Long-term endocrine sequelae after treatment of medulloblastoma: prospective study of growth and thyroid function

Thyroid function disorders and secondary cancer following haematopoietic stem cell transplantation in pediatrics: State of the art and practical recommendations for a risk-based follow-up

Thyroid disorders (TD) represent a remarkable share of all the late morbidities experienced following pediatric haematopoietic stem cell transplantation (HSCT), with long-term reported occurrence often exceeding 70%. In addition, the data collected on wide cohorts of survivors assessed longitudinally outlined a progressive increase in the cumulative incidence of TD as far as 30 years following transplantation. Accordingly, a life-long monitoring of thyroid health is warranted among patients exposed to HSCT in childhood, in order to early detect TD and undertake a prompt dedicated treatment. Although several national and international consortia have provided recommendations for the early detection of thyroid disorders among childhood cancer survivors exposed to radiotherapy and alkylating agents, no guidelines specifically and thoroughly focused on HSCT-related TD have been published to date. As stem cell transplantation has become the standard-of-care in a growing body of non-oncological conditions, this urge has become pivotal. To highlight the challenging issues specifically involving this cohort of patients and to provide clinicians with the proposal of a practical follow-up protocol, we reviewed published literature in the light of the shared experience of a multidisciplinary team of pediatric oncologists, transplantologists, pathologists and endocrinologists involved in the long-term care of HSCT survivors. As a final result, we hereby present the proposals of a practical and customized risk-based approach to tailor thyroid health follow-up based on HSCT-related detrimental factors.

Management and Surveillance of Short- and Long-Term Sequelae of Radiation Therapy for the Treatment of Pediatric Brain Tumors

Radiation therapy (RT) is a mainstay for the treatment of pediatric brain tumors. As improvements in and sophistication of this modality continue to increase the survival of patients, the long-term sequelae of RT pose significant challenges in the clinical management of this patient population as they transition into adulthood. In this special edition, we review the short- and long-term effects of RT for the treatment of pediatric brain tumors and the necessary surveillance required for follow-up.

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.

Declining free thyroxine levels over time in irradiated childhood brain tumor survivors

OBJECTIVE

The incidence of cranial radiotherapy (cRT)-induced central hypothyroidism (TSHD) in childhood brain tumor survivors (CBTS) is reported to be low. However, TSHD may be more frequent than currently suspected, as its diagnosis is challenging due to broad reference ranges for free thyroxine (FT4) concentrations. TSHD is more likely to be present when FT4 levels progressively decline over time. Therefore, we determined the incidence and latency time of TSHD and changes of FT4 levels over time in irradiated CBTS.

DESIGN

Nationwide, 10-year retrospective study of irradiated CBTS.

METHODS

TSHD was defined as 'diagnosed' when FT4 concentrations were below the reference range with low, normal or mildly elevated thyrotropin levels, and as 'presumed' when FT4 declined ≥ 20% within the reference range. Longitudinal FT4 concentrations over time were determined in growth hormone deficient (GHD) CBTS with and without diagnosed TSHD from cRT to last follow-up (paired t-test).

RESULTS

Of 207 included CBTS, the 5-year cumulative incidence of diagnosed TSHD was 20.3%, which occurred in 50% (25/50) of CBTS with GHD by 3.4 years (range, 0.9-9.7) after cRT. Presumed TSHD was present in 20 additional CBTS. The median FT4 decline in GH-deficient CBTS was 41.3% (P < 0.01) to diagnosis of TSHD and 12.4% (P = 0.02) in GH-deficient CBTS without diagnosed TSHD.

CONCLUSIONS

FT4 concentrations in CBTS significantly decline over time after cRT, also in those not diagnosed with TSHD, suggesting that TSHD occurs more frequently and earlier than currently reported. The clinical relevance of cRT-induced FT4 decline over time should be investigated in future studies.

Low- and middle-income countries can reduce risks of subsequent neoplasms by referring pediatric craniospinal cases to centralized proton treatment centers

Few children with cancer in low- and middle-income countries (LMICs) have access to proton therapy. Evidence exists to support replacing photon therapy with proton therapy to reduce the incidence of secondary malignant neoplasms (SMNs) in childhood cancer survivors. The purpose of this study was to estimate the potential reduction in SMN incidence and in SMN mortality for pediatric medulloblastoma patients in LMICs if proton therapy were made available to them. For nine children of ages 2 to 14 years, we calculated the equivalent dose in organs or tissues at risk for radiogenic SMNs from therapeutic and stray radiation for photon craniospinal irradiation (CSI) in a LMIC and proton CSI in a high-income country. We projected the lifetime risks of SMN incidence and SMN mortality for every SMN site with a widely-used model from the literature. We found that the average total lifetime attributable risks of incidence and mortality were very high for both photon CSI (168% and 41%, respectively) and proton CSI (88% and 26%, respectively). SMNs having the highest risk of mortality were lung cancer (16%), non-site-specific solid tumors (16%), colon cancer (5.9%), leukemia (5.4%), and for girls breast cancer (5.0%) after photon CSI and non-site-specific solid tumors (12%), lung cancer (11%), and leukemia (4.8%) after proton CSI. The risks were higher for younger children than for older children and higher for girls than for boys. The ratios of proton CSI to photon CSI of total risks of SMN incidence and mortality were 0.56 (95% CI, 0.37 to 0.75) and 0.64 (95% CI, 0.45 to 0.82), respectively, averaged over this sample group. In conclusion, proton therapy has the potential to lessen markedly subsequent SMNs and SMN fatalities in survivors of childhood medulloblastoma in LMICs, for example, through regional centralized care. Additional methods should be explored urgently to reduce therapeutic-field doses in organs and tissues at risk for SMN, especially in the lungs, colon, and breast tissues.

Measurement of Thyroid Dose by TLD arising from Radiotherapy of Breast Cancer Patients from Supraclavicular Field

BACKGROUND

Breast cancer is the most frequently diagnosed cancer and the leading global cause of cancer death among women worldwide. Radiotherapy plays a significant role in treatment of breast cancer and reduces locoregional recurrence and eventually improves survival. The treatment fields applied for breast cancer treatment include: tangential, axillary, supraclavicular and internal mammary fields.

OBJECTIVE

In the present study, due to the presence of sensitive organ such as thyroid inside the supraclavicular field, thyroid dose and its effective factors were investigated.

MATERIALS AND METHODS

Thyroid dose of 31 female patients of breast cancer with involved supraclavicular lymph nodes which had undergone radiotherapy were measured. For each patient, three TLD-100 chips were placed on their thyroid gland surface, and thyroid doses of patients were measured. The variables of the study include shield shape, the time of patient's setup, the technologists' experience and qualification. Finally, the results were analyzed by ANOVA test using SPSS 11.5 software.

RESULTS

The average age of the patients was 46±10 years. The average of thyroid dose of the patients was 140±45 mGy (ranged 288.2 and 80.8) in single fraction. There was a significant relationship between the thyroid dose and shield shape. There was also a significant relationship between the thyroid dose and the patient's setup time.

CONCLUSION

Beside organ at risk such as thyroid which is in the supraclavicular field, thyroid dose possibility should be reduced. For solving this problem, an appropriate shield shape, the appropriate time of the patient's setup, etc. could be considered.

Endocrine sequelae beyond 10 years in survivors of medulloblastoma

INTRODUCTION

Survival following treatment of paediatric medulloblastomas has significantly improved over the past few decades, but as a consequence, late effects, particularly endocrine sequelae, have been recognized. The complete picture of late effects, however, has been limited by short duration of follow-up.

AIM

To establish the evolution of endocrine sequelae in patients treated for medulloblastoma.

METHODS

Single-centre analysis of medulloblastoma treatment and endocrine sequelae in patients diagnosed between 1982 and 2002.

RESULTS

A total of 109 patients were treated for medulloblastoma, with various treatment modalities involving radio- and chemotherapy. Only 45 (41%) patients remained alive, and details of treatment and late effects were available for 35 (25 m). The median age at diagnosis was 8 (range 2-14) years, and the median follow-up was 18 (range 10-28) years. Growth hormone deficiency (GHD) was the most prevalent hormone deficiency (97%), followed by primary hypothyroidism (60%) and adrenocorticotrophic hormone (ACTH) deficiency (45·5%). The median time from end of treatment to loss of growth hormone was 1·7 (range 0·7-15) years, ACTH deficiency 2·9 (range 0·75-7·5) years and hypothyroidism 4·1 (range 0·7-11·4) years. Twenty-three percentage developed hypogonadism (17% primary and 6% secondary), whilst precocious puberty was seen in 20%. Endocrinopathies appeared to be more prevalent in those treated with concomitant chemotherapy and radiotherapy.

CONCLUSIONS

Prevalence of endocrine sequelae in medulloblastoma survivors is high, and evolution of endocrine dysfunction can occur as late as 15 years from treatment completion; hence, long-term close monitoring of growth, puberty and gonadal function is essential.

Impairments that influence physical function among survivors of childhood cancer

Children treated for cancer are at increased risk of developing chronic health conditions, some of which may manifest during or soon after treatment while others emerge many years after therapy. These health problems may limit physical performance and functional capacity, interfering with participation in work, social, and recreational activities. In this review, we discuss treatment-induced impairments in the endocrine, musculoskeletal, neurological, and cardiopulmonary systems and their influence on mobility and physical function. We found that cranial radiation at a young age was associated with broad range of chronic conditions including obesity, short stature, low bone mineral density and neuromotor impairments. Anthracyclines and chest radiation are associated with both short and long-term cardiotoxicity. Although numerous chronic conditions are documented among individuals treated for childhood cancer, the impact of these conditions on mobility and function are not well characterized, with most studies limited to survivors of acute lymphoblastic leukemia and brain tumors. Moving forward, further research assessing the impact of chronic conditions on participation in work and social activities is required. Moreover, interventions to prevent or ameliorate the loss of physical function among children treated for cancer are likely to become an important area of survivorship research.

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.

Central hypothyroidism following chemotherapy for acute lymphoblastic leukemia

BACKGROUND

It has been suggested that chemotherapy per se might impair the hypothalamus-pituitary-thyroid axis of childhood cancer survivors.

OBJECTIVE

We examined six patients treated for acute lymphoblastic leukemia (ALL) with chemotherapy alone, with suspicious central hypothyroidism (CH).

SUBJECTS AND METHODS

ALL was diagnosed at a mean age of 3.8 years (range 0.3-6 years), the mean follow-up is 6 years (range 6-13 years). Auxological data were recorded, and thyroid function, autoimmunity and ultrasonography (US) were evaluated. Three individuals underwent a thyrotropin-releasing hormone (TRH) test and a magnetic resonance imaging (MRI) scan of the hypothalamic-pituitary region.

RESULTS

All study participants showed negative thyroid autoimmunity, normal thyroid ultrasound, and thyroid-stimulating hormone (TSH) above the normal range; free T4 (fT4) was abnormally low in two patients. After TRH infusion all patients showed TSH increase and slow TSH decline.

CONCLUSIONS

Our study shows that CH could arise at any time after childhood leukemia following only chemotherapy treatment. Although overt hypothyroidism was detected in only two patients, a careful follow-up of thyroid function is also recommended for ALL survivors not treated by irradiation.

Thyroid function and thyroid autoimmunity in childhood acute lymphoblastic leukemia off-therapy patients treated only with chemotherapy

OBJECTIVE

Scanty data are available about the thyroid function in childhood acute lymphoblastic leukemia (ALL) off-therapy patients treated only with chemotherapy. We aimed to assess the prevalence of thyroid autoimmunity and thyroid dysfunction in such patients.

DESIGN

Case-control cross-sectional study.

METHODS

Eighty-four patients diagnosed with ALL and treated only with chemotherapy. Mean age at diagnosis 5.9+/-3.6 yr, at recruitment 12.1+/-4.3 yr. The treatment had been stopped 4.3+/-3.2 yr before recruitment. A control group of 60 subjects was recruited. Free T4, TSH, anti-thyroperoxidase, and anti-thyroglobulin antibodies were measured.

RESULTS

Anti-thyroglobulin and anti-thyroperoxidase antibodies were negative in all patients. TSH was increased in 7 patients (8.3%) and 3 controls (5.0%). Free T4 was within the normal limits in all patients and controls.Mean TSH and free T4 levels did not statistically differ between controls and ALL offtherapy patients. TSH was negatively correlated with the age at the diagnosis (p=0.01) and the age at the end of therapy (p=0.008). Anti-thyroglobulin and/or anti-thyroperoxidase antibodies were detected in 3 controls (5%; vs study group: p=0.038), 1 of them with increased TSH.

CONCLUSIONS

Some patients present hyperthyrotropinemia, without anti-thyroid antibodies, with a prevalence comparable to the control group. The thyroid gland seems more prone to be damaged by chemotherapy at a younger age. We think that a thyroid follow- up in ALL off-therapy patients may be advisable and should be differentiated on the basis of the age at the end of treatment, with more frequent tests for younger patients.

Pediatric medulloblastoma: toxicity of current treatment and potential role of protontherapy

Post-operative craniospinal irradiation and systemic chemotherapy are both necessary in the treatment of pediatric medulloblastoma. Late toxicity is a major problem in long term survivors and significantly affects their quality of life. We have systematically reviewed the literature to examine data on late toxicity, specifically focusing on: endocrine function, growth and bone development, neurocognitive development, second cancers, ototoxicity, gynecological toxicity and health of the offspring, cardiac toxicity and pulmonary toxicity. In this paper, we describe qualitatively the kind of detected side effects and, whenever possible, try to assess their incidence and the relative role of craniospinal irradiation (as opposed to other treatments and to the disease itself) in producing them. Subsequently we examine the possible approach to reduce unwanted effects from craniospinal irradiation to target and non-target tissues and we consider briefly the role of hyperfractionation, tomotherapy and IMRT. We describe the characteristics of protontherapy and its potential for non-target tissues toxicity reduction reviewing the existing physical and dosimetric studies and the (still very limited) clinical experiences. Finally we propose intensity modulated spot scanning protontherapy with multiportal simultaneous optimization (IMPT) as a possible tool for dose distribution optimization within different areas of CNS and potential reduction of target tissues toxicity.

Endocrine outcomes for children with embryonal brain tumors after risk-adapted craniospinal and conformal primary-site irradiation and high-dose chemotherapy with stem-cell rescue on the SJMB-96 trial

PURPOSE

To estimate the cumulative incidence of specific hormone deficiencies and the influence of hypothalamic-pituitary (HP) axis radiation dose in a cohort of children with embryonal brain tumors treated with risk-adapted craniospinal irradiation (CSI), conformal primary site irradiation, and high-dose chemotherapy.

PATIENTS AND METHODS

Clinical data and HP axis radiation dosimetry data were obtained from 88 eligible children. All patients received regular endocrine follow-up that included screening tests of thyroid function and stimulation testing for growth hormone deficiency (GHD), and adrenocorticotropin hormone deficiency.

RESULTS

The cumulative incidence of GHD, thyroid-stimulating hormone (TSH) deficiency, adrenocorticotropic hormone deficiency, and primary hypothyroidism at 4 years from diagnosis was 93% +/- 4%, 23% +/- 8%, 38% +/- 6%, and 65% +/- 7%, respectively. Radiation dosimetry to the HP axis was associated only with the development of TSH deficiency; the 4-year cumulative incidence was 44% +/- 19% and 11% +/- 8% (P = .014) for those receiving more or less than the median dose to the hypothalamus (>or= 42 v < 42 Gy), respectively. The median dose of CSI for the average-risk (AR) patients was 23.4 and 39.6 Gy (36 to 40.5 Gy) for the high-risk patients. The estimated mean decline in height Z-score after radiation therapy was greater in high-risk patients (-0.65 units/yr) when compared with AR patients (-0.54 units/yr; P = .039).

CONCLUSION

Pediatric patients with CNS embryonal tumors are at high risk for treatment-related hormone deficiencies. GHD and primary hypothyroidism were diagnosed in a majority of subjects relatively soon after the completion of therapy. Radiation dose to the hypothalamus in excess of 42 Gy was associated with an increase in the risk of developing TSH deficiency.

Thyroid-stimulating hormone suppression for protection against hypothyroidism due to craniospinal irradiation for childhood medulloblastoma/primitive neuroectodermal tumor

PURPOSE

Hypothyroidism is one of the earliest endocrine effects of craniospinal irradiation (CSI). The effects of radiation also depend on circulating thyroid-stimulating hormone (TSH), which acts as an indicator of thyrocyte function and is the most sensitive marker of thyroid damage. Hence, our study was launched in 1998 to evaluate the protective effect of TSH suppression during CSI for medulloblastoma/primitive neuroectodermal tumor.

PATIENTS AND METHODS

From Jan 1998 to Feb 2001, a total of 37 euthyroid children scheduled for CSI for medulloblastoma/primitive neuroectodermal tumor underwent thyroid ultrasound and free triiodothyronine (FT3), free thyroxine (FT4), and TSH evaluation at the beginning and end of CSI. From 14 days before and up to the end of CSI, patients were administered l-thyroxine at suppressive doses; every 3 days, TSH suppression was checked to ensure a value <0.3 mum/ml. During follow-up, blood tests and ultrasound were repeated after 1 year; primary hypothyroidism was considered an increased TSH level greater than normal range. CSI was done using a hyperfractionated accelerated technique with total doses ranging from 20.8-39 Gy; models were used to evaluate doses received by the thyroid bed.

RESULTS

Of 37 patients, 25 were alive a median 7 years after CSI. They were well matched for all clinical features, except that eight children underwent adequate TSH suppression during CSI, whereas 17 did not. Hypothyroidism-free survival rates were 70% for the "adequately TSH-suppressed" group and 20% for the "inadequately TSH-suppressed" group (p = 0.02).

CONCLUSIONS

Thyroid-stimulating hormone suppression with l-thyroxine had a protective effect on thyroid function at long-term follow-up. This is the first demonstration that transient endocrine suppression of thyroid activity may protect against radiation-induced functional damage.

The natural history of thyroid function abnormalities after treatment for childhood cancer

The aim of the study was to find out which of childhood cancer survivors are at higher risk of thyroid dysfunction, and the timeframe for its development. The consequences of different treatments, particularly chemotherapy, were of interest. Follow-up data for 291 patients from a cohort of 360 patients were available and analysed in this retrospective study. Impaired thyroid function occurred in 71/291 (24%) patients: brain tumours 30/65 (46%), Hodgkin's disease (HD) 10/21 (48%), leukaemia/non Hodgkin's lymphoma (NHL) 19/140 (14%) and others 12/65 (18%). Patients with brain tumours had a higher hazard ratio (HR) over leukaemia/NHL (HR 7.47) but not over HD (HR 1.57). These patients also developed thyroid hypofunction earlier than patients with HD or leukaemia/NHL. Age at diagnosis did not have an effect on the occurrence or timeframe of development of thyroid hypofunction. Radiotherapy (HR 4.68) and radiotherapy combined with chemotherapy (HR 2.90) were associated with a higher risk than chemotherapy alone. Chemotherapy added to radiotherapy tended to increase risk (HR 2.42 95% confidence interval (CI) 1.00-5.87). Craniospinal irradiation did not differ significantly from total body irradiation (TBI) (HR 1.09 95%CI 0.25-4.76) or direct thyroid irradiation (HR 0.81 95%CI 0.32-2.06), but cranial irradiation (CIR) (HR 0.18 95%CI 0.08-0.38) was less harmful to thyroid function. Girls were more prone to effects of irradiation (HR 2.10 95%CI 1.15-3.82). All treatments, excluding surgery, predispose to thyroid dysfunction. Suggestions for follow-up of thyroid function are made.

Treatments for astrocytic tumors in children: current and emerging strategies

Strategies for the treatment of childhood cancer have changed considerably during the last 50 years and have led to dramatic improvements in long-term survival. Despite these accomplishments, CNS tumors remain the leading cause of death in pediatric oncology. Astrocytic tumors form the most common histologic group among childhood brain tumors. They are a heterogeneous group that from a practical therapeutic point of view can be subdivided into low-grade astrocytomas (LGA), optic pathway gliomas (OPG), high-grade astrocytomas (HGA), and brainstem gliomas (BSG). This article focuses on the practical application of treatments that lead to long-term survival, improved quality of life, and reduced long-term complications. Improvement in therapy has led to better outcomes for patients with LGA and OPG. Careful follow-up without any treatment is indicated for a small percentage of patients diagnosed with LGA with an indolent course including children with neurofibromatosis type 1 (NF1). Surgery is the main recommended treatment for children with resectable LGA. Radiation therapy is generally recommended for children with progressive LGA, or after failure of chemotherapy, accomplishing tumor control at 10 years in over 60% of patients. Cytotoxic chemotherapy is usually reserved for children who have had treatment failure with surgery and radiation therapy. It is also offered for children who are too young to be treated with radiation or to defer or avoid radiotherapy. Carboplatin and vincristine achieve 5% complete and 28% partial responses but the use of vincristine is criticized due to poor penetration of the CNS. A regimen of tioguanine, procarbazine, mitolactol, lomustine, and vincristine is frequently administered as an alternative to carboplatin and vincristine in LGA. The introduction of temozolomide has allowed better responses, including a 24% complete response rate compared with 0-5% complete response rates with the previous regimens. OPG are usually histologically LGA, and are treated with similar chemotherapy regimens. OPG is the most common type of brain tumor associated with NF1. Tumor growth in some of these patients is slow with no treatment recommended for an extended period of time. The prognosis for children with the remaining types of astrocytomas remains poor. Surgical resection is typically the first step in the treatment of HGA followed in older children by radiation therapy. The data regarding chemotherapy are mixed. Combination chemotherapy before or after radiation, including cisplatin, carmustine, cyclophosphamide, and vincristine or carboplatin, ifosfamide, cyclophosphamide, and etoposide has provided disappointing results. Clinical trials with temozolomide and agents directed against single targets have not shown substantially better results, but it is hoped that currently conducted studies will provide better outcomes. Diffuse intrinsic BSG are among the most difficult-to-treat brain tumors. Surgical treatment is not recommended for diffuse intrinsic BSG and standard radiation therapy is typically given in children aged >3 years. None of the numerous chemotherapy regimens, including temozolomide, has provided a significant response rate or an improvement in survival. It is expected that newer agents affecting multiple targets such as AEE-788 and antineoplastons, and combinations of single-targeted agents with chemotherapy will provide better results. Careful evaluation of histology, location of the tumor, patient age, and consideration of treatment-related morbidity play an important part in selecting between clinical observation, surgery, radiation, chemotherapy, or investigational agents. The goals of treatment for astrocytic tumors should extend well beyond objective responses and increased survival. Improvement of quality of life is an equally important objective of treatment. Radiation therapy and chemotherapy result in serious late toxicities.

Sensitivity of anterior pituitary hormones to irradiation

Cranial irradiation is used in the management of a diverse group of intracranial pathologies. However, if any part of the hypothalamic-pituitary axis is included in the radiation field, there is a risk of developing neuroendocrine dysfunction. Growth hormone is the most radiosensitive of the anterior pituitary hormones, followed by the gonadotropins, adrenocorticotropic hormone and thyroid-stimulating hormone. A number of factors determine both the occurrence and severity of hypothalamic-pituitary dysfunction, including: the dose of radiation received by the hypothalamic-pituitary axis (determined by a number of factors including total dose and fractionation schedule and ultimately expressed as the biological effective dose); length of time since cranial irradiation; age of the patient at the time of cranial irradiation; type of radiotherapy administered; and the different inherent radiosensitivities of the anterior pituitary hormones. These neuroendocrine abnormalities usually develop a number of years after the initial insult and, therefore, patients who have received cranial irradiation should receive annual endocrine assessments. The establishment of endocrine late-effect clinics for the survivors of childhood cancers have gone some way to addressing this problem; however, other groups of patients, particularly those receiving cranial irradiation in adult life, may not have systematic endocrine assessment.

Late effects of treatment on growth in childhood non-Hodgkin's lymphoma

Growth impairment is one of the most important late sequelae in childhood malignancies. In the last few years, the contribution of cytotoxic agents to growth retardation has been a subject of investigation. The aim of this study was to evaluate the growth impairment in children treated for non-Hodgkin's lymphoma (NHL). The study group comprised 41 children (eight girls, 33 boys) treated for NHL with three different chemotherapy protocols. All patients were in remission at the last visit. The control group consisted of 41 healthy age- and sex-matched children. All patients' standing heights and body weights were measured regularly from the time of diagnosis. Growth parameters were measured both at the time of diagnosis and at the end of treatment (median treatment time: 6 months). Height and weight velocities were calculated at 6 month intervals after the diagnosis until the last visit. The mean height SDS of the patients was -0.66 +/- 1.42 at the diagnosis and 0.29 +/- 1.21 at the last visit. Height SDS of the patients showed a significant improvement at the end of the 2nd year after the diagnosis (p = 0.005) and at the last visit (p = 0.022) (median follow-up time: 48 months after diagnosis). The height velocity SDS increase at the end of the 2nd year was particularly remarkable in short-term protocols such as BFM-90 B-NHL. The sitting height, the sitting height/height ratio and serum insulin-like growth factor-I (IGF-I) levels were found to be lower in the patients than those of control group at the last visit. One can conclude that chemotherapy might cause a reduction in growth velocity during treatment. The cumulative dosages of anti-neoplastic agents and serum IGF-I levels could have been implied in the pathogenesis of growth retardation.

Pathophysiology of radiation-induced growth hormone deficiency: efficacy and safety of GH replacement

Radiation-induced growth hormone deficiency (GHD) is primarily due to hypothalamic damage. GH secretion by the pituitary may be affected either secondary to some degree of quantitative deprivation of hypothalamic input or, if the radiation dose is high enough, by direct pituitary damage. As a consequence, the neurosecretory profile of GH secretion in an irradiated patient remains pulsatile and qualitatively intact. The frequency of pulse generation is unaffected, but the amplitude of the GH pulses is markedly reduced. Over the last 25 years, the final heights achieved by children receiving GH replacement for radiation-induced GHD have improved; these improvements are attributable to refinements in GH dosing schedules, increased use of GnRH analogues for radiation-induced precocious puberty, and a reduced time interval between completion of irradiation and initiation of GH therapy. When retested at the completion of growth, 80-90% of these teenagers are likely to prove severely GH deficient and, therefore, will potentially benefit from GH replacement in adult life. Such long-term GH treatment in patients treated previously for a brain tumor means that critical and continuous surveillance must be devoted to the risk of tumor recurrence and the possibility of second neoplasms.

Long-term follow-up of pediatric cancer survivors: education, surveillance, and screening

Cancer and its treatment predispose childhood cancer survivors to chronic or late occurring health problems that may not become clinically significant until many years after therapy. Frequently, long-term survivors of childhood cancer report late cancer-related effects that diminish quality of life and increase the risk of early mortality. Risk-based health care that involves a personalized plan for surveillance, screening, and prevention is recommended to reduce cancer-related morbidity in childhood cancer survivors. To implement optimal risk-based care, the survivor and health care provider must have accurate information about cancer diagnosis, treatment modalities, and potential cancer-related health risks to guide screening and risk-reducing interventions. However, previous studies evaluating health knowledge of childhood cancer survivors demonstrate noteworthy deficits and misperceptions about their cancer diagnosis, treatment, and cancer-related health risks. In addition, because of the relative rarity of childhood cancer, many health care providers lack familiarity with cancer-related health risks and risk-reduction methods relevant for this population. To correct these deficits, the Scottish Intercollegiate Guidelines Network (SIGN) and the Children's Oncology Group (COG) developed clinical practice guidelines to foster appropriate risk-based survivor care. Herein, we discuss the development, benefits, and limitations of the SIGN and COG guidelines and the foundation they provide for standardizing long-term follow-up care of the ever-growing vulnerable population of childhood cancer survivors.

Standard-Risk Medulloblastoma Treated by Adjuvant Chemotherapy Followed by Reduced-Dose Craniospinal Radiation Therapy: A French Society of Pediatric Oncology Study

Objective

The primary objective of this study was to decrease the late effects of prophylactic radiation without reducing survival in standard-risk childhood medulloblastoma.

Patients and Methods

Inclusion criteria were as follows: children between the ages of 3 and 18 years with total or subtotal tumor resection, no metastasis, and negative postoperative lumbar puncture CSF cytology. Two courses of eight drugs in 1 day followed by two courses of etoposide plus carboplatin (500 and 800 mg/m2 per course, respectively) were administered after surgery. Radiation therapy had to begin 90 days after surgery. Delivered doses were 55 Gy to the posterior fossa and 25 Gy to the brain and spinal canal.

Results

Between November 1991 and June 1998, 136 patients (median age, 8 years; median follow-up, 6.5 years) were included. The overall survival rate and 5-year recurrence-free survival rate were 73.8% ± 7.6% and 64.8% ± 8.1%, respectively. Radiologic review showed that 4% of patients were wrongly included. Review of radiotherapy technical files demonstrated a correlation between the presence of a major protocol deviation and treatment failure. The 5-year recurrence-free survival rate of patients included in this study with all optimal quality controls of histology, radiology, and radiotherapy was 71.8% ± 10.5%. In terms of sequelae, 31% of patients required growth hormone replacement therapy and 25% required special schooling.

Conclusion

Reduced-dose craniospinal radiation therapy can be proposed in standard-risk medulloblastoma provided staging and radiation therapy are performed under optimal conditions.

Evaluating Survivors of Pediatric Cancer

The past 3 decades have seen tremendous improvements in the survival of children diagnosed with cancer, with the 5-year survival rate approaching 80%. This improvement in survival has resulted in a growing population of childhood cancer survivors. Use of cancer therapy at an early age can produce complications that may not become apparent until years later. Approximately two thirds of the survivors of childhood cancer experience at least one late effect and about one fourth experience a late effect that is severe or life-threatening, although psychosocial issues in survivors and family members are often underestimated and may be more prevalent. Long-term complications in childhood cancer survivors, such as impairment in growth and development, neurocognitive dysfunction, cardiopulmonary compromise, endocrine dysfunction, renal impairment, gastrointestinal dysfunction, musculoskeletal sequelae, and subsequent malignancies, are related not only to the specific therapy used but also may be determined by individual host characteristics. We review the known late effects in survivors of childhood in order to suggest reasonable starting points for the evaluation of specific long-term problems in this unique but growing population.

Adult growth hormone replacement therapy and neuroimaging surveillance in brain tumour survivors

OBJECTIVE

Systematic collections of neuroimaging data are nonexistent in brain tumour survivors treated with adult growth hormone replacement therapy (AGHRT). We present our surveillance data.

DESIGN

In 1993, our unit implemented a policy of performing brain scans on every brain tumour survivor before starting AGHRT, with repeat neuroimaging at least once after 12-18 months' treatment. Reports for baseline scans and most recent scans were analysed for this retrospective study.

PATIENTS

All brain tumour survivors who received AGHRT (60 patients) were included in the analysis.

MEASUREMENTS

Evidence and extent of residual tumour, tumour progression, tumour recurrence, and secondary neoplasms (SN) on baseline scan and latest follow-up scan.

RESULTS

All patients had baseline scans performed. Follow-up scans were available in 41/45 (91%) patients who received AGHRT for more than 1 year (mean duration +/- SD of GHRT was 6.7 +/- 3.6 years). Sixteen patients had residual tumours, and SNs (all meningiomas) were demonstrated in three patients on baseline scans. Appearances remained stable in 34 (83%) patients during follow-up (extending to 17.4 +/- 8.3 years after tumour diagnosis). Of the 16 residual primary tumours, an incurable ependymoma continued to grow, and one meningioma progressed slightly in size over 7.7 years. Follow-up scans also revealed continued growth of the SNs detected at baseline, and five additional meningiomas (two in patients with a previous SN, confirming an excess risk in this subgroup, P = 0.02). All SNs occurred on average 22.8 (range 17-37) years after radiotherapy.

CONCLUSIONS

Our data do not suggest an increased rate of recurrence or progression of childhood brain tumours during AGHRT. Nonetheless, vigilance and long-term surveillance are needed in these patients in order to detect and monitor SNs, in particular in patients with a previous history of a SN. We endorse a proactive neuroimaging policy, preferably as part of a larger, controlled trial in the future.

Development of risk-based guidelines for pediatric cancer survivors: the Children's Oncology Group Long-Term Follow-Up Guidelines from the Children's Oncology Group Late Effects Committee and Nursing Discipline

The Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers are risk-based, exposure-related clinical practice guidelines intended to promote earlier detection of and intervention for complications that may potentially arise as a result of treatment for pediatric malignancies. Developed through the collaborative efforts of the Children's Oncology Group Late Effects Committee, Nursing Discipline, and Patient Advocacy Committee, these guidelines represent a statement of consensus from a multidisciplinary panel of experts in the late effects of pediatric cancer treatment. The guidelines are both evidence-based (utilizing established associations between therapeutic exposures and late effects to identify high-risk categories) and grounded in the collective clinical experience of experts (matching the magnitude of risk with the intensity of screening recommendations). They are intended for use beginning 2 or more years following the completion of cancer therapy; however, they are not intended to provide guidance for follow-up of the survivor's primary disease. A complementary set of patient education materials ("Health Links") was developed to enhance follow-up care and broaden the application of the guidelines. The information provided in these guidelines is important for health care providers in the fields of pediatrics, oncology, internal medicine, family practice, and gynecology, as well as subspecialists in many fields. Implementation of these guidelines is intended to increase awareness of potential late effects and to standardize and enhance follow-up care provided to survivors of pediatric cancer throughout the lifespan. The Guidelines, and related Health Links, can be downloaded in their entirety at www.survivorshipguidelines.org.

Irradiation-induced progenitor cell death in the developing brain is resistant to erythropoietin treatment and caspase inhibition

One hemisphere of postnatal day 8 (P8) rats or P10 mice was irradiated with a single dose of 4-12 Gy, and animals were killed from 2 h to 8 weeks after irradiation (IR). In the subventricular zone (SVZ) and the granular cell layer (GCL) of the dentate gyrus, harboring neural and other progenitor cells, nitrosylation and p53 peaked 2-12 h after IR, followed by markers for active caspase-3, apoptosis-inducing factor and TUNEL (6-24 h). Ki67-positive (proliferating) cells had disappeared by 12 h and partly reappeared by 7 days post-IR. The SVZ and GCL areas decreased approximately 50% 7 days after IR. The development of white matter was hampered, resulting in 50-70% less myelin basic protein staining. Pretreatment with erythropoietin did not confer protection against IR. Caspase inhibition by overexpression of XIAP prevented caspase-9 and caspase-3 activation but not cell death, presumably because of increased caspase-independent cell death.

Radiotherapy-induced thyroid disorders

Despite their specific functional consequences, radiotherapy-induced thyroid abnormalities remain under-estimated and underreported. These sequelae may include primary or central hypothyroidism, thyroiditis, Graves' disease, euthyroid Graves' ophthalmopathy, benign adenomas, multinodular goitre and radiation-induced thyroid carcinoma. Primary hypothyroidism, the most common radiation-induced thyroid dysfunction, affects 20-30% of patients administered following curative radiotherapy to the neck region, with approximately half of the events occurring within the first 5 years after therapy. The relative risk of radiation-induced cancer (mainly well-differentiated tumours) is 15-53-fold higher than in non-irradiated population. The aetiology of radiation-induced thyroid injury includes vascular damage, parenchymal cell damage and auto-immune reactions. Total radiotherapy dose, irradiated volume of the thyroid gland, and the extent of prior thyroid resection are among the most important factors associated with the risk of hypothyroidism. The contribution of other treatment modalities (chemotherapy, endocrine therapy) as well as patient- and tumour-related factors is less clear. Reduction in radiation dose to the thyroid gland and hypothalamic/pituitary complex should be attempted whenever possible. New radiotherapy techniques, such as stereotactic radiosurgery, three-dimensional conformal irradiation, intensity modulated radiotherapy and proton therapy allow generally better dose distribution with lower dose to the non-target organs. The diagnostic approach to thyroid radiation injury includes baseline thyroid function assays in all patients undergoing thyroid or parasellar irradiation. Recommended follow-up procedures include at least annual evaluation with a history for symptoms of thyroid dysfunction, clinical examination, and measurement of thyroid hormones and thyrotropin. Management of overt hypothyroidism is based on hormone replacement therapy. Thyroid hormone therapy is also recommended in cases of subclinical hypothyroidism. Treatment of other radiation-induced thyroid disorders (thyroiditis, Graves' disease, thyroid cancer) is similar to that employed in spontaneously occurring conditions. Further improvements in radiotherapy techniques and progress in endocrine diagnostics and therapy may allow better prevention and management of radiation-related thyroid injury.

Long-term neurologic and neurosensory sequelae in adult survivors of a childhood brain tumor: childhood cancer survivor study

PURPOSE

To describe the neurologic and neurosensory deficits in children with brain tumors (BTs), compare incidence of these deficits with that of a sibling control group, and evaluate the factors associated with the development of these deficits.

PATIENTS AND METHODS

Detailed questionnaires were completed on 1,607 patients diagnosed between 1970 and 1986 with a primary CNS tumor. Neurosensory and neurologic dysfunctions were assessed and results compared with those of a sibling control group. Medical records on all patients were abstracted, including radiotherapy dose and volume.

RESULTS

Seventeen percent of patients developed neurosensory impairment. Relative to the sibling comparison group, patients surviving BTs were at elevated risk for hearing impairments (relative risk [RR], 17.3; P = <.0001), legal blindness in one or both eyes (RR, 14.8; P = <.0001), cataracts (RR, 11.9; P = <.0001), and double vision (RR, 8.8; P = <.0001). Radiation exposure greater than 50 Gy to the posterior fossa was associated with a higher likelihood of developing any hearing impairment. Coordination and motor control problems were reported in 49% and 26%, respectively, of survivors. Children receiving at least 50 Gy to the frontal brain regions had a moderately elevated risk for motor problems (RR, 2.0; P <.05). Seizure disorders were reported in 25% of patients, including 6.5% who had a late first occurrence. Radiation dose of 30 Gy or more to any cortical segment of the brain was associated with a two-fold elevated risk for a late seizure disorder.

CONCLUSION

Children surviving BTs are at significant risk for both early and late neurologic or neurosensory sequelae. These sequelae need to be prospectively monitored.

Endocrine and cardiovascular late effects among adult survivors of childhood brain tumors: Childhood Cancer Survivor Study

BACKGROUND

Survivors of childhood brain tumors (CBTs) are at high risk for a variety of late adverse effects. Most research on long-term effects of CBTs has been comprised of single-institution case series without comparison groups. Research on CBT late effects often is focused on neurologic and sensory outcomes, with less emphasis on other potential targets such as the endocrine and circulatory systems. The current study was conducted to contrast the incidence of endocrine and cardiovascular conditions among CBT survivors as a function of treatment and to determine the risk of occurrence of these conditions relative to a sibling comparison group.

METHODS

As part of the Childhood Cancer Survivor Study (CCSS), treatment data were collected from medical records and self-reported late effects were ascertained from a survey questionnaire of 1,607 CBT patients who survived their disease for 5 or more years. For comparison purposes, questionnaire data were also collected from 3418 randomly selected siblings of participants in CCSS.

RESULTS

One or more endocrine conditions were reported by 43% of CBT survivors. Compared with siblings, CBT survivors had a significantly increased risk of late-onset (>/= 5 years postdiagnosis) hypothyroidism (relative risk [RR] = 14.3; 95% confidence interval [95% CI] 9.7-21.0), growth hormone deficiency (RR = 277.8; 95% CI 111.1-694.9), the need for medications to induce puberty (RR = 86.1; 95% CI 31.1-238.2), and osteoporosis (RR = 24.7; 95% CI 9.9-61.4). One or more cardiovascular conditions were reported by 18% of CBT survivors, with an elevated late-onset risk for stroke (RR = 42.8; 95% CI 16.7-109.8), blood clots (RR = 5.7; 95% CI 3.2-10.0), and angina-like symptoms (RR = 2.0; 95% CI 1.5-2.7). Very few late effects were evident among those treated with surgery only, but risks were consistently elevated for those treated with radiation and surgery, and higher still for those who also received adjuvant chemotherapy.

CONCLUSIONS

Childhood brain tumor survivors are at a significantly increased risk for several adverse endocrine and cardiovascular late effects, particularly if they were treated with radiation and chemotherapy. Lifetime medical surveillance and follow-up for potential toxicities are necessary because treatment-related complications may occur many years after therapy.

[Post-radiotherapy hyperthyroidism: a rare complication of cancer treatment in the child]

Abnormalities of thyroid function, specially hypothyroidism, are common complications of head and neck irradiation for childhood cancer. Hyperthyroidism is rare and can be misdiagnosed. We report two observations of this condition.

OBSERVATIONS

The first patient received conventional craniospinal irradiation for a localized medulloblastoma. Three years later, he presented with profuse sweating, irritability and paroxysmal tachycardia. Biologic evaluation revealed a peripheral hyperthyroidism. The patient was treated with antithyroidian hormonal treatment. The second patient received an irradiation for an undifferentiated nasopharyngeal carcinoma. Three years later, she developed a progressive thyrotoxicosis which was attributed to hyperthyroidism after six months of evolution. Hormonal treatment improved the clinical state after several weeks.

CONCLUSION

Hyperthyroidism is a rare complication of head and neck irradiation. This condition justifies a periodic and prolonged evaluation of thyroid function.

Hypothyroidism in children with medulloblastoma: a comparison of 3600 and 2340 cGy craniospinal radiotherapy

PURPOSE

To determine if low-dose craniospinal irradiation (2340 cGy) with chemotherapy is associated with a lower incidence of hypothyroidism compared to standard dose (3600 cGy) with or without chemotherapy in children with medulloblastoma.

PATIENTS AND METHODS

Between 1980 and 1999, 32 patients < or =20 years old survived after craniospinal irradiation with or without chemotherapy. Twenty patients received 3600 cGy craniospinal irradiation (CSI), whereas 12 had 2340 cGy CSI; all patients received a posterior fossa boost to a total dose 5040-5580 cGy. The median ages at the time of CSI for those receiving 2340 cGy and 3600 cGy were 7.2 and 10.2 years, respectively. Chemotherapy (CT) was employed in 22 children. All children who received 2340 cGy had CT consisting of vincristine, CCNU, and either cisplatin or cyclophosphamide. Ten of 20 (50%) patients receiving 3600 cGy had CT; the most common regimen was vincristine, CCNU, and prednisone. Serum-free thyroxine and thyroid-stimulating hormone concentrations were measured in all children at variable times after radiotherapy. Thyroid-stimulating hormone responses to i.v. thyrotrophin-releasing hormone were assessed in those suspected of having central hypothyroidism. Median follow-up for children receiving 2340 cGy was 5 years (range: 2-11.2 years), whereas for those receiving 3600 cGy, follow-up was 12.5 years (range: 2.4-20 years).

RESULTS

Eighteen patients (56%) developed hypothyroidism at a median time after radiotherapy of 41 months (range: 10 months to 18 years). Primary hypothyroidism was more common than central hypothyroidism (38% and 19%). All 7 children <5 years developed hypothyroidism, whereas 9 of 15 (60%) ages 5-10 and 2 of 10 (20%) age >10 years had hypothyroidism (p < 0.001). Hypothyroidism was documented in 10 of 12 (83%) who had 2340 cGy + CT, 6 of 10 (60%) who had 3600 cGy + CT, and 2 of 10 (20%) who had 3600 cGy without CT (p < 0.025).

CONCLUSIONS

Current treatment regimens consisting of chemotherapy and 2340 cGy craniospinal irradiation followed by a posterior fossa boost for medulloblastoma do not show a reduction of hypothyroidism. Young age and use of chemotherapy were associated with a higher incidence of hypothyroidism.

Thyroid dysfunction as a late effect in childhood medulloblastoma: a comparison of hyperfractionated versus conventionally fractionated craniospinal radiotherapy

PURPOSE

Primary hypothyroidism is a common sequela of craniospinal radiotherapy in the treatment of childhood medulloblastoma. Due to the strong radiobiologic rationale, hyperfractionation can reduce the delayed effects of radiation injury.

METHODS AND MATERIALS

The authors compared the incidence of thyroid dysfunction after conventionally fractionated radiotherapy (Group A, n = 20 patients) vs. hyperfractionated radiotherapy (Group B, n = 12 patients) in a group of pediatric patients with posterior fossa primitive neuroectodermal tumor (PNET).

RESULTS

The mean age at the time of tumor diagnosis was 7.4 years in Group A and 8.4 years in Group B. Thyroid function was evaluated yearly, with ultrasonographic examination every 2 years. The patients were followed after diagnosis for a mean of 10.8 years for Group A and 6.0 years for Group B. Approximately 80% of the Group A (16/20) and 33.3% of the Group B (4/12) patients developed primary hypothyroidism within a similar period after irradiation (4.2 vs. 3.5 years, respectively). Analysis by cumulative incidence function demonstrated a significant difference in the risk of developing thyroid dysfunction between these two groups of patients (p < 0.05). Ultrasonography showed reduced thyroid volume in 7 Group A patients and structural changes in 21 patients (17 Group A, 4 Group B cases); a thyroid benign nodule was detected in 2 Group A patients.

CONCLUSIONS

The current study findings suggest that the use of hyperfractionated craniospinal radiotherapy in the treatment of childhood medulloblastoma is associated with a lower risk of these patients' developing late thyroid dysfunction.

Paclitaxel for the treatment of progressive or recurrent childhood brain tumors: a pediatric oncology phase II study

PURPOSE

To assess the efficacy and define the toxicity of paclitaxel given at a dosage of 350 mg/m2 every 3 weeks as a 24-hour continuous infusion to children with recurrent or progressive primary brain tumors.

PATIENTS AND METHODS

Seventy-three eligible patients, ages 4 months to 19 years, with progressive or recurrent primary brain tumors were treated according to a Pediatric Oncology Group (POG) phase II protocol with paclitaxel (POG 9330). Tumor histologic strata included: astrocytoma (n = 4), malignant glioma (n = 13), medulloblastoma (n = 16), brain stem glioma (n = 15), ependymoma (n = 13), and miscellaneous histologies (n = 12). All patients had previous histologic confirmation of a primary intracranial or spinal cord tumor with magnetic resonance imaging or computed tomography documentation of unequivocally measurable progressive or recurrent disease. All patients had received previous therapy including surgery, radiation therapy, and/or chemotherapy, but no patient had been previously treated on more than one phase II trial. Paclitaxel was administered as a 24-hour intravenous infusion at a dosage of 350 mg/m2 every 3 weeks. Neurologic and neuroradiologic reevaluations were performed after every second course. Patients were allowed to continue therapy for a total of 18 cycles in the absence of progressive disease or unacceptable toxicity.

RESULTS

Seventy-five patients were enrolled onto the POG 9330 protocol; two ineligible patients were removed from the study before receiving any therapy. Of the 73 eligible patients, 72 were evaluable for toxicity and 70 were either fully or partially evaluable for disease response. There was one complete response and three partial responses (5.7%). Twenty patients had stable disease for more than 2 months. Toxicities included mild nausea, central nervous system toxicity, myelosuppression, and febrile neutropenia, including one septic death. One grade 2 and two grade 3 allergic reactions occurred. No cardiac toxicities or arthralgias were reported.

CONCLUSION

Paclitaxel is well tolerated in children with recurrent or progressive brain tumors at this dosage and schedule and may result in short-term disease stabilization in this patient population. The lack of a significant number of patients with measurable disease regression, however, precludes it from being identified as an active agent when administered as a single agent by 24-hour continuous infusion.

Cranial irradiation and central hypothyroidism

Cranial irradiation causes thyrotropin (TSH)-releasing hormone (TRH) secretory abnormalities. TRH deficiency leads to abnormal glycosylation of TSH alpha and beta subunits and loss of the normal circadian pattern of TSH secretion (low in the afternoon, a surge in the evening, higher at night). This disruption results in either mixed hypothyroidism (raised TSH with abnormal secretory kinetics) or central hypothyroidism (abnormal secretory kinetics without raised TSH). Although primary hypothyroidism is more common in the general population and cancer survivors, the cumulative incidence of central and mixed hypothyroidism is high during the ten years after cranial irradiation. Monitoring for decline in free thyroxine (FT(4)) and rise in serum TSH, and early recognition using TSH surge and TRH tests, are clinically valuable. Early thyroid hormone replacement therapy to achieve serum FT(4) in the upper half of the normal range is crucial for maintaining optimal health and growth in cancer survivors.

Long-term outcome of treatment with protocols AL841, AL851, and ALHR88 in children with acute lymphoblastic leukemia: results obtained by the Kyushu-Yamaguchi Children's Cancer Study Group

We analyzed the long-term outcome and late effects of treatment in 187 patients with childhood acute lymphoblastic leukemia (ALL) diagnosed between 1984 and 1990. Overall survival and event-free survival rates were 68.2% +/- 3.7% and 63.2% +/- 3.6% at 15 years, respectively. Of 55 patients who relapsed after achieving the first complete remission (CR), only 17.4% were rescued by salvage therapy. The advantage of stem cell transplantation over chemotherapy was observed only in those patients with bone marrow relapse during therapy. The SD for score height in patients maintaining the first CR significantly decreased at the time of final follow-up compared with that at diagnosis: 0.059 to -0.800 (P < .0001). The decrease was remarkable in patients younger than 5 years at diagnosis. Other late effects included mild liver dysfunction in 18% and hepatitis C virus infection in 9%. Congestive heart failure was observed in only 2.9% of patients despite the high cumulative dose of daunorubicin (450 mg/m2). Although the survival rates of patients on our protocols were comparable to those of other study groups, some modification, including reduction in dose of cranial irradiation and/or anticancer drugs, should be considered to reduce late adverse effects in survivors of childhood ALL.

Growth hormone replacement therapy in children with medulloblastoma: use and effect on tumor control

PURPOSE

Progress has been made in the treatment of medulloblastoma, the most common childhood malignant brain tumor: However, many long-term survivors will have posttherapy growth hormone insufficiency with resultant linear growth retardation. Growth hormone replacement therapy (GHRT) may significantly improve growth, but there is often reluctance to initiate GHRT because of concerns of an increased likelihood of tumor relapse.

PATIENTS AND METHODS

This study retrospectively reviewed the use of GHRT for survivors of medulloblastoma in 11 neuro-oncology centers in North America who received initial treatment for disease between 1980 and 1993 to determine its impact on disease control. A Landmark analysis was used to evaluate the relative risk of relapse in surviving patients.

RESULTS

Five hundred forty-five consecutive patients less than 15 years of age at diagnosis were identified. Six-year progression-free survival (mean +/- SD) was 40% +/- 5% in children less than 3 years of age at diagnosis compared with 59% +/- 3% for older patients. Older patients with total or near-total resections (P = .003) and localized disease at diagnosis (P < .0001) had the highest likelihood of survival. One hundred seventy patients (33% +/- 3% of the cohort) received GHRT. GHRT use varied widely among institutions, ranging from 5% to 73%. GHRT was begun a mean of 3.9 years after diagnosis, later in children younger than 3 years at diagnosis (5.4 years). By Landmark analyses, for those surviving 2, 3, and 5 years after diagnosis, there was no evidence that GHRT increased the rate of disease relapse.

CONCLUSION

This large retrospective review demonstrates that GHRT is underutilized in survivors of medulloblastoma and is used relatively late in the course of the illness. GHRT is not associated with an increased likelihood of disease relapse.

Long-term follow-up and residual sequelae after treatment for intracerebral germ-cell tumour in children and adolescents

BACKGROUND

Information on long-term follow-up of children and adolescents treated for intracerebral germ-cell tumour is scant. We report on the results of a small series of patients treated at a single institution.

PATIENTS AND METHODS

Hospital records from 15 patients treated between 1980 and 1998 were reviewed. An attempt was made to correlate sequelae to tumour location and treatment modalities.

RESULTS

This cohort constitutes 5.5% of all brain tumours diagnosed at our institution.

HISTOLOGY

10 germinomas, 2 benign teratomas, 2 malignant teratomas, and one mixed germ-cell tumour. Overall survival was 87%, with a mean follow-up time of 7 years and 8 months. The majority of patients have long-term sequelae involving one or several organ systems. In 66% endocrine, in 47% ophthalmologic, in 60% neuropsychological defects were observed. Endocrine and ophthalmologic sequelae show a correlation to tumour location. Neuropsychological long-term abnormalities are frequent and are associated with cranial irradiation in particular at young age, but less with tumour location, irradiation dose or surgery.

CONCLUSIONS

Our preliminary data suggest that today intracerebral germinomas and mature teratomas have a good prognosis even when a relapse occurs. The outcome for mixed germ-cell tumours and malignant teratomas is less favourable. Although long-term sequelae are present in the majority of patients, there is some evidence that patients treated after 1990 suffer fewer severe long-term defects, thereby indicating that recent treatment protocols may result in a reduction of sequelae.

The cranial-spinal junction in medulloblastoma: does it matter?

PURPOSE

Late effects of treatment in children and young adults with medulloblastoma can be influenced by the technique employed in radiating the craniospinal axis. The purpose of this study is to determine whether the placement of the cranial-spinal junction has an impact on dose to the cervical spinal cord and surrounding organs.

METHODS AND MATERIALS

Five patients underwent computed tomography (CT) simulation in the prone position for craniospinal irradiation. A dose of 36 Gy was prescribed to the entire neuraxis. The doses to the cervical spinal cord and surrounding organs were calculated using a cranial-spinal junction at the C1-C2 vertebral interspace (high junction) or at the lowest point in the neck, with exclusion of the shoulders in the lateral cranial fields (low junction). The volume of critical organs at risk, as well as dose to these structures using the cranial and spinal field(s) were outlined and calculated using the CMS FOCUS 3-dimensional treatment planning system.

RESULTS

The average dose to the cervical spinal cord was 11.9% higher than the prescribed dose with the low junction, and 6.7% higher with the high junction. However, doses to the thyroid gland, mandible, pharynx, and larynx were increased by an average of 29.6%, 75.8%, 70.6%, and 227.7%, respectively, by the use of the high junction compared to the low junction.

CONCLUSION

A higher dose to the cervical spinal cord can be minimized by using a high junction. However, this would be at the cost of substantially increased doses to surrounding organs such as the thyroid gland, mandible, pharynx, and larynx. This can be critical in children and young adults, where hypothyroidism, mandibular hypoplasia, and development of second malignancies may be a late sequela of radiation therapy.

Growth failure after treatment of pediatric brain tumors

OBJECTIVES

Primary brain tumors are the most common solid tumors that occur in childhood. With improved management of these tumors, there are more survivors with long-term sequelae of radiation and chemotherapy including growth failure. The aim of this study was to assess growth prospectively in children with nonpituitary-related primary brain tumors.

METHODS

Forty-one children 3.1 to 13.8 years of age diagnosed consecutively between 1989 and 1992 with a primary nonpituitary-related brain tumor were studied.

RESULTS

Of 34 prepubertal children, 14 (41%) were diagnosed as having growth hormone (GH) deficiency. All 14 children were treated with cranial irradiation. During the first year from completion of brain tumor therapy, the annual height velocity of those children confirmed subsequently as being GH-deficient was 3.06 +/- 1.19 cm compared with 5.29 +/- 2.21 cm for those who were not GH-deficient. During the second year, the annual height velocity was 3.29 +/- 1.14 cm per year for the GH-deficient group compared with 5.48 +/- 1.24 cm per year for the non-GH-deficient group. All children with GH deficiency received cranial irradiation and chemotherapy. Two of 34 children developed precocious puberty. Primary hypothyroidism was diagnosed in 6 of 41 children (12%).

CONCLUSION

We conclude that GH deficiency and primary hypothyroidism are common after cranial irradiation and chemotherapy for nonpituitary-related brain tumors. Linear growth appears to reflect GH status accurately in children with brain tumors. Precise auxologic evaluation is simple and noninvasive and may reflect more accurately GH status than provocative GH testing. These findings reflect the need for prospective growth monitoring of children with nonpituitary-related brain tumors treated with cranial irradiation and chemotherapy. Early diagnosis of GH deficiency facilitates early initiation of GH therapy and optimization of final height.

[Late effects of ionizing radiations on the thyroid gland]

The thyroid is the purest endocrine gland in the body and is likely to produce clinically significant abnormalities after external radiotherapy. Functional clinical modifications after direct irradiation exceeding 30 Gy are essentially related to hypothyroidism which may be clinically overt or subclinical with normal serum free thyroxine levels and high thyrotropin concentrations; the risk of hyperthyroidism, silent thyroiditis and Hashimoto's disease is also increased. Secondary hypothyroidism related to irradiation of the hypothalamus and the pituitary gland may arise with doses over 40-50 Gy following treatment for brain and nasopharyngeal tumors--Morphological glandular modifications induced by radiotherapy are responsible for the appearance of benign adenomas, more rarely cystic degenerations and specially well differentiated papillary or follicular carcinomas among children and adults. After irradiation during childhood for benign or malignant tumors, thyroid cancers are more frequent, higher for younger children, and the relative excess risk is increased from 15.6-to 53-fold; tumors can belatedly occur, more than 35 years after initial therapy. Thereby, in order to limit excess morbidity, it is evident that long term supervision with careful clinical and biological evaluations is necessary for patients who previously received neck, upper mediastinum and pituitary radiation therapy.

Thyroid dysfunction as a late effect in survivors of pediatric medulloblastoma/primitive neuroectodermal tumors: a comparison of hyperfractionated versus conventional radiotherapy

BACKGROUND

Primary hypothyroidism is a common sequela of craniospinal radiotherapy in the treatment of pediatric brain tumors.

METHODS

The authors compared the incidence of primary hypothyroidism after hyperfractionated radiotherapy (HFRT) (n = 14 patients) versus conventionally fractionated radiotherapy (CRT) (n = 34 patients) in a group of pediatric patients with medulloblastoma/primitive neuroectodermal tumors (MB/PNET).

RESULTS

The mean age at the time of tumor diagnosis was 7.9 years in the HFRT group and 8.4 years in the CRT group. The patients were followed for a mean of 4.6 years (HFRT) and 8.3 years (CRT) after diagnosis. Mean radiation doses to the thyroid were similar in both radiotherapy groups (29 gray [Gy] [HFRT] vs. 24 Gy [CRT]). Approximately 14% of the HFRT and 62% of the CRT patients developed primary hypothyroidism within a similar period after irradiation (3.2 years [HFRT] vs. 3.0 years [CRT]). Analysis by cumulative incidence function demonstrated a significant difference in the risk of developing thyroid dysfunction between these two groups of patients (P = 0.02).

CONCLUSIONS

The current study findings suggest that the use of HFRT in the treatment of pediatric patients with MB/PNET is associated with a lower risk of these patients developing primary hypothyroidism.

Endocrine late effects of childhood cancers

Long-term survival in children with cancer has increased markedly in the past 15 years. However, impaired linear growth and thyroid dysfunction that vary according to the age at diagnosis and treatment and to the dose and duration of radiation and chemotherapy have been described in these patients. The impact of cranial irradiation on the hypothalamic-pituitary-adrenal axis and on pubertal maturation has been less well studied. A positive correlation between the age at diagnosis and the age at onset of puberty in children who have been treated with high-dose cranial radiation therapy for central nervous system (CNS) tumors has been found recently. Frank adrenal insufficiency is uncommon after high-dose CNS irradiation, but alterations in the hypothalamic-pituitary-adrenal axis do occur. Assessments of the effects of newer modes of radiation therapy such as hyperfractionated craniospinal radiation suggest a lower incidence of primary hypothyroidism in the long term.

Testing the hypothalamic-pituitary-adrenal axis in survivors of childhood brain and skull-based tumors

The objective of this study was to determine whether a low dose of ACTH (0.2 microg/kg) improves the sensitivity of ACTH testing in detecting hypothalamic-pituitary-adrenal (HPA) axis abnormalities in survivors of childhood brain and skull-based tumors. Twenty-two children who had undergone treatment for brain or skull-based tumors were enrolled in a prospective study to extensively evaluate the HPA axis. Five tests of the adrenal axis were evaluated in each patient, including determination of basal serum cortisol, a standard ACTH test (250-microg i.v. bolus), a low dose ACTH test (0.2 microg/kg i.v. bolus), an insulin tolerance test, and a single dose metyrapone test. Cortisol responses to both ACTH tests were nearly identical. Two patients (9%) failed the low dose ACTH test, whereas three (14%) failed the standard ACTH test; five of the children (23%) failed the insulin tolerance test, and five (23%) had abnormal responses to metyrapone. One child who initially passed the metyrapone test failed the test 19 months later after becoming symptomatic. All children with abnormal metyrapone test results had low levels of basal cortisol secretion. In this study, the low dose ACTH test did not improve the sensitivity of ACTH testing for evaluation of the HPA axis. We conclude that a single morning basal cortisol level is a good screen for testing the HPA axis in children. We recommend confirming HPA axis dysfunction with the single dose metyrapone test, although this test also has limitations.