Nangia Sapna, Burela Nagarjuna, Noufal M P, Patro Kartikeswar, Wakde Manoj Gulabrao, Sharma Dayanada S
Department of Radiation Oncology, Apollo Proton Cancer Centre, Chennai, Tamil Nadu, India.
Department of Medical Physics, Apollo Proton Cancer Centre, Chennai, Tamil Nadu, India.
Radiat Oncol J. 2023 Jun;41(2):69-80. doi: 10.3857/roj.2023.00073. Epub 2023 Jun 1.
Indians have a higher incidence of cardiovascular diseases, often at a younger age, than other ethnic groups. This higher baseline risk requires consideration when assessing additional cardiac morbidity of breast cancer treatment. Superior cardiac sparing is a critical dosimetric advantage of proton therapy in breast cancer radiotherapy. We report here the heart and cardiac-substructure doses and early toxicities in breast cancer patients treated post-operatively with proton therapy in India's first proton therapy center.
We treated twenty breast cancer patients with intensity-modulated proton therapy (IMPT) from October 2019 to September 2022, eleven after breast conservation, nine following mastectomy, and appropriate systemic therapy, when indicated. The most prescribed dose was 40 GyE to the whole breast/chest wall and 48 GyE by simultaneous integrated boost to the tumor bed and 37.5 GyE to appropriate nodal volumes, delivered in 15 fractions.
Adequate coverage was achieved for clinical target volume (breast/chest wall), i.e., CTV40, and regional nodes, with 99% of the targets receiving 95% of the prescribed dose (V95% > 99%). The mean heart dose was 0.78 GyE and 0.87 GyE for all and left breast cancer patients, respectively. The mean left anterior descending artery (LAD) dose, LAD D0.02cc, and left ventricle dose were 2.76, 6.46, and 0.2 GyE, respectively. Mean ipsilateral lung dose, V20Gy, V5Gy, and contralateral breast dose (Dmean) were 6.87 GyE, 14.6%, 36.4%, and 0.38 GyE, respectively.
The dose to heart and cardiac substructures is lower with IMPT than published photon therapy data. Despite the limited access to proton therapy at present, given the higher cardiovascular risk and coronary artery disease prevalence in India, the cardiac sparing achieved using this technique merits consideration for wider adoption in breast cancer treatment.
与其他种族群体相比，印度人患心血管疾病的发病率更高，且往往发病年龄更小。在评估乳腺癌治疗的额外心脏发病率时，需要考虑这种更高的基线风险。在乳腺癌放疗中，质子治疗具有显著的心脏保护剂量优势。我们在此报告印度首个质子治疗中心对乳腺癌患者进行术后质子治疗时的心脏及心脏亚结构剂量和早期毒性反应。
2019年10月至2022年9月，我们对20例乳腺癌患者采用调强质子治疗（IMPT），其中11例为保乳术后患者，9例为乳房切除术后患者，并在必要时进行了适当的全身治疗。最常用的剂量是全乳/胸壁40 GyE，瘤床同步整合加量至48 GyE，合适的淋巴结区域为37.5 GyE，分15次给予。
临床靶区（乳房/胸壁）即CTV40以及区域淋巴结均获得了充分覆盖，99%的靶区接受了95%的处方剂量（V95%>99%）。所有患者和左侧乳腺癌患者的平均心脏剂量分别为0.78 GyE和0.87 GyE。左前降支（LAD）的平均剂量、LAD D0.02cc以及左心室剂量分别为2.76 GyE、6.46 GyE和0.2 GyE。同侧肺平均剂量、V20Gy、V5Gy以及对侧乳腺剂量（Dmean）分别为6.87 GyE、14.6%、36.4%和0.38 GyE。
IMPT对心脏及心脏亚结构的剂量低于已发表的光子治疗数据。尽管目前质子治疗的可及性有限，但鉴于印度心血管疾病风险较高和冠状动脉疾病患病率较高，使用该技术实现的心脏保护值得在乳腺癌治疗中更广泛地采用。
