Hypopituitarism following radiotherapy

Ionizing radiation induces neurotoxicity in Xenopus laevis embryos through neuroactive ligand-receptor interaction pathway

Ionizing radiation (IR) poses a significant threat to both the natural environment and biological health. Exposure to specific doses of ionizing radiation early in an organism's development can lead to developmental toxicity, particularly neurotoxicity. Through experimentation with Xenopus laevis (X. laevis), we examined the effects of radiation on early developmental stage. Our findings revealed that radiation led to developmental abnormalities and mortality in X. laevis embryos in a dose-dependent manner, disrupting redox homeostasis and inducing cell apoptosis. Additionally, radiation caused neurotoxic effects, resulting in abnormal behavior and neuron damage in the embryos. Further investigation into the underlying mechanisms of radiation-induced neurotoxicity indicated the potential involvement of the neuroactive ligand-receptor interaction pathway, which was supported by RNA-Seq analysis. Validation of gene expression associated with this pathway and analysis of neurotransmitter levels confirmed our hypothesis. In addition, we further validated the important role of this signaling pathway in radiation-induced neurotoxicity through edaravone rescue experiments. This research establishes a valuable model for radiation damage studying and provides some insight into radiation-induced neurotoxicity mechanisms.

Incidence of hypopituitarism in adults undergoing radiotherapy for neck and head cancer: protocol for a systematic review and meta-analysis

INTRODUCTION

When children with head and neck cancer receive radiation therapy as part of their treatment, a considerable frequency of hypopituitarism has been recognised. However, in adults, it has been little studied and it is possible that patients may be inadvertently affected. The objective is to estimate the incidence of anterior pituitary dysfunction in adults undergoing radiotherapy for head and neck cancer.

METHODS AND ANALYSIS

A total of five databases will be used to perform the document search: PubMed, Scopus, Web of Science (Core Collection), Ovid-MEDLINE and Embase. Cohort studies will be included without restriction by language or date. The main outcome will be the incidence of adenohypophyseal dysfunction for each axis: prolactin, growth hormone, thyroid-stimulating hormone, adrenocorticotropic hormone, luteinising hormone and follicle-stimulating hormone. Incidence meta-analysis will be performed using the Freeman-Tukey double arcsine method. In addition, a random-effects model will be used along with a 95% CI. Subgroup analyses will be performed according to tumour location, radiation dose and endocrine assessment time. Meta-regression will be applied according to patient's age and time elapsed until diagnosis.

ETHICS AND DISCLOSURE

Since this will be a systematic review of published data, no ethics committee approval is required. The results will be presented at conferences and finally published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42021235163.

Assessing Quality of Life among Radiation-Induced Hypopituitary Patients

Introduction  Radiation-induced hypopituitarism (RIH) has long been recognized as one of the deleterious side effects of skull base radiation. This study aims to assess the quality of life (QoL) among patients with RIH compared with radiated patients who did not develop hypopituitarism using the validated Anterior Skull Base Questionnaire (ASBQ). Methods  This was a single-institution retrospective cohort study. Included patients had a history of anterior skull base tumor, underwent at least one round of radiation to the skull base, and had filled out at least one ASBQ survey after their radiation treatment. Three statistical models were used to determine the effect of hypopituitarism and treatment on QoL scores. Results  A total of 145 patients met inclusion criteria, and 330 ASBQ surveys were analyzed. Thirty-five percent (51/145) had evidence of RIH at some point after their radiation treatment. Those with hypopituitarism had significantly lower overall ASBQ scores across all three models even after adjusting for potential confounders and intraperson correlation (average decrease of 0.24-0.45 on a 5-point Likert scale; p -values ranging from 0.0004 to 0.018). The increase in QoL with hormonal replacement was modulated by time out from radiation, with long-term survivors (5+ years out from radiation) gaining the most benefit from treatment (increase of 0.89 on a 5-point Likert scale, p 0.0412), especially in the vitality domain. Conclusion  This data demonstrates that hypopituitarism is an independent predictor of lower QoL. Early detection and appropriate treatment are essential to avoid the negative impact of hypopituitarism on QoL.

Early short-term effects on catecholamine levels and pituitary function in patients with pheochromocytoma or paraganglioma treated with [177Lu]Lu-DOTA-TATE therapy

Purpose

While there are reports of treatment-related endocrine disruptions and catecholamine surges in pheochromocytoma/paraganglioma (PPGL) patients treated with [177Lu]Lu-DOTA-TATE therapy, the spectrum of these abnormalities in the immediate post-treatment period (within 48 hours) has not been previously evaluated and is likely underestimated.

Methods

The study population included patients (≥18 years) enrolled in a phase 2 trial for treatment of somatostatin receptor (SSTR)-2+ inoperable/metastatic pheochromocytoma/paraganglioma with [177Lu]Lu-DOTA-TATE (7.4 GBq per cycle for 1 - 4 cycles). Hormonal measurements [adrenocorticotropic hormone (ACTH), cortisol, thyroid stimulating hormone (TSH), free thyroxine (FT4), follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone, estradiol, growth hormone, prolactin], catecholamines, and metanephrines were obtained on days-1, 2, 3, 30, and 60 per cycle as per trial protocol, and were retrospectively analyzed.

Results

Among the 27 patients (age: 54 ± 12.7 years, 48.1% females) who underwent hormonal evaluation, hypoprolactinemia (14.1%), elevated FSH (13.1%), and elevated LH (12.5%) were the most frequent hormonal abnormalities across all 4 cycles combined. On longitudinal follow-up, significant reductions were noted in i. ACTH without corresponding changes in cortisol, ii. TSH, and FT4, and iii. prolactin at or before day-30 of [177Lu]Lu-DOTA-TATE. No significant changes were observed in the gonadotropic axis and GH levels. Levels of all hormones on day-60 were not significantly different from day-1 values, suggesting the transient nature of these changes. However, two patients developed clinical, persistent endocrinopathies (primary hypothyroidism: n=1 male; early menopause: n=1 female). Compared to day-1, a significant % increase in norepinephrine, dopamine, and normetanephrine levels were noted at 24 hours following [177Lu]Lu-DOTA-TATE dose and peaked within 48 hours.

Conclusions

[177Lu]Lu-DOTA-TATE therapy is associated with alterations in endocrine function likely from radiation exposure to SSTR2+ endocrine tissues. However, these changes may sometimes manifest as clinically significant endocrinopathies. It is therefore important to periodically assess endocrine function during [177Lu]Lu-DOTA-TATE therapy, especially among symptomatic patients.

Clinical trial registration

https://clinicaltrials.gov/ct2/show/NCT03206060?term=NCT03206060&draw=2&rank=1, identifier NCT03206060.

Evaluation of endocrinological sequelae following particle therapy performed on anterior skull base lesions in the adult population

Background

Radiotherapy has increasingly assumed a central role in the multidisciplinary treatment of skull base lesions. Unfortunately, it is often burdened by relevant radio-induced damage to the pituitary function and the surrounding structures and systems. Patients who were treated with radiotherapy around the sellar region especially have a high risk of developing radio-induced hypopituitarism. Particle therapy has the potential advantage of delivering a higher radiation dose to the target while potentially sparing the sellar region and pituitary function. The aim of this study is to evaluate the pituitary function in adult patients who have undergone hadron therapy for anterior skull base lesions involving or surrounding the pituitary gland.

Methods

This is a retrospective, observational, and noncontrolled study. We evaluated pituitary and peripheral hormone levels in all patients referring to National Center for Oncological Hadrontherapy, Pavia, Italy for anterior skull base tumors. Furthermore, we performed a magnetic resonance imaging for every follow-up to evaluate potential tumoral growth.

Results

We evaluated 32 patients with different tumoral lesions with a mean follow-up of 27.9 months. The mean hadron therapy (HT) dose was 60 ± 14 Gray, with a mean dose per fraction of 2.3 ± 2.1 Gray. Six patients were treated with carbon ions and 26 with protons. Pituitary hormone alteration of some kind was reported for six patients. No patient experienced unexpected severe adverse events related to particle therapy.

Conclusion

Particle radiotherapy performed on anterior skull base lesions has proved to cause limited damage to pituitary function in the adult population.

Effects on the Hypothalamo-Pituitary Axis in Patients with CNS or Head and Neck Tumors following Radiotherapy

BACKGROUND

Knowledge about the precise effects of radiotherapy on hypothalamo-pituitary functions is limited. Reduction of side effects is a major goal of advanced radiotherapy modalities. We assessed strategies for monitoring and replacement of hormone deficiencies in irradiated patients.

METHODS

A search strategy was systematically conducted on PubMed®. Additional articles were retrieved to describe endocrine mechanisms.

RESULTS

45 studies were evaluated from 2000 to 2022. They were predominantly retrospective and highly heterogeneous concerning patient numbers, tumor types, radiotherapy technique and follow-up. Endocrine deficiencies occurred in about 40% of patients within a median follow-up of 5.6 years without a clear difference between radiotherapy modalities. Somatotropic and thyrotropic axes were, respectively, the most and least radiosensitive.

CONCLUSIONS

Current pituitary gland dose constraints may underestimate radiation-induced endocrine deficiencies, thus impairing quality of life. Little difference might be expected between radiation techniques for PG tumors. For non-PG tumors, dose constraints should be applied more systematically.

Post-Operative Medium- and Long-Term Endocrine Outcomes in Patients with Non-Functioning Pituitary Adenomas-Machine Learning Analysis

Post-operative endocrine outcomes in patients with non-functioning pituitary adenoma (NFPA) are variable. The aim of this study was to use machine learning (ML) models to better predict medium- and long-term post-operative hypopituitarism in patients with NFPAs. We included data from 383 patients who underwent surgery with or without radiotherapy for NFPAs, with a follow-up period between 6 months and 15 years. ML models, including k-nearest neighbour (KNN), support vector machine (SVM), and decision tree models, showed a superior ability to predict panhypopituitarism compared with non-parametric statistical modelling (mean accuracy: 0.89; mean AUC-ROC: 0.79), with SVM achieving the highest performance (mean accuracy: 0.94; mean AUC-ROC: 0.88). Pre-operative endocrine function was the strongest feature for predicting panhypopituitarism within 1 year post-operatively, while endocrine outcomes at 1 year post-operatively supported strong predictions of panhypopituitarism at 5 and 10 years post-operatively. Other features found to contribute to panhypopituitarism prediction were age, volume of tumour, and the use of radiotherapy. In conclusion, our study demonstrates that ML models show potential in predicting post-operative panhypopituitarism in the medium and long term in patients with NFPM. Future work will include incorporating additional, more granular data, including imaging and operative video data, across multiple centres.

Outcomes of Patients Treated in the UK Proton Overseas Programme: Non-central Nervous System Group

AIMS

The UK Proton Overseas Programme (POP) was launched in 2008. The Proton Clinical Outcomes Unit (PCOU) warehouses a centralised registry for collection, curation and analysis of all outcomes data for all National Health Service-funded UK patients referred and treated abroad with proton beam therapy (PBT) via the POP. Outcomes are reported and analysed here for patients diagnosed with non-central nervous system tumours treated from 2008 to September 2020 via the POP.

MATERIALS AND METHODS

All non-central nervous system tumour files for treatments as of 30 September 2020 were interrogated for follow-up information, and type (following CTCAE v4) and time of onset of any late (>90 days post-PBT completion) grade 3-5 toxicities.

RESULTS

Four hundred and ninety-five patients were analysed. The median follow-up was 2.1 years (0-9.3 years). The median age was 11 years (0-69 years). 70.3% of patients were paediatric (<16 years). Rhabdomyosarcoma (RMS) and Ewing sarcoma were the most common diagnoses (42.6% and 34.1%). 51.3% of treated patients were for head and neck (H&N) tumours. At last known follow-up, 86.1% of all patients were alive, with a 2-year survival rate of 88.3% and 2-year local control of 90.3%. Mortality and local control were worse for adults (≥25 years) than for the younger groups. The grade 3 toxicity rate was 12.6%, with a median onset of 2.3 years. Most were in the H&N region in paediatric patients with RMS. Cataracts (30.5%) were the most common, then musculoskeletal deformity (10.1%) and premature menopause (10.1%). Three paediatric patients (1-3 years at treatment) experienced secondary malignancy. Seven grade 4 toxicities occurred (1.6%), all in the H&N region and most in paediatric patients with RMS. Six related to eyes (cataracts, retinopathy, scleral disorder) or ears (hearing impairment).

CONCLUSIONS

This study is the largest to date for RMS and Ewing sarcoma, undergoing multimodality therapy including PBT. It demonstrates good local control, survival and acceptable toxicity rates.

Endothelial Dysfunction in Childhood Cancer Survivors: A Narrative Review

Assessment of endothelial dysfunction in cancer survivors may have a role in the early identification of non-communicable diseases and cardiovascular late effects. Oncological therapies may impair endothelial function. Therefore, in patients such as childhood cancer survivors who could benefit from early cardioprotective pharmacological interventions, it is essential to monitor endothelial function, even if the optimal methodology for investigating the multifaceted aspects of endothelial dysfunction is still under debate. Biochemical markers, as well as invasive and non-invasive tools with and without pharmacological stimuli have been studied. Human clinical studies that have examined lifestyle or cancer treatment protocols have yielded evidence showing the involvement of lipid and lipoprotein levels, glycemic control, blood pressure, adiposity, inflammation, and oxidative stress markers on the state of endothelial health and its role as an early indicator of cardiometabolic risk. However, with regards to pharmacological interventions, cautious interpretation of the result attained whilst monitoring the endothelial function is warranted due to methodological limitations and substantial heterogeneity of the results reported in the published studies. In this narrative review, an overview of evidence from human clinical trials examining the effects of cancer therapies on endothelial disease is provided together with a discussion of endothelial function assessment using the different non-invasive techniques available for researchers and clinicians, in recent years.

Stress Axis in the Cancer Patient: Clinical Aspects and Management

Hypothalamus–pituitary–adrenal (HPA) axis alterations are common in cancer patients, mainly due to the different antitumoral therapies, which lead to several acute and late endocrine side effects. This review summarizes the most recent evidence regarding HPA derangement, both in patients with active neoplasms and in cancer survivors, with particular attention to the impact of the different antitumoral treatments, focusing on the major clinical aspects. While acute hormone failure usually results from injury caused directly by tumor burden or surgical interventions, short- and long-term effects are generally due to chemotherapy, radiotherapy and, as more recently shown, to different types of targeted- and immuno-therapy. Adrenal insufficiency (AI) is mostly caused by pituitary or hypothalamic injury rather than a direct damage of the adrenal gland. Moreover, other treatments commonly employed as supportive therapy or in the context of palliative care (i.e., glucocorticoids, opioids) can lead to HPA dysfunction. Epidemiology and pathophysiology of stress axis alterations in cancer patients still require clarification. Since AI may represent a life-threatening condition, monitoring adrenal function in cancer patients is mandatory, especially in subjects who experience fatigue or during stress conditions, in order to promptly start replacement treatment when needed.

Growth Hormone Deficiency and Treatment in Childhood Cancer Survivors

Growth hormone (GH) deficiency is a common pituitary hormone deficiency in childhood cancer survivors (CCS). The identification, diagnosis, and treatment of those individuals at risk are important in order to minimize associated morbidities that can be ameliorated by treatment with recombinant human GH therapy. However, GH and insulin-like growth factor-I have been implicated in tumorigenesis, so there has been concern over the use of GH therapy in patients with a history of malignancy. Reassuringly, GH therapy has not been shown to increase risk of tumor recurrence. These patients have an increased risk for development of meningiomas, but this may be related to their history of cranial irradiation rather than to GH therapy. In this review, we detail the CCS who are at risk for GHD and the existing evidence on the safety profile of GH therapy in this patient population.

Safety of growth hormone (GH) treatment in GH deficient children and adults treated for cancer and non-malignant intracranial tumors-a review of research and clinical practice

Individuals surviving cancer and brain tumors may experience growth hormone (GH) deficiency as a result of tumor growth, surgical resection and/or radiotherapy involving the hypothalamic-pituitary region. Given the pro-mitogenic and anti-apoptotic properties of GH and insulin-like growth factor-I, the safety of GH replacement in this population has raised hypothetical safety concerns that have been debated for decades. Data from multicenter studies with extended follow-up have generally not found significant associations between GH replacement and cancer recurrence or mortality from cancer among childhood cancer survivors. Potential associations with secondary neoplasms, especially solid tumors, have been reported, although this risk appears to decline with longer follow-up. Data from survivors of pediatric or adult cancers who are treated with GH during adulthood are scarce, and the risk versus benefit profile of GH replacement of this population remains unclear. Studies pertaining to the safety of GH replacement in individuals treated for nonmalignant brain tumors, including craniopharyngioma and non-functioning pituitary adenoma, have generally been reassuring with regards to the risk of tumor recurrence. The present review offers a summary of the most current medical literature regarding GH treatment of patients who have survived cancer and brain tumors, with the emphasis on areas where active research is required and where consensus on clinical practice is lacking.

[Clinical guidelines «Precocious puberty»]

The precocious puberty is an urgent problem of pediatric endocrinology characterized by clinical and pathogenetic heterogeneity. The appearance of secondary sex characteristics before the age of 8 years in girls and 9 years in boys requires timely diagnosis and the appointment of pathogenetically justified treatment in order to achieve the target indicators of final growth and prevent social deprivation. The developed clinical guidelines are the main working tool of the practitioner. They briefly and structurally present the main information about the epidemiology and modern classification of рrecocious puberty, methods of its diagnosis and treatment based on the principles of evidence-based medicine.

Occurrence of pituitary hormone deficits in relation to both pituitary and hypothalamic doses after radiotherapy for skull base meningioma

CONTEXT

Little accurate information is available regarding the risk of hypopituitarism after irradiation of skull base meningiomas.

DESIGN

Retrospective study in a single centre.

PATIENTS

48 patients with a skull base meningioma and normal pituitary function at diagnosis, treated with radiotherapy (RXT) between 1998 and 2017 (median follow-up of 90 months).

MEASUREMENTS

The GH, TSH, LH/FSH and ACTH hormonal axes were evaluated yearly for the entire follow-up period. Mean doses delivered to the pituitary gland (PitD) and the hypothalamus (HypoD) were calculated, as well as the doses responsible for the development of deficits in 50% of patients after 5 years (TD50).

RESULTS

At least one hormone deficit was observed in 38% of irradiated patients and complete hypopituitarism in 13%. The GH (35%), TSH (32%) and LH/FSH axes (28%) were the most frequently affected, while ACTH secretion axis was less altered (13%). The risk of hypopituitarism was independently related to planning target volume (PTV) and to the PitD (threshold dose 45 Gy; TD50 between 50 and 54 Gy). In this series, the risk was less influenced by the HypoD, increasing steadily between doses of 15 and 70 Gy with no clear-cut dose threshold.

CONCLUSIONS

Over a median follow-up period of 7.5 years, hypopituitarism occurred in more than one third of patients irradiated for a skull base meningioma, and this prevalence was time- and dose-dependent. In this setting, the risk of developing hypopituitarism was mainly determined by the irradiated target volume and by the dose delivered to the pituitary gland.

Radiation-induced hypothyroidism in patients with nasopharyngeal carcinoma treated with intensity-modulated radiation therapy with or without chemotherapy: Development of a nomogram based on the equivalent dose

OBJECTIVE

The aim of this study was to establish a nomogram for predicting radiation-induced hypothyroidism (RHT) based on an equivalent dose at 2 Gy per fraction (EQD₂) in patients with nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiation therapy (IMRT) with or without chemotherapy.

METHODS

Two hundred forty-four eligible patients with NPC were recruited for this study. Patients' clinical factors and dose-volume parameters of the thyroid gland were retrieved from medical records and the IMRT treatment planning system, respectively. The irradiation doses were converted into EQD₂ for analysis. Least absolute shrinkage and selection operator (LASSO) regression analysis and multivariate logistic regression analysis were performed to identify optimal predictors of RHT for constructing the nomogram.

RESULTS

With a median follow-up of 63.0 months, the cumulative incidence rates of RHT at 3 months and 1-, 2-, 3-, 4- and 5- year after IMRT were 10.2%, 36.2%, 47.6%, 54.2%, 58.8% and 69.4%, respectively. Four independent factors for predicting RHT, including gender, age, pretreatment volume of the thyroid gland and V_35Gy(3Gy) of the thyroid gland, were identified and incorporated into the nomogram. The area under the ROC curve of the nomogram was 0.747 (95% confidence interval 0.685 - 0.809). Calibration curves and DCA curves showed that the nomogram was in good agreement with the actual observations and clinical usefulness.

CONCLUSIONS

The nomogram proposed in this study provides a reliable estimate of RHT risk in patients with NPC after IMRT and appears to have the potential to be a useful tool for widespread clinical applications.

Examination of the Dose-Effect Relationship of Radiation-Induced Hypopituitarism: Results of a Case-Control Study

Purpose

Previous reports have documented a dose-effect relationship for radiation-induced hypopituitarism in patients receiving therapy near or at the base of the skull. We aimed to characterize this long-term endocrinopathy further by examining the effect of dose on both the incidence and severity of toxicity, as well as exploring a possible dose threshold for this effect.

Methods and Materials

Out of an initial 346 patients who had received radiation therapy to the base of the skull, 53 patients with adequate endocrine evaluation were found. Of these, 19 patients who subsequently developed at least 1 endocrinopathy (cases) as well as 17 patients who did not (controls) were identified, for a total of 36. Patients’ charts were reviewed, and endocrinologic laboratory tests recorded. Treatment plans were reviewed and doses to the hypothalamus and pituitary gland were calculated. One-way analysis of variance was used to determine differences between cases and controls, and Pearson's correlation coefficient was used to relate mean pituitary dose to serum free thyroxine, insulin-like growth factor 1, prolactin, cortisol, and luteinizing hormone.

Results

There were 20 men and 16 women, with a median age of 58. Median follow-up was 32 months (range, 18- 85 months). Median total plan dose delivered was 54 Gy (range, 50.4-70 Gy). Independent sample t tests as well as univariate analysis showed a significantly greater dose to the hypothalamus and pituitary of the cases compared with the controls, while other factors were not significantly different between the 2 groups. There was a statistically significant negative correlation (Pearson's correlation coefficient = -0.65, P = .001) between the mean dose to the pituitary gland and the serum free thyroxine. No case of endocrine toxicity was observed at a mean dose to the pituitary below 30 Gy.

Conclusions

Our results suggest that late endocrinopathy is a true deterministic effect, with a dose threshold, and with both the incidence and severity of toxicity being related to the dose.

Proton Beam Therapy in the Treatment of Periorbital Malignancies

Purpose

Periorbital tumor location presents a significant challenge with 3-dimensional conformal radiation therapy or intensity modulated radiation therapy due to high tumor dose needed in the setting of close proximity to orbital structures with lower tolerance. Proton beam therapy (PBT) is felt to be an effective modality in such cases due to its sharp dose gradient.

Materials and Methods

We reviewed our institutional PBT registry and identified 17 patients with tumor epicenters within 2 cm of the eye and optic apparatus treated with passive scatter PBT with comparison volumetric arc therapy plans available. Maximum and mean doses to organs at risk of interest, including optic nerves, optic chiasm, lens, eye ball, pituitary, cochlea, lacrimal gland, and surrounding brain, were compared using the paired Wilcoxon signed rank test. Overall survival was determined using the Kaplan-Meier method.

Results

Median age was 67. Median follow-up was 19.7 months. Fourteen patients underwent upfront resection and received postoperative radiation and 3 received definitive radiation. One patient received elective neck radiation, 2 underwent reirradiation, and 3 had concurrent chemotherapy. There was a statistically significant reduction in mean dose to the optic nerves and chiasm, brain, pituitary gland, lacrimal glands, and cochlea as well as in the maximum dose to the optic nerves and chiasm, pituitary gland, lacrimal glands, and cochlea with PBT. The 18-month cumulative incidence of local failure was 19.1% and 1-year overall survival was 80.9%.

Conclusion

Proton beam therapy resulted in significant dose reductions to several periorbital and optic structures compared with volumetric arc therapy. Proton beam therapy appears to be the optimal radiation modality in such cases to minimize risk of toxicity to periorbital organs at risk.

Pituitary Function after High-Dose 177Lu-DOTATATE Therapy and Long-Term Follow-Up

INTRODUCTION

The pituitary gland has a high expression of somatostatin receptors and is therefore a potential organ at risk for radiation-induced toxicity after 177Lu-DOTATATE treatment.

OBJECTIVE

To study changes in pituitary function in patients with neuroendocrine tumors (NETs) treated with dosimetry-based 177Lu-DOTATATE to detect possible late toxicity.

METHODS

68 patients from a phase II clinical trial of dosimetry-based, individualized 177Lu-DOTATATE therapy were included in this analysis. Patients had received a median of 5 (range 3-9) treatment cycles of 7.4 GBq/cycle. Median follow-up was 30 months (range 11-89). The GH/IGF-1 axis, gonadotropins, and adrenal and thyroid axes were analyzed at baseline and on a yearly basis thereafter. Percent changes in hormonal levels over time were analyzed statistically using a linear mixed model and described graphically using box plots. The absorbed radiation dose to the pituitary was estimated based on post-therapeutic imaging, and the results analyzed versus percent change in IGF-1 levels over time.

RESULTS

A statistically significant decrease in IGF-1 levels was found (p < 0.005), which correlated with the number of treatment cycles (p = 0.008) and the absorbed radiation dose (p = 0.03). A similar decrease, although non-significant, was seen in gonadotropins in postmenopausal women, while in men there was an increase during the first years after therapy, after which the levels returned to baseline. No change was observed in the adrenal or thyroid axes.

CONCLUSIONS

No signs of severe endocrine disorders were detected, although a significant decrease in the GH/IGF-1 axis was found, where dosimetric analyses indicated radiation-induced damage to the pituitary gland as a probable cause.

Radiotherapy and Late Effects

Advances in multimodality care for patients with pediatric cancer continues to improve long-term survival. The use of surgery, chemotherapy, and radiotherapy may lead to debilitating late effects in childhood cancer survivors. It is critically important to understand, mitigate, and screen for late effects to improve the quality of life in childhood cancer survivors. This review summarizes the use of radiotherapy in children, radiobiology of tissue injury, impact of age on late effects, important organ systems affected by radiotherapy during survivorship, and screening for radiotherapy late effects.

Pre- and postoperative need for pituitary hormone replacement in non-adenomatous sellar and parasellar lesions: importance of the sellar encroachment score

Background

Pre-/postoperative pituitary endocrine deficiencies in patients with sellar/parasellar non-adenomatous lesions are poorly described and studies have not considered the effect of sellar invasion on endocrine outcome. The aim of this study was to relate the need for pituitary hormone replacement pre-/postoperatively, with sellar invasion, in non-adenomatous sellar/parasellar lesions.

Methods

Single-centre review of adults with histologically confirmed non-adenomatous sellar/parasellar lesion and follow-up ≥ 3 months or until postop radiotherapy. Pituitary dysfunction was defined by hormone replacement. The sellar encroachment score (0–6) was calculated as the sum of the thirds of radiological encroachment into the sellar region in the coronal and sagittal planes. Multivariate analysis with binary logistic regression was used to determine factors associated with pituitary hormone replacement.

Results

One hundred and seventeen patients were included with a median age of 49 years (range 16–84 years) and median follow-up of 13 months. Surgery was trans-sphenoidal (53%), trans-cranial (36%) or a combination (11%). The commonest histology types were meningioma (n = 33, 28%) and craniopharyngioma (n = 20, 17%). The median sellar encroachment score was 6 (range 0–6). Most (n = 86, 74%) did not require pituitary hormone replacement preoperatively. The need for pituitary hormones increased after surgery in 41 (35%) patients. In multivariate analysis, the sellar encroachment score was the only factor predictive of pre- (OR = 2.6, 95% CI = 1.2–5.5; p = 0.01) and postoperative risk of new pituitary hormone replacement (OR = 4.1, 95% CI = 1.7–10.1, p = 0.002).

Conclusion

A significant proportion of these patients present with need for pituitary hormone replacement that may worsen postoperatively. The degree of sellar encroachment is predictive of pituitary hormone replacement status pre-/postoperatively.

Bone Health Management After Hematopoietic Cell Transplantation: An Expert Panel Opinion from the American Society for Transplantation and Cellular Therapy

Bone health disturbances commonly occur after hematopoietic cell transplantation (HCT) with loss of bone mineral density (BMD) and avascular necrosis (AVN) foremost among them. BMD loss is related to pretransplantation chemotherapy and radiation exposure and immunosuppressive therapy for graft-versus-host-disease (GVHD) and results from deficiencies in growth or gonadal hormones, disturbances in calcium and vitamin D homeostasis, as well as osteoblast and osteoclast dysfunction. Although the pathophysiology of AVN remains unclear, high-dose glucocorticoid exposure is the most frequent association. Various societal treatment guidelines for osteoporosis exist, but the focus is mainly on menopausal-associated osteoporosis. HCT survivors comprise a distinct population with unique comorbidities, making general approaches to bone health management inappropriate in some cases. To address a core set of 16 frequently asked questions (FAQs) relevant to bone health in HCT, the American Society of Transplant and Cellular Therapy Committee on Practice Guidelines convened a panel of experts in HCT, adult and pediatric endocrinology, orthopedics, and oral medicine. Owing to a lack of relevant prospective controlled clinical trials that specifically address bone health in HCT, the answers to the FAQs rely on evidence derived from retrospective HCT studies, results extrapolated from prospective studies in non-HCT settings, relevant societal guidelines, and expert panel opinion. Given the heterogenous comorbidities and needs of individual HCT recipients, answers to FAQs in this article should be considered general recommendations, with good medical practice and judgment ultimately dictating care of individual patients. Readers are referred to the Supplementary Material for answers to additional FAQs that did not make the core set.

Peptide Hormone Regulation of DNA Damage Responses

DNA damage response (DDR) and DNA repair pathways determine neoplastic cell transformation and therapeutic responses, as well as the aging process. Altered DDR functioning results in accumulation of unrepaired DNA damage, increased frequency of tumorigenic mutations, and premature aging. Recent evidence suggests that polypeptide hormones play a role in modulating DDR and DNA damage repair, while DNA damage accumulation may also affect hormonal status. We review the available reports elucidating involvement of insulin-like growth factor 1 (IGF1), growth hormone (GH), α-melanocyte stimulating hormone (αMSH), and gonadotropin-releasing hormone (GnRH)/gonadotropins in DDR and DNA repair as well as the current understanding of pathways enabling these actions. We discuss effects of DNA damage pathway mutations, including Fanconi anemia, on endocrine function and consider mechanisms underlying these phenotypes. (Endocrine Reviews 41: 1 - 19, 2020).

Myalgia and Hematuria in Association with Clonidine and Arginine Administration for Growth Hormone Stimulation Tests

Growth hormone deficiency (GHD) in children has significant impacts on growth and metabolism. Two-agent GH stimulation tests are commonly used to diagnose GHD, and these tests are generally considered safe. We report the case of a 5-year 5-month-old boy with a history of anaplastic ependymoma who underwent GH stimulation testing for growth deceleration using clonidine and arginine. He developed bilateral calf myalgia and gross hematuria within 24 hours of the tests. Myalgia and hematuria resolved spontaneously. Importantly, the literature review and database searches for hematuria identified 6 cases with clonidine and 20 cases with arginine. This case highlights an unusual combination of adverse reactions to clonidine and arginine in children undergoing GH stimulation testing to assess for GHD. Pediatric endocrinologists need to be aware of the potential for these side effects to allow appropriate management, and further studies are needed to clarify the mechanisms and frequency of these side effects. We recommend that patients and families need to be counselled about hematuria as an association of GH testing with these medications.

Oncology and Cardiac Rehabilitation: An Underrated Relationship

Cancer and cardiovascular diseases are globally the leading causes of mortality and morbidity. These conditions are closely related, beyond that of sharing many risk factors. The term bidirectional relationship indicates that cardiovascular diseases increase the likelihood of getting cancer and vice versa. The biological and biochemical pathways underlying this close relationship will be analyzed. In this new overlapping scenario, physical activity and exercise are proven protective behaviors against both cardiovascular diseases and cancer. Many observational studies link an increase in physical activity to a reduction in either the development or progression of cancer, as well as to a reduction in risk in cardiovascular diseases, a non-negligible cause of death for long-term cancer survivors. Exercise is an effective tool for improving cardio-respiratory fitness, quality of life, psychological wellbeing, reducing fatigue, anxiety and depression. Finally, it can counteract the toxic effects of cancer therapy. The protection obtained from physical activity and exercise will be discussed in the various stages of the cancer continuum, from diagnosis, to adjuvant therapy, and from the metastatic phase to long-term effects. Particular attention will be paid to the shelter against chemotherapy, radiotherapy, cardiovascular risk factors or new onset cardiovascular diseases. Cardio-Oncology Rehabilitation is an exercise-based multi-component intervention, starting from the model of Cardiac Rehabilitation, with few modifications, to improve care and the prognosis of a patient's cancer. The network of professionals dedicated to Cardiac Rehabilitation is a ready-to-use resource, for implementing Cardio-Oncology Rehabilitation.

Pituitary Dysfunction after Radiation for Anterior Skull Base Malignancies: Incidence and Screening

Background  Management of anterior cranial base malignancies requires multidisciplinary care. Radiation therapy remains a mainstay of definitive or adjuvant treatment. Apart from primary hypothyroidism, the effects of radiation on the hypothalamic-pituitary axis after high-dose treatment of head and neck malignancies remain poorly described. We describe a comprehensive screening protocol for surveillance and characterize the incidence of pituitary dysfunction after radiation for anterior cranial base malignancies. Methods  A review of patients prospectively enrolled in a skull base registry at an academic center was performed. Included patients had a history of anterior skull base malignancy and external beam radiation to the primary site, with comprehensive post-treatment pituitary serologies and at least 1 year of post-radiation follow-up. Routine hormonal screening was initiated during the study period for all patients with anterior skull base irradiation. Results  Eighty-one patients met inclusion. Fifty-eight patients (71%) demonstrated some laboratory abnormality. Thirty patients (37%) demonstrated evidence of hypopituitarism. Twenty-four (29%) demonstrated central hypogonadism, and 16% of patients showed central hypothyroidism. Ten patients (12%) displayed central adrenal insufficiency with six patients demonstrating panhypopituitarism. Primary tumor location and maximum dose of radiation to the gland appeared to correlate with incidence of hypopituitarism. Conclusion  Radiation for malignancies of the anterior skull base resulted in a 37% incidence of hypopituitarism in our study. Given the potential morbidity of hypopituitarism, we recommend annual post-treatment screening in these patients. We describe a comprehensive set of serologies that can be utilized, and recommend updating clinical guidelines to reflect the necessity of this screening.

Late Effects of Parasellar Lesion Treatment: Hypogonadism and Infertility

Central hypogonadism, also defined as hypogonadotropic hypogonadism, is a recognized complication of hypothalamic-pituitary-gonadal axis damage following treatment of sellar and parasellar masses. In addition to radiotherapy and surgery, CTLA4-blocking antibodies and alkylating agents such as temozolomide can also lead to hypogonadism, through different mechanisms. Central hypogonadism in boys and girls may lead to pubertal delay or arrest, impairing full development of the genitalia and secondary sexual characteristics. Alternatively, cranial irradiation or ectopic hormone production may instead cause early puberty, affecting hypothalamic control of the gonadostat. Given the reproductive risks, discussion of fertility preservation options and referral to reproductive specialists before treatment is essential. Steroid hormone replacement can interfere with other replacement therapies and may require specific dose adjustments. Adequate gonadotropin stimulation therapy may enable patients to restore gametogenesis and conceive spontaneously. When assisted reproductive technology is needed, protocols must be tailored to account for possible long-term gonadotropin insufficiency prior to stimulation. The aim of this review was to provide an overview of the risk factors for hypogonadism and infertility in patients treated for parasellar lesions and to give a summary of the current recommendations for management and follow-up of these dysfunctions in such patients. We have also briefly summarized evidence on the physiological role of pituitary hormones during pregnancy, focusing on the management of pituitary deficiencies.

Thyroid Sequelae of Pediatric Cancer Therapy

The hypothalamic-pituitary-thyroid axis is a common site of unintended, acquired disease either during or after the treatment of cancer. Children treated with external radiation therapy are at the highest risk for developing a thyroid-related late effect, but thyroid dysfunction and second primary thyroid neoplasms can also occur after treatment with radiopharmaceutical agents such as 131I-metaiodobenzylguanidine. Increasingly recognized is the development of early thyroid dysfunction as an off-target consequence of the more novel cancer therapeutics such as the tyrosine kinase inhibitors and immune checkpoint inhibitors. Thyroid sequelae resulting from irradiation may manifest only after years to decades of follow-up, and their resultant clinical symptoms may be indolent and non-specific. Therefore, lifelong monitoring of the childhood cancer survivor at risk for thyroid disease is paramount. In this comprehensive review, the myriad thyroid adverse effects resulting from pediatric cancer treatment are discussed and an overview of screening and treatment of these thyroid sequelae provided.

Are hypothalamic- pituitary (HP) axis deficiencies after whole brain radiotherapy (WBRT) of relevance for adult cancer patients? - a systematic review of the literature

Background

Cranial radiotherapy (cRT) can induce hormonal deficiencies as a consequence of significant doses to the hypothalamic-pituitary (HP) axis. In contrast to profound endocrinological follow-up data from survivors of childhood cancer treated with cRT, little knowledge exists for adult cancer patients.

Methods

A systematic search of the literature was conducted using the PubMed database and the Cochrane library offering the basis for our debate of the relevance of HP axis impairment after cRT in adult cancer patients. Against the background of potential relevance for patients receiving whole brain radiotherapy (WBRT), a particular focus was set on the temporal onset of hypopituitarism and the radiation dose to the HP axis.

Results

Twenty-eight original papers with a total of 1728 patients met the inclusion criteria. Radiation doses to the HP area ranged from 4 to 97 Gray (Gy). Hypopituitarism incidences ranged from 20 to 93% for adult patients with nasopharyngeal cancer or non-pituitary brain tumors. No study focused particularly on hypopituitarism after WBRT. The onset of hypopituitarism occurred as early as within the first year following cRT (range: 3 months to 25.6 years). However, since most studies started follow-up evaluation only several years after cRT, early onset of hypopituitarism might have gone unnoticed.

Conclusion

Hypopituitarism occurs frequently after cRT in adult cancer patients. Despite the general conception that it develops only after several years, onset of endocrine sequelae can occur within the first year after cRT without a clear threshold. This finding is worth debating particularly in respect of treatment options for patients with brain metastases and favorable survival prognoses.

Prevalence of metastases within the hypothalamic-pituitary area in patients with brain metastases

Aim

To quantify the prevalence of brain metastases involving the hypothalamic-pituitary (HT-P) area.

Introduction

Cognitive impairment and fatigue are common side effects of whole brain irradiation (WBI) comprising the quality of life (QoL) for survivors. While the former is related to radiation-induced hippocampal injury, the latter could be secondary to hormonal disbalance as a consequence of radiation of the HT-P area. Thus, sparing both regions from higher irradiation doses could reduce these sequelae.

Methods

T1 contrast medium enhanced magnetic resonance imaging (MRI) scans of 865 patients with brain metastases (4,280 metastases) were reviewed. HT-P area was individually contoured with a margin of 5 mm in order to evaluate the prevalence of brain metastases in this region.

Results

Involvement of the hypothalamic region was found in 26 patients (involvement rate of 3% for patients and 1% for metastases), involvement of the pituitary gland in 9 patients (1% for patients and < 1% for metastases). Binary logistical regression analysis revealed the presence of > 10 brain metastases as the only factor associated with hypothalamic involvement while no distinct factor was associated with an involvement of the pituitary gland.

Conclusion

The low prevalence of metastases within the HT-P area in patients with brain metastases calls for further studies examining whether sparing of this region might improve patients QoL.

Hypothalamic-pituitary axis irradiation dose thresholds for the development of hypopituitarism in adult-onset gliomas

BACKGROUND

Childhood brain tumour survivors who receive cranial radiotherapy undergo regular surveillance for the development ofhypothalamic-pituitary (HP) axis dysfunction. Much less attention has been given to radiation-induced hypopituitarism in patients with malignant brain tumours of adult onset.

DESIGN

Retrospective cohort study.

PATIENTS/MEASUREMENTS

We assessed the effects of cranial radiotherapy (cXRT) on pituitary function in 58 adults (32 male) with gliomas distant to the HP axis. The XRT dose exposure at the HP axis was correlated with individual axis dysfunction to establish dose thresholds.

RESULTS

Mean age at cXRT was 41.2 ± 10.9 years and duration of endocrine follow-up 8.2 ± 5.2 years. Mean XRT dose to the HP axis was 35.9 ± 15.5 Gy. Overall prevalence of radiation-induced hypopituitarism was 84.5%. GH, LH/FSH, ACTH and TSH deficiency were present in 82.8%, 20.7%, 19% and 6.9% of patients, respectively. Hyperprolactinaemia was noted in 10.3% (n = 6) and was persistent in one case. GH deficiency and "any degree of hypopituitarism" positively correlated with the radiotherapy dose to the hypothalamic-pituitary axis. HP axis XRT dose thresholds for the development of GHD, LH/FSH, ACTH and TSH deficiency were established at 10, 30, 32 and 40.8 Gy, respectively. A gradual increase in the prevalence of all anterior pituitary hormone deficits was observed throughout the follow-up period.

CONCLUSIONS

Hypopituitarism post-cXRT in adults with gliomas is a frequent, progressive and dose-dependent phenomenon. Dose thresholds suggest long-term endocrine surveillance is important where the HP axis XRT dose is higher than 30 Gy. Identification of deficits to allow early and appropriate hormone replacement therapy is important to improve well-being in these individuals with limited prognosis.

Fatigue following radiation therapy in nasopharyngeal cancer survivors: A dosimetric analysis incorporating patient report and observer rating

PURPOSE

To explore for fatigue-related regions and the radiotherapy (RT) dose-fatigue relationship in nasopharyngeal cancer (NPC) survivors.

METHODS

Eighty disease-free NPC survivors completed the MD Anderson Symptom Inventory-Head and Neck module (MDASI-HN) after RT. Fatigue was evaluated by the MDASI-HN fatigue item (MDASI-HN-F) and Common Terminology Criteria for Adverse Events v3.0 (CTC-AE), between 6 and 36 months after RT to determine the presence of chronic fatigue. Skull base MRIs and planning CT/RT dose were retrievable for 56 patients. Dosimetric data were extracted for 10 MRI-defined potential fatigue at-risk structures (FARS): brainstem (BS), pituitary gland (PG), hypothalamus (HT), basal ganglia, internal capsule, pineal gland, sub-thalamic nuclei, thalamus, substantia nigra, and hippocampus (HC). Recursive partitioning analysis (RPA) was used to identify dose-volume effects associated with chronic fatigue.

RESULTS

56 pts formed the cohort. Thirty patients (54%) reported any fatigue per MDASI-HN-F. Thirty-three pts (59%) had any fatigue by CTC-AE. The maximum point doses (Dmax) for PG, BS, HC, and HT were numerically higher in patients with fatigue. Dmax and Dmean of the PG were significantly higher in patients with chronic fatigue, p ≤ 0.01. A dose-volume threshold of PG V52 Gy ≥16% (LogWorth 2.4, AUC 0.7) was identified on RPA, and potential sensitivity to the PG doses was observed in younger patients (<53 years-old).

CONCLUSION

A dose-fatigue relationship was identified for the pituitary gland, both patient-reported and observer ratings. We recommend limiting the Dmax of PG to <54 Gy and V52 Gy to <16%, particularly in young NPC patients, during plan optimization when achievable.

Whole-ventricular irradiation for intracranial germ cell tumors: Dosimetric comparison of pencil beam scanned protons, intensity-modulated radiotherapy and volumetric-modulated arc therapy

Background

Whole-ventricular radiotherapy (WV-RT) followed by a boost to the tumor bed (WV-RT/TB) is recommended for intracranial germ cell tumors (IGCT). As the critical brain areas are mainly in the target volume vicinity, it is unclear if protons indeed substantially spare neurofunctional organs at risk (NOAR). Therefore, a dosimetric comparison study of WV-RT/TB was conducted to assess whether proton or photon radiotherapy achieves better NOAR sparing.

Methods

Eleven children with GCT received 24 Gy(RBE) WV-RT and a boost up to 40 Gy(RBE) in 25 fractions of 1.6 Gy(RBE) with pencil beam scanning proton therapy (PBS-PT). Intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) plans were generated for these patients. NOAR were delineated and treatment plans were compared for target volume coverage (TVC), homogeneity index (HI), inhomogeneity coefficient (IC) and (N)OAR sparing.

Results

TVC was comparable for all three modalities. Compared to IMRT and VMAT, PBS-PT showed statistically significant optimized IC, as well as dose reduction, among others, in mean and integral dose to the: normal brain (-35.2%, -32.7%; -35.2%, -33.0%, respectively), cerebellum (-53.7%, -33.1%; -53.6%, -32.7%) and right temporal lobe (-14.5%, -31.9%; -14.7%, -29.9%). The Willis' circle was better protected with PBS-PT than IMRT (-7.1%; -7.8%). The left hippocampus sparing was higher with IMRT. Compared to VMAT, the dose to the hippocampi, amygdalae and temporal lobes was significantly decreased in the IMRT plans.

Conclusions

Dosimetric comparison of WV-RT/TB in IGCT suggests PBS-PT's advantage over photons in conformality and NOAR sparing, whereas IMRT's superiority over VMAT, thus potentially minimizing long-term sequelae.

Metabolic syndrome is a sequela of radiation exposure in hypothalamic obesity among survivors of childhood brain tumors

Survivors of childhood brain tumors may be at risk for early onset of metabolic syndrome, possibly secondary to surgery and/or radiation exposure. This study examines effects of radiation exposure to hypothalamus-pituitary-adrenal axis (HPA) on metabolic risk among survivors of childhood brain tumors. One hundred forty-two met inclusion criteria; 60 had tumor surgery plus radiation exposure (>1 Gray (Gy)) to HPA. The second subgroup of 82 subjects had surgery only and were not exposed to radiation. Both subgroups had survived for approximately 5 years at the time of study. All had clinical evaluation, vital signs, anthropometry, measurement of body composition by dual X-ray absorptiometry and fasting laboratory assays (metabolic panel, insulin, C-peptide, insulin-like growth factor-1, leptin and adiponectin). Body composition data for both subgroups was compared with the National Health and Nutrition Survey (NHANES) subgroup of similar age, gender and body mass index. Cranial surgery was associated with obesity of similar severity in both subgroups. However, survivors exposed to radiation to the HPA also had increased visceral fat mass and high prevalence of growth hormone deficiency and metabolic syndrome. Fat mass alone did not explain the prevalence of the metabolic syndrome in radiation exposure subgroup. Other factors such as growth hormone deficiency may have contributed to metabolic risk. We conclude that prevalence of metabolic syndrome among subjects exposed to hypothalamic radiation was higher than expected from hypothalamic obesity alone. Radiation exposure may exert untoward endocrinopathies due to HPA exposure that worsens metabolic risk. Early screening for metabolic syndrome in this population is indicated.

Reversible Non-parkinsonian Bradykinesia with Impaired Frontal Lobe Function as the Predominant Manifestation of Adrenal Insufficiency

A 69-year-old Japanese man with a history of suprasellar surgery and irradiation developed bradykinesia and mild fatigue without muscle weakness, myalgia, pyramidal or extrapyramidal signs, parkinsonian symptoms, or ataxia. An endocrinological work-up revealed anterior hypopituitarism associated with secondary adrenal insufficiency. Higher brain function tests indicated an impaired frontal lobe function. The patient's bradykinesia, fatigue, and frontal lobe dysfunction improved within 2 weeks after the initiation of corticosteroid replacement therapy. To our knowledge, this is the first reported case of adrenal insufficiency manifesting as non-parkinsonian bradykinesia. Physicians should consider reversible non-parkinsonian bradykinesia associated with frontal lobe dysfunction as an unusual manifestation of adrenal insufficiency.

Protons vs Photons for Brain and Skull Base Tumors

The physical characteristics of proton therapy result in steeper dose gradients and superior dose conformality compared to photon therapy. These properties render proton therapy ideal for skull base tumors requiring dose escalation for optimal tumor control, and may also be beneficial for brain tumors as a means of mitigating radiation-related adverse effects. This review summarizes the literature regarding the role of proton therapy compared to photon therapy in the treatment of adult brain and skull base tumors.

Dosimetric Comparison of Proton Radiation Therapy, Volumetric Modulated Arc Therapy, and Three-Dimensional Conformal Radiotherapy Based on Intracranial Tumor Location

(1) Background: Selecting patients that will benefit the most from proton radiotherapy (PRT) is of major importance. This study sought to assess dose reductions to numerous organs-at-risk (OARs) with PRT, as compared to three-dimensional conformal radiotherapy (3DCRT) and volumetric-modulated arc therapy (VMAT), as a function of tumor location. (2) Materials/Methods: Patients with intracranial neoplasms (all treated with PRT) were stratified into five location-based groups (frontal, suprasellar, temporal, parietal, posterior cranial fossa; n = 10 per group). Each patient was re-planned for 3DCRT and intensity-modulated radiotherapy (IMRT) using similar methodology, including the originally planned target and organ-at-risk (OAR) dose constraints. (3) Results: In parietal tumors, PRT showed the most pronounced dose reductions. PRT lowered doses to nearly every OAR, most notably the optical system and several contralateral structures (subventricular zone, thalamus, hippocampus). For frontal lobe cases, the greatest relative dose reductions in mean dose (D_mean) with PRT were to the infratentorial normal brain, contralateral hippocampus, brainstem, pituitary gland and contralateral optic nerve. For suprasellar lesions, PRT afforded the greatest relative D_mean reductions to the infratentorial brain, supratentorial brain, and the whole brain. Similar results could be observed in temporal and posterior cranial fossa disease. (4) Conclusions: The effectiveness and degree of PRT dose-sparing to various OARs depends on intracranial tumor location. These data will help to refine selection of patients receiving PRT, cost-effectiveness, and future clinical toxicity assessment.

Endocrine Deficiency As a Function of Radiation Dose to the Hypothalamus and Pituitary in Pediatric and Young Adult Patients With Brain Tumors

PURPOSE

There are sparse data defining the dose response of radiation therapy (RT) to the hypothalamus and pituitary in pediatric and young adult patients with brain tumors. We examined the correlation between RT dose to these structures and development of endocrine dysfunction in this population.

MATERIALS AND METHODS

Dosimetric and clinical data were collected from children and young adults (< 26 years of age) with brain tumors treated with proton RT on three prospective studies (2003 to 2016). Deficiencies of growth hormone (GH), thyroid hormone, adrenocorticotropic hormone, and gonadotropins were determined clinically and serologically. Incidence of deficiency was estimated using the Kaplan-Meier method. Multivariate models were constructed accounting for radiation dose and age.

RESULTS

Of 222 patients in the study, 189 were evaluable by actuarial analysis, with a median follow-up of 4.4 years (range, 0.1 to 13.3 years), with 31 patients (14%) excluded from actuarial analysis for having baseline hormone deficiency and two patients (0.9%) because of lack of follow-up. One hundred thirty patients (68.8%) with medulloblastoma were treated with craniospinal irradiation (CSI) and boost; most of the remaining patients (n = 56) received involved field RT, most commonly for ependymoma (13.8%; n = 26) and low-grade glioma (7.4%; n = 14). The 4-year actuarial rate of any hormone deficiency, growth hormone, thyroid hormone, adrenocorticotropic hormone, and gonadotropin deficiencies were 48.8%, 37.4%, 20.5%, 6.9%, and 4.1%, respectively. Age at start of RT, time interval since treatment, and median dose to the combined hypothalamus and pituitary were correlated with increased incidence of deficiency.

CONCLUSION

Median hypothalamic and pituitary radiation dose, younger age, and longer follow-up time were associated with increased rates of endocrinopathy in children and young adults treated with radiotherapy for brain tumors.

Hypothyroidism after Radiation Therapy for Childhood Cancer: A Report from the Childhood Cancer Survivor Study

While thyroid cancer risks from exposure to ionizing radiation early in life are well characterized quantitatively, the association of radiation with nonmalignant, functional thyroid disorders has been less studied. Here, we report on a risk analysis study of hypothyroidism with radiation dose to the thyroid gland and the hypothalamic-pituitary axis among survivors of childhood cancer. Utilizing data from the Childhood Cancer Survivor Study, a cohort of 14,364 five-year survivors of childhood cancer diagnosed at 26 hospitals in the U.S. and Canada between 1970 and 1986 and followed through 2009, the occurrence of hypothyroidism was ascertained among 12,015 survivors through serial questionnaires. Radiation doses to the thyroid gland and pituitary gland were estimated from radiotherapy records. Binary outcome regression was used to estimate prevalence odds ratios for hypothyroidism at five years from diagnosis of childhood cancer and Poisson regression to model incidence rate ratios (RR) after the first five years. A total of 1,193 cases of hypothyroidism were observed, 777 (65%) of which occurred five or more years after cancer diagnosis. The cumulative proportion affected with hypothyroidism (prevalence at five years after cancer diagnosis plus incidence through 30 years after cancer diagnosis) was highest among five-year survivors of Hodgkin lymphoma (32.3%; 95% CI: 29.5-34.9) and cancers of the central nervous system (17.7%; 95% CI: 15.2-20.4). The incidence rate was significantly associated with radiation dose to the thyroid and pituitary. The joint association of hypothyroidism with thyroid and pituitary dose was sub-additive for pituitary doses greater than 16 Gy. In particular, a very strong thyroid radiation dose dependence at low-to-moderate pituitary/hypothalamic doses was diminished at high pituitary doses. Radiation-related risks were higher in males than females and inversely associated with age at exposure and time since exposure but remained elevated more than 25 years after exposure. Our findings indicated that hypothyroidism was significantly associated with treatment with bleomycin (RR = 3.4; 95% CI: 1.6-7.3) and the alkylating agents cyclohexyl-chloroethyl-nitrosourea (CCNU) (RR = 3.0; 95% CI: 1.5-5.3) and cyclophosphamide (RR = 1.3; 95% CI: 1.0-1.8), with a significant dose response for CCNU ( P < 0.01). The risk of hypothyroidism among childhood cancer survivors treated with radiation depends both on direct, dose-dependent radiation-induced damage to the thyroid gland and on dose-dependent indirect effects secondary to irradiation of the hypothalamic-pituitary axis. The dose-response relationship for each site depends on dose to the other. Radiation-related risk persists for more than 25 years after treatment. Treatment with certain chemotherapy agents may increase the risk of hypothyroidism.

Hypothalamic-Pituitary and Growth Disorders in Survivors of Childhood Cancer: An Endocrine Society Clinical Practice Guideline

OBJECTIVE

To formulate clinical practice guidelines for the endocrine treatment of hypothalamic-pituitary and growth disorders in survivors of childhood cancer.

PARTICIPANTS

An Endocrine Society-appointed guideline writing committee of six medical experts and a methodologist.

CONCLUSIONS

Due to remarkable improvements in childhood cancer treatment and supportive care during the past several decades, 5-year survival rates for childhood cancer currently are >80%. However, by virtue of their disease and its treatments, childhood cancer survivors are at increased risk for a wide range of serious health conditions, including disorders of the endocrine system. Recent data indicate that 40% to 50% of survivors will develop an endocrine disorder during their lifetime. Risk factors for endocrine complications include both host (e.g., age, sex) and treatment factors (e.g., radiation). Radiation exposure to key endocrine organs (e.g., hypothalamus, pituitary, thyroid, and gonads) places cancer survivors at the highest risk of developing an endocrine abnormality over time; these endocrinopathies can develop decades following cancer treatment, underscoring the importance of lifelong surveillance. The following guideline addresses the diagnosis and treatment of hypothalamic-pituitary and growth disorders commonly encountered in childhood cancer survivors.

Neonatal outcomes following exposure in utero to fallout from Chernobyl

Iodine 131 (I-131), the principal component of nuclear fallout from the Chernobyl accident, concentrates in the thyroid gland and may pose risks to fetal development. To evaluate this, neonatal outcomes following the accident in April of 1986 were investigated in a cohort of 2582 in utero-exposed individuals from northern Ukraine for whom estimates of fetal thyroid I-131 dose were available. We carried out a retrospective review of cohort members' prenatal, delivery and newborn records. The relationships of dose with neonatal anthropometrics and gestational length were modeled via linear regression with adjustment for potentially confounding variables. We found similar, statistically significant dose-dependent reductions in both head circumference (-1.0 cm/Gy, P = 0.005) and chest circumference (-0.9 cm/Gy, P = 0.023), as well as a similar but non-significant reduction in neonatal length (-0.6 cm/Gy, P = 0.169). Gestational length was significantly increased with increasing fetal dose (0.5 wks/Gy, P = 0.007). There was no significant (P > 0.1) effect of fetal dose on birth weight. The observed associations of radioiodine exposure with decreased head and chest circumference are consistent with those observed in the Japanese in utero-exposed atomic bomb survivors.

Ischemic stroke after radiation therapy for pituitary adenomas: a systematic review

Radiation therapy is widely used for the treatment of residual and recurrent pituitary adenomas and proved to effectively control tumor growth. However, it is suggested that this treatment might result in an increased risk of ischemic stroke. This review aims to evaluate the radiotherapy-related risk of stroke in pituitary adenoma patients. PubMed and Embase databases were systematically searched for current literature on ischemic stroke risk after radiotherapy in pituitary adenoma, in accordance with the PRISMA statement. Two authors independently selected eligible studies and extracted data. The New Castle Ottawa-scale was used for quality assessment. Out of 264 publications, 11 studies were selected, including 4394 irradiated patients. Incidence of ischemic stroke ranged from 0 to 11.6% (mean 6.7%). While one large, long term follow-up study showed a threefold increased risk of stroke after radiation therapy, another nationwide study of high quality found no significant difference in stroke risk after irradiation. Four studies, which applied stereotactic radiosurgery (SRS) or Gamma-knife surgery (GKS), found no ischemic strokes. Included studies described different radiation techniques and regimens and different lengths of follow-up. In conclusion, complications of cerebral ischemia after radiotherapy for pituitary adenoma are infrequently reported. Moreover, after correction for several confounders, no significant difference in ischemic stroke rate between irradiated and non-irradiated patients could be identified.