Methods of nuclear medicine in oncology
- 'Positive scintigraphy' - deposit accumulates radiopharmaceutical (hot deposit);
- 'negative scintigraphy' - deposit accumulates less (cold deposit);
- uses nuclides with a short half-life ( 99m Tc - 6h, 111 In - 67h, 67 Ga - 3.3 days).
Skeletal scintigraphy[edit | edit source]
- Technetium-labeled diphosphonate complexes;
- the amount of accumulation depends on blood flow and osteoblast activity;
- display much earlier than X-ray;
- good for kidneys - lung cancer, breast cancer, prostate cancer, kidney cancer and bladder cancer;
- it is worse for osteolytic processes (myeloma), where there is only a reactive margin.
Liver and spleen scintigraphy[edit | edit source]
- Colloids trapped by RES, pathological deposits in liver appear as "cold";
- however, the defects were not less than 2 cm.
Thyroid scintigraphy[edit | edit source]
- Sodium pertechnetate.
Octreotide scintigraphy[edit | edit source]
- India-labeled octreotide (somatostatin analogue);
- detection of tumors with somatostatin receptors (gastrinoma, carcinoid, VIPom, small cell lung cancer, pheochromocytoma).
Immunoscintigraphy[edit | edit source]
- Radiolabelled Ig (against CEA, etc.).
Single photon emission tomography (SPECT)[edit | edit source]
- Spatial distribution of radiopharmaceuticals in tissue, more accurate assessment of shape and size;
- resolution less than CT;
- PET is considered more preferable.
Positron emission tomography (PET)[edit | edit source]
- Assessment of metabolic activity in tissues;
- uses positron emitters ( 15 O, 13 N, 11 C, 18 F), have a very short half-life , must be produced on site ( 'cyclotron y' );
- only fluorine can be transported ( 'FDG - fluoroureoxyglucose' );
- FDG accumulation indicates metabolic activity (distinguishes active tumor from residual fibrotic tissues).