Dept of Clinical Radiology, University of Heidelberg, INF 400, 69120 Heidelberg, Germany.
BMC Cancer. 2010 Nov 5;10:606. doi: 10.1186/1471-2407-10-606.
Low and intermediate grade chondrosarcomas are relative rare bone tumours. About 5-12% of all chondrosarcomas are localized in base of skull region. Low grade chondrosarcoma has a low incidence of distant metastasis but is potentially lethal disease. Therefore, local therapy is of crucial importance in the treatment of skull base chondrosarcomas. Surgical resection is the primary treatment standard. Unfortunately the late diagnosis and diagnosis at the extensive stage are common due to the slow and asymptomatic growth of the lesions. Consequently, complete resection is hindered due to close proximity to critical and hence dose limiting organs such as optic nerves, chiasm and brainstem. Adjuvant or additional radiation therapy is very important for the improvement of local control rates in the primary treatment. Proton therapy is the gold standard in the treatment of skull base chondrosarcomas. However, high-LET (linear energy transfer) beams such as carbon ions theoretically offer advantages by enhanced biologic effectiveness in slow-growing tumours.
METHODS/DESIGN: The study is a prospective randomised active-controlled clinical phase III trial. The trial will be carried out at Heidelberger Ionenstrahl-Therapie (HIT) centre as monocentric trial. Patients with skull base chondrosarcomas will be randomised to either proton or carbon ion radiation therapy. As a standard, patients will undergo non-invasive, rigid immobilization and target volume definition will be carried out based on CT and MRI data. The biologically isoeffective target dose to the PTV (planning target volume) in carbon ion treatment will be 60 Gy E ± 5% and 70 Gy E ± 5% (standard dose) in proton therapy respectively. The 5 year local-progression free survival (LPFS) rate will be analysed as primary end point. Overall survival, progression free and metastasis free survival, patterns of recurrence, local control rate and morbidity are the secondary end points.
Up to now it was impossible to compare two different particle therapies, i.e. protons and carbon ions, directly at the same facility in connection with the treatment of low grade skull base chondrosarcomas.This trial is a phase III study to demonstrate that carbon ion radiotherapy (experimental treatment) is not relevantly inferior and at least as good as proton radiotherapy (standard treatment) with respect to 5 year LPFS in the treatment of chondrosarcomas. Additionally, we expect less toxicity in the carbon ion treatment arm.
ClinicalTrials.gov identifier: NCT01182753.
低度和中级软骨肉瘤是相对罕见的骨肿瘤。大约 5-12%的软骨肉瘤位于颅底区域。低度软骨肉瘤远处转移的发生率较低，但却是一种潜在致命的疾病。因此，局部治疗在颅底软骨肉瘤的治疗中至关重要。手术切除是主要的治疗标准。不幸的是，由于病变生长缓慢且无症状，因此通常会出现晚期诊断和广泛期诊断。因此，由于与视神经、视交叉和脑干等关键且剂量限制的器官紧密相邻，完全切除受到阻碍。辅助或额外的放射治疗对于提高原发性治疗中的局部控制率非常重要。质子治疗是颅底软骨肉瘤治疗的金标准。然而，高 LET（线性能量传递）射线，如碳离子，通过在生长缓慢的肿瘤中增强生物学效应，理论上具有优势。
方法/设计：该研究是一项前瞻性随机对照的 III 期临床试验。该试验将在海德堡离子束治疗中心（HIT）作为单中心试验进行。颅底软骨肉瘤患者将被随机分配接受质子或碳离子放射治疗。作为标准，患者将接受非侵入性、刚性固定，基于 CT 和 MRI 数据进行靶区定义。碳离子治疗中 PTV（计划靶区）的生物等效靶剂量将分别为 60 GyE ± 5%和 70 GyE ± 5%（标准剂量）。5 年局部无进展生存率（LPFS）将作为主要终点进行分析。总生存率、无进展生存率和无转移生存率、复发模式、局部控制率和发病率是次要终点。
到目前为止，在治疗低度颅底软骨肉瘤时，不可能在同一设施中将两种不同的粒子疗法（质子和碳离子）直接进行比较。这项试验是一项 III 期研究，旨在证明在治疗软骨肉瘤方面，碳离子放射治疗（实验组）在 5 年 LPFS 方面与质子放射治疗（标准治疗）没有显著差异，并且至少同样有效。此外，我们预计在碳离子治疗组中毒性更小。
ClinicalTrials.gov 标识符：NCT01182753。
