Hypopituitarism After Single-Fraction Pituitary Adenoma Radiosurgery

Dosimetric Analysis Based on Patients Treated Using Contemporary Techniques

Christopher S. Graffeo, Michael J. Link, Paul D. Brown, William Francis Young, Bruce E. Pollock

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Purpose: To analyze factors associated with post–stereotactic radiosurgery (SRS) hypopituitarism among radiation-naïve patients with pituitary adenomas who underwent single-fraction SRS between 2007 and 2014. Methods and Materials: This was a retrospective review of 97 patients having single-fraction SRS from 2007 until 2014. Eligible patients had no history of prior radiation, normal age- and sex-specific pituitary function before SRS, and at least 24 months of endocrine follow-up. Forty patients (41%) had hormone-secreting tumors; 57 patients had nonsecreting tumors (59%). The median prescription isodose volume was 2.8 cm3 (interquartile range [IQR], 1.3-4.7); the median tumor margin dose was 20 Gy (IQR, 15-25 Gy). Results: The median follow-up after SRS was 48 months (IQR, 34-68 months). Twenty-seven patients (28%) developed pituitary insufficiency at a median of 22 months (IQR, 12-36 months) after SRS. The rate of new endocrine deficits was 17% at 2 years (95% confidence interval [CI] 10%-25%) and 31% at 5 years (95% CI 20%-42%). Male sex (hazard ratio [HR] 2.38, 95% CI 1.05-5.26, P =.04), smaller pituitary gland volume (HR 0.99, 95% CI 0.99-0.99, P =.01), and higher mean pituitary gland dose (HR 1.31, 95% CI 1.16-1.47, P <.001) were associated with post-SRS hypopituitarism in multivariable analysis. The rate of hypopituitarism for patients with a mean gland dose of <11.0 Gy at 2 years was 2% (95% CI 0%-4%) and at 5 years was 5% (95% CI 0%-11%), whereas rate of hypopituitarism for patients with a mean gland dose of ≥11.0 Gy at 2 years was 31% (95% CI 17%-43%) and at 5 years was 51% (95% CI 34%-65%). Conclusions: Hypopituitarism after pituitary adenoma SRS increases in a time- and dose-dependent manner. Reducing the radiation exposure to the identifiable gland to a mean dose < 11.0 Gy whenever feasible may lower the incidence of new hormonal deficits after pituitary adenoma SRS.

Original languageEnglish (US)
JournalInternational Journal of Radiation Oncology Biology Physics
DOIs
StateAccepted/In press - Jan 1 2018

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Hypopituitarism
Radiosurgery
Pituitary Neoplasms
confidence
Confidence Intervals
intervals
dosage
glands
pituitary gland
hazards
tumors
Pituitary Gland
Radiation
Neoplasms
hormones
Sex Ratio
radiation dosage
radiation
Statistical Factor Analysis
Prescriptions

ASJC Scopus subject areas

  • Radiation
  • Oncology
  • Radiology Nuclear Medicine and imaging
  • Cancer Research

Cite this

@article{5c224ee049e74690848eaad35357e7c3,
title = "Hypopituitarism After Single-Fraction Pituitary Adenoma Radiosurgery: Dosimetric Analysis Based on Patients Treated Using Contemporary Techniques",
abstract = "Purpose: To analyze factors associated with post–stereotactic radiosurgery (SRS) hypopituitarism among radiation-na{\"i}ve patients with pituitary adenomas who underwent single-fraction SRS between 2007 and 2014. Methods and Materials: This was a retrospective review of 97 patients having single-fraction SRS from 2007 until 2014. Eligible patients had no history of prior radiation, normal age- and sex-specific pituitary function before SRS, and at least 24 months of endocrine follow-up. Forty patients (41{\%}) had hormone-secreting tumors; 57 patients had nonsecreting tumors (59{\%}). The median prescription isodose volume was 2.8 cm3 (interquartile range [IQR], 1.3-4.7); the median tumor margin dose was 20 Gy (IQR, 15-25 Gy). Results: The median follow-up after SRS was 48 months (IQR, 34-68 months). Twenty-seven patients (28{\%}) developed pituitary insufficiency at a median of 22 months (IQR, 12-36 months) after SRS. The rate of new endocrine deficits was 17{\%} at 2 years (95{\%} confidence interval [CI] 10{\%}-25{\%}) and 31{\%} at 5 years (95{\%} CI 20{\%}-42{\%}). Male sex (hazard ratio [HR] 2.38, 95{\%} CI 1.05-5.26, P =.04), smaller pituitary gland volume (HR 0.99, 95{\%} CI 0.99-0.99, P =.01), and higher mean pituitary gland dose (HR 1.31, 95{\%} CI 1.16-1.47, P <.001) were associated with post-SRS hypopituitarism in multivariable analysis. The rate of hypopituitarism for patients with a mean gland dose of <11.0 Gy at 2 years was 2{\%} (95{\%} CI 0{\%}-4{\%}) and at 5 years was 5{\%} (95{\%} CI 0{\%}-11{\%}), whereas rate of hypopituitarism for patients with a mean gland dose of ≥11.0 Gy at 2 years was 31{\%} (95{\%} CI 17{\%}-43{\%}) and at 5 years was 51{\%} (95{\%} CI 34{\%}-65{\%}). Conclusions: Hypopituitarism after pituitary adenoma SRS increases in a time- and dose-dependent manner. Reducing the radiation exposure to the identifiable gland to a mean dose < 11.0 Gy whenever feasible may lower the incidence of new hormonal deficits after pituitary adenoma SRS.",
author = "Graffeo, {Christopher S.} and Link, {Michael J.} and Brown, {Paul D.} and Young, {William Francis} and Pollock, {Bruce E.}",
year = "2018",
month = "1",
day = "1",
doi = "10.1016/j.ijrobp.2018.02.169",
language = "English (US)",
journal = "International Journal of Radiation Oncology Biology Physics",
issn = "0360-3016",
publisher = "Elsevier Inc.",

}

TY - JOUR

T1 - Hypopituitarism After Single-Fraction Pituitary Adenoma Radiosurgery

T2 - Dosimetric Analysis Based on Patients Treated Using Contemporary Techniques

AU - Graffeo, Christopher S.

AU - Link, Michael J.

AU - Brown, Paul D.

AU - Young, William Francis

AU - Pollock, Bruce E.

PY - 2018/1/1

Y1 - 2018/1/1

N2 - Purpose: To analyze factors associated with post–stereotactic radiosurgery (SRS) hypopituitarism among radiation-naïve patients with pituitary adenomas who underwent single-fraction SRS between 2007 and 2014. Methods and Materials: This was a retrospective review of 97 patients having single-fraction SRS from 2007 until 2014. Eligible patients had no history of prior radiation, normal age- and sex-specific pituitary function before SRS, and at least 24 months of endocrine follow-up. Forty patients (41%) had hormone-secreting tumors; 57 patients had nonsecreting tumors (59%). The median prescription isodose volume was 2.8 cm3 (interquartile range [IQR], 1.3-4.7); the median tumor margin dose was 20 Gy (IQR, 15-25 Gy). Results: The median follow-up after SRS was 48 months (IQR, 34-68 months). Twenty-seven patients (28%) developed pituitary insufficiency at a median of 22 months (IQR, 12-36 months) after SRS. The rate of new endocrine deficits was 17% at 2 years (95% confidence interval [CI] 10%-25%) and 31% at 5 years (95% CI 20%-42%). Male sex (hazard ratio [HR] 2.38, 95% CI 1.05-5.26, P =.04), smaller pituitary gland volume (HR 0.99, 95% CI 0.99-0.99, P =.01), and higher mean pituitary gland dose (HR 1.31, 95% CI 1.16-1.47, P <.001) were associated with post-SRS hypopituitarism in multivariable analysis. The rate of hypopituitarism for patients with a mean gland dose of <11.0 Gy at 2 years was 2% (95% CI 0%-4%) and at 5 years was 5% (95% CI 0%-11%), whereas rate of hypopituitarism for patients with a mean gland dose of ≥11.0 Gy at 2 years was 31% (95% CI 17%-43%) and at 5 years was 51% (95% CI 34%-65%). Conclusions: Hypopituitarism after pituitary adenoma SRS increases in a time- and dose-dependent manner. Reducing the radiation exposure to the identifiable gland to a mean dose < 11.0 Gy whenever feasible may lower the incidence of new hormonal deficits after pituitary adenoma SRS.

AB - Purpose: To analyze factors associated with post–stereotactic radiosurgery (SRS) hypopituitarism among radiation-naïve patients with pituitary adenomas who underwent single-fraction SRS between 2007 and 2014. Methods and Materials: This was a retrospective review of 97 patients having single-fraction SRS from 2007 until 2014. Eligible patients had no history of prior radiation, normal age- and sex-specific pituitary function before SRS, and at least 24 months of endocrine follow-up. Forty patients (41%) had hormone-secreting tumors; 57 patients had nonsecreting tumors (59%). The median prescription isodose volume was 2.8 cm3 (interquartile range [IQR], 1.3-4.7); the median tumor margin dose was 20 Gy (IQR, 15-25 Gy). Results: The median follow-up after SRS was 48 months (IQR, 34-68 months). Twenty-seven patients (28%) developed pituitary insufficiency at a median of 22 months (IQR, 12-36 months) after SRS. The rate of new endocrine deficits was 17% at 2 years (95% confidence interval [CI] 10%-25%) and 31% at 5 years (95% CI 20%-42%). Male sex (hazard ratio [HR] 2.38, 95% CI 1.05-5.26, P =.04), smaller pituitary gland volume (HR 0.99, 95% CI 0.99-0.99, P =.01), and higher mean pituitary gland dose (HR 1.31, 95% CI 1.16-1.47, P <.001) were associated with post-SRS hypopituitarism in multivariable analysis. The rate of hypopituitarism for patients with a mean gland dose of <11.0 Gy at 2 years was 2% (95% CI 0%-4%) and at 5 years was 5% (95% CI 0%-11%), whereas rate of hypopituitarism for patients with a mean gland dose of ≥11.0 Gy at 2 years was 31% (95% CI 17%-43%) and at 5 years was 51% (95% CI 34%-65%). Conclusions: Hypopituitarism after pituitary adenoma SRS increases in a time- and dose-dependent manner. Reducing the radiation exposure to the identifiable gland to a mean dose < 11.0 Gy whenever feasible may lower the incidence of new hormonal deficits after pituitary adenoma SRS.

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DO - 10.1016/j.ijrobp.2018.02.169

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JO - International Journal of Radiation Oncology Biology Physics

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SN - 0360-3016

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