Positron emission tomography in the detection of residual XXXX .

@entity1 @entity82 @entity419 @entity41 @entity5 @entity4 @entity189
Positron emission tomography measures the metabolic activity of tissue. Because metabolism rates are higher in @entity5 than in normal tissue, positron emission tomography can be used to identify abnormal tissue. Positron emission tomography has proved useful in detecting residual or recurrent @entity5 in the brain and gastrointestinal tract after definitive treatment. We selectively used positron emission tomography in a preliminary trial to examine @entity1 with @entity5 who had previously been treated with organ-preservation therapy with radiation therapy alone or in combination with induction chemotherapy. These @entity1 are often difficult to examine both clinically and radiographically because of posttreatment @entity4 and @entity82 . From 1991 to 1993 @entity1 at our institution who were treated with either radiation therapy or a combination of induction chemotherapy and radiotherapy for @entity189 were evaluated after treatment. If clinical examination was suspicious for @entity41 or recurrence, a computed tomography or magnetic resonance imaging scan was obtained. In 10 @entity1 neither clinical examination nor conventional imaging could absolutely rule out residual/recurrent @entity189 . In these @entity1 positron emission tomography with @entity419 was used to detect disease. The results from positron emission tomography were compared with the results from subsequent biopsy (five @entity1 ) or clinical follow-up. Positron emission tomography had a sensitivity of 67% and a specificity of 57%. The positive predictive value of positron emission tomography was 67%. The negative predictive value of positron emission tomography was 80%.(ABSTRACT TRUNCATED AT 250 WORDS)
