Quantitative analysis in parathyroid adenoma scintigraphy.

Area of Science:

• Nuclear Medicine
• Radiology
• Endocrine Surgery

Background:

• Primary hyperparathyroidism necessitates surgical intervention for cure.
• Parathyroid scintigraphy, including SPECT/CT, is crucial for preoperative lesion localization.
• Understanding radiopharmaceutical uptake patterns aids in differentiating parathyroid adenomas (PTAs).

Purpose of the Study:

• To evaluate time-related changes in radiopharmaceutical uptake in PTAs using quantitative SPECT/CT.
• To assess differences in washout patterns (rapid vs. slow) of 99mTc-MIBI in PTAs.
• To correlate quantitative imaging findings with PTA characteristics.

Main Methods:

• 35 histologically verified PTAs from 33 patients with primary hyperparathyroidism were studied.
• Three-phase SPECT/CT imaging with 99mTc-methoxyisobutylisonitrile (MIBI) was performed.
• Quantitative analysis of SUVmax and retention indexes (RI) at 10, 90, and 180 minutes post-injection was conducted.

Main Results:

• Significant differences in PTA SUVmax and PTA/thyroid gland ratios were observed at 180 minutes between rapid (Group A) and slow (Group B) washout groups.
• Retention indexes for PTAs (RI-PTA) showed significant differences at 90 and 180 minutes.
• No significant differences were found in PTA volumes, thyroid gland SUVmax, or RI-TG between the groups.

Conclusions:

• Parathyroid adenomas with rapid and slow 99mTc-MIBI washout patterns exhibit distinct quantitative characteristics in later phases of SPECT/CT imaging.
• Early-phase quantitative measurements (SUVmax, PTA/thyroid gland ratio) did not reveal significant differences between washout patterns.
• Quantitative analysis of later phases may improve preoperative localization accuracy for primary hyperparathyroidism.