title: Technetium-99m pentavalent dimercaptosuccinic acid imaging in patients with pituitary adenomas.
abstract: We studied the tumor-seeking agent technetium-99m-labeled pentavalent dimercaptosuccinic acid ([99mTc](V)DMSA) to visualize 21 growth hormone (GH)-, nine prolactin (PRL)-, two mixed GH/PRL-, six adrenocorticotrophin (ACTH)-secreting and 15 clinically non-functioning pituitary adenomas, three craniopharyngiomas and one dysgerminoma of the sella. All non-adenomas and 31 out of 53 adenomas were studied before treatment: 22 after surgery and/or radiotherapy. Eight cases of acromegaly were studied before and after chronic treatment with octreotide, whereas three cases of acromegaly, one of prolactinoma and two of non-functioning adenoma were imaged before and after adenomectomy. As a control group, 27 patients without any clinical evidence of pituitary adenoma were studied: 10 of them were operated on previously and treated with iodine-131 for metastatic thyroid carcinoma, 10 had brain tumors and the remaining seven patients had functional pituitary hypersecretion (four Klinefelter's syndrome, two primary hypothyroidism and one Addison's disease). The scintigraphy was repeated after testosterone in Klinefelter's syndrome, L-thyroxine in primary hypothyroidism and cortisone administration in Addison's disease. Seventeen GH-secreting (81%), seven PRL-secreting (78%), three ACTH-secreting (50%), 15 non-functioning (100%) and one (50%) mixed adenoma significantly concentrated [99mTc](V)DMSA, showing elevated tumor-to-background (T/B) ratios. The T/B ratios were similar in untreated and surgically treated adenomas (11.2 +/- 5.6 vs 11.8 +/- 6.2). Radiotherapy significantly lowered the [99mTc](V)DMSA uptake to 5.1 +/- 2.8 (p < 0.1 vs untreated patients). Non-adenomatous lesions of the sella turcica did not concentrate [99mTc](V)DMSA in the pituitary as well as brain tumors and 8 out of 10 metastatic thyroid cancers. The treatment with octreotide normalized GH and insulin-like growth factor I levels and reduced [99mTc](V)DMSA from 15.7 +/- 4.8 to 13.5 +/- 3.9 (p < 0.05). Conversely, adequate substitutive therapy completely inhibited the uptake of the radiotracer in Klinefelter's syndrome, in primary hypothyroidism and in Addison's disease. The [99mTc](V)DMSA scintigraphy showed an overall sensitivity of 81% (43/53) in detecting pituitary adenomas, which was increased to 95% for lesions greater than 10 mm in size. High-quality images with minimal total body radiation were obtained, enabling a good in vivo characterization of viable adenomatous tissue as well as an accurate monitoring of the effects of different therapeutic regimens.
authors.affiliation: Department of Nuclear Medicine, National Cancer Institute, Napoli, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Lastoria
authors.forename: A
authors.initials: A
authors.lastname: Colao
authors.forename: E
authors.initials: E
authors.lastname: Vergara
authors.forename: D
authors.initials: D
authors.lastname: Ferone
authors.forename: P
authors.initials: P
authors.lastname: Varrella
authors.forename: B
authors.initials: B
authors.lastname: Merola
authors.forename: G
authors.initials: G
authors.lastname: Lombardi
authors.forename: M
authors.initials: M
authors.lastname: Salvatore
mesh_terms: D000224:Addison Disease / Q000097:blood / Q000000981:diagnostic imaging / Q000473:pathology; D000236:Adenoma / Q000097:blood / Q000000981:diagnostic imaging* / Q000473:pathology; D000293:Adolescent; D000324:Adrenocorticotropic Hormone / Q000097:blood; D000328:Adult; D000368:Aged; D002648:Child; D003397:Craniopharyngioma / Q000097:blood / Q000000981:diagnostic imaging / Q000473:pathology; D003936:Diagnosis, Computer-Assisted; D004407:Dysgerminoma / Q000097:blood / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D013006:Growth Hormone / Q000097:blood; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000378:metabolism / Q000473:pathology; D007713:Klinefelter Syndrome / Q000097:blood / Q000000981:diagnostic imaging / Q000473:pathology; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds; D010865:Pilot Projects; D010911:Pituitary Neoplasms / Q000097:blood / Q000000981:diagnostic imaging* / Q000473:pathology; D017698:Postmenopause / Q000378:metabolism / Q000502:physiology; D011388:Prolactin / Q000097:blood; D011877:Radionuclide Imaging; D004113:Succimer; D019783:Technetium Tc 99m Dimercaptosuccinic Acid; D013972:Thyrotropin / Q000097:blood
chemical_list: D015609:Organotechnetium Compounds; D019783:Technetium Tc 99m Dimercaptosuccinic Acid; D000324:Adrenocorticotropic Hormone; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D013972:Thyrotropin; D013006:Growth Hormone; D004113:Succimer