PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Not specified Life expectancy: Not specified Hematopoietic: Not specified Hepatic: Not specified Renal: Not specified Other: Not pregnant or nursing Fertile patients must use effective contraception Able to fast for 6 hours Able to lie still for positron emission tomography imaging No second malignancy except previously treated nonmelanomatous skin cancer or carcinoma in situ of the cervix No active infection No inflammatory disease (sarcoidosis or rheumatoid arthritis) No allergy to shellfish or contrast dye used for CT imaging