Indian Journal of Nuclear Medicine

ORIGINAL ARTICLE
Year
: 2015  |  Volume : 30  |  Issue : 3  |  Page : 213--220

Contrast-enhanced [18F] fluorodeoxyglucose-positron emission tomography-computed tomography as an initial imaging modality in patients presenting with metastatic malignancy of undefined primary origin


Avani Jain1, Madhur Kumar Srivastava2, Alok Suresh Pawaskar3, Simon Shelley1, Indirani Elangovan1, Hasmukh Jain4, Somnath Pandey5, Shilpa Kalal1, Jaykanth Amalachandran1 
1 Department of Nuclear Medicine and PET CT, Apollo Hospitals, Chennai, Tamil Nadu, India
2 Department of Nuclear Medicine, JIPMER, Puducherry, India
3 Department of Nuclear Medicine and PET CT, HCG Manavata Cancer Centre, Nashik, Maharashtra, India
4 Department of Nuclear Medicine, Kailash Cancer Hospital and Research Institute, Vadodara, Gujarat, India
5 Department of Nuclear Medicine, Eko Diagnostic Center, Kolkata, West Bengal, India

Correspondence Address:
Avani Jain
Department of Nuclear Medicine, Apollo Main Hospitals, No. 21, Greams Lane, Off. Greams Road, Chennai - 600 006, Tamil Nadu
India

Background: To evaluate the advantages of contrast enhanced F-18-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-contrast enhanced CT [CECT]) when used as an initial imaging modality in patients presenting with metastatic malignancy of undefined primary origin (MUO). Materials and Methods: A total of 243 patients with fine needle aspiration cytology/biopsy proven MUO were included in this prospective study. Patients who were thoroughly evaluated for primary or primary tumor was detected by any other investigation were excluded from the analysis. Totally, 163 patients with pathological diagnosis of malignancy but no apparent sites of the primary tumor were finally selected for analysis. The site of probable primary malignancy suggested by PET-CECT was confirmed by biopsy/follow-up. Results: PET-CECT suggested probable site of primary in 128/163 (78.52%) patients. In 30/35 remaining patients, primary tumor was not detected even after extensive work-up. In 5 patients, where PET-CECT was negative, primary was found on further extensive investigations or follow-up. The sensitivity, specificity, positive predictive value and negative predictive value of the study were 95.76%, 66.67%, 88.28% and 85.71% respectively. Conclusions: F-18 FDG PET-CECT aptly serves the purpose of initial imaging modality owing to high sensitivity, negative and positive predictive value. PET-CECT not only surveys the whole body for the primary malignancy but also stages the disease accurately. Use of contrast improves the diagnostic utility of modality as well as help in staging of the primary tumor. Although benefits of using PET-CECT as initial diagnostic modality are obvious from this study, there is a need for a larger study comparing conventional methods for diagnosing primary in patients with MUO versus PET-CECT.


How to cite this article:
Jain A, Srivastava MK, Pawaskar AS, Shelley S, Elangovan I, Jain H, Pandey S, Kalal S, Amalachandran J. Contrast-enhanced [18F] fluorodeoxyglucose-positron emission tomography-computed tomography as an initial imaging modality in patients presenting with metastatic malignancy of undefined primary origin.Indian J Nucl Med 2015;30:213-220


How to cite this URL:
Jain A, Srivastava MK, Pawaskar AS, Shelley S, Elangovan I, Jain H, Pandey S, Kalal S, Amalachandran J. Contrast-enhanced [18F] fluorodeoxyglucose-positron emission tomography-computed tomography as an initial imaging modality in patients presenting with metastatic malignancy of undefined primary origin. Indian J Nucl Med [serial online] 2015 [cited 2020 Sep 20 ];30:213-220
Available from: http://www.ijnm.in/article.asp?issn=0972-3919;year=2015;volume=30;issue=3;spage=213;epage=220;aulast=Jain;type=0