Radiation Oncology Research Centre, Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran.
Radiation Oncology Department, Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran.
Phys Med. 2018 Jan;45:143-145. doi: 10.1016/j.ejmp.2017.12.016. Epub 2017 Dec 21.
Radiation received by the testes in the course of radiotherapy for rectal cancer may cause oligospermia and azospermia. We sought to determine the dose to the scrotum and testes with thermoluminescence dosimetry (TLD), and compare it to the dose calculated by 3D planning software.
The TLDs were fixed to the scrotum in six points anteriorly and posteriorly in two fractions of radiotherapy. All patients received a 50-50.4 Gy total dose in prone position with 3D-planning. The average dose of TLD measurements was compared to the average of 6 relevant point doses calculated by the planning software.
The mean scrotal dose of radiation in 33 patients as measured by TLD was 3.77 Gy (7.5% of the total prescribed dose), and the mean of point doses calculated by the planning software was 4.11 Gy (8.1% of the total dose), with no significant difference. A significant relationship was seen between the position of the inferior edge of the fields and the mean scrotal dose (P = .04). Also body mass index (BMI) was inversely related with the scrotal dose (P = .049).
We found a dose of about 4 Gy received by the scrotum and testes from a total prescribed dose of 50 Gy in the radiotherapy of rectal carcinoma patients, with TLD measurements confirming testicular dose estimations by the planning software. This dose could be significantly harmful for spermatogenesis. Thus careful attention to the testicular dose in radiotherapy of rectal cancer for men desiring continued fertility is a necessity.
直肠癌放射治疗过程中睾丸接受的辐射可能导致少精症和无精症。我们试图通过热释光剂量测定（TLD）确定阴囊和睾丸的剂量，并将其与 3D 规划软件计算的剂量进行比较。
在放疗的两个分次中，将 TLD 固定在阴囊的前侧和后侧的六个点上。所有患者均在 3D 规划的俯卧位接受 50-50.4Gy 的总剂量。将 TLD 测量的平均剂量与规划软件计算的 6 个相关点剂量的平均值进行比较。
33 例患者 TLD 测量的平均阴囊辐射剂量为 3.77Gy（总处方剂量的 7.5%），规划软件计算的点剂量平均值为 4.11Gy（总剂量的 8.1%），差异无统计学意义。场的下边缘位置与平均阴囊剂量之间存在显著关系（P=0.04）。此外，体重指数（BMI）与阴囊剂量呈负相关（P=0.049）。
我们发现，在接受 50Gy 总处方剂量的直肠癌患者放射治疗中，阴囊和睾丸接受的剂量约为 4Gy，TLD 测量结果证实了规划软件对睾丸剂量的估计。这个剂量可能对精子发生有明显的危害。因此，对于希望保持生育能力的男性，在直肠癌放射治疗中，需要仔细关注睾丸剂量。
