Time Dependence of Radiation-induced Hypothalamic-Pituitary Axis Dysfunction in Adults Treated for Non-pituitary, Intracranial Neoplasms

Hypopituitarism

Partial or complete deficiency of anterior or posterior pituitary hormone production leads to central hypoadrenalism, central hypothyroidism, hypogonadotropic hypogonadism, growth hormone deficiency, or arginine vasopressin deficiency depending on the hormones affected. Hypopituitarism is rare and likely to be underdiagnosed, with an unknown but rising incidence and prevalence. The most common cause is compressive growth or ablation of a pituitary or hypothalamic mass. Less common causes include genetic mutations, hypophysitis (especially in the context of cancer immunotherapy), infiltrative and infectious disease, and traumatic brain injury. Clinical features vary with timing of onset, cause, and number of pituitary axes disrupted. Diagnosis requires measurement of basal circulating hormone concentrations and confirmatory hormone stimulation testing as needed. Treatment is aimed at replacement of deficient hormones. Increased mortality might persist despite treatment, particularly in younger patients, females, and those with arginine vasopressin deficiency. Patients with complex diagnoses, pregnant patients, and adolescent pituitary-deficient patients transitioning to adulthood should ideally be managed at a pituitary tumour centre of excellence.

Management of Complications in Neuro-oncology Patients

OBJECTIVE

The purpose of this article is to familiarize the reader with the spectrum of neurologic and medical complications relevant to the care of patients with neurologic cancer while highlighting best practices to prevent morbidity and mortality. Topics include tumor-related epilepsy, vasogenic edema, complications of corticosteroid use, disruption of the hypothalamic-pituitary axis, venous thromboembolism, and opportunistic infection.

LATEST DEVELOPMENTS

In 2021, a joint guideline from the Society for Neuro-Oncology and the European Association of Neuro-Oncology reaffirmed recommendations first established in 2000 that patients with newly diagnosed brain tumors should not be prescribed an antiseizure medication prophylactically. For those with tumor-related epilepsy, monotherapy with a non-enzyme-inducing anticonvulsant is the preferred initial treatment, and levetiracetam remains the preferred first choice. Surveys of physician practice continue to demonstrate excessive use of glucocorticoids in the management of patients with both primary and metastatic central nervous system malignancy. This is particularly concerning among patients who require checkpoint inhibitors as the efficacy of these agents is blunted by concomitant glucocorticoid use, resulting in a reduction in overall survival. Finally, direct oral anticoagulants have been shown to be safe in patients with brain tumors and are now favored as first-line treatment among those who require treatment for venous thromboembolism.

ESSENTIAL POINTS

Medical care for patients impacted by primary and secondary central nervous system malignancy is complex and requires a committed team-based approach that routinely calls upon the expertise of physicians across multiple fields. Neurologists have an important role to play and should be familiar with the spectrum of complications impacting these patients as well as the latest recommendations for management.

Mitigating Radiotoxicity in the Central Nervous System: Role of Proton Therapy

OPINION STATEMENT

Central nervous system (CNS) radiotoxicity remains a challenge in neuro-oncology. Dose distribution advantages of protons over photons have prompted increased use of brain-directed proton therapy. While well-recognized among pediatric populations, the benefit of proton therapy among adults with CNS malignancies remains controversial. We herein discuss the role of protons in mitigating late CNS radiotoxicities in adult patients. Despite limited clinical trials, evidence suggests toxicity profile advantages of protons over conventional radiotherapy, including retention of neurocognitive function and brain volume. Modelling studies predict superior dose conformality of protons versus state-of-the-art photon techniques reduces late radiogenic vasculopathies, endocrinopathies, and malignancies. Conversely, potentially higher brain tissue necrosis rates following proton therapy highlight a need to resolve uncertainties surrounding the impact of variable biological effectiveness of protons on dose distribution. Clinical trials comparing best photon and particle-based therapy are underway to establish whether protons substantially improve long-term treatment-related outcomes in adults with CNS malignancies.

Prevalence of pituitary hormone dysfunction following radiotherapy for sinonasal and nasopharyngeal malignancies

BACKGROUND

There are limited studies and no surveillance protocols on pituitary dysfunction for adults who underwent anterior skull base radiation.

METHODS

Cross-sectional study of 50 consecutive patients with sinonasal or nasopharyngeal cancer who underwent definitive radiotherapy. The mean radiation doses, prevalence of pituitary dysfunction, and associated factors were calculated.

RESULTS

Pituitary hormone levels were abnormal in 23 (46%) patients, including 6 (12%) with symptomatic abnormalities requiring treatment. The most common hormonal abnormality was hyperprolactinemia (30%), central hypothyroidism (8%) and central hypogonadism (6%). Patients with abnormal pituitary hormone values received higher mean radiation doses to the pituitary gland (1143 cGy, P = 0.04), pituitary stalk (1129 cGy, P = 0.02), optic chiasm (1094 cGy, P = 0.01), and hypothalamus (900 cGy, P = 0.01).

CONCLUSIONS

Nearly half of the patients had abnormal pituitary function, including over a tenth requiring treatment. There may be a dose-dependent association between hormonal dysfunction and radiation.

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.

Neurologic Complications of Cancer Treatment

OBJECTIVE

Advances in cancer treatment have led to extended survival and increased risk of neurologic complications in an aging population. This review summarizes potential neurologic complications in patients who have undergone treatment for neurologic and systemic malignancies.

LATEST DEVELOPMENTS

Radiation and cytotoxic chemotherapy along with other targeted therapies continue to be the mainstay of cancer treatment. These advances in cancer care have led to improved outcomes and increased the need to understand the spectrum of neurologic complications that may arise from treatment. While radiation and older therapies including cytotoxic chemotherapies have side effect profiles that are widely known and well understood, this article serves as a review of the more commonly associated neurologic complications of both traditional and newer treatments being offered to this patient population.

ESSENTIAL POINTS

Neurotoxicity is a common complication of cancer-directed treatment. In general, neurologic complications of radiation therapy are more common in central nervous system malignancies, and neurologic complications of chemotherapy are more common in non-neurologic malignancies. Attempts at prevention, early detection, and intervention remain paramount in the reduction of neurologic morbidity.

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.

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.

Quality evaluation of Panax quinquefolium from different cultivation regions based on their ginsenoside content and radioprotective effects on irradiated mice

Ginsenosides are one of major types of bioactive compounds in American ginseng (AG) and utilized to assess the quality of various AG samples. The contents of ginsenosides showed cultivation region-related variation, which is possibly associated with AG’s pharmacological effect difference. Therefore, to reveal the quality difference of AGs in different cultivation regions, AG samples from seven cultivation regions were evaluated via analyzing their contents of nine ginsenosides and the biochemical parameters in AG-treated irradiated mice. Pre-administration of AG decoctions could reversely modulate the irradiation-induced changes of antioxidant enzymatic activity, cytokine level and hormone level in irradiated mice, which demonstrated that AG had the radioprotective effects due to its antioxidative, immunomodulatory and anti-inflammatory properties. However, this radioprotection effect varied among different cultivation regions of AGs. Collectively, Beijing and Canada-cultivated AGs had the best radioprotection. Heilongjiang and Jilin-originated AGs had the similar pharmacological effects while USA, Shandong and Shaanxi-grown AGs had closer pharmacological effects. This biochemical measurements-based PCA and heatmap clustering of AGs from seven cultivation regions was nearly consistent with ginsencoside content- and the previous serum metabolome-based analyses. However, the pearson correlation analysis revealed that only Rb3 and Rd were significantly correlated with some of assayed biochemical parameters in irradiated mice pretreated with different cultivation regions of AG extracts.

Proton vs. Photon Radiation Therapy for Primary Gliomas: An Analysis of the National Cancer Data Base

Background: To investigate the impact of proton radiotherapy (PBT) on overall survival (OS) and evaluate PBT usage trends for patients with gliomas in the National Cancer Data Base (NCDB).

Methods: Patients with a diagnosis of World Health Organization (WHO) Grade I-IV glioma treated with definitive radiation therapy (RT) between the years of 2004–13 were identified. Patients were stratified based on WHO Grade and photon radiotherapy (XRT) vs. PBT. Univariate (UVA) and multivariable analysis (MVA) with OS were performed by Cox proportional hazards model and log-rank tests. Propensity score (PS) weighting was utilized to account for differences in patient characteristics and to minimize selection bias.

Results: There were a total of 49,405 patients treated with XRT and 170 patients treated with PBT. Median follow-up time was 62.1 months. On MVA, the following factors were associated with receipt of PBT (all p < 0.05): WHO Grade I-II gliomas, treatment at an academic/research program, west geographic facility location, and surgical resection. After PS weighting, all patients treated with PBT were found to have superior median and 5 year survival than patients treated with XRT: 45.9 vs. 29.7 months (p = 0.009) and 46.1 vs. 35.5% (p = 0.0160), respectively.

Conclusions: PBT is associated with improved OS compared to XRT for patients with gliomas. This finding warrants verification in the randomized trial setting in order to account for potential patient imbalances not adequately captured by the NCDB, such as tumor molecular characteristics and patient performance status.

Importance of the Study: This is the first study that compares the outcomes of patients treated with photon based radiotherapy vs. proton based radiotherapy for patients with gliomas. In this retrospective analysis, the results demonstrate that proton therapy is associated with improved outcomes which support ongoing prospective, randomized clinical trials comparing the two modalities in patients with gliomas.

Are hypothyroidism and hypogonadism clinically relevant in patients with malignant gliomas? A longitudinal trial in patients with glioma

BACKGROUND

So far, the development and course of therapy-induced deficiencies in hypothalamic-pituitary hormones in adult patients with malignant gliomas has not received much attention. However, such deficiencies may impact patient's quality of life substantially.

METHODS

In this monocentric longitudinal trial, we examined hormonal levels of TSH, T3, T4, fT3, fT4, FSH, LH, testosterone, estradiol and prolactin in patients with malignant high grade gliomas before the start of radiochemotherapy (RCT), at the end of RCT and then every three months for newly diagnosed patients and every six months in patients diagnosed more than two years before study inclusion. Growth hormone was not measured in this trial.

RESULTS

436 patients (198 female, 238 male) with high-grade gliomas, aged 19-83 years (median 50 years), were included in this study. Low levels of thyroid hormones were observed in around 10% of patients within the first six months of follow up and increasingly after 36 months. Half of premenopausal women at study entry developed premature menopause, 35% showed hyperprolactinemia. Low testosterone levels were measured in 37% of men aged less than 50 years and in 35/63 (55%) of men aged 50 years or older.

DISCUSSION

The results of this study show that a significant percentage of patients with malignant gliomas develop hormonal deficiencies mandating regular clinical follow up, state of the art counseling and if clinically necessary substitution therapy.

Etiology of Hypopituitarism in Adult Patients: The Experience of a Single Center Database in the Serbian Population

There are only a few published studies related to the population-based etiology of hypopituitarism. New risks for developing hypopituitarism have been recognized in the last 10 years. Aim. To present data regarding the etiology of hypopituitarism collected in a tertiary center over the last decade. This is a cross-sectional database study. Patients and Methods. We included 512 patients (pts) with hypopituitarism, with a mean age of 45.9 ± 1.7 yrs (range: 18-82; male: 57.9%). Results. Nonfunctional pituitary adenomas were presented in 205 pts (40.5%), congenital causes in 74 pts (14.6%), while acromegaly and prolactinomas were presented in 37 (7.2%) and 36 (7.0%) patients, respectively. Craniopharyngiomas were detected in 30 pts (5.9%), and head trauma due to trauma brain injury-TBI and subarachnoid hemorrhage-SAH in 27 pts (5.4%). Survivors of hemorrhagic fever with renal syndrome (HFRS) and those with previous cranial irradiation were presented in the same frequency (18 pts, 3.5% each). Conclusion. The most common causes of hypopituitarism in our database are pituitary adenomas. Increased awareness of the other causes of pituitary dysfunction, such as congenital, head trauma, extrapituitary cranial irradiation, and infections, is the reason for a higher frequency of these etiologies of hypopituitarism in the presented database.