Radiation late effects in children treated for orbital rhabdomyosarcoma

Orbital Rhabdomyosarcoma: Comprehensive Review of Epidemiology, Clinical Staging, and Treatment Outcomes

BACKGROUND

Orbital rhabdomyosarcoma (RMS), the most common primary malignant orbital tumor in childhood, presents unique challenges in management due to its genetic basis and abnormal cellular proliferation. Management has evolved from surgical excision to multimodal approaches, including surgery, radiotherapy, and chemotherapy. This review explores trends in epidemiology, pathophysiological insights, and treatment evolution to delineate optimal therapeutic strategies.

METHODS

A literature search was conducted across PubMed and Scopus databases up to March 4, 2024, using keywords related to orbital RMS. Studies were selected based on predefined criteria, focusing on clinical presentation, diagnostic modalities, management strategies, and outcomes. Data extraction and analysis were performed independently by 2 reviewers, with quality assessment based on the Oxford Center for Evidence-Based Medicine 2011 guidelines and Joanna Briggs Institute checklists.

RESULTS

The review synthesized data from 17 studies, highlighting demographic patterns, clinical characteristics, staging, and treatment approaches. Most patients were male and white, with a higher proportion of early-stages diagnoses. The embryonal subtype was the most common, and treatment has shifted toward radiation therapy and combined modalities. In orbital RMS, several modalities are applied in treatment. There are radiotherapy, surgical interventions, and chemotherapy. Recent studies put more emphasis on the long-term outcome of the disease about orbital bone development and facial symmetry.

CONCLUSIONS

Management of orbital RMS has evolved significantly, with a current emphasis on multimodal treatment strategies. Future research should focus on optimizing therapeutic approaches to balance effective tumor control with the preservation of orbital function and esthetics.

The need for consensus on delineation and dose constraints of dentofacial structures in paediatric radiotherapy: Outcomes of a SIOP Europe survey

Background and purpose

Children receiving radiotherapy for head-and-neck tumours often experience severe dentofacial side effects. Despite this, recommendations for contouring and dose constraints to dentofacial structures are lacking in clinical practice. We report on a survey aiming to understand current practice in contouring and dose assessment to dentofacial structures.

Methods

A digital survey was distributed to European Society for Paediatric Oncology members of the Radiation Oncology Working Group, and member-affiliated centres in Europe, Australia, and New Zealand. The questions focused on clinical practice and aimed to establish areas for future development.

Results

Results from 52 paediatric radiotherapy centres across 27 countries are reported. Only 29/52 centres routinely delineated some dentofacial structures, with the most common being the mandible (25 centres), temporo-mandibular joint (22), dentition (13), orbit (10) and maxillary bone (eight). For most bones contoured, an 'As Low As Reasonably Achievable' dose objective was implemented. Only four centres reported age-adapted dose constraints.The largest barrier to clinical implementation of dose constraints was firstly, the lack of contouring guidance (49/52, 94%) and secondly, that delineation is time-consuming (33/52, 63%). Most respondents who routinely contour dentofacial structures (25/27, 90%) agreed a contouring atlas would aid delineation.

Conclusion

Routine delineation of dentofacial structures is infrequent in paediatric radiotherapy. Based on survey findings, we aim to 1) define a consensus-contouring atlas for dentofacial structures, 2) develop auto-contouring solutions for dentofacial structures to aid clinical implementation, and 3) carry out treatment planning studies to investigate the importance of delineation of these structures for planning optimisation.

Dose-Effect Analysis of Early Changes in Orbital Bone Morphology After Radiation Therapy for Rhabdomyosarcoma

PURPOSE

In survivors of orbital embryonal rhabdomyosarcoma (ERMS), late effects include facial deformation and asymmetry. We sought to quantify orbital asymmetry in ERMS survivors and characterize the dose effect of radiation to the orbital bones.

METHODS AND MATERIALS

We evaluated the most recent follow-up magnetic resonance imaging (MRI) in 17 children (≤21 years old) with stage 1 group III orbital ERMS treated with proton therapy between 2007 and 2018. For all patients, the orbital socket volumes were calculated and compared with the contralateral, unirradiated orbital socket. Patient age, orbital tumor quadrant, and the radiation dose delivered to the major orbital bones (maxillary, frontal, and zygomatic bones) were recorded and correlated with the orbital socket volume difference.

RESULTS

The mean age at diagnosis was 5.4 years old (range, 1.1-9.7 years). All patients received a prescription dose of 45 GyRBE. The mean time interval between radiation and MRI was 2.9 years (range, 0.8-3.2 years). The mean age at most recent MRI was 8.4 years (range, 2.3-12.9 years). In 16 of 17 patients, the volume of the ipsilateral orbit was significantly smaller than the contralateral orbit on follow-up MRI (P ≤ .0001). In one patient with nonviable tumor in situ, the irradiated orbit was larger. The volume difference increased with follow-up time and did not correlate with age at treatment or age at MRI. A dose >40 GyRBE to all bones of the orbital rim was associated with a significant decrease in orbital volume (P < .05), but an isolated dose of >40 GyRBE to either the frontal, maxillary, or zygomatic bone was not.

CONCLUSIONS

Despite the dosimetric precision of proton therapy, orbital asymmetry will develop after >40 GyRBE to multiple bones of the orbital rim. These data may be used to guide treatment planning and counsel patients on expected cosmesis.

Physical activity and fitness among pediatric cancer survivors: a meta-analysis of observational studies

PURPOSE

The number of pediatric cancer survivors has increased dramatically over recent decades. Prior studies involving pediatric cancer survivors have reported reduced physical activity and fitness levels. Thus, the aim of this meta-analysis was to synthesize previous findings on physical activity and fitness levels of pediatric cancer survivors, who had completed cancer treatment and are in complete remission compared with age-matched, non-athletic healthy controls with no history of cancer diagnosis.

METHODS

Three electronic databases (PubMed, Web of Science, and EBSCO) were searched using a combination of 24 terms. Observational studies examining the post-treatment physical activity and/or fitness levels of pediatric cancer survivors compared with that of non-cancer controls and published in peer-reviewed, English-language journals before August 22, 2018 were eligible. Random-effect models were used in Comprehensive Meta-Analysis software for effect-size estimations of eight studies for physical activity and eight for fitness.

RESULTS

The studies included a total sample of 2628; 1413 pediatric cancer survivors and 1215 non-cancer controls. Both physical activity and fitness were significantly lower in childhood cancer survivors than in non-cancer controls (g = - 0.889; 95% confidence interval [CI] = - 1.648 - 0.130; p = 0.022) and (g = - 1.435; 95% CI = - 2.615 - 0.225; p = 0.017), respectively, with high heterogeneity.

CONCLUSIONS

Pediatric cancer sequelae and its treatment may limit participation in physical activity and fitness activities by survivors of pediatric cancer. Accentuating the need to incorporate physical activity and fitness into treatment protocols and post-treatment recommendations may improve pediatric cancer survivors' health and well-being.

Facial asymmetry in head and neck rhabdomyosarcoma survivors

INTRODUCTION

Radiotherapy is essential for achieving and maintaining local control in head and neck rhabdomyosarcoma (HNRMS) patients. However, radiotherapy may cause outgrowth disturbances of facial bone and soft tissue, resulting in facial asymmetry. The aim of this study was to develop a method to visualize and measure facial asymmetry in HNRMS survivors using three-dimensional (3D) imaging techniques.

METHODS

Facial deformity was evaluated in a multidisciplinary clinical assessment of 75 HNRMS survivors, treated with external beam radiotherapy (EBRT, n = 26) or Ablative surgery, MOulage brachytherapy, and REconstruction (AMORE, n = 49). Individual facial asymmetry was measured using 3D photogrammetry and expressed in a raw asymmetry index and a normalized sex-age-ethnicity-matched asymmetry signature weight. Facial asymmetry was also compared between British and Dutch controls and between survivors and their matched controls.

RESULTS

Facial asymmetry was more pronounced with increasing age (P < 0.01) in British controls compared with Dutch controls (P = 0.04). Survivors developed more facial asymmetry than matched controls (P < 0.001). The clinical assessment of facial deformity correlated with the raw asymmetry index (r = 0.60, P < 0.001).

DISCUSSION

3D imaging can be used for objective measurement of facial asymmetry in HNRMS survivors. The raw asymmetry index correlated with a clinical assessment of facial deformity. Comparisons between treatment groups seemed inappropriate given the differences in facial asymmetry between British and Dutch controls. In future studies, pretreatment images could act as matched controls for posttreatment evaluation.

Hearing loss in survivors of childhood head and neck rhabdomyosarcoma: a long-term follow-up study

OBJECTIVES

To determine the hearing status of survivors treated for head and neck rhabdomyosarcoma (HNRMS) at long-term follow-up.

DESIGN

Cross-sectional long-term follow-up study.

SETTING

Tertiary comprehensive cancer centre.

PARTICIPANTS

Survivors treated for HNRMS during childhood in two concurrent cohorts; survivors in London had been treated with external beam radiotherapy (EBRT-based local therapy); survivors in Amsterdam were treated with AMORE (Ablative surgery, MOuld technique afterloading brachytherapy and surgical REconstruction) if feasible, otherwise EBRT (AMORE-based local therapy).

MAIN OUTCOME MEASURES

We assessed hearing status of HNRMS survivors at long-term follow-up. Hearing thresholds were obtained by pure-tone audiometry.

METHODS

We assessed the hearing thresholds, the number of patients with clinically relevant hearing loss and hearing impairment graded according to the Common Terminology Criteria for Adverse Events version 4.0 (CTCAEv4) and Boston criteria. Furthermore, we compared hearing loss between survivors treated with EBRT-based local therapy (London) and AMORE-based local therapy (Amsterdam).

RESULTS

Seventy-three survivors were included (median follow-up 11 years). We found clinically relevant hearing loss at speech frequencies in 19% of survivors. Multivariable analysis showed that survivors treated with EBRT-based treatment and those with parameningeal tumours had significantly more hearing impairment, compared to survivors treated with AMORE-based treatment and non-parameningeal tumours.

CONCLUSIONS

One in five survivors of HNRMS developed clinically relevant hearing loss. AMORE-based treatment resulted in less hearing loss compared to EBRT-based treatment. As hearing loss was highly prevalent and also occurred in survivors with orbital primaries, we recommend systematic audiological follow-up in all HNRMS survivors.

Impairments that influence physical function among survivors of childhood cancer

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

Ethical analysis as a tool for addressing treatment controversies: radiotherapy timing in children with orbital rhabdomyosarcoma as a case example

PURPOSE

The treatment of orbital rhabdomyosarcoma is a topic of debate between North American and European clinicians, with the utility of radiation therapy as part of initial management in question. Despite differences in philosophy, the dominant North American approach of upfront radiation and the dominant European approach of radiation only in the event of recurrence yield a similar rate of overall survival. We sought to identify the ethical arguments for each approach.

METHODS

Established moral principles and appeals in contemporary medical ethics were utilized to identify the ethical arguments supporting each treatment approach. The potential for technologic advances to alter the analysis was considered.

RESULTS

Emphasizing the principle of beneficence, the North American approach seeks to reduce recurrence rates. In contrast, the European approach seeks to avoid radiation-induced sequelae, emphasizing the principle of nonmaleficence. Both approaches are based on well-established ethical principles, evidence, and clinical experience. Thus, both approaches currently appear to have legitimacy and should be included in the informed consent process. However, if treatment-related toxicity is reduced through improvements in radiation delivery, the North American approach could emerge as ethically superior.

CONCLUSIONS

Ethical analysis can aid in addressing challenges that arise when professional practices and perspectives differ in the management of cancer patients.

Changes in health status among aging survivors of pediatric upper and lower extremity sarcoma: a report from the childhood cancer survivor study

OBJECTIVE

To evaluate health status and participation restrictions in survivors of childhood extremity sarcomas.

DESIGN

Members of the Childhood Cancer Survivor Study cohort with extremity sarcomas who completed questionnaires in 1995, 2003, or 2007 were included.

SETTING

Cohort study of survivors of extremity sarcomas.

PARTICIPANTS

Childhood extremity sarcoma survivors (N=1094; median age at diagnosis, 13y (range, 0-20y); current age, 33y (range, 10-53y); 49% male; 87.5% white; 75% had lower extremity tumors) who received their diagnosis and treatment between 1970 and 1986.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Prevalence rates for poor health status in 6 domains and 5 suboptimal social participation categories were compared by tumor location and treatment exposure with generalized estimating equations adjusted for demographic/personal factors and time/age.

RESULTS

In adjusted models, when compared with upper extremity survivors, lower extremity survivors had an increased risk of activity limitations but a lower risk of not completing college. Compared with those who did not have surgery, those with limb-sparing (LS) and upper extremity amputations (UEAs) were 1.6 times more likely to report functional impairment, while those with an above-the-knee amputation (AKA) were 1.9 times more likely to report functional impairment. Survivors treated with LS were 1.5 times more likely to report activity limitations. Survivors undergoing LS were more likely to report inactivity, incomes <$20,000, unemployment, and no college degree. Those with UEAs more likely reported inactivity, unmarried status, and no college degree. Those with AKA more likely reported no college degree. Treatment with abdominal irradiation was associated with an increased risk of poor mental health, functional impairment, and activity limitation.

CONCLUSIONS

Treatment of lower extremity sarcomas is associated with a 50% increased risk for activity limitations; upper extremity survivors are at a 10% higher risk for not completing college. The type of local control influences health status and participation restrictions. Both of these outcomes decline with age.

Brachytherapy as part of the multidisciplinary treatment of childhood rhabdomyosarcomas of the orbit

INTRODUCTION

Rhabdomyosarcomas in the orbit form a major challenge in terms of cure without severe side effects in childhood cancer. Our specifically developed approach consists of applying brachytherapy to the tumor area using a mold. Analysis of its results for 20 patients was performed.

METHODS AND MATERIALS

Thirteen patients were referred for brachytherapy if complete remission was not reached after chemotherapy (Group I) and 7 in case of relapse (Group II). In total, 20 patients were treated between 1991 and 2007. Four were female and 16 male; their ages varied from 1.1 to 16.5 years, with an average of 8.5 years. After macroscopically radical tumor resection, molds with holes drilled to hold flexible catheters were placed into the orbit. The dose to the clinical target volume was 40-50 Gy.

RESULTS

Three patients of Group I and 1 patient of Group II developed local recurrence and underwent exenteration. The progression-free survival in Group I is 71.9% (95% CI 0.44-1.0), in Group II 85.7% (95% CI 0.60-1.0), the overall 5-year survival rate of the entire group is 92% (95% CI 0.76-1.0). During treatment, no serious side effects were observed. The late complications encountered in this series were cataract in 2 patients, 1 of whom also developed mild retinopathy. Two patients with ptosis needed surgical correction. No facial asymmetries or bone growth anomalies were observed.

CONCLUSIONS

This entire procedure of brachytherapy with a mold offers a tailor-made treatment for orbital rhabdomyosarcomas with only few signs of late toxicity.

Orbital rhabdomyosarcoma

BACKGROUND

Although rhabdomyosarcoma (RMS) is a rare tumor among the entire group of mesenchymal malignancies, it is a relatively common lesion and significant challenge for the ocular oncologist in terms of its diagnosis and management.

METHODS

A comprehensive literature search of articles published over the past 30 years in PubMed was conducted.

RESULTS

Orbital RMS usually presents as a space-occupying lesion in the orbit during the first decade and may mimic other neoplastic or inflammatory masses. The tumor has predilection for the superior nasal quadrant of the orbit. The clinical manifestations depend on the location of the tumor within the orbit and its rate of growth. The common histopathologic types are embryonal and alveolar varieties. CT and MR imaging are important in the evaluation of this tumor. Particular attention should be placed on the bone invasion and extension of the tumor into the intracranial cavity and paranasal sinuses. Treatment usually consists of a combination of chemotherapy and radiation therapy following excisional biopsy.

CONCLUSIONS

Survival of orbital RMS has improved due to advances in chemotherapy and radiotherapy. Posttreatment complications, including side effects of radiotherapy and secondary orbital malignancies, as well as visual dysfunction, occur more often and present new challenges due to improved long-term survival.

Effects of therapy on dentofacial development in long-term survivors of head and neck rhabdomyosarcoma: the memorial sloan-kettering cancer center experience

PURPOSE

To describe potential effects of multimodality therapy on dental and facial development in long-term survivors of head and neck rhabdomyosarcoma.

PATIENTS AND METHODS

The medical records of all patients aged 20 years or less presenting between 1985 and 1996 with a diagnosis of rhabdomyosarcoma and treated by protocol were reviewed. Head and neck rhabdomyosarcoma patients who were followed in the Dental Service and were alive and free of disease with at least a 5-year follow-up were included in the review. Ten patients satisfied the inclusion criteria and form the basis of this report. The median age at diagnosis of the 10 patients was 4.3 years (range 10 months to 19.5 years). All patients were treated with chemotherapy, two patients underwent surgery, and all but one patient received external beam radiation therapy.

RESULTS

Clinical or radiographic dentofacial abnormalities were observed in 8 of the 10 (80%) patients. Abnormalities included enamel defects, bony hypoplasia/facial asymmetry, trismus, velopharyngeal incompetency, tooth/root agenesis, and disturbance in root development. Bony hypoplasia and disturbance in root formation were the most common findings.

CONCLUSIONS

Multimodality therapy for head and neck rhabdomyosarcoma can result in dentofacial abnormalities that affect the patient's quality of life. The care of the long-term survivor requires a multidisciplinary approach, including early involvement of the dental team.

Rhabdomyosarcoma: review for the ophthalmologist

Rhabdomyosarcoma is a malignant neoplasm that is composed of cells with histopathologic features of striated muscle in various stages of embryogenesis. It can occur in several sites in the body, including the ocular region. Ocular rhabdomyosarcoma is defined as the occurrence of this tumor in the area of the eye. Most ocular rhabdomyosarcomas arise in the soft tissues of the orbit but they can rarely occur in the other ocular adnexal structures and even within the eye. The purpose of this review is to provide a brief overview of rhabdomyosarcoma and a more detailed review of orbital rhabdomyosarcoma, with emphasis on changing concepts in the diagnosis and management of this ophthalmic neoplasm.

Quantification of late complications after radiation therapy

BACKGROUND

An increasing number of patients survive cancer after having received radiation therapy. Therefore, the occurrence of late normal tissue complications among long-term survivors is of particular concern.

METHODS

Sixty-three patients treated by radical surgery and irradiation for rectal carcinoma were subjected to an unconventional sandwich therapy. Preoperative irradiation was given in four fractions of 5 Gy each applied within 2 or 3 days; postoperative irradiation consisted mostly of 15 x 2 Gy (range, 20-40 Gy). A considerable proportion of these patients developed severe late complications (Radiother Oncol 53 (1999) 177). The data allowed a detailed analysis of complication kinetics, leading to a new model which was tested using data from the literature.

RESULTS

Data on late complications were obtained for eight different organs with a follow-up of up to 10 years. For the various organs, the percentage of patients being free from late complications, plotted as a function of time after start of radiation therapy, was adequately described by exponential regression. From the fit, the parameter p(a) was obtained, which is the percentage of patients at risk in a given year of developing a complication in a given organ during that year. The rate p(a) remained about constant with time. Following sandwich therapy, the annual incidence of complications in the bladder, ileum, lymphatic and soft tissue, and ureters was about the same (p(a)=10-14%/year), whereas complications in bone or dermis occurred at lower rates (4.7 or 7.5%/year, respectively).

DISCUSSION

Numerous data sets collected from published reports were analyzed in the same way. Many of the data sets studied were from patients in a series where there was a high incidence of late effects. Three types of kinetics for the occurrence of late effects after radiotherapy were identified: Type 1, purely exponential kinetics; Type 2, exponential kinetics, the slope of which decreased exponentially with time; Type 3, curves composed of two components, a fast initial decline followed by an exponential decrease. For each kind of kinetics, provided that the dose distribution is not too heterogeneous, the incidence of late effects appears to occur at exponential or approximately exponential kinetics, even many years after treatment. This implies that a random process might be involved in the occurrence of late radiation sequelae.

CONCLUSIONS

There might be a lifelong risk of developing late complications, of which patients and clinicians should be aware. It appears worthwhile to try to identify, in follow-up examinations of patients after radiation therapy, what kind of processes might be involved in triggering subclinical residual injury to develop into a clinically manifest late effect.

Localized paediatric orbital rhabdomyosarcoma: influence of imaging on treatment

AIM

Orbital rhabdomyosarcoma is the most common primary malignant orbital tumour in children and has a good prognosis. The purpose of this paper was to review the imaging and consequent treatment of patients with localized orbital rhabdomyosarcoma from around the U.K.

MATERIALS AND METHODS

Patients were identified through the U.K. Children's Cancer Study Group (UKCCSG) database. Investigations and therapy were dictated by the Malignant Mesenchymal Tumour '89 (MMT89) protocol. Imaging and radiological reports of 16 patients from 12 centres were reviewed. The number of patients receiving radiotherapy, timing of radiotherapy, and adherence to treatment protocols were assessed.

RESULTS

Local radiologists' reports and imaging techniques varied between sequential examinations and centres. The imaging was adequate for management. No reports quoted measurements of the tumours. Treatment protocols were not always followed rigidly with regard to a residual mass at day 80 post-diagnosis. However, the protocol was not explicit for all outcomes. Fifteen out of 16 patients eventually received radiotherapy.

CONCLUSION

There is no standardization of imaging between centres. The presence or absence of a post-therapeutic residue should be stated in the radiology report. Further investigation is needed to differentiate between fibrosis and recurrent tumour. Radiotherapy for residual mass at day 80 is probably more important than standardizing radiological technique.