Late endocrine sequelae after radiotherapy of pediatric brain tumors are independent of tumor location

Central Endocrine Complications Among Childhood Cancer Survivors Treated With Radiation Therapy: A PENTEC Comprehensive Review

PURPOSE

Children who receive cranial radiation therapy (RT) as a component of treatment for malignancy are often at risk of long-term central endocrine toxicity secondary to radiation to the hypothalamic-pituitary axis (HPA). A comprehensive analysis was performed of central endocrine late effects in survivors of childhood cancer treated with RT as part of the Pediatric Normal Tissue Effects in the Clinic (PENTEC) consortium.

METHODS AND MATERIALS

A systematic review of the risk of RT-related central endocrine effects was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). A total of 4629 publications were identified, of which 16 met criteria for inclusion in dose modeling analysis, with a total of 570 patients in 19 cohorts. Eighteen cohorts reported outcomes for growth hormone deficiency (GHD), 7 reported outcomes for central hypothyroidism (HT), and 6 reported outcomes for adrenocorticotropic hormone (ACTH) deficiency.

RESULTS

Normal tissue complication probability modeling for GHD (18 cohorts, 545 patients) yielded D50 = 24.9 Gy (95% CI, 20.9-28.0) and γ50 = 0.5 (95% CI, 0.27-0.78). The normal tissue complication probability model fit for whole brain irradiation in children with a median age of >5 years indicated a 20% risk of GHD for patients who receive a mean dose of 21 Gy in 2-Gy fractions to the HPA. For HT, among 7 cohorts (250 patients), D50 = 39 Gy (95% CI, 34.1-53.2) and γ50 = 0.81 (95% CI, 0.46-1.35), with a 20% risk of HT in children who receive a mean dose of 22 Gy in 2-Gy fractions to the HPA. For ACTH deficiency (6 cohorts, 230 patients), D50 = 61 Gy (95% CI, 44.7-119.4) and γ50 = 0.76 (95% CI, 0.5-1.19); there is a 20% risk of ACTH deficiency in children who receive a mean dose of 34 Gy in 2-Gy fractions to the HPA.

CONCLUSIONS

RT dose to the HPA increases the risk of central endocrine toxicity, including GHD, HT, and ACTH deficiency. In some clinical situations, these toxicities may be difficult to avoid, and counseling of patients and families with respect to anticipated outcomes is important.

Alterations in hypothalamic-pituitary axis (HPA) hormones 6 months after cranial radiotherapy in adult patients with primary brain tumors outside the HPA region

BACKGROUND

Cranial radiotherapy is a common treatment for brain tumors, but it can affect the hypothalamic-pituitary (H-P) axis and lead to hormonal disorders. This study aimed to compare serum levels of HPA hormones before and after cranial radiation.

MATERIALS AND METHODS

This study involved 27 adult patients who underwent brain tumor resection before the initiation of radiotherapy, and none had metastatic brain tumors. All participants had the HPA within the radiation field, and their tumors were located in brain areas outside from the HPA. Serum levels of HPA hormones were recorded both before and 6 months after cranial radiotherapy.

RESULTS

A total of 27 adult patients, comprising 16 (59.3%) males and 11 (40.7%) females, with a mean age of 56.37 ± 11.38 years, were subjected to evaluation. Six months post-radiotherapy, serum levels of GH and TSH exhibited a significant decrease. Prior to radiotherapy, a substantial and direct correlation was observed between TSH and FSH (p = 0.005) as well as LH (p = 0.014). Additionally, a significant and direct relationship was noted between serum FSH and LH (p < 0.001) before radiotherapy. After radiotherapy, a significant and direct correlation persisted between TSH and FSH (p = 0.003) as well as LH (p = 0.005), along with a significant and direct relationship between serum FSH and LH (p < 0.001). Furthermore, a significant and direct association was identified between changes in serum GH levels and FSH (p = 0.04), as well as between serum LH and FSH (p < 0.001).

CONCLUSION

Reduced serum levels of HPA hormones are a significant complication of cranial radiotherapy and should be evaluated in follow-up assessments.

Giant Pediatric Supratentorial Tumor: Clinical Feature and Surgical Strategy

PURPOSE

To analyze the clinical character of giant pediatric supratentorial tumor (GPST) and explore prognostic factors.

MATERIALS AND METHODS

We analyzed the clinical data comprising of 35 cases of GPST from a single center between January 2015 and December 2020. The tumor volume was measured by 3D slicer software based on preoperative magnetic resonance imaging (MRI). Glasgow Outcome Scale (GOS) was used to evaluate the short-term prognosis.

RESULT

The tumor volume varied from 27.3 to 632.8 ml (mean volume 129.8 ml/ median volume 82.8 ml). Postoperative histopathological types include ependymoma, pilocytic astrocytoma, choroid plexus papilloma (CPP), craniopharyngioma, primitive neuroectoderm tumor (PNET), choroid plexus carcinoma (CPC), immature teratoma, atypical teratoid rhabdoid tumor (AT/RT), anaplastic astrocytoma, and gangliocytoma. Tumors in children younger than 3 years and tumors located at the hemispheres appeared to be larger than their respective counterparts, though no statistical significance was found. A patient with giant immature teratoma died during the operation because of excessive bleeding. Postoperative complications include cerebrospinal fluid subgaleal collection/effusion, infection, neurological deficits, and seizures. The mean GOS score of patients with GPST in 6 months is 3.43 ± 1.12, and 83% of patients (29/35) showed improvement. Favorable GPST characteristics to indicated better GOS included small tumor (≤100 ml) (p = 0.029), low-grade (WHO I-II) (p = 0.001), and gross total resection (GTR) (p = 0.015). WHO grade was highly correlated with GOS score (correlation coefficient = -0.625, p < 0.001). GTR and tumor volume were also correlated (correlation coefficient = -0.428, p = 0.010).

CONCLUSION

The prognosis of GPST is highly correlated with the histopathological type. Smaller tumors are more likely to achieve GTR and might lead to a higher GOS score. Early diagnosis and GTR of the tumor are important for GPST management.

Growth hormone deficiency and other endocrinopathies after childhood brain tumors: results from a close follow-up in a cohort of 242 patients

PURPOSE

Brain tumors are the most common solid tumor in children. The prevalence of survivors from these cancers has been increasing, presenting endocrine sequelae in more than 40% of the cases. Our aim was to characterize the endocrinopathies diagnosed in this population, exploring the outcomes of growth hormone treatment.

METHODS

We have performed a retrospective analysis of the survivors that were followed-up through a close protocol at our endocrine late-effects clinic.

RESULTS

242 survivors, followed during 6.4 (0-23.4) years, were considered. The median age at tumor diagnosis was 6.7 (0-18) years and pilocytic astrocytoma was the most frequent neoplasm (33.5%). The prevalence of endocrinopathies was of 71.5%, with growth hormone deficiency being the most frequent (52.9%). An indirect correlation between the age at the beginning of somatropin and growth velocity in the first year of treatment was observed. Those treated with craniospinal radiotherapy presented a smaller final upper/lower segments ratio comparing with those that only received cranial radiotherapy. However, their final height was not compromised when compared to their family height target. We found pubertal delay in 12%; accelerated/precocious puberty in 13.2%; central and primary hypogonadism in 21.9% and 3.3%, respectively; primary and central hypothyroidism in 23.6% and 14.5%, respectively; thyroid nodules in 7.4%; ACTH deficiency in 10.3% and diabetes insipidus in 12%.

CONCLUSION

This study reveals a higher prevalence of endocrinopathies in brain tumors survivors and explores the influence of craniospinal irradiation in the adult body proportions. It reinforces the importance of routine follow-up among survivors.

Outcomes After Gamma Knife Stereotactic Radiosurgery in Pediatric Patients with Cushing Disease or Acromegaly: A Multi-Institutional Study

OBJECTIVE

Pituitary adenomas comprise about 3% of all intracranial tumors in pediatric patients. This study examines the role of stereotactic radiosurgery in the management of pediatric acromegaly or patients with Cushing disease (CD).

METHODS

From an international consortium, we retrospectively collected treatment and outcome data on pediatric adrenocorticotrophic hormone and growth hormone-secreting pituitary adenomas treated with Gamma Knife radiosurgery (GKRS). There were a total of 36 patients including 24 with CD and 12 with acromegaly. The data were analyzed to assess outcomes including tumor control, endocrine remission, and adverse effects. Statistical analysis was performed to determine correlation between clinical/treatment parameters and outcomes.

RESULTS

At the last follow-up after GKRS, endocrine remission rates for CD and acromegaly were 80% and 42%, respectively. Tumor control was achieved in 87.5% of patients with CD and in 42% of patients with acromegaly. New pituitary hormone deficiency occurred in 7 of the 36 patients at a median time of 18 months after GKRS (range, 12-81 months). The predictive factors for endocrine remission were age <15 years (P = 0.015) and margin dose (P = 0.042). The median endocrine follow-up was 63.7 months (range, 7-246 months).

CONCLUSIONS

GKRS affords reasonable rates of endocrine remission and tumor control in most pediatric patients with functioning adenomas. The most common post-GKRS complication was hypopituitarism, although this occurred in only a few patients. Given the larger at-risk period for pediatric patients, further study is required to evaluate for delayed recurrences and hypopituitarism.

Endocrine Health Problems Detected in 764 Patients Evaluated in a Late Effects Clinic

Background

Many pediatric cancer survivors have endocrine conditions. After treatment with alkylating agents, steroids, methotrexate, and radiation, several endocrine dysfunctions may appear. Surveillance for late effects is recommended by guidelines worldwide.

Objective

The objective of this study was to describe the endocrine outcomes of 764 patients followed during a 20 years' period in our out-patient clinic.

Design

We retrospectively reviewed the medical records.

Patients

The study included 764 patients whose oncological or hematological dangerous diseases appeared before they were 18 years old. Larger groups were constituted by leukemias, central nervous tumors, and lymphomas.

Outcome Measures

The frequency and types of endocrine conditions were analyzed.

Results

1,091 endocrine conditions were observed in all groups. The most common types of endocrine conditions were problems with growth and the thyroid. We found puberty abnormalities and bone problems in third and fourth places of frequency. ACTH insufficiency was found in seventh place.

Conclusion

Endocrine dysfunctions are very common in survivor populations. Endocrinologists should be aware of international guidelines and make an effort to optimize screening and treatment of endocrine effects of cancer therapy. The crucial period is the puberty with growth spurt failure and accelerated maturity both of which can bring future social and professional difficulties.

Outcomes for pediatric patients with central nervous system germ cell tumors treated with proton therapy

Purpose

We assessed outcomes after proton therapy (PT) for central nervous system germinomas or non-germinomatous germ cell tumors (NGGCTs) in children.

Patients and methods

We identified children with germ cell tumors of the central nervous system who received proton therapy in 2006–2009 and extracted information on tumor response, treatment failures, and toxicity.

Results

Of the 20 identified patients (median age 12 years [range 3–16]), 9 had germinoma and 11 NGGCTs; 19 patients received three-dimensional conformal PT and 1 scanning-beam PT. Fourteen patients had craniospinal irradiation (CSI), 4 had ventricular irradiation that excluded the 4th ventricle, and 2 had whole-ventricle irradiation. All received involved-field boosts. At a median follow-up interval of 5.6 years (range, 0.3–8.2 years), 1 patient with germinoma had an out-of-field failure in the 4th ventricle and 2 with NGGCT died from disease progression after CSI. Rates of local control, progression-free survival, and overall survival at 5 years were 89%, 89%, and 100% for patients with germinoma; corresponding rates for NGGCTs were 82%, 82%, and 82%. The most common late toxicity (9 patients [45%]) was endocrinopathy.

Conclusions

PT for CNS germ cell tumors is associated with acceptable disease control rates and toxicity profiles.

Late Effects of Treatment of Pediatric Central Nervous System Tumors

Central nervous system tumors represent the most common solid malignancy in childhood. Improvement in treatment approaches have led to a significant increase in survival rates, with over 70% of children now surviving beyond 5 years. As more and more children with CNS tumors have longer survival times, it is important to be aware of the long-term morbidities caused not only by the tumor itself but also by tumor treatment. The most common side effects including poor neurocognition, endocrine dysfunction, neurological and vascular late effects, as well as secondary malignancies, are discussed within this article.

Results of sequential chemoradiotherapy for intracranial germinoma

PURPOSE

To evaluate the efficacy of sequential chemoradiotherapy (CRT) for intracranial germinoma by long-term follow-up.

MATERIALS AND METHODS

We retrospectively evaluated 23 consecutive intracranial germinoma patients without spinal dissemination, who had been treated by sequential CRT. All patients except for one were biopsied or surgically resected before treatment and all patients received both cranial and spinal magnetic resonance imaging. Three cycles of induction chemotherapy composed of etoposide and platinum agents were administered. The prescription of radiotherapy was 24 Gy per 12 fractions. No patients received spinal irradiation.

RESULTS

All patients accomplished CRT and achieved complete remission. No severe acute and late toxicities were observed. Median follow-up time was 11.8 years. The 5- and 10-year overall survival rates were 100 and 100 %, and relapse-free survival rates were 96 and 89 %, respectively. Three patients developed intracranial recurrence and all of them were successfully salvaged by additional CRT. All patients were alive without disease at final follow-up.

CONCLUSION

Treatment of 24 Gy of sequential CRT for intracranial germinoma might be promising as an alternative to radiotherapy alone. Spinal irradiation may not be necessary for patients who had no spinal dissemination and who were treated with CRT.

Sleep disordered breathing risk in childhood cancer survivors: an exploratory study

BACKGROUND

Sleep disordered breathing (SDB) is emerging as a significant health condition for children. The purpose of this study is to evaluate SDB symptoms in childhood cancer survivors and identify associations with quality of life (QOL) and psychological symptoms.

PROCEDURE

A sample of 62 survivors aged 8-18 years were recruited during routine survivorship visits. All subjects and their parents completed questionnaires to evaluate sleep, QOL and psychological symptoms; scales included were: Pediatric Sleep Questionnaire, Sleep Disordered Breathing Subscale (PSQ-SDBS), Pediatric Quality of Life Inventory (PedsQL) and Depression Anxiety Stress Scale (DASS-21). Continuous data were used for all scales and a threshold score of >0.33 on the PSA-SDBS was used to identify risk of SDB. The relationships between measures of sleep and independent variables were examined using Pearson correlations and multiple linear regression models for significant associations.

RESULTS

Of the 62 subjects enrolled, underlying diagnoses included 29 leukemias, 30 solid tumors and 3 non-malignant diseases. Nineteen percent of subjects were identified as having SDB risk on the PSQ-SDBS. The lowest mean PedsQL subscale score for parent and child ratings were school QOL; Parent mean 73(±SD 19) and Child mean 71(±SD 20). The severity of SDB per the PSQ was significantly associated with reduced total and school QOL which remained significant after adjusting for stress.

CONCLUSIONS

Symptoms suggestive of SDB are common in childhood cancer survivors with negative implications for overall quality of life and school performance.

GH replacement therapy and second neoplasms in adult survivors of childhood cancer: a retrospective study from a single institution

PURPOSE

Growth hormone deficiency (GHD) is the most common endocrine late effect observed in childhood cancer survivors (CCS) previously submitted to cranial irradiation. Radiation therapy can also increase the risk of second neoplasms (SNs). Since in previous studies GH replacement therapy was associated with increased incidence of neoplasia, we explored the association between SNs and GH replacement therapy in a cohort of CCS with GHD.

METHODS

Within the clinical cohort of CCS referred to the Transition Unit for Childhood Cancer Survivors of Turin between November 2001 and December 2012, we considered all patients who developed GHD as a consequence of cancer therapies. GHD was always diagnosed in childhood. To evaluate the quality of data, our cohort was linked to the Childhood Cancer Registry of Piedmont.

RESULTS

GHD was diagnosed in 49 out of 310 CCS included in our clinical cohort. At least one SN was diagnosed in 14 patients, meningioma and basal cell carcinoma being the most common SNs. The cumulative incidence of SNs was similar in GH-treated and -untreated patients (8 SNs out of 26 GH-treated and 6 out of 23 GH-untreated patients; p = 0.331). Age, sex and paediatric cancer type had no impact on SNs development.

CONCLUSIONS

In our CCS, GH replacement therapy does not seem to increase the risk of SNs. Anyway, independently from replacement therapy, in these patients we observed an elevated risk of SNs, possibly related to previous radiation therapy, which suggests the need of a close long-term follow-up.

The impact of surgical resection of giant supratentorial brain tumor in pediatric patients: safety and neurological outcome evaluated in 23 consecutive cases

OBJECTIVE

This study aims to evaluate the impact of gross total resection of giant supratentorial brain tumors (GSBT) on survival and neurological outcome in a consecutive single-center pediatric series.

METHODS

Clinical data of 23 patients under 18 years of age operated with GSBT (≥5 cm in diameter) were reviewed to determine epidemiological aspects, clinical presentation, associated factors, histopathological features, and outcome. Volumetric measurements were performed on magnetic resonance imaging or computed tomography scans obtained at the time of the initial surgical procedure.

RESULTS

The group included 23 patients (mean age 4.5 years). Signs and symptoms of raised intracranial pressure were present in 19 patients (82.6%). The most frequent tumor location was the parietal lobe in 19 patients (82.6%), and the mean tumor volume was 208 cm(3). Gross total or radical resection was achieved in all patients. Histopathological analysis revealed malignant brain tumors in 18 cases (78.2%). The most common neoplasm was choroid plexus carcinoma in seven (30.4 %). Mean intraoperative blood transfusion volume was 51.2 ml/kg. Chemotherapy and/or radiotherapy were performed as adjuvant treatment in 16 patients (69.5%). Mean length of follow-up was 36.7 months. Tumor malignancy grade significantly correlated with recurrence of the disease (P = 0.03) and death (P = 0.01), as opposed to tumor location, size, and extension to the ventricles.

CONCLUSIONS

Our clinical experience suggests that tumor mass reduction by en bloc surgery seems to be an effective approach in pediatric patients with GSBT, relieving symptoms related to raised intracranial pressure and providing a better response to adjuvant treatment.

High prevalence of early hypothalamic-pituitary damage in childhood brain tumor survivors: need for standardized follow-up programs

INTRODUCTION

Childhood brain tumor survivors (CBTS) are at increased risk to develop endocrine disorders. Alerted by two cases who experienced delay in diagnosis of endocrine deficiencies within the first 5 years after brain tumor diagnosis, our aim was to investigate the current screening strategy and the prevalence of endocrine disorders in survivors of a childhood brain tumor outside of the hypothalamic-pituitary region, within the first 5 years after diagnosis.

PROCEDURES

Firstly, we performed a retrospective study of 47 CBTS treated in our center, diagnosed between 2008 and 2012. Secondly, the literature was reviewed for the prevalence of endocrine disorders in CBTS within the first 5 years after diagnosis.

RESULTS

Of 47 CBTS eligible for evaluation, in 34% no endocrine parameters had been documented at all during follow up. In the other 66%, endocrine parameters had been inconsistently checked, with different parameters at different time intervals. In 19% of patients an endocrine disorder was found. At literature review 22 studies were identified. The most common reported endocrine disorder within the first 5 years after diagnosis was growth hormone deficiency (13-100%), followed by primary gonadal dysfunction (0-91%) central hypothyroidism (0-67%) and primary/subclinical hypothyroidism (range 0-64%).

CONCLUSION

Endocrine disorders are frequently seen within the first 5 years after diagnosis of a childhood brain tumor outside of the hypothalamic-pituitary region. Inconsistent endocrine follow up leads to unnecessary delay in diagnosis and treatment. Endocrine care for this specific population should be improved and standardized. Therefore, high-quality studies and evidence based guidelines are warranted.

Growth failure and nutrition considerations in chronic childhood wasting diseases

Growth failure is a common problem in many children with chronic diseases. This article is an overview of the most common causes of growth failure/growth retardation that affect children with a number of chronic diseases. We also briefly review the nutrition considerations and treatment goals. Growth failure is multifactorial in children with chronic conditions, including patients with cystic fibrosis, chronic kidney disease, chronic liver disease, congenital heart disease, human immunodeficiency virus, inflammatory bowel disease, short bowel syndrome, and muscular dystrophies. Important contributory factors to growth failure include increased energy needs, increased energy loss, malabsorption, decreased energy intake, anorexia, pain, vomiting, intestinal obstruction, and inflammatory cytokines. Various metabolic and pathologic abnormalities that are characteristic of chronic diseases further lead to significant malnutrition and growth failure. In addition to treating disease-specific abnormalities, treatment should address the energy and protein deficits, including vitamin and mineral supplements to correct deficiencies, correct metabolic and endocrinologic abnormalities, and include long-term monitoring of weight and growth. Individualized, age-appropriate nutrition intervention will minimize the malnutrition and growth failure seen in children with chronic diseases.

Clinical trials in cellular immunotherapy for brain/CNS tumors

High-grade gliomas are the most common type of primary malignant brain/CNS tumor. There have been only modest advances in surgical techniques, radiotherapy and chemotherapy for high-grade gliomas over the past several decades. None of these have provided a major improvement in survival for patients. Recently, immunotherapy has been explored for the treatment of high-grade gliomas. Immunotherapy capitalizes on the specificity of the host immune system to selectively target tumor cells for destruction, while sparing normal brain parenchyma, thus making it a particularly attractive option. This article provides a comprehensive review of published clinical trials evaluating cellular immunotherapy in primary brain/CNS tumors.

Endocrine health problems detected in 519 patients evaluated in a pediatric cancer survivor program

CONTEXT

Many pediatric cancer survivors have endocrine conditions. Surveillance for late effects is recommended by national guidelines. Endocrine surveillance is recommended after alkylating agents, steroids, methotrexate, and radiation.

OBJECTIVE

The objective of the study was to describe the endocrine outcomes in patients followed up in a program that uses national screening guidelines.

DESIGN

The design of the study was a medical records review.

SETTING

The study was conducted in the Comprehensive Cancer Survivor Program, an academic pediatric oncology program.

PARTICIPANTS

The study included 519 pediatric and young adult survivors of noncentral nervous system childhood malignancies between January 1, 2001, and December 15, 2005.

INTERVENTION

Patients were evaluated with history, physical examinations, and evaluations recommended in the Children's Oncology Group's Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent and Young Adult Cancers.

OUTCOME MEASURES

The frequency and types of endocrine conditions were measured.

RESULTS

Four hundred eighty endocrine conditions were observed in 299 survivors (57.6% of survivors). The most common types of endocrine conditions were problems with weight and gonadal function. In a Cox regression model, stem cell transplant, radiation, and older age at cancer diagnosis were associated with higher hazard of an endocrine condition. Radiation, stem cell transplant, and sarcoma diagnosis were associated with growth problems.

CONCLUSIONS

Endocrine disorders were common after pediatric cancers. Endocrinologists should be aware of national guidelines, anticipate referral of pediatric cancer survivors, and participate in further research to optimize screening for and treatment of endocrine effects of cancer therapy.

Growth hormone secretion after conformal radiation therapy in pediatric patients with localized brain tumors

PURPOSE

Growth hormone deficiency (GHD) after radiation therapy negatively affects growth and development and quality of life in children with brain tumors.

PATIENTS AND MATERIALS

Between 1997 and 2008, 192 pediatric patients with localized primary brain tumors (ependymoma, n = 88; low-grade glioma, n = 51; craniopharyngioma, n = 28; high-grade glioma, n = 23; and other tumor types, n = 2) underwent provocative testing of GH secretion by using the secretogogues arginine and L-dopa before and after (6, 12, 36, and 60 months) conformal radiation therapy (CRT). A total of 664 arginine/l-dopa test procedures were performed.

RESULTS

Baseline testing revealed preirradiation GHD in 22.9% of tested patients. On the basis of data from 118 patients, peak GH was modeled as an exponential function of time after CRT and mean radiation dose to the hypothalamus. The average patient was predicted to develop GHD with the following combinations of the time after CRT and mean dose to the hypothalamus: 12 months and more than 60 Gy; 36 months and 25 to 30 Gy; and 60 months and 15 to 20 Gy. A cumulative dose of 16.1 Gy to the hypothalamus would be considered the mean radiation dose required to achieve a 50% risk of GHD at 5 years (TD(50/5)).

CONCLUSION

GH secretion after CRT can be predicted on the basis of dose and time after irradiation in pediatric patients with localized brain tumors. These findings provide an objective radiation dose constraint for the hypothalamus.

Time course of hypothalamic-pituitary deficiency in adults receiving cranial radiotherapy for primary extrasellar brain tumors

BACKGROUND

No longitudinal data on hypothalamic-pituitary (HP) function are available in patients who had received cranial radiation therapy (CRT) for primary extrasellar brain tumors (PBT).

PURPOSE

To investigate the effects of CRT on HP function in adults with PBT.

PATIENTS AND METHODS

Twenty-six adults irradiated for PBT and six CRT naive controls were studied. CRT was delivered with 6 MV X-ray by a linear accelerator (2 Gy fraction schedule). Gross Tumor Volume (GTV) excluded the HP region that was contoured on the planning CT. Median dose to the HP region was 41.8 Gy (IQR: 30.7-49.8).

RESULTS

All controls maintained normal HP function. Hypopituitarism developed in 38% of CRT patients (GH deficiency 29%, ACTH 22%, TSH 14%, gonadotropin 4%, no abnormal prolactin level or diabetes insipidus). All HP failures occurred within 32 months after CRT.

CONCLUSIONS

Adults undergoing CRT for PBT are at increased risk for HP dysfunction within 3 years from CRT. Endocrine surveillance is recommended also in adults patients exposed to CRT for primary brain tumors distant from HP region.