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

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

Annals of Nuclear Medicine ◽

10.1007/bf02988238 ◽

2001 ◽

Vol 15 (4) ◽

pp. 321-327 ◽

Cited By ~ 11

Author(s):

Toyoyuki Kojima ◽

Sunao Mizumura ◽

Shin-ichiro Kumita ◽

Tatsuo Kumazaki ◽

Akira Teramoto

Keyword(s):

Pituitary Gland ◽

Pituitary Adenomas ◽

Technetium 99M ◽

Normal Pituitary Gland ◽

Pituitary Glands

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MENSURATION OF THE NORMAL PITUITARY GLAND FROM MAGNETIC RESONANCE IMAGES IN 96 DOGS

Veterinary Radiology & Ultrasound ◽

10.1111/j.1740-8261.2001.tb00915.x ◽

2001 ◽

Vol 42 (2) ◽

pp. 130-133 ◽

Cited By ~ 13

Author(s):

Hege Kippenes ◽

Patrick R. Gavin ◽

Susan L. Kraft ◽

Ronald D. Sande ◽

Russell L. Tucker

Keyword(s):

Magnetic Resonance ◽

Pituitary Gland ◽

Magnetic Resonance Images ◽

Normal Pituitary Gland

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Pituitary dimensions and volume measurements in pregnancy and post partum

Acta Radiologica ◽

10.1080/02841859809172152 ◽

1998 ◽

Vol 39 (1) ◽

pp. 64-69 ◽

Cited By ~ 4

Author(s):

H. Dinç ◽

F. Esen ◽

A. Demirci ◽

A. Sari ◽

H. Resit Gümele

Keyword(s):

Pituitary Gland ◽

Matched Control ◽

Post Partum ◽

Three Dimensions ◽

Maximum Height ◽

Third Trimester ◽

Normal Pituitary Gland ◽

Volume Measurements ◽

Length Width ◽

The Mean

Purpose: Our purpose was to clarify and further characterize the changes in height, length, width, volume, and shape in the normal pituitary gland and in width in the infundibulum during pregnancy and the first 6 months post partum. Material and Methods: Cranial MR imaging was performed in 78 women who were pregnant in the second or third trimester or who were post partum, and in 18 age-matched control subjects who were not pregnant. Volume measurements were performed in 2 ways; volume 1=1/2xheightxlengthxwidth; and volume 2=area (measured by trackball)xslice thickness Results: Gland volume, height, width, length, and convexity, and infundibular width increased during pregnancy. the highest values were seen during the 3 days immediately post partum. When compared with volunteers, volumes 1 and 2 showed the largest increase (120%) among the parameters. Gland height showed the best correlation (r=0.94, p>0.00001) with gestational age. the mean height of the gland was 8.76 mm in the third trimester. None of the pregnant women had a gland height of above 10 mm during pregnancy. Only 2 subjects had gland heights of 10.04 and 10.2 mm during the 0–3 days post partum. After this first post-partum period of 3 days, the gland size, shape, and volume and the infundibular width returned to normal within 6 months Conclusion: the pituitary gland enlarges in three dimensions throughout pregnancy. During pregnancy, the volume of the gland shows the highest percentage of increase compared to its length, height, and width. the maximum height of the gland does not exceed 10 mm during pregnancy but it may exceed 10 mm during the 3 days immediately post partum.

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The Normal Pituitary Gland

Atlas of Sellar and Parasellar Lesions ◽

10.1007/978-3-319-22855-6_8 ◽

2016 ◽

pp. 91-98

Author(s):

Gabriel Zada ◽

M. Beatriz S. Lopes ◽

Srinivasan Mukundan ◽

Edward Laws

Keyword(s):

Pituitary Gland ◽

Normal Pituitary Gland

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Diseases of the Pituitary Gland

Escourolle and Poirier's Manual of Basic Neuropathology ◽

10.1093/med/9780190675011.003.0014 ◽

2018 ◽

pp. 373-394

Author(s):

Vânia Nosé ◽

Sandro Santagata ◽

Edward R. Laws

Keyword(s):

Cell Differentiation ◽

Infectious Diseases ◽

Pituitary Gland ◽

Pituitary Adenomas ◽

Sella Turcica ◽

Vascular Lesions ◽

Malignant Neoplasms ◽

Systemic Diseases ◽

Pathological Findings ◽

Hormone Production

Diseases of the pituitary gland are common, and the most frequently encountered lesions within the sella turcica and pituitary are described and illustrated in details in this chapter. The lesions present within this chapter include cysts and malformations, vascular lesions, inflammatory disorders, infectious diseases, systemic diseases, and both benign and malignant neoplasms. The most common neoplasms of the pituitary are the pituitary adenomas, and these are described in detail including the numerous subtypes depending on the cell differentiation and hormone production. The chapter contains numerous tables and figures illustrating the pathological findings.

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