The Value of Targeting CXCR4 With 68Ga-Pentixafor PET/CT for Subtyping Primary Aldosteronism

Clinical value of 68Ga-pentixafor PET/CT in patients with primary aldosteronism and bilateral lesions: preliminary results of a single-centre study

BACKGROUND

Subtype diagnosis of primary aldosteronism (PA) is used to determine treatment, and the potential utility of 68Ga-pentixafor PET/CT for investigation of PA has long been recognized. The study aimed to evaluate the clinical value of 68Ga-pentixafor PET/CT in the diagnosis and prognosis of patients with bilateral lesions identified by CT.

METHODS

In total, 25 patients with PA and bilateral lesions on CT were retrospectively evaluated. All patients underwent 68Ga-Pentixafor PET/CT and adrenal vein sampling. The analysis focused on establishing the relationship between bilateral adrenal lesions SUVmax and the ratio of bilateral adrenal lesions SUVmax (CON) and clinical diagnosis, treatment outcomes, and KCNJ5 gene status.

RESULTS

The concordance rate between 68Ga-Pentixafor PET/CT and adrenal venous sampling was 65.2% (15/23). The lateralization results of 68Ga-pentixafor PET/CT supported the clinical decisions of 20 patients with PA, 90% of whom showed effectiveness in treatment. The SUVmax on the dominant side of the surgically treated patients was higher than that of patients treated with drugs. The SUVmax of the KCNJ5 mutant group was higher than that of the KCNJ5 wild group, and 68Ga-Pentixafor uptake was correlated with KCNJ5 gene status.

CONCLUSIONS

68Ga-Pentixafor PET/CT proves beneficial for patients with PA with bilateral lesions on CT. The treatment is generally effective based on the results of PET lateralization. Simultaneously, a certain relationship exists between 68Ga-Pentixafor PET/CT and KCNJ5 gene status, warranting further analysis.

A comparison of the performance of 68Ga-Pentixafor PET/CT versus adrenal vein sampling for subtype diagnosis in primary aldosteronism

Objective

To investigate the diagnostic efficiency and prognostic value of 68Ga-Pentixafor PET/CT in comparison with adrenal vein sampling (AVS) for functional lateralization in primary aldosteronism (PA). Histology and long-term clinical follow-up normally serve as the gold standard for such diagnosis.

Methods

We prospectively recruited 26 patients diagnosed with PA. All patients underwent 68Ga-Pentixafor PET/CT and AVS. Postsurgical biochemical and clinical outcomes of patients with unilateral primary aldosteronism (UPA), as diagnosed by PET/CT or AVS, were assessed by applying standardized Primary Aldosteronism Surgical Outcome (PASO) criteria. Immunohistochemistry (IHC) was performed to detect the expression of aldosterone synthase (CYP11B2) and CXCR4.

Results

On total, 19 patients were diagnosed with UPA; of these, 13 patients were lateralized by both PET/CT and AVS, four patients were lateralized by PET-only, and two by AVS-only. Seven subjects with no lateralization on AVS and PET received medical therapy. All patients achieved complete biochemical success except one with nodular hyperplasia lateralized by AVS alone. The consistency between PET/CT and AVS outcomes was 77% (20/26). Moreover, CYP11B2-positive nodules were all CXCR4-positive and showed positive findings on PET. Patients who achieved complete biochemical and clinical success had a higher uptake on PET as well as stronger expression levels of CXCR4 and CYP11B2.

Conclusion

Our analysis showed that 68Ga-Pentixafor PET/CT could enable non-invasive diagnosis in most patients with PA and identify additional cases of unilateral and surgically curable PA which could not be classified by AVS. 68Ga-Pentixafor PET/CT should be considered as a first-line test for the future classification of PA.

Preoperative supine time for adrenal venous sampling: a prospective randomized controlled trial

BACKGROUND

Primary aldosteronism (P.A.) is the most common form of secondary hypertension, accounting for 5% of hypertensive patients and 17-23% of patients with resistant hypertension. Compared to primary hypertension, P.A. is more prone to cause severe organ damage and even early death. Adrenal venous sampling (AVS) is a practical confirmatory test for subtyping aldosterone-producing adenoma and bilateral adrenal hyperplasia, helping physicians to make an accurate decision between surgery or medication. According to guidelines, supine in bed before AVS is recommended for a desirable result of AVS. However, investigations about the most optimal preoperative supine time before AVS are lacking.

METHODS/DESIGN

This is a multi-center prospective randomized controlled study. One hundred twenty patients diagnosed as P.A. and willing for AVS examination will be included. Participants will be randomly allocated to a 15-min supine time group or 2-h supine time group. The primary outcome is the degree of biochemical remission (serum potassium and orthostatic ARR). The secondary outcomes are degrees of clinical remission (blood pressure, type and dose of antihypertensive drugs), the technical success rate, and the adverse event of AVS (selective index ≥ 2 is considered successful surgery without corticotropin stimulation).

DISCUSSION

P.A. is an intractable public health problem, and many techniques including AVS have been developed to identify this disease correctly. This study will help to understand whether the length of preoperative supine time would affect the diagnostic efficacy of AVS and thus help to formulate a more reasonable AVS procedure.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05658705. Registered on 10 September 2022.

Advances in PET Imaging of the CXCR4 Receptor: [68Ga]Ga-PentixaFor

[68Ga]Ga-PentixaFor, a PET agent targeting CXCR4 is emerging as a versatile radiotracer with promising applications in oncology, cardiology and inflammatory disease. Preclinical work in various cancer cell lines have demonstrated high specificity and selectivity. In human investigations of several tumors, the most promising applications may be in multiple myeloma, certain lymphomas and myeloproliferative neoplasms. In the nononcologic setting, [68Ga]Ga-PentixaFor could greatly improve detection for primary aldosteronism and other endocrine abnormalities. Similarly, atherosclerotic disease and other inflammatory conditions could also benefit from enhanced identification by CXCR4 targeting. Rapidly cleared from the body with a favorable imaging and radiation dosimetry profile that has been already studied in over 1000 patients, [68Ga]Ga-PentixaFor is a worthy agent for further clinical exploration with potential for theranostic applications in hematologic malignancies.

Approaching Primary Aldosteronism as a Common Disease

OBJECTIVE

To describe the approach to primary aldosteronism as a common disease.

METHODS

The study methods involved are literature review and personal experience.

RESULTS

Primary aldosteronism is the most common form of endocrine hypertension, yet screening rates are abysmally low. Major reasons for low screening rates include misconceptions about the drug interference and limited access to adrenal vein sampling expertise for subtyping. The workup of primary aldosteronism is greatly simplified by considering the condition as a continuum with low-renin primary hypertension. Thus, the purpose of the evaluation is not a yes/no dichotomous diagnosis but rather a gauging of how likely the patient has a lateralized source and will benefit from unilateral adrenalectomy. This approach favors the selective rather than universal use of cross-sectional imaging and adrenal vein sampling but promotes the liberal use of mineralocorticoid-receptor antagonists.

CONCLUSION

The review will develop a practical approach to the patient using a series of questions with answers from the literature.