18F-FDG PET/CT-directed biopsy: does it offer incremental benefit?
OBJECTIVE
To study whether the metabolic information provided by a prior PET/computed tomography (CT) scan can add valuable information and an incremental benefit while performing image-guided biopsies.


METHODS
Fluorine-18 fluorodeoxyglucose (F-FDG) PET/CT findings of 112 patients were available before biopsy and were considered for analysis. Biopsies were performed using standard techniques only after the needle tip was confirmed to be in the portion of the lesion corresponding to the hypermetabolic area seen on PET. This was achieved by visual coregistration and also by software registration algorithms that registered the intraprocedural CT images with the preselected PET/CT data. Only those biopsies for which a definitive histopathological diagnosis could be made were considered 'diagnostic'. Cases in which PET/CT added an incremental value were divided into three categories.


RESULTS
A total of 112 patients (66 male and 46 female, age range 16-74 years) underwent a biopsy based on PET findings. The biopsy sites were as follows: lung, 54; lymph nodes, 27; bone, 12; and soft-tissue masses/deposits, 19. Out of the 112 biopsies, an incremental benefit was seen overall in 53 patients (47.3%): in 40.7% (22/54) of patients who underwent lung biopsies, 44.4% (12/27) of those who underwent lymph node biopsies, 66.6% (8/12) of those who underwent bone biopsies and 57.8% (11/19) of those who underwent soft-tissue biopsies. Out of the cases that showed an incremental benefit, the highest number (30) belonged to the category in which the biopsy sample was obtained from the focal hypermetabolic portion of the apparently larger morphological lesion seen on CT.


CONCLUSIONS
PET/CT data coregistered with intraprocedural CT images can guide needle placement in the viable portion of the lesion, thus increasing the chances of achieving a definitive diagnosis. This approach can offer a significant incremental benefit while performing image-guided biopsies.
Departments of Nuclear Medicine and Molecular Imaging, Tata Memorial Hospital, Mumbai, India.
Nilendu C
NC
Purandare
Aniruddha V
AV
Kulkarni
Suyash S
SS
Kulkarni
Diptiman
D
Roy
Archi
A
Agrawal
Sneha
S
Shah
Venkatesh
V
Rangarajan
D000293:Adolescent; D000328:Adult; D000368:Aged; D001706:Biopsy / Q000379:methods*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008198:Lymph Nodes / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D009369:Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012107:Research Design; D014057:Tomography, X-Ray Computed; D055815:Young Adult
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18