Usefulness of semi-quantitative analysis in 123I metaiodobenzylguanidine SPECT/CT for the differentiation of pheochromocytoma and cortical adenoma

• Published in: Annals of nuclear medicine 2022, Vol.36 (1), p.95-102
• Main Authors: Kitamura, Yoshiyuki, Baba, Shingo, Isoda, Takuro, Maruoka, Yasuhiro, Sasaki, Masayuki, Nishie, Akihiro, Ishigami, Kousei
• Format: Article
• Language: English
• Subjects: Adenoma; Females; Imaging; Liver; Males; Medical imaging; Medicine; Medicine & Public Health; Muscles; Neuroendocrine tumors; Nuclear Medicine; Original Article; Performance evaluation; Pheochromocytoma; Quantitative analysis; Radiology; Scintigraphy; Single photon emission computed tomography; Tumors
• ISSN: 0914-7187; 1864-6433; 1864-6433
• DOI: 10.1007/s12149-021-01690-9

Objective 123 I metaiodobenzylguanidine (MIBG) scintigraphy is a useful tool for the diagnosis of pheochromocytomas (PHEOs), but some PHEOs are difficult to differentiate from cortical adenoma (CA) or normal adrenal uptake by visual evaluation alone. A new semi-quantitative analysis using 123 I MIBG SPECT/CT is thus expected. Herein, we introduce the tumor-to-liver count ratio (T/L) and the tumor-to-muscle count ratio ( T / M ). Methods We examined the cases of 21 patients with PHEOs (10 males, 11 females; age 24–80, median 61 years) and 23 patients with CA (15 males and 8 females, age 30–78, median 58 years). The visual scoring based on 123 I MIBG planar images (planar score) and SPECT images (SPECT score) was used as the conventional evaluation. Using 123 I MIBG SPECT/CT findings, we calculated the semi-quantitative values of the count ratio using the maximum or mean count of the tumor and the liver or muscle as the reference organ ( T / L max , T / L mean , T / M max and T / M mean ). Each evaluation of the PHEOs and CAs was compared, and the diagnosing performance was evaluated based on an ROC analysis. Results The area under curve (AUC) values were as follows: the planar score, 0.833; SPECT score, 0.813; T / L max , 0.986; T / L mean , 0.975; T / M max , 0.955; and T / M mean , 0.933. The AUC for T / M max was significantly higher than those of the planar score, and SPECT score by ROC analysis ( p