Early detection of a colon cancer on health screening by PET/CT

Nan-Jing Peng, MD Department Nuclear Medicine

Abstract: Whole-body FDG-PET has been used to screen underlying malignancy of health people for decades. Recently, PET/CT has been advocated as a tool for improvement of diagnosis by FDG-PET. We assessed the PET/CT results of asymptomatic individuals for health screening in our PET center. The final confirmation of cancer was based on pathologic report. Here, a case of colon cancer was presented.

96/1/22 PET/CTThis study shows:1. asymmetric mild FDG uptake in right nasopharynx (SUVmax: 2.4) with slight fullness of pharyngeal recess seen on PET/CT fusion images.2. smaller left thyroid lobe corresponding to prior operation for benign thyroid nodule 13 years ago.3. a focal area of increased FDG uptake at mid-descending colon (SUVmax: early: 3.7, first delayed: 4.2, second delayed: 4.7) without definite morphologic lesion seen on PET/CT fusion images. 4. osteophyte formation in T and L spine, more arising from anterior vertebral bodies of T9 to T12.5. asymmetric uptake in articular surface of right hip joint (SUVmax: 1.9) likely due to arthritis or muscular stress.6. presence of normal FDG distribution in the brain, ocular muscles, tonsils, salivary glands, intrinsic laryngeal muscles, breasts, heart, great vessels, liver, spleen, kidneys, ureters and urinary bladder.

It is our understanding that the 55 year-old female has history of (1) occult blood s/p colon fiberoscopy revealed diverticulum, (2) thyroid nodule s/p operation 13 years ago, (3) unilateral oophorectomy due to ovarian cyst 30 years ago, for physical check-up.

Impression: 1. Asymmetric mild glucose hypermetabolism in right nasopharynx with slight fullness, more in favor of normal variant or mild inflammation rather than malignancy.2. A focal area of persistent glucose hypermetabolism at mid-descending colon, etiology unknown, malignancy can not be ruled out.

A focal area of increased FDG uptake at mid-descending colon (SUVmax early: 3.7, first delayed: 4.2, second delayed: 4.7).