Behzadi Sophie T, Duesberg Mathias, Moser Rebecca, Duma Marciana-Nona, Oechsner Markus, Kiesl Sophia, Nano Jana, Combs Stephanie E, Borm Kai J
Department of Radiation Oncology, TUM School of Medicine and Health, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.
Department of Radiation Oncology, Helios Clinics of Schwerin - University Campus of MSH Medical School Hamburg, Schwerin, Germany.
Clin Transl Radiat Oncol. 2024 Jul 30;48:100831. doi: 10.1016/j.ctro.2024.100831. eCollection 2024 Sep.
In a relevant number of primary breast cancer patients, lymphatic drainage to the contralateral internal mammary nodes (cIMN) is being observed. Nevertheless, so far lymphatic drainage pathway to the cIMN is largely neglected during adjuvant radiotherapy.
This study evaluated the incidental dose to the cIMN for 120 volumetric modulated arc therapy (VMAT) treatment plans for node positive breast in dependence of internal mammary node irradiation (IMNI) and deep inspiration breath hold (DIBH). Additionally, incidental dose distribution to the cIMN based on the field design in the MA20, EORTC22922/10925 and AMAROS trials was assessed.
The incidental dose (Dmean ± SD) to the cIMN-CTV was 13.0 (±4.7) Gy with a maximum dose of < 30 Gy in 113/120 cases. If IMNI was included (n = 80), the Dmean to the cIMN-CTV was significantly higher compared to no IMNI, but still comparably low (n = 40; 14.3 Gy vs. 9.6 Gy; p = 0.0001). Furthermore, the dose in the cIMN during free breathing (n = 80) was higher compared to DIBH (n = 40; 13.9 Gy vs. 11.2 Gy; p = 0.002).Simulated treatment plans based on the randomized RNI trials revealed neglectable dose coverage of the cIMN (Dmean 1.0-1.8 Gy) for all protocols.
Neither in the randomized RNI trials nor during contemporary treatment techniques clinically relevant dose distribution to the cIMN was observed. Further studies are warranted to assess the potential impact of intended irradiation of cIMN in high-risk patients.
在相当数量的原发性乳腺癌患者中，观察到存在向对侧内乳淋巴结（cIMN）的淋巴引流。然而，迄今为止，在辅助放疗期间，cIMN的淋巴引流途径在很大程度上被忽视了。
本研究评估了120例针对淋巴结阳性乳腺癌的容积调强弧形放疗（VMAT）治疗计划中，根据内乳淋巴结照射（IMNI）和深吸气屏气（DIBH）情况，cIMN所接受的附带剂量。此外，还评估了基于MA20、EORTC22922/10925和AMAROS试验中的射野设计，cIMN的附带剂量分布情况。
在113/120例病例中，cIMN临床靶区（CTV）的附带剂量（平均剂量±标准差）为13.0（±4.7）Gy，最大剂量<30 Gy。如果包括IMNI（n = 80），cIMN-CTV的平均剂量与不进行IMNI相比显著更高，但仍然相对较低（n = 40；14.3 Gy对9.6 Gy；p = 0.0001）。此外，自由呼吸时（n = 80）cIMN的剂量高于DIBH时（n = 40；13.9 Gy对11.2 Gy；p = 0.002）。基于随机化区域淋巴结照射（RNI）试验模拟的治疗计划显示，所有方案中cIMN的剂量覆盖可忽略不计（平均剂量1.0 - 1.8 Gy）。
无论是在随机化RNI试验中，还是在当代治疗技术中，均未观察到cIMN有临床相关的剂量分布。有必要进行进一步研究，以评估对高危患者有意照射cIMN的潜在影响。
