Muschitz S, Petrow P, Briot E, Petit C, De Crevoisier R, Duvillard P, Morice P, Haie-Meder C
Brachytherapy Unit, Department of Radiotherapy, Institut Gustave Roussy, Villejuif, France.
Radiother Oncol. 2004 Nov;73(2):187-94. doi: 10.1016/j.radonc.2004.07.028.
This study correlates the treated volume, the GTV and the CTV at the time of intracavitary brachytherapy (BT) with the histopathological findings obtained by surgery (S) in 33 patients (pts) with cervix carcinoma.
Sixteen pts (group I), FIGO stage IB1 (1), IB2 (4), IIB (10), IIIB (1), received external beam radiotherapy (EBT) with a total dose of 45 Gy in 5 weeks and concomitant CISPLATIN 40 mg/m(2) weekly, followed by BT up to a total dose of 15 Gy. S was performed 6-8 weeks thereafter. Seventeen pts (group II), FIGO IA2 (1), IB1 (14), IIB (2), were treated by BT alone with a total dose of 60 Gy and S after 6-8 weeks. All pts had a MRI examination after BT with a moulded applicator in situ for exact delineation of GTV, CTV and critical organs and a 3D dosimetry directly from MRI data.
In group I (EBT + BT + S), the histopathological findings showed complete tumour sterilization (CR) in 56% of pts. Residual disease (RD) was found in 43%. Dosimetric data showed in pts with CR a larger mean treated volume (213 vs. 166 cm(3)) and a better mean coverage of the GTV and the CTV by the reference isodose (99 and 91%) as in pts with RD (85 and 77%). In group II (BT + S), CR was found in 52%, RD in 41%. Dosimetric data showed a larger mean treated volume (154 vs. 109 cm(3)) for pts with RD and a mean coverage of the GTV and the CTV by the reference isodose of 97 and 84% vs. 89 and 80% for pts with CR.
An incomplete coverage of the GTV and/or the CTV by the reference isodose is an important risk factor for RD at the time of surgery. Furthermore, for pts who received BT alone, tumour size seemed to be a limiting factor for an accurate coverage of the CTV by the reference isodose.
本研究将33例宫颈癌患者腔内近距离放疗（BT）时的治疗体积、大体肿瘤体积（GTV）和临床靶体积（CTV）与手术（S）获得的组织病理学结果进行关联。
16例患者（I组），国际妇产科联盟（FIGO）分期为IB1期（1例）、IB2期（4例）、IIB期（10例）、IIIB期（1例），接受外照射放疗（EBT），5周内总剂量达45 Gy，同时每周给予顺铂40 mg/m²，随后进行BT，总剂量达15 Gy。此后6 - 8周进行手术。17例患者（II组），FIGO分期为IA2期（1例）、IB1期（14例）、IIB期（2例），仅接受BT治疗，总剂量60 Gy，6 - 8周后进行手术。所有患者在BT后使用塑形施源器原位进行MRI检查，以精确勾画GTV、CTV和关键器官，并直接从MRI数据进行三维剂量测定。
在I组（EBT + BT + S）中，组织病理学结果显示56%的患者肿瘤完全消退（CR）。43%的患者存在残留病灶（RD）。剂量学数据显示，CR患者的平均治疗体积更大（213 vs. 166 cm³），参考等剂量线对GTV和CTV的平均覆盖情况更好（分别为99%和91%），而RD患者分别为85%和77%。在II组（BT + S）中，52%的患者为CR，41%的患者为RD。剂量学数据显示，RD患者的平均治疗体积更大（154 vs. 109 cm³），参考等剂量线对GTV和CTV的平均覆盖情况分别为97%和84%，而CR患者分别为89%和80%。
参考等剂量线对GTV和/或CTV覆盖不完全是手术时出现RD的重要危险因素。此外，对于仅接受BT治疗的患者，肿瘤大小似乎是参考等剂量线精确覆盖CTV的限制因素。
