Clinical Trial Details
— Status: Recruiting
Administrative data
| NCT number |
NCT06076538 |
| Other study ID # |
STU-2022-1158 |
| Secondary ID |
|
| Status |
Recruiting |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
August 1, 2023 |
| Est. completion date |
June 1, 2028 |
Study information
| Verified date |
November 2023 |
| Source |
University of Texas Southwestern Medical Center |
| Contact |
UTSW Radiology Clinical Research Office |
| Phone |
214-645-1568 |
| Email |
RCRO[@]utsouthwestern.edu |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational
|
Clinical Trial Summary
The frequency of kidney tumors found incidentally on imaging studies performed for unrelated
reasons continues to increase leading to more surgeries and ablations for the treatment of
renal masses thought to be cancer. However, about 20% of these masses are not cancerous and
do not require treatment. Many cancerous kidney tumors are indolent and can be followed
safely with imaging (i.e., particularly tumors <2 cm and in patients with limited life
expectancy), while some tumors are both malignant and aggressive, with a higher potential to
spread outside the kidney and require treatment.
The purpose of this observational study is to assess the ability of Fludeoxyglucose (18F)
(FDG) PET/MR to distinguish different types of kidney tumors. The investigators hypothesize
that PET/MR will better show differences between aggressive and both indolent and benign
kidney masses compared to the currently used radiologic scans.
Participants will be selected from those who have been scheduled to receive a
contrast-enhanced MRI for their regular care due to a suspicious kidney mass. Participants
will have their MRI on a hybrid PET/MR scanner capable of obtaining both MRI and PET images.
While they are receiving their standard of care MRI exam, patients will also receive a
research FDG PET exam. Participants will have an IV placed for administration of the MRI
contrast agent, just as they would if they were not taking part in the study. The same IV
will be used to give the FDG radiopharmaceutical for the PET scan and furosemide (a
diuretic), to help empty the bladder before the scan and help better see the kidneys on the
scans. Both FDG and furosemide are FDA approved medications. Participants will have only one
visit with the research team which will last ~2.5 hours and will include collection of the
participant's regularly scheduled MRI.
If participants undergo surgery to remove the tumor, the study will collect samples of the
removed tissue for research. If participants receive a biopsy of the tumor, the study may
collect an additional sample of the tumor for research.
After the PET/MRI, participants will not have additional visits with the study team, but the
study team may call every 6-12 months for up to 2 years to see how they are doing and ask
about their health. The study team will review the medical record for any changes to their
diagnosis, updates to their medical history, new scans ordered by their regular doctor, or
recent lab or biopsy results.
Description:
Renal cell carcinoma (RCC) is most commonly diagnosed as an incidental small renal mass (SRM,
≤4cm [cT1a]). The incidence of RCC has markedly increased in the last few decades due to the
widespread utilization of cross-sectional imaging. The increased detection of renal masses
has resulted in an accompanying increase in the number of surgeries and ablations performed
for a mass suspected of being a cancer. However, despite aggressive treatment of SRMs over
the last few decades, there has not been a substantial decrease in kidney cancer-specific
mortality suggesting an over-treatment effect - i.e., many patients may not benefit from
extirpative or ablative treatment. Furthermore, approximately 20% of small (≤4 cm) solid
renal masses are benign neoplasms, mostly oncocytoma and angiomyolipoma. Benign masses
generally do no harm and can be ignored or followed up as they do not limit a patient's
lifespan. Even when malignant, small solid masses are frequently indolent with low rates of
local disease progression or metastasis. The proportion of benign diagnoses and indolent RCCs
is higher among solid masses smaller than 2 cm. Although percutaneous renal mass biopsy can
offer a definitive diagnosis, it is not feasible in every patient, and carries a high
non-diagnostic rate (14-19%), has low negative predictive value (63%) and underestimates
tumor grade. For these reasons, combined with a desire to identify aggressive renal masses
with increased risk of progression or metastasis promptly and decrease patient morbidity and
health-care costs related to unnecessary treatments, there is a need for developing imaging
techniques that better characterize renal masses. In addition to differentiating benign from
malignant disease, distinction between indolent malignant renal masses from aggressive
neoplasms is important for decision making, with the later typically requiring prompt
intervention. In contrast, active surveillance may be favored for patients with indolent
malignancies, particularly for those with competing comorbidities and limited life
expectancy. Unfortunately, the lack of reliable predictors of oncologic behavior have also
limited the wide clinical adoption of active surveillance as a management strategy.
Aggressive renal masses are classified by the presence of any high grade (HG, International
Society of Urogenital Pathology (ISUP) grade 3 or 4 out of 4) features on histology or the
presence of sarcomatoid and rhabdoid features, coagulative necrosis.
Alternatively, a diagnosis of the histologic subtype of RCC may assist in management
decisions. For example, clear cell renal cell carcinoma (ccRCC) is the most common histology
and metastasizing tumor. The clear cell likelihood score (ccLS) is a 5-tier system developed
at the University of Texas Southwestern Medical Center (UTSW) to predict the likelihood of a
solid renal mass to represent a clear cell renal cell carcinoma. In a multicenter,
retrospective study, the reported pooled sensitivity, specificity, and positive predictive
value for ccRCCs using a ccLS of 4 or 5 were 75% (95% CI: 68, 81), 78% (95% CI: 72, 84), and
76% (95 CI: 69, 81), respectively. The negative predictive value for a ccLS of 1 or 2 was 88%
(95% CI: 81,93).
Patients referred for MRI of an indeterminate renal mass will be eligible for this study.
PET/MRI in this study will be performed as a replacement of the standard-of-care MRI
examination. Thus, the PET component of the PET/MR examination is a research procedure.
Patients will be screened for any contraindication of MRI (e.g., unsafe indwelling device) as
it is routinely done in the Department of Radiology for clinical MRI examinations. Patients
will be administered with 12 mCi of FDG I.V, which is consistent with the FDG radiation dose
patients receive for FDG PET/CT examinations performed as standard of care. Patients will
receive 20 mg of furosemide 60 min after administration of FDG. The patient will be asked to
empty their bladder as much as needed for the following 60 min. The patient will then be
placed on the PET/MRI table 60 min after administration of FDG for a 10 min quick PET/MR
acquisition the abdomen. The patient will be removed from the scanner and asked to empty
their bladder as needed. The patient will be placed on the MRI scanner again 120 min after
the administration of FDG to complete their standard of care MRI. A gadolinium-enhanced MRI
of the kidneys will be obtained using the standard clinical protocol for MRI of renal masses
at UTSW. An extracellular gadolinium-based contrast agent will be administered during the MRI
and is not part of the study procedures. PET data of the kidneys will be acquired
simultaneously during the MRI examination as part of the study procedures. UTSW standard
operating procedures will be followed with regards to fasting and blood glucose measurements
for patients undergoing FDG PET imaging in this study. PET images will be coregistered to MRI
data and mean and maximum standardized uptake value in the renal mass will be calculated. MRI
images will be interpreted using the standard clinical report and a ccLS will be provided.
For patients undergoing standard of care biopsy, an extra core will be obtained for future
research from participants who opt-in to have extra core collected when they sign informed
consent form. If the renal mass is resected surgically, a piece of discarded tissue will be
collected for similar correlative studies. The extra core or the discarded tissue will be
used for histology and metabolomics analysis to understand the correlation of FDG uptake and
tumor metabolism.
