Kato Rans, Robin De Roover, Gert De Meerleer, Karin Haustermans, Charlien Berghen, Kenneth Poels
Department of Radiation Oncology, University Hospitals Leuven, Leuven, Belgium.
Phys Imaging Radiat Oncol. 2025 Jul 5;35:100808. doi: 10.1016/j.phro.2025.100808. eCollection 2025 Jul.
Achieving optimal local control is pivotal in the context of metastasis-directed therapy (MDT) in delaying further metastatic spread. The clear correlation between the biological equivalent dose (BED) and local control, with rates reaching 99 % when BED exceeds 100 Gy using an α:β ratio of 3, underlines the importance of investigating advanced radiation modalities.
MATERIALS & METHODS: A planning study was conducted in 20 patients treated for 38 lesions to compare photon based and proton based stereotactic radiation therapy in oligoprogressive metastatic castration-refractory prostate cancer patients. The primary objective was to determine whether proton therapy is achieving a satisfactory BED of > 100 Gy using the voxel wise minimum dose in more patients when compared with photon therapy respecting the dose constraints for the organs-at-risk.
Volumetric Modulated Arc Therapy (VMAT) and Intensity Modulated Proton Therapy (IMPT) achieved a satisfactory BED > 100 Gy in 75 % and 78 % of the cases, respectively. A significance difference was observed in favor of IMPT for vowel-wise minimum gross tumor volume (GTV) D (p < 0.001). IMPT provided significant organs at risk (OAR) sparing, making it a promising modality for reducing long-term toxicities.
Proton therapy may reduce long-term treatment-related toxicities and be more effective for re-irradiation. It achieves a satisfactory BED of > 100 Gy in more patients as photon therapy with a statistically significant advantage in voxel wise minimum GTV D.
在转移导向治疗（MDT）中实现最佳局部控制对于延缓进一步的转移扩散至关重要。生物等效剂量（BED）与局部控制之间存在明确的相关性，当使用α:β比值为3时，BED超过100 Gy时局部控制率可达99%，这凸显了研究先进放疗方式的重要性。
对20例接受治疗的38个病灶进行了一项计划研究，以比较寡进展性转移性去势抵抗性前列腺癌患者基于光子和基于质子的立体定向放射治疗。主要目的是确定与光子治疗相比，质子治疗在更多患者中使用体素-wise最小剂量时是否能达到>100 Gy的令人满意的BED，同时符合危及器官的剂量限制。
容积调强弧形放疗（VMAT）和调强质子放疗（IMPT）分别在75%和78%的病例中实现了>100 Gy的令人满意的BED。在元音-wise最小总体肿瘤体积（GTV）D方面观察到有利于IMPT的显著差异（p<0.001）。IMPT显著减少了危及器官（OAR）的剂量，使其成为降低长期毒性的一种有前景的治疗方式。
质子治疗可能降低长期治疗相关毒性，并且在再照射方面更有效。与光子治疗相比，它在更多患者中实现了>100 Gy的令人满意的BED，在体素-wise最小GTV D方面具有统计学显著优势。
