Functional Pituitary Adenomas
Conditions
Keywords
PET-18 Fluoro ethyl tyrosine, Functional pituitary adenoma, Indeterminate MRI
Brief summary
Pituitary adenomas (PAs) are common benign tumors, but their potential for tumor aggression and hormone secretion make them serious tumors. In particular, patients with secreting tumors \[prolactinomas (prolactin secretion), acromegaly (growth hormone), Cushing's disease (ACTH), thyrotropic adenomas (TSH)\] have increased morbidity and mortality. They may be small and/or undetectable by magnetic resonance imaging (MRI), the current gold standard for morphological evaluation of pituitary lesions. The diagnosis of recurrence in a patient who has already undergone surgery also raises the problem of distinguishing between a lesion and postoperative remodeling. The detection of these tumors therefore represents a significant challenge in guiding therapeutic management.Nuclear medicine could solve this challenge, particularly radiopharmaceuticals (MRPs) used in PET (positron emission tomography) combined with CT scans. A few studies have evaluated MRPs in the context of APs, with those targeting amino acid metabolism proving to be the most promising, particularly carbon-11-labeled methionine (11C-MET). In retrospective studies only, 11C-MET PET has shown excellent performance in all situations where MRI fails (detection rate \>80%), but the extremely short half-life of 11C requires heavy infrastructure, limiting its access in routine clinical practice.18Fluoroethyl-Tyrosine (18FET) is also a PET MRP targeting amino acid metabolism used in France in neuro-oncology with performance equivalent to 11C-MET, and which has the advantage of being available daily in all nuclear medicine centers. The performance of 18FET in APs is almost unknown, with only two retrospective studies recently published, including 22 patients with Cushing's disease on the one hand and 17 patients with prolactinoma on the other: The detection rates were particularly interesting (82% and 100% respectively), but it is imperative to confirm these data prospectively and to evaluate the performance of this MRP in other functional types, which is therefore the purpose of this study.
Interventions
DRUGfluoroethyl-L tyrosine (18F)
The protocol consists of a single arm involving the administration of the radiopharmaceutical 18FET (IASOglio). This will be administered once during the study, directly intravenously with an activity of 200 +/- 15MBq, as recommended by the European EANM/EANO/RANO guidelines and used in retrospective studies investigating the contribution of 18FET in AP. Included patients will have fasted for at least 4 hours beforehand. PET image acquisition will begin as soon as the radiopharmaceutical is injected.
Sponsors
University Hospital, Lille
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
DIAGNOSTIC
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Male and/or female * Aged 18 years or older * Suspected of having a functional pituitary adenoma (prolactinoma - Cushing's disease - acromegaly - thyrotropic adenoma), de novo or recurrence/persistence * With indeterminate pituitary MRI * Patient covered by social security * Patient willing to comply with all study procedures and duration * Patient eligible for surgery and/or radiotherapy in case of positive 18FET PET scan
Exclusion criteria
* Pregnancy * Known hypersensitivity to radiopharmaceuticals * Administrative reasons: inability to receive informed information, inability to participate in the entire study, lack of coverage by the social security system, refusal to sign the consent form * Contraindication to surgery and radiotherapy in the case of positive 18FET PET * Patients who are active alcohol users * Patients suffering from liver disease or severe uncontrolled epilepsy * Patients deprived of their liberty (guardianship, curatorship, etc.)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Describe the ability of 18FET PET to detect functional pituitary adenomas in patients with de novo, recurrent, or persistent functional AP when pituitary MRI is non-contributive. | 2 months +/- 2 months | Frequency of patients for whom PET would be useful among patients with a positive 18FET PET result.The gold standard will be defined by the pathological examination of the surgical specimen in the case of surgery, or by the possibility of stopping or gradually reducing medical treatment while maintaining normalized hormone secretion in the case of radiotherapy. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Describe the frequency of patients positive for 18FET PET in patients with de novo, recurrent, or persistent functional AP when pituitary MRI is non-contributive. | 2 months +/- 2 months | Frequency of patients with positive 18FET PET scans. |
| Describe SUVmax based on the 18FET PET scan result | 2 months +/- 2 months | SUVmax (g/mL) based on the result of the 18FET PET scan (patients negative on the 18FET PET scan, patients positive on the 18FET PET scan and successfully treated, and patients positive on the 18FET PET scan but not treated or treatment failure). |
| Describe Adenoma/healthy brain ratio based on the 18FET PET scan result | 2 months +/- 2 months | Based on the result of the 18FET PET scan (patients negative on the 18FET PET scan, patients positive on the 18FET PET scan and successfully treated, and patients positive on the 18FET PET scan but not treated or treatment failure). |
| Describe kinetic parameters based on the 18FET PET scan result. | 2 months +/- 2 months | Kinetic parameters (time to peak in minutes) based on the result of the 18FET PET scan (patients negative on the 18FET PET scan, patients positive on the 18FET PET scan and successfully treated, and patients positive on the 18FET PET scan but not treated or treatment failure). |
| Measure the concordance of the 18FET PET scan results between three readers. | 2 months +/- 2 months | Concordance will be measured by the Krippendorf coefficient. |
| Describe the proportion of patients who, following 18FET PET, received therapeutic treatment targeting the adenoma (surgery and/or external radiation therapy). | 1 year +/- 2 months | Frequency of patients undergoing surgery and frequency of patients undergoing radiation therapy among patients who tested positive on 18FET PET scans. |
Countries
France
Contacts
CONTACTBenjamin CHEVALIER, MD
PRINCIPAL_INVESTIGATORBenjamin CHEVALIER, MD
University Hospital, Lille
Outcome results
None listed