Value of multi-parameter 123I-MIBG scintigraphy in the differential diagnosis of Parkinson's disease

Abstract

Background: ¹²³I-MIBG scintigraphy plays a significant role in diagnosing Parkinson's disease (PD), with most studies primarily targeting cardiac uptake and relying on traditional ratio-based parameters for assessment. However, due to variations in scanning conditions and image processing methodologies, the clinical utility of different parameters remains a subject of debate. This study aims to evaluate the diagnostic accuracy of multi-parameter ¹²³I-3-Iodobenzylguanidine (MIBG) scintigraphy and to identify the most reliable metrics for distinguishing PD from Parkinson-plus syndromes.

Result: We recruited 56 PD patients and 44 non-PD controls, who underwent ¹²³I-MIBG scintigraphy and clinical evaluation. MIBG uptake and washout rates (WR) for the heart, salivary glands, and thyroid were assessed, with semi-quantitative methods used to calculate heart-to-mediastinum (H/M) and gland-to-background (P/B, S/B, T/B) ratios. Diagnostic efficacy was evaluated using receiver operating characteristic (ROC) curves. The H/M ratio and cardiac WR parameters scintigraphy exhibited excellent diagnostic efficacy for PD and PPS. The 4 h H/M ratio showed superior diagnostic performance with an area under the ROC curve (AUC) of 0.980. Background and time decay correction improved cardiac WR diagnostic performance (AUC = 0.963). Although P/B, S/B, and T/B ratios showed no significant differences for differential diagnosis, the WR values of the parotid and thyroid glands exhibited moderate diagnostic efficacy with AUCs of 0.648 and 0.638, respectively.

Conclusion: The heart H/M ratio and cardiac WR in ¹²³I-MIBG scintigraphy show high diagnostic efficacy for both diagnosing and differentiating PD. Including cardiac WR in routine assessments is recommended. The diagnostic potential of WR in the parotid and thyroid glands also holds promise for PD diagnosis. Incorporating these parameters could enhance the accuracy of PD diagnosis, particularly in clinical scenarios where concurrent cardiac disease may confound the diagnosis.

Keywords: 3-Iodobenzylguanidine; Parkinson disease; Parkinsonism-plus syndrome; Salivary glands; Thyroid gland.

Fig. 1

a Cardiac ROI Delineation Method. b Salivary Gland and Thyroid ROI Delineation Method (using a non-PD patient's 15-min image). *The purple lines in the P region represent the thyroid ROI automatically delineated by the software using a 50% threshold

Fig. 2

Evaluation of 3-Iodobenzylguanidine (MIBG) Uptake in the Heart, Parotid Gland, Submandibular Gland, and Thyroid at 15 Min (a) and 4H (b) Using Ratio Parameters for Differentiating Parkinson's disease (PD) and Non-PD Patients

Fig. 3

Evaluation of 15 Min and 4 H Cardiac MIBG Uptake Using H/M Ratio in Differentiating PD from Other Parkinson-Plus Syndromes: Multiple System Atrophy (MSA), Progressive Supranuclear Palsy (PSP), Corticobasal Degeneration (CBD), and Essential Tremor (ET)

Fig. 4

Comparative Analysis of WR between PD and Non-PD Groups: Evaluation of WR in Cardiac, Parotid, Submandibular, and Thyroid Glands between PD and Non-PD Groups (a). Evaluation of WR in Cardiac by Method 1 and Method 2 between PD and Non-PD Groups (b)

Fig. 5

ROC Curve Analysis of the 15 Min and 4 H H/M Ratios, Cardiac WR Calculated by Two Methods, and Parotid and Thyroid WR for the Diagnosis of PD

Fig. 6

ROC Curve Analysis of the 15 Min and 4 H H/M Ratios and Cardiac WR Calculated by Two Methods for Differentiating PD from MSA (a) and PSP (b)

Fig. 7

Correlation Analysis Between WR_H2 and WR_P (a), as well as Between WR_H2 and WR_T (b)