Imaging Tumor Hypoxia With 18F-EF5 PET in Recurrent or Metastatic Clear Cell Ovarian Cancer
This study involves one visit to the BCCA - Vancouver Centre to undergo one EF5-PET/CT scan.
The visit will take about 4 hours to complete and no follow-up visits are required.
- Participants will fill out a short medical questionnaire asking routine information
(treatment history, previous surgeries, medications, allergies, etc.) that will take
about 5-10 minutes to complete.
- Next they will be weighed and vital signs measured (blood pressure, heart rate and
blood oxygen saturation).
- An IV is inserted into a vein in the participant's arm. At the same, a small amount of
blood will be taken to measure their blood glucose level.
- The participant will receive an IV dose of 18F-EF5.
- Five minutes after the injection, blood pressure and heart rate will be checked again.
- Participants will then be free to leave the functional imaging department for a period
of 180 minutes while the 18F-EF5 circulates throughout their body. Participants are
free to eat as normal during this period.
- Participants will undergo the 18F-EF5 PET scan, which will take about 20 minutes. The
participant will need to lie still on the scanner bed during the entire scan.
- The 18F-EF5 PET scan will be reviewed by a BC Cancer Agency doctor specialized in PET
and the results will be sent to their referring doctor.
Optional Biopsy Procedure:
Participants will have the opportunity of participating in an optional biopsy procedure for
the purposes of further studying contemporaneous tumour tissue (contemporaneous with the
EF5-PET) for markers of hypoxia, apoptosis, angiogenesis etc. The tissue will also be
compared to archival material, and this will allow researchers to study the evolving changes
in tumours following treatment.
Patients who consent to undergo a biopsy will be booked to the Diagnostic Imaging Department
at the Vancouver Centre. Ultrasound guidance will be use to obtain up to 5 core biopsies
from an accessible lesion(s). Up to 2 distinct tumour areas may be sampled. The standard
procedure required for a core biopsy will be followed, which will include pre-biopsy lab
tests, sterile technique, and when needed, post biopsy observation.
The core biopsies will be formalin fixed and paraffin embedded (FFPE). A BCCA pathologist
will review representative slides of each paraffin block to ensure the presence of tumour
tissue. The FFPE block will then be sent to the laboratory for immunohistochemistry staining
and further interpretation.
Observational Model: Case-Only, Time Perspective: Prospective
Ability of 18F-EF5 to detect areas of tumour hypoxia in clear cell tumours of the ovary
18F-EF5 uptake will be evaluated semi-quantitatively by determining the tumor-to-muscle activity ratio (T/M). Standardized uptake values (SUV) will be calculated for suspicious areas using a region of interest drawn around the target area on the PET images where SUV = (peak activity/mL in region of interest) / (injected activity/g of body weight). A Tumor-to-muscle ratio of >1.5 is considered positive.
Anna Tinker, MD, FRCPC
British Columbia Cancer Agency
Canada: Health Canada