TY - JOUR
T1 - Biological Effective Dose as a Predictor of Hypopituitarism after Single-Fraction Pituitary Adenoma Radiosurgery
T2 - Dosimetric Analysis and Cohort Study of Patients Treated Using Contemporary Techniques
AU - Graffeo, Christopher S.
AU - Perry, Avital
AU - Link, Michael J.
AU - Brown, Paul D.
AU - Young, William F.
AU - Pollock, Bruce E.
N1 - Publisher Copyright:
© 2021 Congress of Neurological Surgeons 2021.
PY - 2021/4/1
Y1 - 2021/4/1
N2 - BACKGROUND: Hypopituitarism is the most frequent complication after pituitary adenoma stereotactic radiosurgery (SRS) and is correlated with increasing radiation to the pituitary gland. Biological effective dose (BED) is a dosimetric parameter that incorporates a time component to adjust for mechanisms of deoxyribonucleic acid repair activated during treatment. OBJECTIVE: To assess mean gland BED as a predictor of post-SRS hypopituitarism, as compared to mean gland dose, in a contemporary cohort study of patients undergoing single-fraction SRS for pituitary adenoma. METHODS: Cohort study of 97 patients undergoing single-fraction SRS from 2007 to 2014. Eligible patients had no prior pituitary irradiation, normal pre-SRS endocrine function, and >24 mo of endocrine follow-up. Cox proportional hazards analysis was used to assess mean gland dose and BED as predictors of new post-SRS hypopituitarism. RESULTS: Median post-SRS follow-up was 48 mo (interquartile range [IQR], 34-68). A total of 27 patients (28%) developed new hypopituitarism at a median 22 mo (IQR, 12-36). Actuarial rates of new endocrinopathy were 17% at 2 yr (95% CI 10%-25%) and 31% at 5 yr (95% CI 20%-42%). On univariate analysis, sex (P =. 02), gland volume (P =. 03), mean gland dose (P <. 0001), and BED significantly predicted new hypopituitarism (P <. 0001). After adjusting for sex and gland volume, BED > 45 Gy2.47 and mean gland dose > 10 Gy were significantly associated increased risk of hypopituitarism (hazard ratio [HR] = 14.32, 95% CI = 4.26-89.0, P <. 0001; HR = 11.91, 95% CI = 3.54-74.0, P <. 0001). CONCLUSION: BED predicted hypopituitarism more reliably than mean gland dose after pituitary adenoma SRS, but additional studies are needed to confirm these results.
AB - BACKGROUND: Hypopituitarism is the most frequent complication after pituitary adenoma stereotactic radiosurgery (SRS) and is correlated with increasing radiation to the pituitary gland. Biological effective dose (BED) is a dosimetric parameter that incorporates a time component to adjust for mechanisms of deoxyribonucleic acid repair activated during treatment. OBJECTIVE: To assess mean gland BED as a predictor of post-SRS hypopituitarism, as compared to mean gland dose, in a contemporary cohort study of patients undergoing single-fraction SRS for pituitary adenoma. METHODS: Cohort study of 97 patients undergoing single-fraction SRS from 2007 to 2014. Eligible patients had no prior pituitary irradiation, normal pre-SRS endocrine function, and >24 mo of endocrine follow-up. Cox proportional hazards analysis was used to assess mean gland dose and BED as predictors of new post-SRS hypopituitarism. RESULTS: Median post-SRS follow-up was 48 mo (interquartile range [IQR], 34-68). A total of 27 patients (28%) developed new hypopituitarism at a median 22 mo (IQR, 12-36). Actuarial rates of new endocrinopathy were 17% at 2 yr (95% CI 10%-25%) and 31% at 5 yr (95% CI 20%-42%). On univariate analysis, sex (P =. 02), gland volume (P =. 03), mean gland dose (P <. 0001), and BED significantly predicted new hypopituitarism (P <. 0001). After adjusting for sex and gland volume, BED > 45 Gy2.47 and mean gland dose > 10 Gy were significantly associated increased risk of hypopituitarism (hazard ratio [HR] = 14.32, 95% CI = 4.26-89.0, P <. 0001; HR = 11.91, 95% CI = 3.54-74.0, P <. 0001). CONCLUSION: BED predicted hypopituitarism more reliably than mean gland dose after pituitary adenoma SRS, but additional studies are needed to confirm these results.
KW - Biological effective dose
KW - Complications
KW - Hypopituitarism
KW - Pituitary adenoma
KW - Stereotactic radiosurgery
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U2 - 10.1093/neuros/nyaa555
DO - 10.1093/neuros/nyaa555
M3 - Article
C2 - 33469668
AN - SCOPUS:85102964587
SN - 0148-396X
VL - 88
SP - E330-E335
JO - Neurosurgery
JF - Neurosurgery
IS - 4
ER -