Schaller Sabrina, Strnad Vratislav, Schweizer Claudia, Lubgan Dorota, Merten Ricarda, Fietkau Rainer, Bert Christoph, Karius Andre
Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany.
Comprehensive Cancer Center Erlangen EMN (CCC Erlangen-EMN), Erlangen, Germany.
Clin Transl Radiat Oncol. 2025 May 8;53:100968. doi: 10.1016/j.ctro.2025.100968. eCollection 2025 Jul.
Model-based dose calculation algorithms (MBDCAs) are increasingly applied in brachytherapy, but their considerations in dose-response analyses is still lacking. This study aimed to assess correlations between both TG-43 and MBDCA dosimetry and reports on clinical outcomes for oral cavity brachytherapy.
We considered 158 patients with oral cavity cancer treated in our institution between 2012 and 2021. Survival outcomes and toxicity (soft tissue necrosis, osteoradionecrosis, mucositis, xerostomia) were reported for a median follow-up of 80 months (2-152 months). All clinical, TG-43 based treatment plans were re-calculated using a MBDCA integrated into our planning system. Differences considering several target volume, tissue, and bone dose parameters were evaluated. Parameter correlations with clinical outcomes and thresholds associated with increased toxicity were investigated.
Cumulative local recurrence, soft-tissue necrosis, osteoradionecrosis, mucositis, and xerostomia rate were 21 %, 22 %, 28 % and 79 % considering all patients. Substantial differences between MBDCA and TG-43 were observed, especially regarding high-dose areas with changes up to 19 %. A number of dose-toxicity correlations were observed, as for osteoradionecrosis (1.6 % vs. 10.3 % for bone D ≥ 59.3 Gy), soft tissue necrosis (16 % vs. 32 % for tissue D ≥ 87.7 Gy), and local recurrence (13 % vs. 25 % for dose non-uniformity ratio < 0.29) (using the MBDCA). Target volumes ≥ 10.2-11.8ccm were associated with increased rates of soft tissue necrosis and mucositis. Dosimetric thresholds and correlations differed between TG-43 and MBDCA.
For oral cavity brachytherapy, several important dosimetric thresholds associated with increased toxicity were determined. MBDCAs for corresponding dose calculations should be advanced and used in clinical practice.
基于模型的剂量计算算法（MBDCA）在近距离放射治疗中的应用日益广泛，但在剂量反应分析中的考量仍显不足。本研究旨在评估TG-43和MBDCA剂量测定法之间的相关性，并报告口腔近距离放射治疗的临床结果。
我们纳入了2012年至2021年在我院接受治疗的158例口腔癌患者。报告了生存结果和毒性反应（软组织坏死、骨放射性坏死、粘膜炎、口干症），中位随访时间为80个月（2 - 152个月）。所有基于TG-43的临床治疗计划均使用集成在我们计划系统中的MBDCA重新计算。评估了几个靶区体积、组织和骨剂量参数的差异。研究了参数与临床结果的相关性以及与毒性增加相关的阈值。
考虑所有患者，累积局部复发率、软组织坏死率、骨放射性坏死率、粘膜炎率和口干症率分别为21%、22%、28%和79%。观察到MBDCA和TG-43之间存在显著差异，尤其是在高剂量区域，变化高达19%。观察到一些剂量与毒性的相关性，如骨放射性坏死（骨D≥59.3 Gy时，MBDCA为1.6%，TG-43为10.3%）、软组织坏死（组织D≥87.7 Gy时，MBDCA为16%，TG-43为32%）和局部复发（剂量不均匀比<0.29时，MBDCA为13%，TG-43为25%）（使用MBDCA）。靶区体积≥10.2 - 11.8 ccm与软组织坏死和粘膜炎发生率增加相关。TG-43和MBDCA的剂量测定阈值及相关性有所不同。
对于口腔近距离放射治疗，确定了几个与毒性增加相关的重要剂量测定阈值。应改进用于相应剂量计算的MBDCA并应用于临床实践。
