Single photon emission computed tomography (SPECT) is a nuclear medicine tomographic imaging technique which uses gamma rays for detection of cancer or infection. It is different from other imaging techniques as it is able to provide true three dimensional image data of cross-sectional slices through the human body using tomographic reconstruction algorithm to edit images taken from various angles. The three dimensional data obtained using SPECT can be manipulated by the surgeon during diagnosis or treatment to show image of thin cross-sectional slices along any chosen axis of the body.

The SPECT imaging technique is most valuable in detecting metastasized cancer in sentinel nodes which are often found in human body in unexpected areas. Once the radioisotope iodine-123 is injected into human body for single photon emission computed tomographic scan, this radioactive material is transmitted through the lymphatic fluid into the lymph nodes through out the body. The sentinel nodes are immediately detected by producing a sharp three dimensional image.

Single photon emission computed tomography not only helps to detect the lymph node affected by metastasized cancer, but also helps the surgeon to plan the surgical approach for treatment in a different way. With a clear three dimensional image of SPECT scan, surgeon can plan the length and location of his incision in a more precise way.

SPECT scans have a distinct advantage over other scans such as Positron Emission Tomography [PET] scans which is the fact that SPECT scans cost considerably less.

Source: Siemens AG