technetium-tc-99m-exametazime and Abdominal-Neoplasms

A technique is described for manually outlining a volume of interest (VOI) in a three-dimensional SPECT dataset. Regions of interest (ROIs) are drawn on three orthogonal maximum intensity projections. Image masks based on these ROIs are backprojected through the image volume and the resultant 3D dataset is segmented to produce the VOI. The technique has been successfully applied in the exclusion of unwanted areas of activity adjacent to the brain when segmenting the organ in SPECT imaging using 99mTc HMPAO. An example of its use for segmentation in tumour imaging is also presented. The technique is of value for applications involving semi-automatic VOI definition in SPECT.

Topics: 3-Iodobenzylguanidine; Abdominal Neoplasms; Brain; Humans; Image Processing, Computer-Assisted; Iodine Radioisotopes; Radiopharmaceuticals; Radiotherapy, Computer-Assisted; Technetium Tc 99m Exametazime; Tissue Distribution; Tomography, Emission-Computed, Single-Photon

A total of 343 leucocyte scans labelled with technetium-99m hexamethylpropylene amine oxime were reviewed that had been performed in 338 patients suspected of having abdominal infection or inflammation. There was uptake by malignant abdominal tumours in 10 cases (2.9%), which represents 62.5% of known malignancies at the time of the scintigram. Accumulation was seen in 8 patients with adenocarcinoma of the colon associated with a secondary infection in the tumour or pericolic inflammation. A large tumour that had spread beyond the bowel wall was related to a positive scintigram. Accumulation was also found twice in a malignant fibrous histiocytoma in which bleeding and an inflammatory reaction to necrosis were probably responsible for the uptake. The relevant treatment was delayed for 2 weeks-2 months in 4 patients with adenocarcinoma of the colon in whom the positive uptake was regarded as confirmation of the clinically suspected acute diverticulitis.

Topics: Abdominal Neoplasms; Adenocarcinoma; Adult; Aged; Aged, 80 and over; Apudoma; Female; Histiocytoma, Benign Fibrous; Humans; Leukocytes; Lymphoma, Non-Hodgkin; Male; Middle Aged; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Retrospective Studies; Technetium Tc 99m Exametazime