Irradiation-induced growth failure

A comprehensive review of the new FIGO classification of ovulatory disorders

BACKGROUND

The World Health Organization (WHO) system for the classification of disorders of ovulation was produced 50 years ago and, by international consensus, has been updated by the International Federation of Gynecology and Obstetrics (FIGO).

OBJECTIVE AND RATIONALE

This review outlines in detail each component of the FIGO HyPO-P (hypothalamic, pituitary, ovarian, PCOS) classification with a concise description of each cause, and thereby provides a systematic method for diagnosis and management.

SEARCH METHODS

We searched the published articles in the PubMed database in the English-language literature until October 2022, containing the keywords ovulatory disorders; ovulatory dysfunction; anovulation, and each subheading in the FIGO HyPO-P classification. We did not include abstracts or conference proceedings because the data are usually difficult to assess.

OUTCOMES

We present the most comprehensive review of all disorders of ovulation, published systematically according to the logical FIGO classification.

WIDER IMPLICATIONS

Improving the diagnosis of an individual's ovulatory dysfunction will significantly impact clinical practice by enabling healthcare practitioners to make a precise diagnosis and plan appropriate management.

Three case reports of radiation-induced glioblastoma after complete remission of acute lymphoblastic leukemia

Radiation therapy is sometimes performed to control intracranial acute lymphoblastic leukemia (ALL), but may lead to radiation-induced malignant glioma. The clinical, radiological, histological, and molecular findings are described of three cases of radiation-induced glioblastoma after the treatment for ALL. They received radiation therapy at age 6-8 years. The latency from radiation therapy to the onset of radiation-induced glioblastoma was 5-10 years. Magnetic resonance imaging demonstrated diffuse lesions with multiple small enhanced lesions in all cases. Histological examination showed that the tumors consisted of mainly small round astrocytic atypical cells in one case, and astrocytic atypical cells with elongated cytoplasm and nuclear pleomorphism with small cell component in two cases. Microvascular proliferation was present in all cases. Immunohistochemical analysis for B-Raf V600E, and mutational analysis for the isocitrate dehydrogenase (IDH) 1, IDH2, and H3F3A gene revealed the wild-type alleles in all three cases. The integrated diagnoses were IDH wild-type glioblastoma, and local irradiation and concomitant temozolomide were performed. After the initial treatment, significant shrinkage of the diffuse lesion and enhanced lesion was found in all cases. Radiation-induced glioblastoma occurring after the treatment for ALL had unique clinical, radiological, histological, and molecular characteristics in our three cases.

Growth impairment and gonadal axis abnormalities are common in survivors of paediatric brain tumours

AIM

Childhood brain tumour survivors have a high risk of endocrine morbidity. This study evaluated the growth, pubertal development and gonadal function in survivors of childhood brain tumours and identified factors associated with the problems we observed.

METHODS

The 52 subjects (52% male) were diagnosed in 1983-1997 and treated for brain tumours at Tampere University Hospital, Finland. They were followed up at a mean age of 14.2 (3.8-28.7) years, a mean of 7.5 (1.5-15.1) years after diagnosis.

RESULTS

We found that 30 (58%) participants had a lower height standard deviation score at follow-up than at diagnosis and short stature at follow-up was associated with tumour malignancy (p = 0.005), radiotherapy (p = 0.004), chemotherapy (p = 0.024), growth hormone deficiency (p < 0.001), hypogonadism (p = 0.044) and delayed puberty (p = 0.021). We found that five needed sex hormones to induce puberty, one had precocious puberty, 12 (23%) had growth hormone deficiency and eight (22%) of the 36 pubertal or postpubertal patients had hypogonadism. Testicular volume was low in 83% of late or postpubertal male survivors.

CONCLUSION

Growth impairment, growth hormone deficiency and hypogonadism were common in childhood brain tumour survivors and low testicular volume was also common in male survivors. Lifelong annual follow-up checks are indicated for survivors.

Blunted response to a growth hormone stimulation test is associated with unfavorable cardiovascular risk factor profile in childhood cancer survivors

BACKGROUND

Childhood cancer survivors (CCS) are at risk for growth hormone (GH) deficiency. CCS are also at increased risk for early mortality from cardiovascular (CV) disease, but the association between GH levels and CV risk remains poorly understood. The goal of this study was to examine the cross-sectional association between stimulated GH levels and CV risk factors in CCS younger than 18 years.

PROCEDURE

A total of 276 CCS (147 males, 14.4 ± 2.6 years) ≥5 years after cancer diagnosis, and 208 sibling controls (112 males, 13.6 ± 2.4 years) participated in this cross-sectional study, which included anthropometry, body composition, and metabolic studies. Blunted response (BR) was defined as peak GH level <7 µg/L after clonidine and arginine. Insulin sensitivity (M(lbm) ) was measured by euglycemic hyperinsulinemic clamp. Statistical analyses used linear and logistic regression accounting for sibling clustering, adjusted for age, sex, Tanner stage, and adiposity.

RESULTS

Thirty-four (12%) CCS showed BR to GH stimulation. BR CCS were shorter and had a lower IGF-1 than controls; only 6 of 34 received cranial radiation therapy. CCS with normal stimulated GH response were similar to controls for CV risk factors. Conversely, BR CCS had greater adiposity, higher lipids, and lower M(lbm) than controls. Differences in lipids and M(lbm) between BR CCS and controls remained significant after adjustment for BMI or visceral fat.

CONCLUSIONS

BR to GH stimulation is prevalent in CCS youth and is associated with an unfavorable CV risk factor profile. Further studies are needed to establish the mechanisms of these associations.

Growth and development after hematopoietic cell transplant in children

Hematopoietic cell transplantation (HCT) following high-dose chemotherapy or chemoradiotherapy for children with malignant or nonmalignant hematologic disorders has resulted in an increasing number of long-term disease-free survivors. The preparative regimens include high doses of alkylating agents, such as CY with or without BU, and may include TBI. These agents impact the neuroendocrine system in growing children and their subsequent growth and development. Children receiving high-dose CY or BUCY have normal thyroid function, but those who receive TBI-containing regimens may develop thyroid function abnormalities. Growth is not impacted by chemotherapy-only preparative regimens, but TBI is likely to result in growth hormone deficiency and decreased growth rates that need to be treated with synthetic growth hormone therapy. Children who receive high-dose CY-only have normal development through puberty, whereas those who receive BUCY have a high incidence of delayed pubertal development. Following fractionated TBI preparative regimens, approximately half of the patients have normal pubertal development. These data demonstrate that the growth and development problems after HCT are dependent upon the preparative regimen received. All children should be followed for years after HCT for detection of growth and development abnormalities that are treatable with appropriate hormone therapy.

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.

Final adult height of patients who received hematopoietic cell transplantation in childhood

Growth impairment and growth hormone (GH) deficiency are complications after total body irradiation (TBI) and hematopoietic cell transplantation (HCT). To determine the impact of GH therapy on growth, the final heights of 90 GH-deficient children who underwent fractionated TBI and HCT for malignancy were evaluated. Changes in height standard deviation (SD) from the diagnosis of GH deficiency to the achievement of final height were compared among 42 who did and 48 who did not receive GH therapy. At HCT, GH-treated patients were younger (P = .001), more likely to have undergone central nervous system irradiation (P = .007), and shorter (P = .005) than patients who did not receive GH therapy. After HCT, GH deficiency was diagnosed at 1.5 years (range, 0.8-9.5 years) for GH-treated and 1.2 years (range, 0.9-8.8 years) for nontreated patients. GH therapy was associated with significantly improved final height in children younger than 10 years at HCT (P = .0001), but GH therapy did not impact the growth of older children. Girls (P = .0001) and children diagnosed with acute myelogenous leukemia (AML), chronic myelogenous leukemia (CML), or myelodysplastic syndromes (MDS) (compared with acute lymphoblastic leukemia [ALL] or non-Hodgkin lymphoma [NHL]; P = .02) also showed more rapid growth than their counterparts. These data demonstrate that GH therapy improves the final height of young children after fractionated TBI.

Endocrine complications of high-dose therapy with stem cell transplantation

Evaluations of endocrine function following hematopoietic cell transplantation demonstrate that the endocrine function abnormalities observed are related to the type of transplant preparative regimen received. Children given high dose cyclophosphamide (CY) only have normal thyroid function, normal growth and development. Children who received a busulfan (BU) plus CY preparative regimen usually have normal thyroid function, normal prepubertal growth, delayed or absent pubertal development, and blunted post-pubertal growth. Recipients of preparative regimens containing total body irradiation may be anticipated to have some thyroid dysfunction, impaired growth rates and delayed or absent pubertal development. Post-pubertal teens and young adults are likely to have gonadal function recover if they received a preparative regimen with CY only but are likely to have primary gonadal failure if they received a preparative regimen with BU or total body irradiation. Individuals whose gonadal function becomes normal have become parents of normal children. All patients who receive a marrow transplant should be followed long-term for development of endocrine function abnormalities.

Endocrine complications of pediatric brain tumors: case series and literature review

The survival rate for childhood cancer, including brain tumors, is increasing. As a result, long-term sequelae of chemotherapy and radiotherapy are also increasing. The purpose of this study was to determine the frequency of endocrine complications of therapy for brain tumors in pediatric patients. Endocrinopathy was observed in 19 of 20 (95%) of patients with supratentorial midline tumors. Fifty-seven patients with nonmidline tumors (22 supratentorial, 35 posterior fossa) were followed for a mean of 4.6 +/- 2.4 years. Twenty-two endocrinopathies occurred in 16 patients treated as follows: one of 23 patients (0.4%) had surgery alone, zero of four (0%) had chemotherapy alone, eight of 18 (44%) had radiotherapy alone, and seven of 12 (58%) had both radiotherapy and chemotherapy. Endocrine disturbance was particularly common after craniospinal radiation (10 of 18 [55%]). Growth failure occurred in none of 23 patients who had surgery alone, in one of four patients who had chemotherapy (25%), in 11 of 18 patients who had radiotherapy (61%), in seven of 12 patients who received both radiotherapy and chemotherapy (58%), and in 12 of 18 patients who had craniospinal radiation (67%). In conclusion, endocrine and growth disturbances are uncommon with surgery alone, although they occurred in 53 and 60%, respectively, of patients treated with cranial irradiation for a brain tumor. This finding underscores the importance of routine endocrinology follow-up for all brain tumor patients receiving cranial irradiation. Literature review and endocrine surveillance recommendations are included.

Radiation dose-volume effects on growth hormone secretion

PURPOSE

Growth hormone (GH) deficiency is a known consequence of central nervous system irradiation. The relationship between the dose to the hypothalamus and the time to onset of clinically significant GH deficiency is unknown. Conformal radiotherapy (CRT) techniques allow for a more accurate determination of hypothalamic dosimetry. We correlated the dosimetry of the hypothalamus and the peak GH value after CRT in children with localized primary brain tumors.

METHODS AND MATERIALS

The arginine tolerance/L-dopa test was performed before (baseline) and repeated 6 and 12 months after CRT in 25 children (median age 4.8 years) with ependymoma (n = 15) or low-grade (n = 8) or high-grade (n = 2) astrocytoma. None had evidence of GH deficiency (arginine tolerance/L-dopa peak GH level >10 ng/mL [10 microg/L]) at baseline. Peak GH levels were modeled as a function of time after CRT and volume of the hypothalamus receiving a dose within the specified intervals of 0-20 Gy, 20-40 Gy, and 40-60 Gy. The model was used to predict the change in the peak GH levels over time (0-12 months) and fit under the assumption that the integral effect of irradiation was a linear sum of the products of the volume receiving a particular dose and the impact of that dose.

RESULTS

The peak GH level declined during the 0-12 months after CRT (p < 0.0001). GH deficiency was observed in 11 children at 6 months and a total of 20 children at 12 months. As expected, the effect of the dose interval 0-20 Gy was smaller than the 20-40-Gy dose interval; the largest effect was noted with the dose interval 40-60 Gy. The peak GH level may be predicted using the following estimating equation within the time limit of 0-12 months: GH(t)=Exp[ln(bGH)-(0.00058V(0-20 Gy)+0.00106V(20-40 Gy)+0.00156V(40-60 Gy))x t], where bGH is the baseline peak GH level, V(0-20 Gy), V(20-40 Gy), and V(40-60 Gy) is the percent-volume of the hypothalamus irradiated from 0 to 20 Gy, 20 to 40 Gy, and 40 to 60 Gy, respectively, and t is time after irradiation. When included in the model, the rate of decline in the peak GH response also was influenced by hydrocephalus and tumor location.

CONCLUSION

The peak GH response within 12 months after CRT depends on hypothalamic dose-volume effects and may be predicted on the basis of a linear model that sums the effects of the entire distribution of dose. The modeled effects may be used to optimize radiotherapy and minimize and treat GH deficiency.

Endocrine sequelae of cancer therapy in childhood

New treatments for neoplastic diseases of childhood have significantly increased patients' long-term survival and the importance of recognizing and correcting late complications of medical therapy. In this review, we examine both central nervous system (CNS) and non-CNS-related endocrine morbidities associated with chemotherapy and radiation therapy of childhood cancer. These include effects on growth, puberty, fertility, thyroid and adrenal function which may present many years after the successful treatment of underlying disease.

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.

Growth hormone status in adults treated for acute lymphoblastic leukaemia in childhood

OBJECTIVE

Growth hormone status was assessed in a cohort of 32 (16 male) adults who had received cranial irradiation (XRT) in childhood as part of their treatment for acute lymphoblastic leukaemia (ALL) and compared with 35 age matched young adults (18 male).

DESIGN

Height and weight were measured in all subjects and the heights of the patients at XRT were obtained from their case notes. Each patient and control underwent two provocative tests of growth hormone (GH) secretion using insulin (0.2 IU/kg body weight) and arginine (20 g/m2). Basal serum insulin like growth factor-1 (IGF-1) and IGFBP-3 (binding protein-3) concentrations were also measured.

RESULTS

The patient group had a significantly lower peak GH response to both provocative tests (P < 0.01), and lower IGF-1 and IGFBP-3 levels compared with the normal controls (P < 0.01). Nine of the patient group were severely GH deficient (peak GH response < 9 mU/l to both provocative agents) and a further 12 patients were GH insufficient (peak GH response < 20 mU/l to both tests with at least one peak GH response > 9 mU/l). Overall a significant median change in height from XRT to final height of -0.5 SDS was found which was even greater in the severely GH deficient group (median change in height of -2.1 SDS).

CONCLUSION

These data suggest that a significant proportion of adults treated with cranial XRT in childhood with irradiation doses between 18-25 Gy, as part of their treatment for ALL, are severely GH deficient now and should be considered for GH replacement. Changes in GH secretion evolve with time following irradiation-induced damage to the hypothalamic-pituitary axis; therefore long-term surveillance will be required in those remaining patients, in whom GH status is considered currently to be insufficient or even normal.

Relapse of intracranial germinoma 23 years postirradiation in a patient given growth hormone replacement

There is no clear evidence that growth hormone replacement therapy for treatment-related growth hormone deficiency in patients with childhood intracranial malignancies has a role in tumour relapse or second malignancy. A 16-year-old girl with an intracranial germinoma was treated with local radiotherapy and subsequently received growth hormone replacement therapy as an adult. Three years after starting growth hormone therapy, 23 years after her radiotherapy treatment, the patient's tumour recurred. Surveillance requirements for patients receiving growth hormone in this setting are discussed.

Growth and neuroendocrine dysfunction following therapy for childhood cancer

Poor linear growth and short adult stature are common complications following successful treatment of childhood cancer. Although several factors contribute to the impaired growth of these patients, growth potential is most reduced following radiotherapy to the head or spine. Younger age at treatment and female sex seem to be significant and independent risk factors for short adult height. Early diagnosis and timely therapy of the endocrine sequelae of cancer treatment (i.e., GH deficiency, hypothyroidism, and precocious puberty) ensure that these individuals will reach their optimum growth potential. For patients exposed to high-dose radiotherapy (> 35-40 Gy) to the region of the hypothalamus and pituitary gland, a variety of neuroendocrine abnormalities in addition to GH deficiency and early sexual development may occur, including deficiencies of LH/FSH, TSH, and ACTH as well as hypersecretion of prolactin. Because these problems may develop many years after irradiation, patients at risk for neuroendocrine disturbances require long-term endocrine follow-up.

The effects of irradiation and chemotherapy on growth

The effects of cancer therapy on growth are reviewed. The effects of radiation and chemotherapy on growth hormone production and growth hormone responsiveness by peripheral tissues are examined. The effects of radiotherapy and chemotherapy on other endocrine function pertaining to growth also are discussed. An approach to surveillance of pediatric cancer survivors pertaining to growth and development is suggested.

Growth in children after bone marrow transplantation for acute myelogenous leukemia as compared to acute lymphocytic leukemia

Previous studies of growth in children following bone marrow transplantation for leukemia have demonstrated poor growth with little ability to "catch-up" two to four years after transplantation. Because of small patient numbers, these studies did not distinguish patients with differing types of leukemia. 12 children with acute myelogenous leukemia who survived over 3 years after transplantation were compared with 12 who survived transplantation for acute lymphoblastic leukemia. The initial height standard deviation scores were similar in both groups prior to transplantation. The height standard deviation scores in the acute lymphoblastic leukemia group decreased for each of the 5 years after transplantation while the height score for the acute myelogenous leukemia group after 5 years was not statistically different from pre-transplantation. The growth of the children with myelogenous leukemia was better possibly because these children were older, had received less cranial irradiation at the time of transplantation, and had a lower incidence of severe chronic graft-versus-host disease.

Intellectual performance after presymptomatic cranial radiotherapy for leukaemia: effects of age and sex

Cognitive outcome, as measured by verbal and performance IQs, was compared in 35 girls and 47 boys who were in first remission for acute lymphoblastic leukaemia. All children had received presymptomatic cranial radiotherapy and intrathecal methotrexate. The mean age at diagnosis was 4.2 years and the mean elapsed time from initial diagnosis to intellectual assessment was 7.1 years. Results showed that children irradiated before the age of 4 years were impaired in certain aspects of non-verbal ability, as well as in measures of short term memory and attention, calculated by factor scores derived from selected subtests of the IQ test. Subtests requiring verbal and non-verbal reasoning showed the greatest impairment after early diagnosis and treatment. In addition girls were selectively impaired in verbal IQ and other aspects of verbal ability, with the degree of impairment exacerbated by early treatment. No relationship was found between degree of impairment and either time since treatment or number of methotrexate injections. It is concluded that early age at irradiation increases the risk of impaired intellectual outcome, particularly in girls.

Radiation and neuroregulatory control of growth hormone secretion

OBJECTIVE

Cranial irradiation frequently results in growth hormone (GH) deficiency. Patients with radiation-induced GH deficiency usually remain responsive to exogenous growth hormone releasing hormone, implying radiation damages the hypothalamus rather than the pituitary. Little is known about the effect of cranial irradiation on the neuroendocrine control of GH secretion. This study was to determine the effect of cranial irradiation on somatostatin tone.

DESIGN

Somatostatin tone was examined by manipulating cholinergic tone in young adults with radiation-induced GH deficiency and a control population. Each individual underwent three separate studies: the GH response to 100 micrograms GHRH-(1-29)-NH2 was assessed alone, and 60 minutes after pyridostigmine or pirenzepine.

PATIENTS

Eight young male adults with radiation induced GH deficiency following treatment in childhood for a brain tumour or acute lymphoblastic leukaemia, and ten healthy adult men were studied.

MEASUREMENTS

Serum growth hormone was measured at 15-minute intervals throughout each of the three study periods.

RESULTS

One of 10 controls and four of eight irradiated subjects had a peak GH level to GHRH analogue of less than 20 mU/l. After pretreatment with pyridostigmine, all subjects except one irradiated subject had a peak GH level of greater than 20 mU/l. Pretreatment with pyridostigmine and pirenzepine significantly modified the GH response to GHRH analogue within both groups (P < 0.0005). Pretreatment with pyridostigmine significantly enhanced the GH response to GHRH analogue (median (range) area under the curve, 9029 (1956-20940) mU/l/min in controls vs 1970 (628-3608) mU/l/min in the irradiated group) compared with GHRH analogue alone (1953 (512-16140) mU/l/min in control group vs 997 (266-3488) mU/l/min in the irradiated group). Pretreatment with pirenzepine significantly attenuated the GH response to GHRH analogue (552 (64-1274) mU/l/min in controls vs 305 (134-2726) mU/l/min in irradiated group). Between the groups there was no significant difference in GH area under the curve (AUC) after GHRH analogue alone. There was a significantly (P = 0.0014) greater increment of GH secretion after pyridostigmine and GHRH analogue compared with GHRH analogue alone (difference in AUC of pyridostigmine+GHRH analogue and GHRH analogue alone 6348 (696-12856) mU/l controls vs 542 (120-1340) mU/l in the irradiated group) and significantly (P = 0.033) greater suppression of GH secretion after pirenzepine and GHRH analogue compared with GHRH analogue alone (difference in AUC of GHRH analogue alone and pirenzepine+GHRH analogue 1644 (222-15205) mU/l in controls vs 479 (469-1623) mU/l in the irradiated group) in the control population compared with those who had received cranial irradiation in childhood.

CONCLUSIONS

These data suggest that cranial irradiation reduces but does not abolish somatostatin (SRIH) tone and also reduces endogenous GHRH secretion. Although SRIH tone is reduced, it can be increased by cholinergic manipulation and is therefore not irreversibly fixed. This has possible implications if GHRH analogues were used to treat children with radiation induced GH deficiency.

Growth following single fraction and fractionated total body irradiation for bone marrow transplantation

Total body irradiation (TBI) is used as preparative regimen prior to bone marrow transplantation (BMT). Since there are more long-term survivors, follow up studies are important. We have performed a retrospective analysis of growth for 49 children, who had undergone treatment with cyclophosphamide and TBI before BMT. Of these patients 26 received single fraction (SF) TBI as a dose of 900-1000 cGy, whereas 23 received fractionated (FF) TBI as a total dose of either 1200 cGy divided in six fractions or 1440 cGy divided in eight fractions over 3 days. Half of the patients in the SF-TBI group, and 9 in the FF-TBI group had received low-dose cranial irradiation prior to TBI. In all groups a decrease in height SDS was observed. By evaluating the major factors leading to growth impairment the influence of cranial irradiation, which was demonstrable in the 1st year after TBI, could not be shown after 3 years. At this time growth was significantly more impaired in the SF group with a mean height SDS of -0.9 (+/- SD 0.9) compared to a mean height SDS -0.22 (1.02) in the FF group (P < 0.05). Measurement of segmental proportions showed a significant difference in SDS for sitting height in comparison to SDS for subischial leg length, irrespective of the TBI regimen. This was already evident 1 year after TBI and decreased during the following years. Twenty four of the patients (17 in the single fraction and 7 in the fractionated TBI group) were treated with growth hormone, but demonstrated an inappropriate response with absent catch-up growth in their legs.(ABSTRACT TRUNCATED AT 250 WORDS)

Growth and growth hormone in children during and after therapy for acute lymphoblastic leukaemia

Growth impairment and growth hormone (GH) deficiency have been reported in children treated for acute lymphoblastic leukaemia (ALL). We have studied growth and GH secretion in a group of 50 patients, affected by ALL, during a 2- to 5-year period after diagnosis, and in 12 "long-term-survivors". We observed a significant decrease in growth velocity during the 1st year (in particular during the first 6 months) of therapy and a catch-up growth after the end of therapy. "Long-term survivors" did not exhibit a significant reduction of height standard deviation score (SDS), as compared to height SDS at diagnosis. None of the patients showed GH deficiency. Our data indicate that chemotherapy significantly affects growth of patients treated for ALL, whereas radiotherapy-at the doses used in this study-does not induce GH deficiency, at least not within 9 years after diagnosis.

Growth in children after bone marrow transplantation for advanced neuroblastoma compared with growth after transplantation for leukemia or aplastic anemia

The linear growth of 26 children with progressive and advanced neuroblastoma treated with high-dose chemotherapy, total body irradiation, and bone marrow transplantation between 1978 and 1988 at the Children's Hospital of Philadelphia was compared with the growth of 33 children who had transplants for leukemia and of 12 who had transplants for aplastic anemia. The mean growth velocity, expressed as a standard deviation score, for the children who underwent bone marrow transplantation for neuroblastoma was -2.83. This was significantly (p less than 0.005) less than the standard deviation scores for children with transplants for acute lymphoblastic leukemia, acute nonlymphocytic leukemia, and aplastic anemia, which were -0.98, -0.07, and -1.05, respectively. A 6-year follow-up study of 32 long-term survivors of cancer revealed that the 11 patients with neuroblastoma continued to grow poorly, whereas a comparison group of 21 survivors of bone marrow transplantation for leukemia had essentially normal growth 2 years after the procedure. Major therapeutic differences between the two groups included the doses of local radiotherapy and the type and number of cytotoxic agents used. In comparison with the relatively mild growth-inhibiting effects of preparative regimens for leukemia and aplastic anemia, the very intensive preparative regimens used in patients with neuroblastoma have significant negative effects on growth.

Impaired pubertal growth in acute lymphoblastic leukaemia

The growth of 182 patients who were long term survivors of childhood acute lymphoblastic leukaemia was retrospectively analysed. All remained in first remission and were treated with either 1800 or 2400 cGy of cranial irradiation. None had been treated with either testicular or spinal irradiation. Ninety three (51 boys, 42 girls) were treated with 2400 cGy and 89 (42 boys, 47 girls) were treated with 1800 cGy cranial irradiation. All patients were treated with standard chemotherapy including intrathecal methotrexate in similar dose regimens in either group. Mean age (SD) at diagnosis in the group treated with 2400 cGy was 4.8 (2.6) years and mean age in the group treated with 1800 cGy was 6.5 (3.3) years. Mean height SD score at diagnosis in the 2400 cGy group was +0.29 and final height achieved was -0.63. Mean height SD score at the start of treatment in the group treated with 1800 cGy was +0.40 and mean final height was -0.53. There was a similar reduction in height SD score in both groups during the pubertal growth spurt. The decrement in height SD score was greater when treatment was administered at less than 7 years of age in either dose regimen, both in prepubertal and pubertal growth. However, the decrease in height SD score was found to be greater in girls than boys. There was a trend in both sexes for the onset of puberty to be at a younger age with a lower treatment dose of radiotherapy. However, in girls treated with the lower dose regimen there was a significant reduction in the mean age of onset of puberty which was 9.9 years. Our data suggest that girls treated at less than 7 years of age have a severe impairment of pubertal growth, which is probably a combination of the dual endocrinopathy of premature puberty and growth hormone insufficiency.

Growth hormone deficiency following radiation therapy of primary brain tumors in children

The medical records of 123 patients treated for brain tumors at Children's Hospital and Medical Center, Seattle, Washington, between 1985 and 1987 were reviewed. The endocrinological complications of radiation therapy and the effectiveness of growth hormone (GH) replacement therapy were assessed. These were the first 2 years after synthetic GH became available. The disease pathology was confirmed at craniotomy or biopsy in 108 patients. Ninety-five children completed radiation therapy and 65 of these were alive at the time of review; these 65 children represent the study population. The most common tumor types were medulloblastoma, craniopharyngioma, and ependymoma. Endocrine evaluation was initiated with changes in the patients' growth velocity. Patient workup included skeletal x-ray films for determination of bone and analysis of thyroxin, thyroid-stimulating hormone, and somatomedin-C levels. Following 1-dopa and clonidine stimulation, provocative studies of GH levels were performed. Growth hormone failure and short stature were observed in 26 children, most commonly in the 2nd year after tumor treatment. Eight patients with GH failure were also hypothyroid. Hormone replacement therapy was initiated with recombinant GH, 0.05 mg/kg/day, and all children so treated showed an increase in height, with eight patients experiencing catch-up growth. There were no complications of therapy or tumor recurrence. Studies of baseline bone age and somatomedin-C levels on completion of radiation therapy are recommended. Comprehensive endocrine studies should follow changes in the patients' growth velocity. With early GH replacement, catch-up growth is possible and normal adult heights may be achieved.

Dose dependency of time of onset of radiation-induced growth hormone deficiency

Growth hormone (GH) secretion during insulin-induced hypoglycemia was assessed on 133 occasions in 82 survivors of childhood malignant disease. All had received cranial irradiation with a dose range to the hypothalamic-pituitary axis of 27 to 47.5 Gy (estimated by a schedule of 16 fractions over 3 weeks) and had been tested on one or more occasions between 0.2 and 18.9 years after treatment. Results of one third of the GH tests were defined as normal (GH peak response, greater than 15 mU/L) within the first 5 years, in comparison with 16% after 5 years. Stepwise multiple linear regression analysis showed that dose (p = 0.007) and time from irradiation (p = 0.03), but not age at therapy, had a significant influence on peak GH responses. The late incidence of GH deficiency was similar over the whole dose range (4 of 26 GH test results normal for less than 30 Gy and 4 of 25 normal for greater than or equal to 30 Gy after 5 years), but the speed of onset over the first years was dependent on dose. We conclude that the requirement for GH replacement therapy and the timing of its introduction will be influenced by the dose of irradiation received by the hypothalamic-pituitary axis.

Management of growth hormone deficiency through puberty

As a model of the growth hormone (GH) dependence of growth in prepuberty and puberty, the growth of 182 children (93 boys, 89 girls) who survived in first remission for treatment of acute lymphoblastic leukaemia was examined. Chemotherapy regimens, including intrathecal methotrexate, were similar in all patients, but CNS treatment differed, in that one group received 2400 cGy cranial irradiation, while the other received 1800 cGy. There was a significant decrease in height SDS during prepuberty, which was equivalent in both sexes, whereas there was a much greater decrease in pubertal growth in girls than in boys. Girls treated with the lower dose regimen of cranial irradiation had their onset of pubertal maturation significantly advanced, to a mean of 9.9 years (p less than 0.001). Previous studies have indicated that the duration of puberty is shortened by GH treatment in patients with idiopathic multiple pituitary hormone deficiency or isolated GH deficiency (GHD). To determine whether an increase in the dose of GH administered during the adolescent growth spurt would improve final height, a prospective randomized trial was performed in 32 children (25 boys, 7 girls) with isolated GHD treated with a GH dose regimen of 15 IU/m2/week as daily s.c. injections. At the onset of the pubertal growth spurt, the patients were randomized either to an unchanged dose or to 30 IU/m2/week. There was no significant change in height velocity with the doubled dose of GH, but there was a trend in the advancement of pubertal maturation which was considered to be dose related. It is suggested that these findings are of relevance to the treatment of GHD in puberty, especially in girls with early or precocious puberty occurring as a consequence of low-dose cranial irradiation.(ABSTRACT TRUNCATED AT 250 WORDS)

Radiation and hypothalamic-pituitary function

In adults, hypopituitarism is a common consequence of external radiotherapy. The clinical manifestations may be subtle and develop insidiously many years after radiotherapy. Anterior pituitary deficiencies can therefore only be detected by regular testing, including dynamic tests of GH and ACTH reserve. Although the deficiencies most commonly develop in the order GH, gonadotrophins, ACTH then TSH, this sequence may not be predictable in an individual patient and comprehensive testing is therefore required. The tests should ideally be performed annually for at least 10 years after treatment or until deficiency has been detected and treated. It is not only the patients with pituitary disease who are at risk of developing hypopituitarism after radiotherapy. Any patient who receives a total dose of irradiation of 20 Gy or more to the hypothalamic-pituitary axis is at risk of hypopituitarism, although the threshold dose may be lower than this. This is particularly important in the long-term survivors of malignant disease in whom endocrine morbidity may be relatively common and in whom this can be easily treated, with consequent improvement in quality of life. Whilst patients who receive a high total dose of irradiation are at increased risk of developing multiple deficiencies, a higher fraction size also increases the risk of anterior pituitary failure. There is good evidence that the earliest damage to the hypothalamic-pituitary axis after external radiotherapy is at the level of the hypothalamus. However, patients who undergo pituitary ablation with interstitial radiotherapy or heavy particle beams are likely to sustain direct damage to the pituitary. In these patients, the sequence in which individual pituitary hormone deficiencies develop is generally the same as that observed with the hypothalamic damage after conventional external radiotherapy. The increasing use of radiotherapy as a means of treatment for malignant disease means that new groups of patients with potential for endocrine dysfunction are emerging. Whole body irradiation in the preparation for bone marrow transplant is one such treatment and although hypothalamic-pituitary damage appears to be confined to GH deficiency in children, longitudinal experience is limited to date, particularly in adults. The treatment of malignant disease in childhood is of particular importance in terms of the delayed endocrine sequelae. The hypothalamic-pituitary axis may not be the only endocrine tissue damaged by treatment in these patients and management is therefore more complicated. In the growing child, the potential association of growth hormone deficiency, gonadal failure or premature puberty and thyroid dysfunction mean that expert endocrine supervision is essential for optimum long-term outcome.

Management of growth failure in the treatment of malignant disease

Growth failure due to endocrine dysfunction as a result of treatment for malignant disease is becoming increasingly common. It may occur after cranial or craniospinal irradiation given in the treatment of acute lymphoblastic leukemia and brain tumors, and is often coupled with early or precocious puberty. It also occurs after neck and gonadal radiation and is particularly severe after total body irradiation where multiple endocrine deficiencies frequently occur. Failure to appreciate its occurrence or failure to institute therapy early enough may lead to short stature in adult life. Accurate and regular monitoring of standing and sitting height, bone age, and endocrine data should be undertaken by the oncologist in close collaboration with an endocrinologist, to ensure appropriate management of the patient.

Wilms tumour in a patient with growth hormone replacement therapy

Wilms tumour was found in a Japanese boy aged 5 years 9 months with isolated growth hormone (GH) deficiency and some congenital anomalies. He had received pituitary GH replacement therapy from the age of 2 years 1 month to 4 years 7 months and after a 1 year interval he received biosynthetic GH for 2 months until the tumour became clinically apparent. This was the sixth known patient with GH deficiency to develop a malignant neoplasm during or after GH replacement therapy and the first with a solid tumour in Japan since 1975, when treatment with pituitary GH for patients with GH deficiency was introduced.

Growth hormone therapy and leukaemia

Following an initial report from Japan in 1987, 15 growth hormone (GH)-deficient patients developed leukaemia during or following GH treatment. Nearly all available pituitary and biosynthetic growth hormones have been used. In 14 of these 15 patients GH treatment was initiated in 1975 or later with doses between 4.5 and 18IU/m2 per week. The therapy period was between 0.17 and 8.0 years. Leukaemia occurred 0.2-11 years after the start of GH treatment. GH affects normally and abnormally growing blood cells in vitro and in animal experiments, but the clinical data in humans do not indicate GH induction of tumour growth. Seven out of the 14 patients under discussion had an additional increased leukaemia risk. Two other patients had been treated only for a very short time. Though no clear evidence of a strikingly augmented leukaemia incidence in GH-treated patients is found worldwide, the available data call for increased attention.

Medical cost of curing childhood acute lymphoblastic leukaemia

Between 1970 and 1979 acute lymphoblastic leukaemia was diagnosed in 378 children at this hospital. The outcome for the 181 survivors was examined six or more years after diagnosis to assess morbidity in an unselected group of long term survivors. One hundred and thirty seven of the survivors were in first remission and probably cured (group I). Forty four (group II) had had one or more relapses, some of whom, who had isolated extramedullary relapses, also have a good chance of cure. In group I 136 patients had prophylactic cranial or craniospinal irradiation, while patients in group II, in addition to having that treatment, received local testicular (17) or craniospinal radiation (seven) for testicular or central nervous system relapse. Eight had additional prophylactic cranial radiotherapy after bone marrow relapse, and six had total body irradiation before bone marrow transplantation. The incidence of clinically important growth and endocrine morbidity was 20% in group I and 68% in group II. The morbidity in patients in group I was mainly attributable to early pubertal maturation. In group II 30 patients had growth failure, of whom 19 had gonadal failure from testicular or total body irradiation, 14 had growth hormone deficiency after doses of cranial irradiation of over 2400 cGy, and 10 had spinal growth impairment after craniospinal irradiation. Two also had early pubertal maturation. Five out of six patients who received total body irradiation had multiple endocrine deficiency. Neuropsychological sequelae of treatment were seen in 40 (42%) of 96 schoolchildren in group I and in 12 (38%) of 32 schoolchildren in group II. Postinfective sequelae of treatment were found in patients in both groups. These results show that the survivors who were in their first remission had a 42% residual morbidity related to treatment compared with an 82% morbidity in the survivors of one or more relapses who had multiple treatments.

The effect of total body irradiation and bone marrow transplantation during childhood and adolescence on growth and endocrine function

Seventeen children (11 M, 6 F) with acute leukaemia and myeloproliferative disorders were investigated for growth and endocrine dysfunction. All had undergone bone marrow transplantation prepared with cyclophosphamide and single fraction total body irradiation (900-1000 cGy) between 1.5 and 3.8 (mean 2.2) years previously. The majority of children exhibited growth failure, which was of multiple aetiology. Ten patients, of whom eight had had previous prophylactic cranial irradiation, had evidence of growth hormone deficiency based on the reduced growth hormone response to insulin induced hypoglycaemia. Three patients had evidence of hypothalamic damage as shown by their growth hormone response to 200 micrograms GHRH (1-29) NH2 intravenously. Gonadal failure was common, assessed clinically, and biochemically by basal gonadotrophin and sex steroid concentrations. All four girls of adolescent age (10.6-14.1 years) had ovarian failure requiring sex steroid replacement. Of the eight boys of adolescent age (12.3-18.3 years), two had testicular failure requiring sex steroid supplements. Both of these had had previous testicular irradiation. Five others had compensated gonadal failure, and one had normal Leydig cell function. Abnormalities of the TSH response to TRH occurred in 10 patients but only three had overt hypothyroidism. Unlike growth hormone deficiency, gonadal and thyroid dysfunction showed no correlation with previous cranial radiotherapy.

Precocious and premature puberty associated with treatment of acute lymphoblastic leukaemia

Early puberty in 28 children (23 girls, five boys) treated for acute lymphoblastic leukaemia (ALL) at a mean age of 4.0 years (range 1.4-7.8) is described. All but one had received prophylactic cranial irradiation (1800-2400 cGy) and three children had received additional cranial or craniospinal irradiation as treatment for relapse of their leukaemia. Mean age for the onset of puberty was 8.8 (SD 0.8) years in the girls and 9.3 (0.8) years in the boys; this is greater than two standard deviations from the mean for normal girls and boys. Five children (three girls, two boys) had precocious puberty. The onset of puberty occurred at greater than two standard deviations from the mean for normal girls and boys in 14(13%) girls and 4(3%) boys treated at less than eight years of age between 1970 and 1985. In a group of 55 girls treated for ALL who had survived in first remission for six years or more from diagnosis, there was a relation between young age at onset of treatment and early menarche. We suggest that premature activation of the hypothalamic-pituitary-gonadal axis occurs as a consequence of hypothalamic dysfunction due to cranial irradiation. Precocious and premature puberty in children treated for ALL may be an important factor in contributing to short stature.

Effect of spinal irradiation on growth

Standing height, sitting height, and leg length were measured in 79 patients (aged 16-30 years), who had been given craniospinal irradiation (n = 37) or cranial irradiation (n = 42) in childhood for a brain tumour and had completed their growth. Their measurements were compared with established standards for sitting height and leg length in British children (aged 16-18 years). To examine the effects of spinal irradiation on spinal growth independent of growth hormone deficiency we analysed the leg length (LL) minus sitting height (SH) standard deviation score (SDS) and used the cranial group as controls. There was an overall significant difference between the median craniospinal LL-SH SDS (1.98) and the median cranial LL-SH SDS (0.545). Within the craniospinal group there was a significant correlation with age at treatment, but there was no such correlation for the cranial group. After splitting age at treatment into three groups (0 less than 5, 5 less than 10, and 10-15 years) there was a significant difference between the LL-SH SDS of the craniospinal and cranial groups for each of the age ranges. In conclusion, spinal irradiation has a profound effect on spinal growth and the younger the child is when given irradiation the greater the subsequent skeletal disproportion. Our most conservative figures indicate that the eventual loss in height is 9 cm when irradiation is given at 1 year, 7 cm when given at 5 years, and 5.5 cm when given at 10 years.