|
|||||
|
|
||||||
Journal of Clinical Oncology, Vol 26, No 7 (March 1), 2008: pp. 1112-1118 © 2008 American Society of Clinical Oncology. DOI: 10.1200/JCO.2008.13.5293 Endocrine Outcomes for Children With Embryonal Brain Tumors After Risk-Adapted Craniospinal and Conformal Primary-Site Irradiation and High-Dose Chemotherapy With Stem-Cell Rescue on the SJMB-96 Trial
From the Division of Neuro-Oncology, Department of Oncology, Division of Radiation Oncology, Department of Radiological Sciences, Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, NY; and Division of Endocrinology, Department of Biostatistics, St Jude Children's Research Hospital, Memphis, TN Corresponding author: Amar Gajjar, MD, Division of Neuro-Oncology, Department of Oncology, St Jude Children's Research Hospital, 332 North Lauderdale St, Memphis, TN 38105; e-mail: amar.gajjar{at}stjude.org
Purpose To estimate the cumulative incidence of specific hormone deficiencies and the influence of hypothalamic-pituitary (HP) axis radiation dose in a cohort of children with embryonal brain tumors treated with risk-adapted craniospinal irradiation (CSI), conformal primary site irradiation, and high-dose chemotherapy. Patients and Methods Clinical data and HP axis radiation dosimetry data were obtained from 88 eligible children. All patients received regular endocrine follow-up that included screening tests of thyroid function and stimulation testing for growth hormone deficiency (GHD), and adrenocorticotropin hormone deficiency.
Results The cumulative incidence of GHD, thyroid-stimulating hormone (TSH) deficiency, adrenocorticotropic hormone deficiency, and primary hypothyroidism at 4 years from diagnosis was 93% ± 4%, 23% ± 8%, 38% ± 6%, and 65% ± 7%, respectively. Radiation dosimetry to the HP axis was associated only with the development of TSH deficiency; the 4-year cumulative incidence was 44% ± 19% and 11% ± 8% (P = .014) for those receiving more or less than the median dose to the hypothalamus ( Conclusion Pediatric patients with CNS embryonal tumors are at high risk for treatment-related hormone deficiencies. GHD and primary hypothyroidism were diagnosed in a majority of subjects relatively soon after the completion of therapy. Radiation dose to the hypothalamus in excess of 42 Gy was associated with an increase in the risk of developing TSH deficiency.
Embryonal brain tumors, which include medulloblastoma, primitive neuroectodermal tumors (PNET), and atypical teratoid/rhabdoid tumors, are the most common malignant brain tumors in children. With modern multimodality therapy, the prognosis for newly diagnosed children older than 3 years of age has improved significantly. The best reported results for children with completely resected, nonmetastatic medulloblastoma show a 5-year overall survival in excess of 80%, whereas those with higher risk disease have a 5-year overall survival approaching 70%.1,2 Survival outcomes for patients with PNET and atypical teratoid/rhabdoid tumors are less favorable than for medulloblastoma in a comparable age group.3-6 Improvement in survival seen with this group of tumors has resulted in an increased emphasis on the quality of the long-term survival. Late effects, such as neurocognitive, neurologic, and neuroendocrine deficits, have been extensively reported after successful therapy in these children.7-10 These effects are likely the result of a complex interaction between the tumor, the different treatment modalities, and individual characteristics in a growing and developing child.11,12 Endocrine deficits after multimodality therapy for brain tumors in children include growth hormone deficiency (GHD) and resultant impaired linear growth, and thyroid hormone, adrenocorticotropic hormone (ACTH), and sex steroid deficiencies.12-16 These deficits significantly impact quality of life and require judicious management. Craniospinal irradiation (CSI) has been a long-established component of care in children with embryonal brain tumors, and damage to the hypothalamic-pituitary (HP) axis is an important factor in the development of endocrinopathies. Endocrine sequelae after irradiation depend on total dose and specific clinical factors, including age.16-19 Previous studies have been either too small, reported on a specific endocrine deficiency, or lacked prospectively collected therapy and endocrine data. Furthermore, long-term endocrine outcomes and their clinical correlates, including HP axis radiation dosimetry, have not been reported in a large cohort of children treated for embryonal brain tumors. At our institution, we have completed a prospective clinical trial (St Jude Medulloblastoma [SJMB]-96) that examined the efficacy of risk-adapted craniospinal and conformal primary site irradiation, and high-dose chemotherapy with autologous stem-cell support after maximal surgical resection.1 In this article, we report the cumulative incidence of HP and thyroid dysfunction in this uniformly treated cohort of children with embryonal brain tumors treated prospectively with risk-adapted therapy.
Patients Between October 1996 and May 2003, 94 children with newly diagnosed, embryonal brain tumors were treated on the SJMB-96 protocol at St Jude Children's Research Hospital (Memphis, TN). Institutional review board approval was received, and written informed consent was obtained from all patients, parents, or legal guardians for trial participation.
Eligibility
RT and Chemotherapy
Clinical Data Collection Basic demographic and clinical characteristics, including specific therapy and disease–related data, were derived from individual patient charts and institutional databases. The hypothalamus and pituitary were separately contoured for each patient on axial T1-weighted, magnetic-resonance imaging (postcontrast) that was coregistered to the treatment planning computed tomography image. Radiation dosimetry was available for 87 of the 88 assessable patients. The mean cumulative dose of radiation to the hypothalamus and pituitary was determined for each patient. The mean cumulative dose of radiation to the thyroid gland could not be accurately assessed in this patient cohort because of practical considerations described in the following paragraph. Craniospinal irradiation includes cranial and spinal fields that are conventionally matched at the base of the neck to shield prevertebral cervical soft tissues, including the larynx and, when possible, the thyroid gland. The junction of the field is moved cephalad in 1-cm increments every five fractions during the treatment course to reduce the risk of spinal cord injury. This may increase exposure of part or all of the thyroid gland to the exit dose of the photon spinal field. When in the path of the radiation beam, the thyroid gland typically receives 70% to 80% of the prescribed spinal exit dose; however, the range may vary widely depending on the size of the patient and other parameters, including measures taken to shape the dose to conform to the anterior and posterior curvature of the spinal canal. More accurate assessment of thyroid dosimetry would require that special maneuvers be performed on a daily basis to measure dose at the level of the thyroid and to monitor patient positioning; these maneuvers have not been practical. Based on our assessment, when all or part of the thyroid gland is subtended by the irradiated volume, the thyroid dose in AR and HR patients would be—with large standard deviations—16 and 25 Gy, respectively.
Endocrine Assessment
Statistical Considerations
The cumulative incidence of hormone deficiency was estimated using the methods proposed by Prentice et al.22 Statistical tests developed by Gray were used to examine the differences in the cumulative incidence of hormone deficiency by radiation dose.23 Height was converted to age and sex-matched z score using EpiInfo, Version 3.3.2 (Centers for Disease Control and Prevention, Atlanta, GA) and Centers for Disease Control and Prevention 2000 growth reference data. A general linear mixed model was used to estimate the change in patients' height z scores during the time interval from the start of RT to the start of GH replacement therapy or the date of the last height measurement. Given that pubertal production of gonadal and adrenal steroids increase GH secretion, only patients who were Tanner stage 1 were included in this analysis; this only excluded three patients. The analysis was adjusted for patients' age at tumor diagnosis. The differences in the intercepts and slopes of the change in height z scores over time by risk group were examined. Statistical significance was determined at the P
Study Population A total of 94 patients were enrolled onto SJMB-96 at St Jude Children's Research Hospital. Five patients died as a result of disease within 1 year of diagnosis. One patient did not receive chemotherapy at parental request and was lost to endocrine follow-up at 1.65 years without any evidence of endocrine deficits, leaving 88 patients for evaluation. Clinical characteristics by risk category are listed in Table 1. Sixteen patients in the cohort have experienced disease progression, with only five receiving additional irradiation at the time of progression as follows: two patients, local RT only; one patient, spinal RT only; and two patients, both local and spinal RT.
Hypothalamus and Pituitary Radiation Dosimetry There was a significant correlation between the radiation dose to the hypothalamus and pituitary ( = 0.75; P < .0001); the median dose to the hypothalamus and pituitary in all patients was 44.0 Gy (range, 26.1 to 57.7 Gy) and 42.1 Gy (range, 26.3 to 56.9 Gy), respectively. The median dose to both structures was significantly higher in the HR group (hypothalamus, 50.5 Gy; pituitary, 49.7 Gy) compared with the AR group (hypothalamus, 38.6 Gy; pituitary, 39.8 Gy; P < .0001). The radiation dose to the hypothalamus is listed in Table 2 by risk category and location of primary tumor. Because the radiation dose to the hypothalamus and pituitary was similar, and the hypothalamus was considered the organ at risk when considering postirradiation growth hormone, ACTH, and TSH deficiencies,24 the current study has correlated the incidence of neuroendocrine dysfunction with the median dose to the hypothalamus.
GH Deficiency GH status was determined for 70 patients (79.5%), of whom 66 (94%) were found to be GHD. GHD was diagnosed at a median of 1.8 years (range, 0.9 to 4.3 years) after the initiation of RT. The cumulative incidence of GHD was 93% ± 4% at 4 years (Fig 2). The radiation dose received by the hypothalamus was similar in patients who developed GHD (median, 42.6 Gy; range, 26.3 to 56.9 Gy) compared with patients who did not (median, 39.4 Gy; range, 33.2 to 42.3 Gy). Furthermore, there was no association between RT dose to the hypothalamus and the cumulative incidence of GHD deficiency (Fig 3A).
TSH Deficiency Thyroid-function test results were available for 87 patients (99%). TSH deficiency was diagnosed in nine patients (10%) at a median of 1.8 years (range, 1.1 to 3.7 years) from the initiation of RT. The 4-year cumulative incidence of TSH deficiency was 23% ± 8% (Fig 2) with a cumulative incidence of 17% ± 9% and 31% ± 15% in AR and HR patients, respectively (P = .049). The median dose to the hypothalamus was higher in patients with TSH deficiency compared with patients who did not develop TSH deficiency (50.1 v 40.7 Gy, respectively), and there was a significant relationship between RT dose to the hypothalamus and the cumulative incidence of TSH deficiency (P = .014), with estimates at 4 years of 44% ± 19% v 11% ± 8% (Fig 3B).
ACTH Deficiency
PHT
Growth
In this article, we describe endocrine outcomes for a large, uniformly treated and comprehensively evaluated cohort of patients with CNS embryonal tumors. The therapeutic approach of the SJMB-96 trial differs from both historical and contemporary studies, and provides the opportunity to compare cure rates as well as examine late effects of therapy. The mean radiation dose to the HP axis in our study was similar to that reported by several other groups who examined HP axis dosimetry in smaller groups of children with medulloblastoma/PNET.11,17,25 The availability of contemporary imaging-based dosimetry has allowed us to correlate uniquely accurate, patient-based HP axis radiation dosimetry data with endocrine outcomes in our patient population. We have confirmed the findings of others that GHD is very common in children treated for intracranial brain tumors, where therapy involves significant radiation doses to the HP axis.12,13,15-17,26-29 The effect of HP axis radiation dose on the cumulative incidence of GHD could not be examined in the current study because 86 of the 88 patients (98%) received more than 27 Gy to the HP axis, which is the reported threshold for almost certain GH dysfunction.30,31 Only a small number of AR patients were not diagnosed with GHD, whereas all HR patients developed GHD. These AR patients had normal values of insulinlike growth factor-1 and insulinlike growth factor-binding protein-3 on their screening tests, and had normal growth or had reached their adult height at the time of enrollment onto the study. The differences in decline in height z score that we observed between the two risk groups may well be due to the differences in radiation doses to the spine between the two groups, given that almost all patients had evidence of GHD and our institutional policy of GH replacement was uniformly applied. The only reported data in children treated with 18 Gy CSI for medulloblastoma indicate GHD requiring GH-replacement therapy in all seven surviving children. However, despite GHD, height was less affected in those treated with 18 Gy CSI compared with children receiving higher dose CSI. Of note, sitting height was relatively preserved in those treated with lower dose CSI, suggesting that the dose of CSI radiation is an important determinant of final height.16,17 By contrast, Gurney et al,26 in reporting final height data from the Childhood Cancer Survivor Study, did not find that spinal radiation seemed to be an independent predictor of reduced growth once HP axis radiation dose was taken into account. Unfortunately, we did not have data on sitting heights to help determine the differential impact of spinal radiation and HP axis radiation on growth. Given the progressive decline in height over time, timely initiation of GH, especially in those diagnosed at a young age, would appear to be both effective and safe.27-32 We have reported a 4-year cumulative incidence of ACTH deficiency in 38% of our cohort, which is higher than the incidence reported by others after similar therapy. No cases of central adrenal insufficiency were reported in a small study (n = 20) by Heikens et al (1998).33 However, insufficiency of the HP-adrenal axis has been reported in up to 29% of patients in cohorts of children treated with cranial irradiation or CSI for brain tumors.12,34,35 It is possible that our results may be related, at least in part, to differences in the type of tests used to assess HP-adrenal function (eg, ACTH stimulation and oral metyrapone v insulin tolerance testing), and the fact that our patients were studied serially and not just at a single point in time.35,36 The cumulative incidence of TSH deficiency of 23% ± 8% at 4 years in the current study is somewhat higher than the 4.5% to 6.3% incidence from other series of childhood brain tumor survivors.14,24 Absolute case numbers in these studies are small, and thus a single case of central hypothyroidism has a significant impact on percentage cumulative incidence. Moreover, our patients were studied serially over time, and thus our numbers more accurately reflect the true incidence of affected patients. We were able to demonstrate a relationship between HP axis radiation dose greater than 42 Gy and the development of TSH, which underscores and reinforces the findings from prior, smaller studies.14,24 Primary hypothyroidism was seen in 51% of our cohort, with a 4-year cumulative incidence of 65%. These results are similar to the incidence of primary hypothyroidism reported by others after standard-dose CSI for medulloblastoma.19,37 The incidence of primary hypothyroidism may be underestimated in our study population in those patients who had superimposed central hypothyroidism. Xu et al17 observed only one case of hypothyroidism in a group of seven surviving children with medulloblastoma treated with 18 Gy CSI. The current, prospective Children's Oncology Group study may help answer whether reduced CSI dose translates into a reduced risk of primary hypothyroidism. Data from this prospective study accurately estimate the incidence of endocrine deficits associated with therapeutically effective irradiation doses to the HP axis and the craniospinal axis currently used for children with embryonal brain tumors. Efforts to reduce long-term endocrine toxicity in this group of patients will need to focus on better ways to minimize HP axis dose and limit the dose to the thyroid gland.
Although all authors completed the disclosure declaration, the following author(s) indicated a financial or other interest that is relevant to the subject matter under consideration in this article. Certain relationships marked with a "U" are those for which no compensation was received; those relationships marked with a "C" were compensated. For a detailed description of the disclosure categories, or for more information about ASCO's conflict of interest policy, please refer to the Author Disclosure Declaration and the Disclosures of Potential Conflicts of Interest section in Information for Contributors. Employment or Leadership Position: None Consultant or Advisory Role: None Stock Ownership: None Honoraria: Charles A. Sklar, Novo Nordisk, Genentech, Pfizer Research Funding: None Expert Testimony: None Other Remuneration: None
Conception and design: Stephen J. Laughton, Thomas E. Merchant, Charles A. Sklar, Larry E. Kun, Amar Gajjar Financial support: Amar Gajjar Administrative support: Amar Gajjar Provision of study materials or patients: Thomas E. Merchant, Larry E. Kun, Maryam Fouladi, Alberto Broniscer, E. Brannon Morris, Robert P. Sanders, Matthew J. Krasin, John Shelso, Amar Gajjar Collection and assembly of data: Stephen J. Laughton, Thomas E. Merchant, Charles A. Sklar, John Shelso, Zang Xiong, Dana Wallace, Amar Gajjar Data analysis and interpretation: Stephen J. Laughton, Thomas E. Merchant, Charles A. Sklar, Larry E. Kun, Maryam Fouladi, Alberto Broniscer, E. Brannon Morris, Robert P. Sanders, Matthew J. Krasin, John Shelso, Zang Xiong, Dana Wallace, Amar Gajjar Manuscript writing: Stephen J. Laughton, Thomas E. Merchant, Charles A. Sklar, Larry E. Kun, Alberto Broniscer, E. Brannon Morris, Robert P. Sanders, Matthew J. Krasin, John Shelso, Zang Xiong, Dana Wallace, Amar Gajjar Final approval of manuscript: Stephen J. Laughton, Thomas E. Merchant, Charles A. Sklar, Larry E. Kun, Amar Gajjar
We thank Robert H. Lustig, MD, Susan R. Rose, MD, and Robert K. Danish, MD, for the clinical endocrine care provided to this cohort of patients; and James M. Boyett, PhD, for his insightful critique and review of the manuscript.
Supported by the Cancer Center (CORE) support Grant No. CA 21765 from the National Institutes of Health, Musicians Against Childhood Cancer (MACC), the Noyes Brain Tumor Foundation, and the American Lebanese Syrian Associated Charities (ALSAC). Presented in part at the 12th International Symposium on Pediatric Neuro-Oncology, June 6-9, 2006, Nara, Japan, and at the 40th Annual Meeting of the American Society of Clinical Oncology, June 1-5, 2007, Chicago, IL. Authors' disclosures of potential conflicts of interest and author contributions are found at the end of this article.
1. Gajjar A, Chintagumpala M, Ashley D, et al: Excellent outcomes after risk-adapted craniospinal radiation therapy followed by a short period of high-dose chemotherapy and stem-cell rescue in children with newly diagnosed medulloblastoma: Results of a prospective multicenter trial (SJMB-96). Lancet Oncol 7:813-820, 2006[Medline] 2. Packer RJ, Gajjar A, Vezina G, et al: Phase III study of craniospinal radiation therapy followed by adjuvant chemotherapy for newly diagnosed average-risk medulloblastoma. J Clin Oncol 24:4202-4208, 2006 3. Timmermann B, Kortmann R-D, Kuhl J, et al: Role of radiotherapy in the treatment of supratentorial primitive neuroectodermal tumors in childhood: Results of the Prospective German Brain Tumor Trials HIT 88/89 and 91. J Clin Oncol 20:842-849, 2002 4. Cohen BH, Zeltzer PM, Boyett JM, et al: Prognostic factors and treatment results for supratentorial primitive neuroectodermal tumors in children using radiation and chemotherapy: A Children's Cancer Group randomized trial. J Clin Oncol 13:1687-1696, 1995 5. Tekautz TM, Fuller CE, Blaney S, et al: Atypical teratoid/rhabdoid tumors (ATRT): Improved survival in children 3 years of age and older with radiation therapy and high-dose alkylator-based chemotherapy. J Clin Oncol 23:1491-1499, 2005 6. Packer RJ, Biegel JA, Blaney S, et al: Atypical teratoid/rhabdoid tumor of the central nervous system: Report on workshop. J Pediatr Hematol Oncol 24:337-342, 2002[CrossRef][Medline] 7. Mulhern RK, Merchant TE, Gajjar A, et al: Late neurocognitive sequelae in survivors of brain tumours in childhood. Lancet Oncol 5:399-408, 2004[CrossRef][Medline] 8. Mulhern RK, Palmer SL, Merchant TE, et al: Neurocognitive consequences of risk-adapted therapy for childhood medulloblastoma. J Clin Oncol 23:5511-5519, 2005 9. Packer RJ, Gurney JG, Punyko JA, et al: Long-term neurologic and neurosensory sequelae in adult survivors of a childhood brain tumor: Childhood cancer survivor study. J Clin Oncol 21:3255-3261, 2003 10. Packer RJ, Meadows AT, Rorke LB, et al: Long-term sequelae of cancer treatment on the central nervous system in childhood. Med Pediatr Oncol 15:241-253, 1987[Medline] 11. Olshan JS, Gubernick J, Packer RJ, et al: The effects of adjuvant chemotherapy on growth in children with medulloblastoma. Cancer 70:2013-2017, 1992[CrossRef][Medline] 12. Spoudeas HA, Charmandari E, Brook CGD: Hypothalamo-pituitary-adrenal axis integrity after cranial irradiation for childhood posterior fossa tumors. Med Pediatr Oncol 40:224-229, 2003[CrossRef][Medline] 13. Pasqualini T, Diez B, Domene H, et al: Long-term endocrine sequelae after surgery, radiotherapy, and chemotherapy in children with medulloblastoma. Cancer 59:801-806, 1987 14. Oberfield SE, Allen JC, Pollack J, et al: Long-term endocrine sequelae after treatment of medulloblastoma: Prospective study of growth and thyroid function. J Pediatr 108:219-223, 1986[CrossRef][Medline] 15. Gurney JG, Kadan-Lottick NS, Packer RJ, et al: Endocrine and cardiovascular late effects among adult survivors of childhood brain tumors: Childhood Cancer Survivor Study. Cancer 97:663-673, 2003[CrossRef][Medline] 16. Xu WZ, Janss A, Moshang T: Adult height and adult sitting height in childhood medulloblastoma survivors. J Clin Endocrinol Metab 88:4677-4681, 2003 17. Xu W, Janss A, Packer RJ, et al: Endocrine outcome in children with medulloblastoma treated with 18 Gy of craniospinal radiation therapy. Neuro-oncol 6:113-118, 2004 18. Merchant TE, Goloubeva O, Pritchard DL, et al: Radiation dose-volume effects on growth hormone secretion. Int J Radiat Oncol Biol Phys 52:1264-1270, 2002[CrossRef][Medline] 19. Chin D, Sklar C, Donahue B, et al: Thyroid dysfunction as a late effect in survivors of pediatric medulloblastoma/primitive neuroectodermal tumors. Cancer 80:798-804, 1997[CrossRef][Medline] 20. Chang CH, Housepian EM, Herbert C Jr: An operative staging system and a megavoltage radiotherapeutic technic for cerebellar medulloblastomas. Radiology 93:1351-1359, 1969[Medline] 21. Rose SR, Danish RK, Kearney NS, et al: ACTH deficiency in childhood cancer survivors. Pediatr Blood Cancer 45:808-813, 2005[CrossRef][Medline] 22. Prentice RL, Kalbfleisch JD, Peterson AV Jr, et al: The analysis of failure times in the presence of competing risks. Biometrics 34:541-554, 1978[CrossRef][Medline] 23. Gray RJ: A class of K-sample tests for comparing the cumulative incidence of a competing risk. Ann Stat 16:1141-1154, 1988[CrossRef] 24. Sklar CA, Constine LS: Chronic neuroendocrinological sequelae of radiation therapy. Int J Radiat Oncol Biol Phys 31:1113-1121, 1995[CrossRef][Medline] 25. Schmiegelow M, Lassen S, Weber L, et al: Dosimetry and growth hormone deficiency following cranial irradiation of childhood brain tumors. Med Pediatr Oncol 33:564-571, 1999[CrossRef][Medline] 26. Gurney JG, Ness KK, Stovall M, et al: Final height and body mass index among adult survivors of childhood brain cancer: Childhood Cancer Survivor Study. J Clin Endocrinol Metab 88:4731-4739, 2003 27. Packer RJ, Boyett JM, Janss AJ, et al: Growth hormone replacement therapy in children with medulloblastoma: Use and effect on tumor control. J Clin Oncol 19:480-487, 2001 28. Brownstein CM, Mertens AC, Mitby PA, et al: Factors that affect final height and change in height standard deviation scores in survivors of childhood cancer treated with growth hormone: A report from the Childhood Cancer Survivor Study. J Clin Endocrinol Metab 89:4422-4427, 2004 29. Shalet SM, Beardwell CG, Pearson D, et al: The effect of varying doses of cerebral irradiation on growth hormone production in childhood. Clin Endocrinol (Oxf) 5:287-290, 1976[Medline] 30. Gleeson HK, Stoeter R, Ogilvy-Stuart AL, et al: Improvements in final height over 25 years in growth hormone (GH)-deficient childhood survivors of brain tumors receiving GH replacement. J Clin Endocrinol Metab 88:3682-3689, 2003 31. Swerdlow AJ, Reddingius RE, Higgins CD, et al: Growth hormone treatment of children with brain tumors and risk of tumor recurrence. J Clin Endocrinol Metab 85:4444-4449, 2000 32. Sklar CA, Mertens AC, Mitby P, et al: Risk of disease recurrence and second neoplasms in survivors of childhood cancer treated with growth hormone: A report from the Childhood Cancer Survivor Study. J Clin Endocrinol Metab 87:3136-3141, 2002 33. Heikens J, Michiels EM, Behrendt H, et al: Long-term neuro-endocrine sequelae after treatment for childhood medulloblastoma. Eur J Cancer 34:1592-1597, 1998[CrossRef][Medline] 34. Schmiegelow M, Feldt-Rasmussen U, Rasmussen AK, et al: Assessment of the hypothalamo-pituitary-adrenal axis in patients treated with radiotherapy and chemotherapy for childhood brain tumor. J Clin Endocrinol Metab 88:3149-3154, 2003 35. Grinspoon SK, Biller BM: Clinical review 62: Laboratory assessment of adrenal insufficiency. J Clin Endocrinol Metab 79:923-931, 1994[CrossRef][Medline] 36. Oelkers W: Adrenal insufficiency. N Engl J Med 335:1206-1212, 1996 37. Paulino AC: Hypothyroidism in children with medulloblastoma: A comparison of 3600 and 2340 cGy craniospinal radiotherapy. Int J Radiat Oncol Biol Phys 53:543-547, 2002[Medline] Submitted July 17, 2007; accepted November 1, 2007.
This article has been cited by other articles:
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|||||||||||
|
Copyright © 2008 by the American Society of Clinical Oncology, Online ISSN: 1527-7755. Print ISSN: 0732-183X
|