Spinal deformity induced by radiotherapy for solid tumours in childhood: a long-term follow up study

Risks of Spinal Abnormalities and Growth Impairment After Radiation to the Spine in Childhood Cancer Survivors: A PENTEC Comprehensive Review

PURPOSE

A PENTEC (Pediatric Normal Tissue Effects in the Clinic) review was performed to estimate the dose-volume effects of radiation therapy on spine deformities and growth impairment for patients who underwent radiation therapy as children.

METHODS AND MATERIALS

A systematic literature search was performed to identify published data for spine deformities and growth stunting. Data were extracted from 12 reports of children irradiated to the spine (N = 603 patients). The extracted data were analyzed to find associations between complication risks and the radiation dose (conventional fractionation throughout) as impacted by exposed volumes and age using the mixed-effects logistic regression model. When appropriate, corrections were made for radiation modality, namely orthovoltage beams.

RESULTS

In the regression analysis, the association between vertebral dose and scoliosis rate was highly significant (P < .001). Additionally, young age at time of radiation was highly predictive of adverse outcomes. Clinically significant scoliosis can occur with doses ≥15 Gy to vertebrae during infancy (<2 years of age). For children irradiated at 2 to 6 years of age, overall scoliosis rates of any grade were >30% with doses >20 Gy; grade 2 or higher scoliosis was correlated with doses ≥30 Gy. Children >6 years of age remain at risk for scoliosis with doses >30 Gy; however, most cases will be mild. There are limited data regarding the effect of dose gradients across the spine on degree of scoliosis. The risk of clinically meaningful height loss was minimal when irradiating small volumes of the spine up to 20 Gy (eg, flank irradiation), except in infants who are more vulnerable to lower doses. Growth stunting was more frequent when larger segments of the spine (eg, the entire spine or craniospinal irradiation) were irradiated before puberty to doses >20 Gy. The effect was modest when patients were irradiated after puberty to doses >20 Gy.

CONCLUSIONS

To reduce the risk of kyphoscoliosis and growth impairment, the dose to the spine should be kept to <20 Gy for children <6 years of age and to <10 to 15 Gy in infants. The number of vertebral bodies irradiated and dose gradients across the spine should also be limited when possible.

Predictive Factors Associated With Radiation Myelopathy in Pediatric Patients With Cancer: A PENTEC Comprehensive Review

PURPOSE

Radiation myelitis (RM) is a rare complication of radiation therapy (RT). The Pediatric Normal Tissue Effects in the Clinic spinal cord task force aimed to identify RT dose effects and assess risk factors for RM in children. Through systematic review, we analyzed RT dose, fraction size, latency between completion of RT and toxicity, chemotherapy use, age when irradiated, and sex.

METHODS AND MATERIALS

We conducted literature searches of peer-reviewed manuscripts published from 1964 to June 2017 evaluating RM among children. Normality of variables was assessed with Kolmogorov-Smirnov or Shapiro-Wilk tests. Spearman's rank correlation coefficients were used to test correlations between RT dose/fraction size and latency between RT and development of toxicity.

RESULTS

Of 1329 identified and screened reports, 144 reports were fully reviewed and determined to have adequate data for analysis; 16 of these reports had a total of 33 cases of RM with a median age of 13 years (range, 0.2-18) at the time of RT. The most common primary tumor histologies were rhabdomyosarcoma (n = 9), medulloblastoma (n = 5), and Hodgkin lymphoma (n = 2); the most common chemotherapy agents given were vincristine (n = 15), intrathecal methotrexate (n = 12), and intrathecal cytarabine (n = 10). The median RT dose and fraction size were 40 Gy (range, 24-57.4 Gy) and 1.8 Gy (range, 1.3-2.6 Gy), respectively. RT dose resulting in RM in patients who also received chemotherapy was lower than in those not receiving chemotherapy (mean 39.6 vs 49.7 Gy; P = .04). There was no association of age with RT dose. The median latency period was 7 months (range, 1-29). Higher RT dose was correlated with longer latency periods (P = .03) to RM whereas sex, age, fraction size, and chemotherapy use were not. Two of 17 patients with adequate follow-up recovered from RM; unfortunately, it was fatal in 6 of 15 evaluable patients. Complication probability modeling was not possible because of the rarity of events.

CONCLUSIONS

This report demonstrates a relatively short latency from RT (with or without chemotherapy) to RM and a wide range of doses (including fraction sizes) associated with RM. No apparent association with age at the time of RT could be discerned. Chemotherapy appears to reduce spinal cord tolerance. Recovery from RM is rare, and it is often fatal.

Early disc degeneration in radiotherapy-treated childhood brain tumor survivors

BACKGROUND

Childhood brain tumor (BT) survivors have an increased risk of treatment-related late effects, which can reduce health-related quality of life and increase morbidity. This study aimed to investigate lumbar disc degeneration in magnetic resonance imaging (MRI) in adult survivors of radiotherapy-treated childhood BT compared to age and sex-matched population controls.

METHODS

In this cross-sectional comparative study, 127 survivors were identified from hospital registries. After a mean follow-up of 20.7 years (range 5-33.1), 67 survivors (mean age 28.4, range 16.2-43.5) were investigated with MRI and compared to 75 sex-matched population-based controls. Evaluated MRI phenotypes included Pfirrmann grading, , intervertebral disc protrusions, extrusions, and high-intensity-zone-lesions (HIZ). Groups were also compared for known risk factors of lumbar intervertebral disc (IVD) degeneration.

RESULTS

Childhood BT survivors had higher Pfirrmann grades than controls at all lumbar levels (all p < 0.001). Lumbar disc protrusions at L4-5 (p = 0.02) and extrusions at L3-4 (p = 0.04), L4-5 (p = 0.004), and L5-S1 (p = 0.01) were significantly more common in the BT group compared to the control. The survivor cohort also had significantly more HIZ-lesons than the controls (n=13 and n=1, p=0.003). Age at diagnosis was associated with lower degree of IVD degeneration (p < 0.01). Blood pressure correlated with IVD degeneration (P < 0.05).

CONCLUSIONS

Signs of early disc degeneration related to tumor treatment can be seen in the IVDs of survivors. Disc degeneration was more severe in children treated in adolescence.

Incidence and Management of Pleural Effusions in Patients with Wilms Tumor: A Pediatric Surgical Oncology Research Collaborative Study

Wilms tumor (WT) is the most common renal malignancy in children. Children with favorable histology WT achieve survival rates of over 90%. Twelve percent of patients present with metastatic disease, most commonly to the lungs. The presence of a pleural effusion at the time of diagnosis of WT may be noted on staging imaging; however, minimal data exist regarding the significance and prognostic importance of this finding. The objectives of this study are to identify the incidence of pleural effusions in patients with WT, and to determine the potential impact on oncologic outcomes. A multi-institutional retrospective review was performed from January 2009 to December 2019, including children with WT and a pleural effusion on diagnostic imaging treated at Pediatric Surgical Oncology Research Collaborative (PSORC) participating institutions. Of 1,259 children with a new WT diagnosis, 94 (7.5%) had a pleural effusion. Patients with a pleural effusion were older than those without (median 4.3 vs 3.5 years; p=0.004), and advanced stages were more common (local stage III 85.9% vs 51.9%; p<0.0001). Only 14 patients underwent a thoracentesis for fluid evaluation; 3 had cytopathologic evidence of malignant cells. Event-free and overall survival of all children with WT and pleural effusions was 86.2% and 91.5%, respectively. The rate and significance of malignant cells present in pleural fluid is unknown due to low incidence of cytopathologic analysis in our cohort; therefore, the presence of an effusion does not appear to necessitate a change in therapy. Excellent survival can be expected with current stage-specific treatment regimens.

Treatment of Kyphosis Arising Secondary to Laminectomy and Irradiation in the Pediatric Population

The effects of radiation therapy and laminectomy on the growing spine have been well documented. Due to compromised bone quality after irradiation, spinal fusion has a high failure rate. The aim of this study was to evaluate treatment of post-laminectomy and post-irradiation kyphosis in children using a vascularized rib graft (VRG) to augment anterior spinal fusion and posterior spinal fusion. Data were collected retrospectively from electronic medical records for all patients treated at a single institution for post-laminectomy and post-irradiation kyphosis who underwent VRG to augment spinal fusions done between December 2003 and August 2015. Five patients were included in the analysis. Imaging studies were analyzed by 2 senior pediatric orthopedic surgeons and a pediatric orthopedic surgery fellow. The outcome for all 5 patients who underwent VRG were considered successful at most recent clinical follow-up. Success was defined as the following: complete fusion evident through computed tomography scan, no implant failure, and no kyphosis progression. Follow-up ranged from 21 to 63 months. One patient experienced 2 complications: esophageal tear and deep infection. Spinal fusion with a VRG is a viable treatment option for children who have developed kyphosis following laminectomy and irradiation. On long-term follow-up, there has been no evidence of progression of kyphosis for patients who were treated with VRG in either the primary fusion procedure or in subsequent revision procedures. A VRG provides a non-irradiated, vascularized bone graft to bridge the irradiated segments, increasing the stability of the spine. [Orthopedics. 2021;44(4):e563-e569.].

An Analysis of Vertebral Body Growth after Proton Beam Therapy for Pediatric Cancer

Simple Summary

Radiotherapy has a key role in treatment of pediatric cancer and has greatly improved survival in recent years. However, vertebrae are often included in the irradiated area, and this may affect growth after treatment. In this study, we examined the relationship of the dose of proton beam therapy with subsequent growth of 353 vertebral bodies in 23 children (10 boys, 13 girls) with a median age at treatment of 4 years old and a median observation period of 13.9 months. Most importantly, we found that the growth rate of vertebral bodies decreased even at a low proton beam therapy dose, which indicates the need for careful planning of the irradiation area in this patient population. Growth inhibition was clearly dose-dependent, and proton beam therapy had the same growth inhibitory effect as photon radiotherapy, at least within the irradiated field.

Abstract

Impairment of bone growth after radiotherapy for pediatric bone cancer is a well-known adverse event. However, there is limited understanding of the relationship between bone growth and irradiation dose. In this study, we retrospectively analyzed bone growth impairment after proton beam therapy for pediatric cancer. A total of 353 vertebral bodies in 23 patients under 12 years old who received proton beam therapy were evaluated. Compared to the non-irradiated vertebral body growth rate, the irradiated vertebral body rate (%/year) was significantly lower: 77.2%, 57.6%, 40.8%, 26.4%, and 14.1% at 10, 20, 30, 40, and 50 Gy (RBE) irradiation, respectively. In multivariate analysis, radiation dose was the only factor correlated with vertebral body growth. Age, gender, and vertebral body site were not significant factors. These results suggest that the growth rate of the vertebral body is dose-dependent and decreases even at a low irradiated dose. This is the first report to show that proton beam therapy has the same growth inhibitory effect as photon radiotherapy within the irradiated field.

Difficulties in Treating Postirradiation Kyphosis in Adults: A Series of Five Cases

STUDY DESIGN

Clinical case series.

OBJECTIVE

To assess objective outcomes of surgical correction of post-external beam radiation therapy (ERBT) kyphosis in a series of five adults.

SUMMARY OF BACKGROUND DATA

EBRT is a well-established treatment for many cancers in children and adults. One complication associated with EBRT is postirradiation spine deformity. Scoliosis is the most common deformity, but kyphosis also occurs frequently. Differences in deformity patterns are likely related to the location and intensity of radiation. To our knowledge, no studies have addressed treatment of these deformities in adults, and the most recent case series (of children) was published in 2005.

METHODS

We present a series of five adults who underwent surgery for postirradiation kyphosis, with a mean follow-up of 3.8 years (range, 2.5-6.2 years).

RESULTS

Surgery improved the kyphotic deformity in all patients. Overall mean kyphotic deformity correction was 56° and was larger for cervical/cervicothoracic deformities (mean, 76°) than for lumbar deformities (mean, 42°) at midterm follow-up. Patients reported significant improvements in pain and self-image. Consistent with prior case series of children, we observed a high rate of complications (mean, 1.4 complications per patient) in adults. Three patients each underwent an unplanned surgical procedure because of a complication.

CONCLUSION

The surgical treatment of postirradiation kyphotic spinal deformity is challenging, with common postoperative complications such as infection, instrumentation failure, and pseudarthrosis. However, with modern surgical techniques and spinal instrumentation, excellent deformity correction can be achieved and maintained. We recommend performing a two-stage procedure for cervicothoracic deformity, with anterior release followed by posterior fusion and instrumentation. In thoracolumbar deformities, correction can be achieved through single-stage posterior fusion. Rigid spinopelvic fixation with sacral-alar-iliac screws and second-stage anterior lumbar interbody fusion at L5-S1 is recommended to reduce nonunion risk. Cement augmentation of proximal and distal anchors can help prevent junctional failure.

LEVEL OF EVIDENCE

Level IV.

Practice Patterns Among Radiation Oncologists Treating Pediatric Patients With Proton Craniospinal Irradiation

PURPOSE

Craniospinal irradiation (CSI) is an important component of therapy for many pediatric central nervous system malignancies. Proton therapy is increasingly available and used for minimizing radiation exposure to normal tissues. The absence of an exit dose with proton therapy mandates decisions regarding coverage of the vertebral bodies (VB) in non-skeletally mature patients. Although the contents within the thecal sac represent the true clinical target volume (CTV), some physicians target the entire VB in growing children because of concerns over asymmetrical growth. This study aims to assess current practice patterns regarding VB coverage for pediatric patients undergoing CSI.

METHODS AND MATERIALS

Pediatric radiation oncologists were identified from the Particle Therapy Co-Operative Group pediatric subcommittee membership or affiliation with US proton centers. Potential participants were contacted by e-mail with a link to an institutional review board-approved, anonymized web-based survey distributed in June 2017 with follow-up in October 2017. The survey used skip logic and included up to 11 questions regarding practice patterns.

RESULTS

Thirty-three physicians responded to the survey (39%), 5 of which were excluded for lack of recent pediatric proton CSI experience. Of the 28 included responses, 23 physicians sometimes treat the entire VB and 5 physicians report always treating the entire VB. Most common responses regarding anterior CTV expansion for uncertainty were no expansion (n = 9) and 3 to 4 mm (n = 8). Most physicians modify the anterior CTV margin to protect normal structures, most commonly esophagus (n = 15), thyroid (n = 6), heart (n = 5), bowel (n = 4), and pharynx (n = 2).

CONCLUSIONS

Vertebral body coverage in proton CSI varies among radiation oncologists in respect to target delineation, CTV expansions, and modifications for organs at risk. These data suggest the radiation oncology community may benefit from a standardized approach to pediatric proton-based CSI.

Musculoskeletal outcomes and the effect of radiation to the vertebral bodies on growth trajectories for long-term survivors of high-risk neuroblastoma

OBJECTIVE

Here, we report musculoskeletal outcomes and the impact of radiotherapy dose on vertebral body growth for an institutional series of long-term survivors of high-risk neuroblastoma.

METHODS

We conducted a retrospective study of 23 patients who were disease-free and at least 36 months from the end of treatment. The patients were initially treated from July 2003 to May 2012. Patient records were reviewed for growth percentiles (obtained at approximately 6-month intervals from onset of treatment to the last follow-up) and musculoskeletal comorbidities. RT plans and most recent surveillance CT scans were reviewed for locations of in-field vertebral bodies and corresponding vertebral growth patterns.

RESULTS

The median follow-up was 7.93 years. The median prescribed radiation dose was 21.6 Gy. Musculoskeletal abnormalities included scoliosis (5 patients), muscular hypoplasia (3), and hypodontia (1). The median growth percentile at treatment onset was 35.5 (range, 4.7-100) versus 10 (0-94.1) at the last follow-up. The median numbers of vertebral bodies encompassed (by at least half of their volume) by the 5-, 10-, 15-, and 20-Gy isodose lines were 7 (mean, 6.78), 7 (6.56), 6 (6.17), and 6 (5.52), respectively. Sixteen patients (70.0%) had in-field abnormalities in vertebral body growth, manifesting as stretches of successive vertebral bodies at the same height, while normally there is a gradual vertebral body height increase progressing caudally down the spinal column.

CONCLUSIONS

Musculoskeletal abnormalities, below average height, and stunted in-field vertebral body growth are routine in long-term survivors of high-risk neuroblastoma. Sparing vertebral bodies when feasible may lead to improvement in patient growth trajectories.

Compulsory military service as a measure of later physical and cognitive performance in male survivors of childhood cancer

BACKGROUND

Compromised physical fitness and cognitive difficulties have been reported as late effects of cancer treatment during childhood. To assess this issue, the military rankings of cancer survivors in medical checkups at call-up, and conscripts' physical and cognitive performance during the first weeks of compulsory military education were compared to those of matched population controls without a history of cancer.

MATERIAL AND METHODS

A total of 1680 male patients born between 1960 and 1992 with a malignancy diagnosed before the age of 16 who were alive at the call-up age (18 years) were identified using the Finnish Cancer Registry, and five age, sex and place of residence matched controls for each patient using the Population Register Centre. Data on military service were gathered from Finnish Defense Forces. A conditional logistic regression analysis, the GEE-method with the cumulative logit link function, the chi-square test, the chi-square test for trend and a one-way analysis of variance were used in different analyses.

RESULTS

Cancer survivors were exempted from military service more often than the controls (p < .001). The fit-for-service frequency was highest for survivors of kidney tumors (68%) and lowest after irradiated brain tumors (19%). In service, the results of the 12-min running test were poorer than those of controls for leukemia/non-Hodgkin lymphoma (p = .03) and brain tumor (p = .01) survivors. Interestingly, the standing long-jump test was the only muscle test for which survivor groups performed worse than controls. Performance on cognitive tests only differed from controls in brain tumor survivors.

CONCLUSIONS

Exemption from service is still common under the current guidelines, but fit-for-service survivors do well in military education. These results can be used for reassuring survivors that completion of military service is possible for those fulfilling the national general guidelines for military fitness.

Effects of vertebral-body-sparing proton craniospinal irradiation on the spine of young pediatric patients with medulloblastoma

Purpose

To investigate the long-term effects of vertebral-body-sparing proton craniospinal irradiation (CSI) on the spine of young patients with medulloblastoma.

Methods and materials

Six children between the ages of 3 and 5 years with medulloblastoma were treated with vertebral-body-sparing proton CSI after maximal safe resection. Radiation therapy was delivered in the supine position with posterior beams targeting the craniospinal axis, and the proton beam was stopped anterior to the thecal sac. Patients were treated with a dose of either 23.4 Gy or 36 Gy to the craniospinal axis followed by a boost to the posterior fossa and any metastatic lesions. Chemotherapy varied by protocol. Radiographic effects on the spine were evaluated with serial imaging, either with magnetic resonance imaging scans or plain film using Cobb angle calculations, the presence of thoracic lordosis, lumbar vertebral body-to-disc height ratios, and anterior-posterior height ratios. Clinical outcomes were evaluated by patient/family interview and medical chart review.

Results

Overall survival and disease free survival were 83% (5/6) at follow-up. Median clinical and radiographic follow-up were 13.6 years and 12.3 years, respectively. Two patients were clinically diagnosed with scoliosis and treated conservatively. At the time of follow-up, no patients had experienced chronic back pain or required spine surgery. No patients were identified to have thoracic lordosis. Diminished growth of the posterior portions of vertebral bodies was identified in all patients, with an average posterior to anterior ratio of 0.88, which was accompanied by compensatory hypertrophy of the posterior intervertebral discs.

Conclusion

Vertebral-body-sparing CSI with proton beam did not appear to cause increased severe spinal abnormalities in patients treated at our institution. This approach could be considered in future clinical trials in an effort to reduce toxicity and the risk of secondary malignancy and to improve adult height.

Complications in the surgical management of children with malignant solid tumors

With improvement in the outcomes for children with cancer has come an increasing focus on minimizing the morbidity from therapeutic interventions, including surgical procedures, while continuing to have a high likelihood of cure. Thus, an appreciation for the potential complications of surgery, both acute and long term, is critical when considering the risks and benefits of any procedure performed on a child with cancer. Although not meant to be an exhaustive review, here we discuss the most common and significant surgical complications that may occur when performing diagnostic, therapeutic, or supportive procedures in children with the most common malignant solid tumors.

Myxopapillary ependymomas in children: imaging, treatment and outcomes

Myxopapillary ependymomas (MPEs) are rare spinal tumors in children. The natural history and clinical course of pediatric MPEs are largely unknown and the indication for adjuvant therapy remains to be clarified. We performed an IRB-approved, retrospective review of children with MPEs treated at the Dana-Farber/Boston Children's Cancer and Blood Disorder Center between 1982 and 2013. Eighteen children (age range 8-21 years, median age 14 years) met inclusion criteria. We reviewed the histopathology, magnetic resonance imaging, tumor location and stage, surgical management, adjuvant therapy, and clinical outcomes. The median follow-up duration was 9.4 years (range 1-30 years). Children most commonly presented with pain, scoliosis, and urinary symptoms. All primary tumors were located in the lower thoracic or lumbar spine. Nine children (50%) had leptomeningeal tumor seeding at presentation, most commonly located within the distal thecal sac. A gross-total resection was achieved in nine children (50%). Three children were treated with irradiation following initial surgery. No child received adjuvant chemotherapy at diagnosis. The 10-year event-free survival (EFS) was 26% ± 14.8. Children with disseminated disease trended towards inferior EFS compared to those with localized disease (10-year EFS 12.7% ± 12 vs. 57 ± 25%, p value 0.07). The 10-year overall survival was 100%. The efficacy of adjuvant irradiation could not be assessed due to the small sample size. Although children with MPEs frequently present with disseminated tumor and/or develop recurrent or progressive disease, their overall survival is excellent. Treatment should aim to minimize both tumor- and therapy-related morbidity.

Renal tumours: long-term outcome

Childhood cancer is rare, with an incidence of 100 new cases per million children and with renal tumours contributing 7% of cases. The introduction of multimodality treatment, surgery, radiotherapy and chemotherapy, has led to an exponential increase in the 5-year survival rate to >80%. However, this successful treatment has led to the development of late adverse effects. These treatment-related effects can cause premature deaths and increased morbidity compared with patients' peers. Radiation causes damage to tissue and organs within the radiation field, affecting growth and function, and is largely responsible for the leading cause of death, namely, second malignant neoplasms. Another important late effect is cardiac dysfunction due to anthracycline use with or without cardiac radiation. In addition, a few patients have genetic abnormalities predisposing to Wilms tumour development, which result in renal dysfunction in the long term and may be exacerbated by cancer treatment regimens. Awareness of late consequences of cancer treatment is important, as early recognition can improve outcome. When presented with a patient with a history of renal tumours, it is vital to enquire about previous treatment to understand whether it is relevant to the presenting problem.

Late effects of treatment for wilms tumor

Advancements in surgery, radiotherapy, and chemotherapy have greatly improved the cures rates for children with Wilms tumor. However, a number of therapy-related late effects have been observed in long-term survivors. Generally, late complications are a consequence of treatment type and intensity; the use of radiotherapy and anthracyclines increases the risk of these complications. This commentary highlights some clinically significant late sequelae-musculoskeletal effects, cardiac toxicity, reproductive problems, renal dysfunction, and the development of second malignant neoplasms. Careful medical and epidemiological monitoring of survivors can provide critical information to further optimize therapy while minimizing long-term sequelae.

Spinal deformity after intra-operative radiotherapy for paediatric patients

The purpose of this study was to clarify the incidence and characteristics of late-onset complications of the spine in children who underwent intra-operative radiation therapy (IORT) for common paediatric malignant tumours. 12 children with more than 4 years of follow-up after IORT were included and, in 11 of these, thoracic and/or lumbar spines were irradiated. To compare doses of irradiation to the spine with the resulting deformities, dose simulations of IORT were carried out on two selected cases using a radiation treatment planning system with a pencil-beam algorithm. The mean follow-up period was 135 months (range, 53-234 months). Radiographic reviews found spinal deformity in six patients. Only one patient was symptomatic and the spinal deformity was severe (Grade 3), whereas spinal deformity was mild in the remaining five patients without clinical symptoms (Grade 1). In all of the six patients, anterior wedge-shaped deformity was dominant, and scoliosis was found in only two patients. In one particular case with nephrectomy, irradiation had penetrated much deeper than usual at the site of nephrectomy, and dose distribution was asymmetric, causing clinically significant spinal deformity with scoliosis. In conclusion, specific deformities of the spine observed after IORT can be explained on the basis of dose distribution of the electron beam to the spine.

Current management of Wilms' tumor in children

PURPOSE

Wilms' tumor is the most common renal tumor in children. Outcomes have improved dramatically over the past few decades, but important treatment questions remain. These include the role of molecular biologic markers in stratifying patients for therapy or targeting tumors for treatment. We present a summary of these advances and outline the current treatment of Wilm's tumor.

MATERIALS AND METHODS

The medical literature and results of all cooperative group studies reporting treatment of children with Wilms' tumor were reviewed.

RESULTS

Overall survival exceeds 90% for most patients with nephroblastoma. However, outcomes for patients with rhabdoid tumors and diffuse anaplasia remain poor. The role of renal sparing surgery in patients with bilateral tumors is clear, but for children with unilateral tumors it continues to be defined.

CONCLUSIONS

Current protocols conducted by pediatric oncology groups are beginning to incorporate biologic features to stratify patients for therapy. Treatment strategies continue to focus on limiting late effects of treatment while maintaining an excellent survival. New therapies are needed to treat the high-risk patients who continue to have high relapse and mortality rates.

Efficacy of spinal instrumentation and fusion in the prevention of postlaminectomy spinal deformity in children with intramedullary spinal cord tumors

Postlaminectomy spinal deformity is a frequent problem after resection of a pediatric spinal cord tumor. However, the use of spinal fusion done at the time of resection in preventing the development of deformity is unknown. The purpose of our study was to assess the effectiveness of single-stage laminectomy, spinal cord decompression, and fusion for the prevention of postlaminectomy spinal deformity in children with intramedullary spinal cord tumors. Clinical charts and radiographs of 33 children with spinal cord tumors were reviewed for treatment description, preoperative spinal alignment, postoperative spinal alignment, and subsequent medical and surgical treatment. Spinal deformity was graded by predefined criteria. Significant spinal deformity developed in 10 of 17 children with laminectomy only, 3 of 4 children with laminoplasty, and 3 of 12 children with spinal fusion (2/6 with instrumentation, 1/6 with in situ fusion). Excluding patients that progressed to paraplegia, 9 of 16 patients treated with resection without fusion compared with 1 of 10 patients treated with resection and fusion developed a spinal deformity (P = 0.04). Among skeletally mature children that did not progress to paraplegia, 9 of 15 treated with resection without fusion compared with 1 of 7 patients treated with resection and fusion developed a deformity (P = 0.05). Removal of greater than 4 laminae (P = 0.03) was found to be associated with the development of postresection spinal deformity.

Wilms tumour: prognostic factors, staging, therapy and late effects

Wilms tumour is the most common malignant renal tumour in children. Dramatic improvements in survival have occurred as the result of advances in anaesthetic and surgical management, irradiation and chemotherapy. Current therapies are based on trials and studies primarily conducted by large multi-institutional cooperatives including the Société Internationale d'Oncologie Pédiatrique (SIOP) and the Children's Oncology Group (COG). The primary goals are to treat patients according to well-defined risk groups in order to achieve the highest cure rates, to decrease the frequency and intensity of acute and late toxicity and to minimize the cost of therapy. The SIOP trials and studies largely focus on the issue of preoperative therapy, whereas the COG trials and studies start with primary surgery. This paper reviews prognostic factors and staging systems for Wilms tumour and its current treatment with surgery and chemotherapy. Surgery remains a crucial part of treatment for nephroblastoma, providing local primary tumour control and adequate staging and possibly controlling the metastatic spread and central vascular extension of the disease. Partial nephrectomy, when technically feasible, seems reasonable not only in those with bilateral disease but also in those with unilateral disease where the patient has urological disorders or syndromes predisposing to malignancy. Partial nephrectomy, however, is frequently not sufficient for an anaplastic variant of tumour. The late effects for Wilms tumour and its treatment are also reviewed. The treatment of Wilms tumour has been a success story, and currently in excess of 80% of children diagnosed with Wilms tumour can look forward to long-term survival, with less than 20% experiencing serious morbidity at 20 years from diagnosis. The late complications are a consequence of the type and intensity of treatment required, which in turn reflects the nature and extent of the original tumour. Continual international trial development and participation will improve matching of treatment needs with prognosis, reducing long-term complications in the majority. The advent of molecular markers of disease severity and improved functional imaging might help.

Pediatric iatrogenic spinal deformity

This article reviews current published literature regarding pediatric iatrogenic spinal deformity, with particular emphasis on the cervical spine. The results of published series reporting the incidence, etiology, age, risk factors, surgical techniques, and treatment options are summarized. Iatrogenic deformity resulting from radiation therapy and a variety of surgical procedures are addressed.

Risk factors for scoliosis in children with neuroblastoma

PURPOSE

To determine the risk factors for scoliosis in children treated for neuroblastoma.

METHODS AND MATERIALS

From 1957 to 1997, 58 children with neuroblastoma were treated at one institution and have survived a minimum of 5 years. There were 35 boys and 23 girls with a median age of 6 months (range, 2 weeks to 15 years) at initial diagnosis. Primary site was located in the adrenal gland in 25 (43.1%), abdominal/nonadrenal in 16 (27.6%), thoracic in 12 (20.7%), cervical in 3 (5.3%), and pelvic region in 2 (3.5%). The International Neuroblastoma Staging System (INSS) stage was Stage 1 in 10 (17.2%), Stage 2A in 7 (12.1%), Stage 2B in 5 (8.6%), Stage 3 in 22 (37.9%), Stage 4 in 4 (6.9%), and Stage 4S in 10 (17.2%). Thirty-three (56.9%) received chemotherapy whereas 5 (8.6%) had a laminectomy as part of the surgical procedure. Twenty-seven (46.6%) received radiotherapy (RT). Beam energy was 1.25 MV in 11 (41%), 250 kV in 10 (37%), 4 MV in 4 (15%), and 6-MV photons in 1 patient. One patient received 300 cGy in 1 fraction total skin RT using 6-MeV electrons. For the remaining patients, fraction size was 100 cGy in 6 (22%), 150-180 cGy in 11 (41%), 200 cGy in 4 (15%), and 250-300 cGy in 3. Three patients had total body irradiation at 333 cGy for 3 fractions. For all children who received RT, median total dose was 2000 cGy (range, 300-3900 cGy). Patients who were treated with RT had plain films of the irradiated area every 1 to 2 years until at least the age of puberty. Median follow-up was 10 years (range, 5-46 years).

RESULTS

The overall 5-, 10-, and 15-year scoliosis-free rates were 87.6%, 79.0%, and 76.0% respectively. Twelve (21%) developed scoliosis at a median time of 51 months (range, 8-137 months). The degree of scoliosis was mild (< or =20 degrees ) in 8 (67%). Four had scoliosis ranging from 30 degrees to 66 degrees ; 3 of these patients required surgical intervention, whereas 1 had an underlying Duchenne muscular dystrophy which manifested itself 8 years after diagnosis of neuroblastoma. Median time to scoliosis was 23 months (range, 8-54 months) in children who had a laminectomy. On multivariate analysis, both history of laminectomy (p = 0.0005) and use of RT (p = 0.0284) were found to be risk factors for development of scoliosis. Gender, age at diagnosis, INSS stage, primary site, and use of chemotherapy were not found to be significant. Both RT fraction size and beam energy were also not significant, but increasing total RT dose was found to be significant (p = 0.0039). The 15-year scoliosis-free rates were 20% for children who had a laminectomy and 81.3% for those who did not have a laminectomy. The 15-year scoliosis-free rates for children treated with RT doses 0 cGy, 1-1750 cGy, 1751-2300 cGy, and >2300 cGy were 91.7%, 87.5%, 51.4%, and 44.4% respectively.

CONCLUSIONS

Treatment-related factors, namely laminectomy and radiotherapy, were found to increase the risk of scoliosis in patients with neuroblastoma. Children who had a laminectomy were more likely to manifest scoliosis earlier. Increasing RT dose was found to impact adversely on the development of scoliosis.

Stature loss following treatment for Wilms tumor

BACKGROUND

The study was designed to estimate reduction in adult stature induced by megavoltage radiation therapy (RT) of the spine in children treated for Wilms tumor and to ascertain whether the dose reduction in successive National Wilms Tumor Study Group (NWTSG) trials has mitigated late effects of RT in these children.

PROCEDURE

Effects of RT dose, age at treatment, and chemotherapy on stature of 2,778 children with Wilms or another solid tumor of the kidney were analyzed using statistical models accounting for the dependence of height on gender and advancing age. Model predictions were validated by descriptive analysis of heights measured at 17 to 18 years of age for 205 patients.

RESULTS

Radiation-induced reductions below normal height depended on dose, portal size, and age at treatment and were not augmented by doxorubicin or cyclophosphamide. Younger children were more strongly affected. Predicted height deficit at age 18 years was 1.8 cm for a child treated with 10 Gy to the flank at age 4 years. Observed height deficits at age 1 7 to 18 years were 4.1 cm for 57 patients who received 15-24 Gy at a mean age of 55 months and zero for 16 children who received RT doses under 15 Gy at a mean age of 83 months.

CONCLUSIONS

Reduction in stature following RT to the pediatric spine is dose- and age-dependent, persists into adulthood, and is not exacerbated by doxorubicin or cyclophosphamide. Average height deficits observed at maturity for children receiving doses currently recommended by the NWTSG are clinically nonsignificant.

Radiotherapy omitted in the treatment of selected children under 3 years of age with stage III favorable histology Wilms tumor

BACKGROUND

Current treatment of stage III favorable histology (FH) Wilms tumor is surgery, radiotherapy to residual disease, and "triple" chemotherapy (vincristine, dactinomycin, and doxorubicin) for 12 months. This study tests the hypothesis that some stage III patients, especially very young children with minimal residual abdominal disease, might be successfully treated without radiotherapy, thereby avoiding the adverse late effects associated with radiotherapy.

PROCEDURE

From 1984, radiotherapy was omitted from the treatment of 8 carefully selected children who were younger than 3 years of age at diagnosis with stage III Wilms tumor by virtue of microscopic residual disease after surgery and whose lymph nodes were not involved by tumors. They were followed with bimonthly abdominal ultrasound examinations to assess local control.

RESULTS

Follow-up is now from 2 to 12 years (median 6 years) and 7 of the 8 children are alive and well with no abdominal recurrence. One child relapsed in the lungs and despite further treatment died of progressive disease. The disease-free survival (DFS) and overall survival (OS) are therefore both 87.5%.

CONCLUSIONS

The DFS and OS in this admittedly small sample are consistent with the survival rates for stage III FH Wilms tumor in the first United Kingdom Children's Cancer Study Group (UKCCSG), North American (NWTS), and European (SIOP) Wilms Tumor studies, Larger numbers of patients are needed to determine whether or not this treatment approach is generally applicable, but we conclude that some children in this stage III "substage" may be treated successfully without radiotherapy.

Postlaminectomy and postirradiation kyphosis in children and adolescents

This is a retrospective review of 12 patients treated for severe postlaminectomy and postirradiation kyphosis by one surgeon from 1977 to 1994. The average age of the patients was 15 years with a range from 2 to 35 years. The duration of followup ranged from 24 months to 156 months with an average of 65 months. All patients had undergone multilevel laminectomies or irradiation of the thoracic or lumbar spine for an intraspinal lesion or trauma. The average preoperative kyphosis was 84 degrees and this was reduced to an average of 39 degrees after surgery. There were no pseudarthroses and there was an average loss of correction of 5 degrees. There were no complaints of back pain. Moderately severe but flexible kyphoses were treated in three patients by posterior instrumentation and spinal fusion. The other nine patients had combined anterior release or decompression and fusion combined with posterior instrumentation and spinal fusion. Bracing failed to halt the progressive kyphosis in those patients for whom it had been attempted. The only major complications in this series were two wound infections in patients previously treated with irradiation.

Long-term results of therapy for stage C neuroblastoma

BACKGROUND

The appropriate therapy for Stage C neuroblastoma (NB) is uncertain. Because of the need for information applicable to the development of new randomized trials, we deemed it appropriate to investigate the patient characteristics, survival, patterns of failure, and complications of therapy in these children.

METHODS

Search of the medical records of Duke University Medical Center from 1/1/60 to 3/1/95 disclosed 146 patients with NB, which included 13 Stage C patients.

RESULTS

Mean age at diagnosis was 3.6 years. Twelve patients had primary abdominal tumors (92%) and one had a thoracic primary (8%). Twelve (92%) of the patients received chemotherapy including cyclophosphamide. 11 (85%). Adriamycin, 6 (46%), cisplatinum, 4 (30%), and VP 16, 4 (30%). All patients received radiotherapy (RT, mean dose administered 22.6 +/- 8 Gy). With a mean follow-up of 8 years, the 10-year overall survival was 54% and the relapse-free survival was 46%. Four patients relapsed in the primary operative tumor bed and primary RT field, two relapsed in mediastinal or left supraclavicular lymph nodes as well as distantly following treatment of upper abdominal primaries, and in one the site of relapse is unknown. Long-term complications of therapy included two children who developed secondary malignancies associated with RT, two girls who developed primary ovarian failure, five children with clinically significant kyphosis and scoliosis, and one who suffered postoperative wound dehiscence following RT.

CONCLUSIONS

Although this study did not include modern techniques of staging with n-myc amplification and DNA index, the occurrence of next echelon nodal failures gives credence to the continuation of the dialogue concerning the appropriate role of "prophylactic" irradiation to mediastinal and left supraclavicular nodes in locally advanced upper abdominal NB. Documentation of significant long-term ill effects reinforces the need to critically evaluate the indications for RT.