Van Limbergen E, Briot E, Drijkoningen M
Department of Radiotherapy, University Hospital St. Rafaël, Leuven, Belgium.
Int J Radiat Oncol Biol Phys. 1990 May;18(5):1239-44. doi: 10.1016/0360-3016(90)90464-u.
Inappropriate positioning of interstitial Iridium 192 implants, used as booster dose in the breast conserving treatment of mammary cancer, may cause disturbing teleangiectasia of the breast skin, when high radiation doses are delivered on the dermal blood vessels. Based on the localization of the vascular plexuses in human breast skin, and on the dose distribution around different types of interstitial implants, a method is described to avoid overlap between the high dose area of the implant and the blood vessels in the skin. The latter are demonstrated to run within the first 5 mm under the epiderm. For source lengths varying from 5 to 8 cm, simple mathematical relations exist between the maximal security margin (MSM) and intersource distance (E) for single plane implants (MSM = 0.4 (E + 1)), double plane square implants (MSM = 0.4 E) and double plane triangular implants (MSM = 0.4 (E - 1)). We developed a device to measure precisely the distance between the radioactive wires and the overlying skin, along the whole source trajectory. Using this method, the occurrence of teleangiectasia in the breast skin after interstitial implants with Ir 192 may be significantly reduced.
在乳腺癌保乳治疗中用作增强剂量的组织间铱192植入物定位不当，当高辐射剂量作用于真皮血管时，可能会导致令人不安的乳腺皮肤毛细血管扩张。基于人类乳腺皮肤中血管丛的定位以及不同类型组织间植入物周围的剂量分布，本文描述了一种避免植入物高剂量区域与皮肤血管重叠的方法。结果表明，皮肤血管位于表皮下的前5毫米内。对于长度在5至8厘米之间变化的源，对于单平面植入物（最大安全 margin，MSM = 0.4 (E + 1)）、双平面方形植入物（MSM = 0.4 E）和双平面三角形植入物（MSM = 0.4 (E - 1)），最大安全 margin（MSM）与源间距离（E）之间存在简单的数学关系。我们开发了一种装置，可沿整个源轨迹精确测量放射性导线与上方皮肤之间的距离。使用这种方法，铱192组织间植入后乳腺皮肤毛细血管扩张的发生率可能会显著降低。
