Radiation Oncology Department, IRCCS Regina Elena National Cancer Institute, 00144 Rome, Italy.
Medical Physics Unit, IRCCS Regina Elena National Cancer Institute, 00144 Rome, Italy.
Curr Oncol. 2024 Sep 5;31(9):5224-5232. doi: 10.3390/curroncol31090386.
In high-risk breast cancer patients with skin infiltration, the administration of a uniform dose to superficial tissues is fundamental in order to reduce local skin relapse. A personalized bolus may prevent the potential inadequate dose distribution of a standard bolus due to air gaps between the bolus and the skin. In this pilot study, we introduced into clinical practice the use of a personalized 3D-printed bolus filled with ultrasound transmission gel.
Seven patients undergoing radiotherapy after mastectomy were selected. A 3D-printed bolus dosimetric assessment was performed with MOSFET dosimeters on an anthropomorphic phantom and, subsequently, on three selected cases with increasing bolus shape irregularity. Acute/late toxicity and local control were assessed.
Overall, for the clinical cases, the percentage median difference between the measured and calculated doses was -2.7% (-7.0-4.9%). The median follow-up was 21 months. After two years, one patient showed G2 pain, one patient manifested G1 telangiectasia, one patient showed G1 hyperpigmentation, and two patients had no relevant toxicity.
A personalized 3D-printed bolus filled with ultrasound gel may easily reproduce the standard bolus' consistency and provide accurate coverage of the target area with tolerable acute/late toxicity grades. This is a pilot study, and further investigations are needed.
在皮肤浸润的高危乳腺癌患者中，为了降低局部皮肤复发的风险，对浅表组织进行均匀剂量的给药至关重要。个性化的挡块可能会防止由于挡块和皮肤之间的气隙而导致标准挡块潜在的剂量分布不足。在这项初步研究中，我们将使用填充有超声传输凝胶的个性化 3D 打印挡块引入临床实践。
选择 7 名接受乳房切除术后放疗的患者。在人体模型上并随后在 3 个具有逐渐增加的挡块形状不规则性的选定病例上，使用 MOSFET 剂量计对个性化挡块的剂量评估进行了 3D 打印。评估了急性/晚期毒性和局部控制情况。
总体而言，对于临床病例，测量剂量和计算剂量之间的中位数百分比差异为-2.7%（-7.0-4.9%）。中位随访时间为 21 个月。两年后，1 名患者出现 G2 疼痛，1 名患者出现 G1 毛细血管扩张，1 名患者出现 G1 色素沉着过度，2 名患者无相关毒性。
填充有超声凝胶的个性化 3D 打印挡块可以轻松复制标准挡块的一致性，并以可耐受的急性/晚期毒性等级为目标区域提供准确的覆盖。这是一项初步研究，需要进一步的研究。
