Patients with differentiated thyroid cancer may have asymptomatic involvement of renal and/or adrenal gland, particularly if they are elderly and have associated metastases to other organs, which may remain undetected if these patients are not subjected to radioiodine treatment. Our experience also emphasises the role of routine post-radioiodine therapy whole body scan with high degree of clinical suspicion, which may reveal lesions otherwise not discernable in low dose whole body scan. All suspicious lesions should be subjected to structural imaging like ultrasound, CT or MRI for confirmation. In this setting, the role of radioiodine therapy is primarily aimed at palliation that might prolong their survival, probably reduce further spread and thus overall improve the quality of life.

Positron emission tomography is a functional diagnostic imaging technique, which can accurately measure in vivo distribution of a radiopharmaceutical with high resolution. The ability of positron emission tomography to study various biologic processes opens up new possibilities for both research and day-to-day clinical use. Positron emission tomography has progressed rapidly from being a research technique in laboratories to a routine clinical imaging modality becoming part of armamentarium for the medical profession. The most widely used radiotracer in positron emission tomography is 18F-fluoro-2-deoxy-D-glucose (FDG), which is an analog of glucose. FDG uptake in cells is directly proportional to glucose metabolism of cells. Since glucose metabolism is increased many fold in malignant tumors, positron emission tomography has a high sensitivity and high negative predictive value. Positron emission tomography with FDG is now the standard of care in initial staging, monitoring the response to therapy and management of lung cancer, colorectal cancer, lymphoma, melanoma, esophageal cancer, head and neck cancer and breast cancer. The aim of this article is to review the clinical applications of positron emission tomography in oncology.

Remnant thyroid mass estimation by Tc-99m pertechnetate single-photon emission computed tomography is a simple technique and allows overcoming the dependence on structural imaging techniques or making empirical assumptions during dosimetry.

These results suggest that the 4 h rest gated 201Tl study gives a reliable value for the LVEF compared to 2-D ECHO and can be used in routine clinical practice.

BACKGROUND:We report the use of positron emission tomography (PET) using