Patients and Treatments
1,227 early stage EC cases were included (Table 1). The pathology of most patients was endometrioid adenocarcinoma (92.7%, n = 1138). Percentage of HR, HIR, IR and LR groups were: 25.9% (n = 318), 19.2% (n = 235), 27.2% (n = 334) and 27.7% (n = 340), respectively.
Table 1
Baseline Clinical Characteristics for all Patients Treated from 2003 to 2017
| Patients(N = 1,227) |
Clinical Characteristic | No. | % |
Age, years | | |
Mean | 56.2 | |
Range | 23–86 | |
Lymphadenectomy | | |
No | 361 | 29.4 |
Yes | 866 | 70.6 |
Mean Number. | 23.7 | |
Range | 1–99 | |
Stage(FIGO 2009) | | |
IA | 566 | 46.1 |
IB | 500 | 40.7 |
II | 161 | 13.1 |
Diameter | | |
< 2cm | 141 | 11.5 |
≥ 2cm | 685 | 55.8 |
Missing | 401 | 32.7 |
Grade† | | |
G1 | 395 | 34.7 |
G2 | 518 | 45.5 |
G3 | 219 | 19.2 |
Missing | 6 | 0.5 |
Myometrial invasion | | |
< 1/2 | 638 | 52.0 |
≥ 1/2 | 581 | 47.4 |
Missing | 8 | 0.7 |
Invasion of lower uterine segment | | |
No | 885 | 72.1 |
Yes | 342 | 27.9 |
Lympho-vascular Space Invasion | | |
Present | 222 | 18.1 |
Absent | 1005 | 81.9 |
Chemotherapy | | |
No | 997 | 81.3 |
Yes | 230 | 18.7 |
Abbreviation: FIGO, International Federation of Gynecology and Obstetrics |
†: only for endometrioid adenocarcinoma |
A hysterectomy and bilateral salpingo-oophorectomy surgery was performed for all cases. A total of 70.6% of all patients underwent lymphadenectomy. All patients underwent adjuvant RT, which included EBRT alone (n = 122), or with VBT (n = 491) and VBT alone (n = 614). EBRT was delivered to the pelvic lymphatic drainage regions and upper part of vagina. Adjuvant chemotherapy was administered to 18.7% of all patients and was used as a sequential or concurrent treatment modality.
RT Pattern Evolvement
An increasing tendency was found towards utilization for VBT alone overall. EBRT with VBT was the main treatment modality from 2003 to 2010 and VBT dominated from 2011. In 2003, there was no record of VBT alone, and the proportion rose to 81.1% in 2017. Meanwhile, the proportion of EBRT with VBT decreased. In 2003, 95.0% of patients received combined EBRT and VBT, and the proportion decreased to 17.3% in 2017. The proportion of EBRT alone remained stable in the corresponding period (Fig. 1).
In this research, trends of VBT alone, and EBRT with or without VBT were stratified by 4 risk groups (Table 2). Data demonstrated that the utilization of VBT alone increased remarkablely among all groups from 2003 to 2017 while the proportion of EBRT with or without VBT decreased correspondingly in the period. In the LR group, VBT became the main adjuvant treatment early in the second five years (2008–2012). In the IR and HIR groups, VBT dominated in the third five years (2013–2017). In the HR group, EBRT with or without VBT remained the main adjuvant treatment modality from 2003 to 2017.
Table 2
Clinical Practice of VBT alone and EBRT (with or without VBT) among Different Risk Groups from 2003 to 2017
Patients(N = 1,227) |
| | 2003–2007 (%) | 2008–2012 (%) | 2013–2017 (%) | p |
Low-risk (N = 340) | VBT alone (N = 243) | 36.1 * | 61.7 * | 85.8 * | 0.000 |
| EBRT with or without VBT (N = 97) | 63.9 * | 38.3 * | 14.2 * | |
Intermediate -risk (N = 334) | VBT alone (N = 184) | 6.1 * | 48.6 | 67.0 * | 0.000 |
| EBRT with or without VBT (N = 150) | 93.9 * | 51.4 | 33.0 * | |
High-intermediate-risk (N = 235) | VBT alone (N = 139) | 0.0 * | 42.0 | 66.3 * | 0.000 |
| EBRT with or without VBT (N = 96) | 100.0 * | 58.0 | 33.7 * | |
High-risk (N = 318) | VBT alone (N = 48) | 0.0 | 13.0 | 17.4 | 0.013 |
| EBRT with or without VBT (N = 270) | 100.0 | 87.0 | 82.6 | |
Note: * adjusted residuals, only values greater than ± 3 were marked. |
Abbreviation: EBRT, External Beam Radiation; VBT, Vaginal Brachytherapy |
Treatment planning and dose fractionation
A total of 1105 patients received VBT, including 614 cases of VBT alone and 491 cases of VBT as a boost to EBRT. For patients receiving VBT, the vaginal irradiated target was mostly the proximal 3 to 5 cm (93.5%) of the vagina. The proximal 2 cm accounted for 6.3% and proximal 6 to 7 cm for 0.2% of the patients. Cylinders were the most commonly used applicators, followed by ovoids. A total of 1056 (95.6%) patients were treated with vaginal cylinders, including 154 (14.6%) single, central channel applicators and 902 (85.4%) multichannel vaginal applicators. For treatment of the vagina, the choice of applicator was both institution and doctor-dependent.
In terms of VBT planning pattern, 990 (89.6%) practitioners performed two-dimensional VBT technique, and others (115, 10.4%) used a three-dimensional VBT technique. For the former, all practitioners specified the dose to a 0.5cm depth from the vaginal surface, while for the latter, clinical target volume was formed by expanding a 0.5cm margin around the vaginal cylinder applicator. High-dose-rate appeared to be the only approach, accounting for 100% of all patients with diverse dose fractionation regimens. As to VBT alone, a total of 13 dose-fractionation schemes were performed, and for VBT boost, 17 dose-fractionation schemes were used. Overall, for VBT alone, the most common schedule was six fractions 5Gy each, accounting for 87.8% (539/614) of all patients, followed by eight fractions 5Gy each (2.6%, 16/614) (Fig. 2). For VBT boost, the most common schedule was two fractions 5Gy each (42.4%, 208/491), followed by four fractions 5Gy each (24.0%, 118/491) (Fig. 3).
In all, 613 patients received EBRT. The median dose and fractions for EBRT was 50 Gy (ranging from 39.6 to 54.0 Gy), and 25 fractions (ranging from 20 to 30 fx) respectively. For treatment planning, the computer tomography-based intensity modulated radiotherapy technique (IMRT) (n = 302, 49.3%) accounted for most, followed by conventional technique (n = 166, 27.0%) and three-dimensional conformal radiotherapy modality (3D-CRT) (n = 145, 23.7%). In 2003, all patients received conventional RT. Along the 15 years of the study, conventional RT has been gradually replaced by 3D-CRT and IMRT. 3D-CRT peaked in 2011 (73.7%) and then gradually replaced by IMRT.
As to timing of adjuvant radiotherapy, when VBT alone was used, most patients initiated radiotherapy at 4–6 (45.0%, n = 276) weeks postoperatively. 25.6% (n = 157), 20.8% (n = 128) and 8.6% (n = 53) of patients initiated VBT alone at 6–8, > 8 and 2–4 weeks postoperatively, respectively. When EBRT was used, timing of radiotherapy was equally distributed. Patients initiated EBRT at 4–6 (32.0%, n = 196), > 8 (25.3%, n = 155), 2–4 (24.0%, n = 147) and 6–8 (18.7%, n = 115) weeks, respectively.