Date of Award


Document Type


Degree Name

Master of Medicine (MMed)

First Supervisor/Advisor

Dr. Sheila Waa

Second Supervisor/Advisor

Dr. Samuel Nguku Gitau


AKU-East Africa


Background: 18F –fluoro-2-deoxyglucose (18F-FDG PET), an imaging modality that provides metabolic information of cancers, is integral in the diagnostic workup of many malignancies. Most oncological FDG PET scans are acquired from the base of the skull to the upper thighs, as lesions that take up FDG are usually within this field of view. Routine inclusion of brain within the field of view of all oncological 18FDG PET/CT studies leads to increase of both time of acquisition and radiation dose (albeit marginal) delivered by the CT component of the study, therefore one can debate if addition brain in oncological 18FDG PET-CT has any an additional value.

Objective: To identify the prevalence of unsuspected intracranial findings in patients undergoing routine oncological 18 FDG PET CT examinations in Aga Khan University Hospital (AKUHN)with the inclusion of the brain in the field of view.

Methods: All patients who underwent oncological limited whole-body 18 FDG PET/CT scan between February 2019 to December 2021 were retrospectively reviewed and those who met the inclusion criteria were included. For each study, the patient’s age, sex, type of malignancy, disease stage, presence of clinically unsuspected intracranial finding, and the clinical information reviewed. Clinical impact (change in disease stage or management) of the identified intracranial findings was also obtained.

Results: A total of 3523 oncological limited whole body FDG PET, the prevalence of clinically unsuspected intracranial findings detected was 132 cases (3.7%) and of these findings, the clinically significant unsuspected intracranial findings was 62 cases (1.4%). The most common intracranial finding identified was metastasis followed by subclinical vascular findings. 22 cases underwent a follow up MRI brain and out of these cases the sensitivity and specificity were 94.7 % and 66.7%. Change in management was seen in 25/32(78%) cases that were followed up in our facility.

Conclusion and Recommendation: The study shows an added benefit in inclusion of brain in the field of view as it leads to early detection and crucial change in management especially for cancers that have a propensity to metastasis to the brain such as breast and lung cancer.