Selection of the Most Appropriate Radiation Treatment Modality for Children’s Cancers: A Paediatric Radiation Oncology Society (PROS) Position Paper on the Ethical Utilization of Proton Therapy
Reply to “Proper tumor classification and growth rate are key elements when considering indications and results of radiotherapy for head and neck paragangliomas”
Abstract Purpose Proton therapy is currently used in the management of pediatric tumors to decrease late toxicities. However, one of the criticisms of proton therapy is the limited data regarding efficacy on disease control. The purpose of this study was to examine local and distant control rates after proton therapy for neuroblastoma. Methods and materials Eighteen patients with high‐risk ( n = 16) and locally recurrent neuroblastoma ( n = 2) were treated with curative intent and received proton therapy to the primary site and up to three post‐induction MIBG‐avid metastatic sites. Primary sites ( n = 18) were treated to 21–36 Gy (relative biological effectiveness [RBE]), and metastatic sites ( n = 16) were treated to 21–24 Gy (RBE). Local control and survival rates were calculated using the Kaplan–Meier method. Results With a median follow‐up of 60.2 months, two‐ and five‐year local control rates at the irradiated primary site were 94% and 87%, respectively. No failures at irradiated distant metastatic sites were observed. The five‐year progression‐free survival (PFS) was 64%, and the five‐year overall survival (OS) was 94%. The extent of surgical resection was not associated with local control, PFS, or OS. No radiation‐related nephropathy or hepatopathy was reported. Conclusions Excellent local control was achieved using proton therapy to the primary and post‐induction MIBG‐positive distant sites. The predominant site of failure is progression in post‐induction non‐MIBG‐avid distant sites. Although proton therapy provides high rates of local control with acceptable toxicity for neuroblastoma, further advances in systemic therapy are needed for the improved control of systemic disease.
Increased risk of pseudoprogression among pediatric low-grade glioma patients treated with proton versus photon radiotherapy
Abstract Background Paraganglioma of the head and neck (HNPGL) are rare often benign tumors. Surgery and radiation therapy (RT) are the main treatment choices. We present an analysis of outcome and toxicity after RT from 13 institutions of the Rare Cancer Network. Methods Data were collected using a questionnaire concerning patients' characteristics, treatment, and outcome. A total of 81 patients with 82 HNPGL were analyzed. Results The median follow‐up was 48 months (1‐456). Sixty‐two lesions were treated with conventional RT and 20 lesions with stereotactic RT. Local control (LC) was achieved in 69 out of 77 lesions. Late toxicity occurred in 17 patients. Patients treated with stereotactic RT experienced neither disease progression nor late toxicity. Four patients with a follow‐up longer than 20 years experienced disease progression. Conclusion RT for HNPGL offered good local control with acceptable toxicity. Stereotactic RT might offer better results. Long‐term follow‐up is required.
RONC-11. EVALUATION OF DIFFERENT RADIOTHERAPY TECHNIQUES ON INCIDENTAL RADIATION DOSES TO THE WHOLE VENTRICULAR SYSTEM DURING FOCAL IRRADIATION FOR NON GERMINOMATOUS GERM CELL TUMOURS AFTER CHEMOTHERAPY
The Rare Cancer Network (RCN) was formed in the early 1990's to create a global network that could pool knowledge and resources in the studies of rare malignancies whose infrequency prevented both their study with prospective clinical trials. To date, the RCN has initiated 74 studies resulting in 46 peer reviewed publications. The First International Symposium of the Rare Cancer Network took place in Nice in March of 2014. Status updates and proposals for new studies were heard for fifteen topics. Ongoing studies continue for cardiac sarcomas, thyroid cancers, glomus tumors, and adult medulloblastomas. New proposals were presented at the symposium for primary hepatic lymphoma, solitary fibrous tumors, Rosai-Dorfman disease, tumors of the ampulla of Vater, salivary gland tumors, anorectal melanoma, midline nuclear protein in testes carcinoma, pulmonary lymphoepithelioma-like carcinoma, adenoid cystic carcinoma of the trachea, osteosarcomas of the mandible, and extra-cranial hemangiopericytoma. This manuscript presents the abstracts of those proposals and updates on ongoing studies, as well a brief summary of the vision and future of the RCN.
Radiotherapy for marginally resected, unresectable or recurrent giant cell tumor of the bone: a rare cancer network study
The role of radiotherapy for local control of marginally resected, unresectable, and recurrent giant cell tumors of bone (GCToB) has not been well defined. The number of patients affected by this rare disease is low. We present a series of 58 patients with biopsy proven GCToB who were treated with radiation therapy. A retrospective review of the role of radiotherapy in the treatment of GCToB was conducted in participating institutions of the Rare Cancer Network. Eligibility criteria consisted of the use of radiotherapy for marginally resected, unresectable, and recurrent GCToB. Fifty-eight patients with biopsy proven GCToB were analyzed from 9 participating North American and European institutions. Forty-five patients had a primary tumor and 13 patients had a recurrent tumor. Median radiation dose was 50 Gy in a median of 25 fractions. Indication for radiation therapy was marginal resection in 33 patients, unresectable tumor in 13 patients, recurrence in 9 patients and palliation in 2 patients. Median tumor size was 7.0 cm. A significant proportion of the tumors involved critical structures. Median follow-up was 8.0 years. Five year local control was 85%. Of the 7 local failures, 3 were treated successfully with salvage surgery. All patients who received palliation achieved symptom relief. Five year overall survival was 94%. None of the patients experienced grade 3 or higher acute toxicity. This study reports a large published experience in the treatment of GCToB with radiotherapy. Radiotherapy can provide excellent local control for incompletely resected, unresectable or recurrent GCToB with acceptable morbidity.