Methods of nuclear medicine in oncology

Scintigraphy

 *  '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

 * 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

 * Colloids trapped by RES, pathological deposits in liver appear as "cold";
 * however, the defects were not less than 2 cm.

Thyroid scintigraphy

 * Sodium pertechnetate.

Octreotide scintigraphy

 * India-labeled octreotide (somatostatin analogue);
 * detection of tumors with somatostatin receptors (gastrinoma, carcinoid, VIPom, small cell lung cancer, pheochromocytoma).

Immunoscintigraphy

 * Radiolabelled Ig (against CEA, etc.).

Single photon emission tomography (SPECT)

 * 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)

 * 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).