 mCi/kg) dose level had both grade 3 thrombocytopenia and grade 3 neutropenia that persisted for at least 2 weeks but were reversible. The maximum tolerated dose was 58.09 MBq/kg (1.57 mCi/kg) 131I-chTNT-1/B MAB. Of the 21 patients, one developed a moderate human antichimeric antibody (HACA) response and 6 developed low HACA responses. CONCLUSIONS: The infusion of 131I-chTNT-1/B MAB was well tolerated, without significant nonhematological toxicity. No patient obtained a complete or partial response, based on tumor cross-product response criteria. Tumor localization was seen in patients with dose levels at, and exceeding, 50.23 MBq/kg (1.36 mCi/kg) 131I-chTNT-1/B MAB.

The strong but nonspecific relationship between 18F-FDG uptake in the lower-extremity veins and venous thromboembolism.

Venous thromboembolism (VTE) can present as deep vein thrombosis (DVT) and/or acute pulmonary embolism (PE). In fluorine-18 fluorodeoxyglucose (18F-FDG) PET/CT, 18F-FDG activity along the deep veins of the lower extremities (LE) is often observed and, unless it is associated with focal intense activity, is not considered abnormal. However, anecdotally it has been associated with the placement of an inferior vena cava filter. In this short paper we intend to investigate this association. We found 10 patients who were investigated in the vascular laboratory by means of either LE or upper-extremity duplex or a chest computed tomography with PE protocol, or who had undergone the placement of an inferior vena cava filter between 27 April 2010 and 7 January 2013 and who had also undergone one or more 18F-FDG-PET scan(s) that included the LE. Seventeen patients without venous 18F-FDG uptake were added as controls. 18F-FDG uptake visualized in the LE was scored as the number of positive LE veins and the extent of the radiotracer uptake. The time intervals between the VTE event and the 18F-FDG-PET scan(s) were recorded. The time intervals between the most remote and the closest 18F-FDG-PET before a VTE event averaged 79 ± 101 and 49 ± 82 days, respectively, and the closest and the most remote 18F-FDG-PET after the VTE event averaged 58 ± 50 and 122 ± 124 days. The extent of uptake in the LE veins averaged 7 ± 2 for the patients with an acute DVT on LE duplex and 5 ± 3 for those with negative or chronic DVT on LE duplex (P=nonsignificant). Two patients (n=3 and 10) were negative for VTE events and had an extent of 0. The number of positive events correlated slightly with the extent of venous uptake (r=0.69). The 17 control patients without venous uptake on 18F-FDG-PET had no history of VTE. There was an association between LE venous uptake of 18F-FDG and risk for VTE. The association was not related to the location of the VTE, nor to the timing of the VTE.

Grover disease (transient acantholytic dermatosis) in acute myeloid leukemia on FDG PET/CT.

A 48-year-old man with a newly diagnosed acute myeloid leukemia developed purpuric rash on day 6 after chemotherapy. Skin biopsy on day 8 demonstrated Grover disease. Triamcinolone treatment started on day 10 with subjective improvement on day 15. Initial FDG PET/CT on day 12 demonstrated rarely seen diffuse skin uptake that was interpreted as technical artifact and repeated on day 16. Accurately reviewing both PET and CT imaging would prevent confusion between diffuse cutaneous hypermetabolic activity and a technical artifact. Grover disease usually affects the trunk and may be related to the elimination of chemotherapy agents by sweating.

The pivotal role of FDG-PET/CT in modern medicine.

The technology behind positron emission tomography (PET) and the most widely used tracer, 2-deoxy-2-[18F]fluoro-D-glucose (FDG), were both conceived in the 1970s, but the latest decade has witnessed a rapid emergence of FDG-PET as an effective imaging technique. This is not least due to the emergence of hybrid scanners combining PET with computed tomography (PET/CT). Molecular imaging has enormous potential for advancing biological research and patient care, and FDG-PET/CT is currently the most widely used technology in this domain. In this review, we discuss contemporary applications of FDG-PET and FDG-PET/CT as well as novel developments in quantification and potential future indications including the emerging new modality PET/magnetic resonance imaging.