Proton radiotherapy for pediatric sarcoma

Malignant spindle cell tumors of the posterior fossa in children: case series and review of management

OBJECTIVE

The WHO Classification of Tumours of the Central Nervous System (2016) classifies nonmeningothelial malignant spindle cell tumors involving the extraaxial tissues of the posterior fossa as melanocytic tumors and malignant mesenchymal tumors (sarcomas). The objective of this study was to conduct a review of the literature pertaining to the management strategies of posterior fossa malignant spindle cell tumors in the pediatric population.

METHODS

The authors performed an institutional search of their pathology database for patients younger than 18 years of age who presented with posterior fossa malignant spindle cell tumors. A literature review was also performed using the PubMed database, with "posterior fossa" or "spindle cell tumors" or "Ewing sarcoma" or "high-grade" or "spindle cell sarcoma" or "leptomeningeal melanocytoma" as keywords. The database search was restricted to pediatric patients (age ≤ 18 years). Parameters reported from the literature review included patient age, tumor location, presenting symptoms, treatment modalities (resection, chemotherapy, and/or radiotherapy), leptomeningeal spread at or after the time of treatment, and follow-up length and resulting outcome.

RESULTS

The authors report 3 rare cases of posterior fossa malignant spindle cell tumors, including Ewing sarcoma in a 13-year-old male; high-grade spindle cell sarcoma, not otherwise specified in a 10-year-old male; and primary leptomeningeal melanocytoma in a 16-year-old female. All 3 patients underwent resection and radiotherapy and either chemotherapy or targeted immunotherapy. At the last follow-up, all patients were alive with either resolution or stable disease.

CONCLUSIONS

A review of these 3 cases and the existing literature support managing patients with intracranial malignant spindle cell tumors with multimodal therapy that can include a combination of resection, radiotherapy, and chemotherapy or immunotherapy to prolong progression-free and overall survival.

Parameningeal alveolar rhabdomyosarcoma in a child

This is the case of a parameningeal alveolar rhabdomyosarcoma (ARMS) in a 13-year-old boy who presented with painless loss of vision in the right eye, but very few other physical signs. The ARMS diagnosis was confirmed with imaging and molecular characterisation of the tumour. Despite tolerating the initial chemotherapy and radiotherapy regimens, there was leptomeningeal recurrence and the patient unfortunately passed away. Parameningeal ARMS occurs in an area of the body, which leads to a wide variety of possible presenting symptoms, creating a long list of differentials that can delay treatment. This tumour subtype has a poor prognosis, and due to the location of the tumour around vital structures in the head, treatment toxicities must be taken into account. This highlights the necessity for having a strong index of suspicion for this tumour in atypical presentations in children, and the necessity for prompt treatment to prevent leptomeningeal disease from occurring.

Recent Advances and Challenges in the Treatment of Rhabdomyosarcoma

Rhabdomyosarcoma, the most common soft tissue sarcoma noted in childhood, requires multimodality treatment, including chemotherapy, surgical resection, and/or radiation therapy. The majority of the patients with localized rhabdomyosarcoma can be cured; however, the long-term outcomes in patients with metastatic rhabdomyosarcoma remain poor. The standard chemotherapy regimen for patients with rhabdomyosarcoma is the combination of vincristine, actinomycin, and cyclophosphamide/ifosfamide. In recent clinical trials, modifications of the standard chemotherapy protocol have shown improvements in the outcomes in patients with rhabdomyosarcoma. In various type of malignancies, new treatments, such as molecular targeted drugs and immunotherapies, have shown superior clinical outcomes compared to those of standard treatments. Therefore, it is necessary to assess the benefits of these treatments in patients with rhabdomyosarcoma. Moreover, recent basic and clinical studies on rhabdomyosarcoma have reported promising therapeutic targets and novel therapeutic approaches. This article reviews the recent challenges and advances in the management of rhabdomyosarcoma.

The Ever-Changing World of Limb Salvage Surgery for Malignant Bone Tumors

The treatment of malignant bone tumors, also called bone sarcomas, has changed dramatically over the past 50 years owing to the advances in chemotherapy, immunotherapy, targeted therapy, radiation, prosthetic technology, and surgical advances. There are 3 main primary bone cancers: osteosarcoma, Ewing's sarcoma (or Ewing's family of sarcoma), and chondrosarcoma. Before advances in limb preservation techniques and before the development of prosthetic replacement, the treatment for a malignant bone tumor of the extremity was amputation. This article discusses the progression of surgical treatment of malignant bone cancers.

Erectile function after treatment for rhabdomyosarcoma of prostate and bladder

INTRODUCTION

Rhabdomyosarcoma (RMS) accounts for 5% of all pediatric tumors; 15-20% of these tumors are located in the urogenital tract, mostly originating from the prostate or bladder. In the light of the steadily improving prognosis for patients with RMS through interdisciplinary-multimodal study protocols with 60-70% long-term survivors, non oncological aspects such as erectile function (EF) have become increasingly important. The aim of this study was to evaluate EF in patients having undergone treatment for RMS of the bladder and prostate.

DESIGN

The medical records of 24 male patients having undergone surgical treatment for pelvic RMS between 1975 and 2014 were reviewed, and follow-up was obtained. Erectile function was determined using the Self-Estimation Index of Erectile Function-No Sexual Intercourse (SIEF-NS) and the Erection Hardness Scale (EHS). Potential prognostic factors were evaluated in respect to their impact on EF.

RESULTS

Thirteen patients were included in the study (median age 20 years). Median follow-up period was 12.7 years (1.09-39.85). All patients completed the EHS; nine patients completed the SIEF-NS. All three patients with preserved erectile function (EHS = 4) showed a score indicating no or minimal impairment on sexual function on SIEF-NS (median 33). None of these patients had undergone external radiotherapy, and radical cystoprostatectomy had been performed before the third year of life in two out of three. The remaining patients had erectile dysfunction (EHS = 0). Three patients had an unsatisfying treatment attempt with sildenafil. Seven patients, including all with failures of oral PDE-5-inhibitors, were successfully treated with intracavernous injection of Alprostadil (Summary Table).

DISCUSSION

This was the largest study, to date, evaluating erectile EF in patients treated for RMS of the bladder or prostate. EF was preserved in some patients, despite aggressive treatment modalities. Patients affected by erectile dysfunction after therapy showed limited response to PDE-5 inhibitors, but even after failure of the latter, an intracavernous injection of Alprostadil showed a significant improvement in EHS and SIEF-NS. Limitations of the study included the retrospective nature, small sample size, and heterogeneity of underlying disease, stage, and treatment modalities used.

CONCLUSIONS

The results suggested that in a subset of patients, EF was preserved after radical surgical treatment of RMS, especially in young boys. Intracavernous injection of Alprostadil was effective, even after failure of PDE-5-inhibitors, and should be offered to patients without spontaneous erections, whereas PDE-5-inhibitors appeared to be largely ineffective. External radiation therapy appeared to have a negative impact on EF.

Proton therapy in paediatric oncology: an Irish perspective

BACKGROUND

Proton therapy (PT) is a radiotherapy treatment modality that uses protons, rather than conventional photons. PT is often used in paediatric oncology due to its reported capability to reduce acute and late adverse treatment effects. As PT is unavailable in Ireland, patients are referred abroad for treatment.

AIMS

To: (1) produce a descriptive study of Irish children referred abroad for PT, and (2) discuss the case for PT in general.

METHODS

A retrospective review of all children referred for PT before October 2015 was performed. Information was gathered regarding demographics, diagnosis, referral timeline, adverse effects attributable to PT, current status and cost. A review of the relevant literature was performed.

RESULTS

Seventeen children treated in Ireland have been referred abroad for PT. The largest number was in the 0-4 year old group. At initial diagnosis the median age was 4.8 years. The average cost per child was €37,312. Two patients suffered disease relapse. Four have encountered PT-related adverse effects.

CONCLUSION

Despite the fact that >100,000 patients worldwide have been treated with PT, the level of published evidence to support superiority over conventional treatment remains low. It is debated that randomised control trials in this area would be inconsistent with the principle of clinical equipoise. In contrast, there is a call for level 1 evidence to justify drastic changes in patient care, particularly in light of recent reports of unexpected toxicities. In time, careful evaluation, follow-up and clinical trials will likely support the preferential use of PT in children.

Dosimetric Comparison and Potential for Improved Clinical Outcomes of Paediatric CNS Patients Treated with Protons or IMRT

Background: We compare clinical outcomes of paediatric patients with CNS tumours treated with protons or IMRT. CNS tumours form the second most common group of cancers in children. Radiotherapy plays a major role in the treatment of many of these patients but also contributes to late side effects in long term survivors. Radiation dose inevitably deposited in healthy tissues outside the clinical target has been linked to detrimental late effects such as neurocognitive, behavioural and vascular effects in addition to endocrine abnormalities and second tumours. Methods: A literature search was performed using keywords: protons, IMRT, CNS and paediatric. Of 189 papers retrieved, 10 were deemed relevant based on title and abstract screening. All papers directly compared outcomes from protons with photons, five papers included medulloblastoma, four papers each included craniopharyngioma and low grade gliomas and three papers included ependymoma. Results: This review found that while proton beam therapy offered similar clinical target coverage, there was a demonstrable reduction in integral dose to normal structures. Conclusions: This in turn suggests the potential for superior long term outcomes for paediatric patients with CNS tumours both in terms of radiogenic second cancers and out-of-field adverse effects.