Radiol Clin North Am 2001 Sep;39(5):883-917
Positron emission tomography imaging in oncology.
Delbeke D, Martin WH.
The applications for FDG-PET imaging are rapidly growing and accepted in the
field of oncology. FDG-PET imaging does not replace other imaging modalities,
such as CT, but seems to be very helpful in specific situations where CT has
known limitations, such as differentiation of benign from malignant
indeterminate lesions on CT, differentiation of post-treatment changes versus
recurrent tumor, differentiation of benign from malignant lymph nodes, and
monitoring therapy. The biggest use of FDG-PET presently is in N and M staging
of various body tumors. The addition of FDG-PET in the evaluation of oncologic
patients in well-defined algorithms including a combination of imaging studies
seems to be cost effective by accurately identifying patients who benefit from
invasive procedures and saving unnecessary costly invasive procedures on
patients who do not benefit from them. Although PET imaging may decrease the
cost of health care by reducing the number of invasive procedures,
implementation of clinical PET has been hindered by the high cost of the
purchase, operation expenses, and maintenance of PET systems; the need for
immediate access to a source of 18F (owing to the 110-minute half-life); and the
limited reimbursement for clinical procedures by third-party payers. These
combined factors have resulted in the development by manufacturers of hybrid
gamma camera systems capable of performing positron imaging. These systems can
be used to image conventional radiopharmaceuticals used in general nuclear
medicine and positron-emitting radiopharmaceuticals. The performance of these
camera-based PET systems has improved markedly over the past few years with the
introduction of thicker NaI (T1) crystals, iterative reconstruction algorithms,
and attenuation correction. These new developments in medical imaging
instrumentation have contributed to the expansion of the number of cyclotrons,
and have driven the concept of commercial FDG distribution centers.
