Is technetium-99m-MIBI taken up by the normal pituitary gland? A comparison of normal pituitary glands and pituitary adenomas

OBJECTIVE Stereotactic radiosurgery (SRS) provides a safe and effective therapeutic modality for patients with pituitary adenomas. The mechanism of delayed endocrine deficits based on targeted radiation to the hypothalamic-pituitary axis remains unclear. Radiation to normal neuroendocrine structures likely plays a role in delayed hypopituitarism after SRS. In this multicenter study by the International Radiosurgery Research Foundation (IRRF), the authors aimed to evaluate radiation tolerance of structures surrounding pituitary adenomas and identify predictors of delayed hypopituitarism after SRS for these tumors. METHODS This is a retrospective review of patients with pituitary adenomas who underwent single-fraction SRS from 1997 to 2019 at 16 institutions within the IRRF. Dosimetric point measurements of 14 predefined neuroanatomical structures along the hypothalamus, pituitary stalk, and normal pituitary gland were made. Statistical analyses were performed to determine the impact of doses to critical structures on clinical, radiographic, and endocrine outcomes. RESULTS The study cohort comprised 521 pituitary adenomas treated with SRS. Tumor control was achieved in 93.9% of patients over a median follow-up period of 60.1 months, and 22.5% of patients developed new loss of pituitary function with a median treatment volume of 3.2 cm3. Median maximal radiosurgical doses to the hypothalamus, pituitary stalk, and normal pituitary gland were 1.4, 7.2, and 11.3 Gy, respectively. Nonfunctioning adenoma status, younger age, higher margin dose, and higher doses to the pituitary stalk and normal pituitary gland were independent predictors of new or worsening hypopituitarism. Neither the dose to the hypothalamus nor the ratio between doses to the pituitary stalk and gland were significant predictors. The threshold of the median dose to the pituitary stalk for new endocrinopathy was 10.7 Gy in a single fraction (OR 1.77, 95% CI 1.17–2.68, p = 0.006). CONCLUSIONS SRS for the treatment of pituitary adenomas affords a high tumor control rate with an acceptable risk of new or worsening endocrinopathy. This evaluation of point dosimetry to adjacent neuroanatomical structures revealed that doses to the pituitary stalk, with a threshold of 10.7 Gy, and doses to the normal gland significantly increased the risk of post-SRS hypopituitarism. In patients with preserved pre-SRS neuroendocrine function, limiting the dose to the pituitary stalk and gland while still delivering an optimal dose to the tumor appears prudent.

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MRI of pituitary adenomas: the position of the normal pituitary gland

Neuroradiology ◽

10.1007/bf00593264 ◽

1994 ◽

Vol 36 (4) ◽

pp. 295-297 ◽

Cited By ~ 8

Author(s):

M. Sumida ◽

T. Uozumi ◽

K. Mukada ◽

K. Arita ◽

K. Kurisu ◽

...

Keyword(s):

Pituitary Gland ◽

Pituitary Adenomas ◽

Normal Pituitary Gland

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Angiogenesis in Pituitary Adenomas and the Normal Pituitary Gland

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jcem.85.3.6485 ◽

2000 ◽

Vol 85 (3) ◽

pp. 1159-1162 ◽

Cited By ~ 73

Author(s):

Helen E. Turner ◽

Zsusha Nagy ◽

Kevin C. Gatter ◽

Margaret M. Esiri ◽

Adrian L. Harris ◽

...

Keyword(s):

Pituitary Gland ◽

Pituitary Adenomas ◽

Anterior Pituitary ◽

Pituitary Tumors ◽

Anterior Pituitary Gland ◽

Ulex Europaeus ◽

Normal Pituitary Gland ◽

Ulex Europaeus Agglutinin I ◽

Acth Secreting ◽

Tumor Types

Abstract Angiogenesis is essential for tumor growth beyond a few millimeters in diameter, and the intratumoral microvessel count that represents a measure of angiogenesis has been correlated with tumor behavior in a variety of different tumor types. To date no systematic study has assessed pituitary tumors of different secretory types, correlating vascular count with tumor size. The vascular densities of pituitary tumors and normal anterior pituitary were therefore assessed by counting vessels labeled using the vascular markers CD31 and ulex europaeus agglutinin I. One hundred and twelve surgically removed pituitary adenomas (30 GH-secreting, 25 prolactinomas, 15 ACTH-secreting, and 42 nonfunctioning tumors) were compared with 13 specimens of normal anterior pituitary gland. The vascular counts in the normal anterior pituitary gland were significantly higher (P < 0.05) than those in the tumors using both CD31 and ulex europaeus agglutinin I. In addition, microprolactinomas were significantly less vascular (P < 0.05) than macroprolactinomas, although there was no such difference between vascular densities of microadenomas and macroadenomas producing GH. ACTH-secreting tumors were, like microprolactinomas, of much lower vascular density than the normal pituitary and other secreting and nonsecreting tumor types. In marked contrast to other tumors, pituitary adenomas are less vascular than the normal pituitary gland, suggesting that there may be inhibitors of angiogenesis that play an important role in the behavior of these tumors.

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Endocrinological outcome after pituitary transposition (hypophysopexy) and adjuvant radiotherapy for tumors involving the cavernous sinus

Journal of Neurosurgery ◽

10.3171/2011.2.jns10566 ◽

2011 ◽

Vol 115 (1) ◽

pp. 55-62 ◽

Cited By ~ 22

Author(s):

Philipp Taussky ◽

Ricky Kalra ◽

Jeroen Coppens ◽

Jahan Mohebali ◽

Randy Jensen ◽

...

Keyword(s):

Pituitary Gland ◽

Stereotactic Radiosurgery ◽

Cavernous Sinus ◽

Stereotactic Radiotherapy ◽

Pituitary Adenomas ◽

Residual Tumor ◽

Fractionated Stereotactic Radiotherapy ◽

Normal Pituitary Gland ◽

Radiotherapy Treatment

Object Stereotactic radiosurgery and fractionated stereotactic radiotherapy are commonly used in the treatment of residual or recurrent benign tumors of the skull base and cavernous sinus. A major risk associated with radiosurgical or radiotherapy treatment of residual or recurrent tumors adjacent to normal functional pituitary gland is radiation of the pituitary, which frequently leads to the development of hypopituitarism. The authors have used a technique of pituitary transposition to reduce the radiation dose to the normal pituitary gland in cases of planned radiosurgical treatment of residual tumor within the cavernous sinus. Here, the authors analyze the long-term endocrinological outcomes in patients with residual and recurrent tumors who undergo hypophysopexy and adjuvant radiosurgical or conformal fractionated radiotherapy treatment. Methods Pituitary transposition involves placement of a fat graft between the normal pituitary gland and residual tumor in the cavernous sinus. A sellar exploration for tumor resection is performed, the pituitary gland is transposed from the region of the cavernous sinus, and the graft is interposed between the pituitary gland and the residual tumor. The residual tumor may then be treated with stereotactic radiosurgery or conformal fractionated radiation therapy. The authors evaluated endocrinological outcome, safety of the procedure, and postoperative complications in patients who underwent this procedure during a 7-year period. Results Hypophysopexy has been used in 34 patients with nonfunctioning pituitary adenomas (19), functional pituitary adenomas (8), chordomas (2), meningiomas (2), chondrosarcoma (1), hemangiopericytoma (1), or hemangioma (1) involving the sella and cavernous sinus. Follow-up (radiographic and endocrinological) has been performed yearly in all patients. Two patients experienced postoperative endocrine deficits before radiosurgery (1 transient), but none of the patients developed new hypopituitarism during the median 4-year follow-up (range 1–8 years) after radiosurgery or fractionated stereotactic radiotherapy. Conclusions The increased distance between the normal pituitary gland and the residual tumor facilitates treatment of the tumor with radiosurgery or radiotherapy and effectively reduces the incidence of radiation injury to the normal pituitary gland when compared with historical controls.

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Accumulation of 11C-methionine in the normal pituitary gland on 11C-methionine PET

Acta Radiologica ◽

10.1177/0284185116651005 ◽

2016 ◽

Vol 58 (3) ◽

pp. 362-366 ◽

Cited By ~ 5

Author(s):

Noriaki Tomura ◽

Toshiyuiki Saginoya ◽

Yasuaki Mizuno ◽

Hiromi Goto

Keyword(s):

Pituitary Gland ◽

Linear Regression Analysis ◽

Standardized Uptake Value ◽

Pituitary Tumors ◽

Emission Tomography ◽

The Past ◽

Normal Pituitary Gland ◽

Positron Emission ◽

Pet Ct ◽

Pituitary Glands

Background For pituitary tumors, positron emission tomography (PET) with 11C-methonine (MET) has been reported as feasible to facilitate diagnosis. MET is well-known to accumulate in the normal pituitary glands, but almost no studies have examined the degree of MET accumulation in the normal pituitary gland. Purpose To investigate accumulation of MET in normal pituitary gland on PET/CT. Material and Methods Among patients who underwent PET/CT using MET over the past 7 years, 77 patients who fulfilled our criteria for normal pituitary glands were retrospectively selected. Maximum standardized uptake value (SUVmax) for the pituitary gland was measured. Results SUVmax of MET in the pituitary gland was in the range of 0.9–6.6 (mean ± standard deviation = 2.60 ± 1.04). A negative correlation between SUVmax and patient age (y = −0.032 × + 4.29, n = 77, r = 0.55) was found by linear regression analysis. SUVmax of the pituitary gland did not differ significantly between women and men. Conclusion MET shows strong accumulation in normal pituitary gland. PET/CT would thus be feasible to differentiate between normal and abnormal pituitary glands.

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Expression analysis of cyclins in pituitary adenomas and the normal pituitary gland

Clinical Endocrinology ◽

10.1046/j.1365-2265.2000.01088.x ◽

2000 ◽

Vol 53 (3) ◽

pp. 337-344 ◽

Cited By ~ 39

Author(s):

Turner ◽

Nagy ◽

Sullivan ◽

Esiri ◽

Wass

Keyword(s):

Pituitary Gland ◽

Expression Analysis ◽

Pituitary Adenomas ◽

Normal Pituitary Gland

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METABOLIC STUDIES WITH 131I-LABELED THYROXINE. II.

Acta Endocrinologica ◽

10.1530/acta.0.0440475 ◽

1963 ◽

Vol 44 (3) ◽

pp. 475-480 ◽

Cited By ~ 1

Author(s):

R. Grinberg

Keyword(s):

Spinal Cord ◽

Central Nervous System ◽

Nervous System ◽

Optic Nerve ◽

Pituitary Gland ◽

Time Interval ◽

Time Intervals ◽

Pituitary Glands ◽

The Central Nervous System ◽

Tentative Explanation

ABSTRACT Radiologically thyroidectomized female Swiss mice were injected intraperitoneally with 131I-labeled thyroxine (T4*), and were studied at time intervals of 30 minutes and 4, 28, 48 and 72 hours after injection, 10 mice for each time interval. The organs of the central nervous system and the pituitary glands were chromatographed, and likewise serum from the same animal. The chromatographic studies revealed a compound with the same mobility as 131I-labeled triiodothyronine in the organs of the CNS and in the pituitary gland, but this compound was not present in the serum. In most of the chromatographic studies, the peaks for I, T4 and T3 coincided with those for the standards. In several instances, however, such an exact coincidence was lacking. A tentative explanation for the presence of T3* in the pituitary gland following the injection of T4* is a deiodinating system in the pituitary gland or else the capacity of the pituitary gland to concentrate T3* formed in other organs. The presence of T3* is apparently a characteristic of most of the CNS (brain, midbrain, medulla and spinal cord); but in the case of the optic nerve, the compound is not present under the conditions of this study.

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THE EXTRACTION OF PROLACTIN FROM HUMAN PITUITARY GLANDS

Acta Endocrinologica ◽

10.1530/acta.0.0490001 ◽

1965 ◽

Vol 49 (1) ◽

pp. 1-16 ◽

Cited By ~ 12

Author(s):

M. Apostolakis

Keyword(s):

Growth Hormone ◽

Pituitary Gland ◽

List Type ◽

Distilled Water ◽

Hormone Activity ◽

Isoelectric Precipitation ◽

Human Pituitary ◽

Pituitary Glands ◽

Prolactin Content ◽

The Mean

ABSTRACT A method for the extraction of prolactin from human pituitary glands is described. It is based on acetone drying, distilled water extraction, acetone and isoelectric precipitation. Two main products are obtained: Fraction R8 with a mean prolactin activity of 12.2 IU/mg and fraction U8 with a mean prolactin activity of 8.6 IU/mg. The former fraction does not contain any significant gonadotrophin activity and the latter contains on an average 50 HMG U/mg. In both cases contamination with ACTH and MSH is minimal. The growth hormone activity of both these fractions is low. It is postulated that in man too, prolactin and growth hormone are two distinct hormones. A total of 1250 human pituitary glands have been processed by this method. The mean prolactin content per pituitary gland has been found to be 73 IU.

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ACTION OF ENZYME DIGESTED PITUITARY GLANDS OF THE SKIPPER-FROG ON THE OVULATION OF THE SAME

Acta Endocrinologica ◽

10.1530/acta.0.xxxiii0255 ◽

1960 ◽

Vol XXXIII (II) ◽

pp. 255-260 ◽

Cited By ~ 3

Author(s):

L. S. Ramaswami ◽

A. B. Lakshman

Keyword(s):

Pituitary Gland ◽

Constant Temperature ◽

Constant Temperature Bath ◽

Predominant Role ◽

Lower Vertebrates ◽

Pituitary Glands ◽

Stimulating Factor

ABSTRACT By using enzymes, the gonadotrophic factors in the skipper-frog pituitary glands have been selectively inactivated or destroyed. By incubating a known number of pituitary gland homogenate with ptyalin in a constant temperature bath for 5–6 h the follicle-stimulating factor is inactivated; with trypsin or pepsin, the luteinizing factor is inactivated. Bioassay on gravid skipper-frogs indicate that the ptyalin digested homogenate brings about profuse spawning while the trypsin or pepsin digested homogenates do not. When a combination of ptyalin digested and trypsin digested homogenates is injected into fresh gravid skipper-frogs, poor spawning is brought about. These experiments show that the luteinizing factor alone brings about more profuse spawning than when it is combined with the follicle-stimulating factor. It is likely, therefore, that in the lower vertebrates the luteinizing factor of the pituitary gland plays a more predominant role. The exact proportions in which the different dosages for the control and test animals are administered are also tabulated.

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