Are 7.5 Gy×2 fractions more efficient than 6 Gy×3 in exclusive postoperative endometrial cancer brachytherapy? A clinical and dosimetrical analysis.
Radiother Oncol
; 189: 109909, 2023 12.
Article
in En
| MEDLINE
| ID: mdl-37699447
ABSTRACT
PURPOSE:
To compare two vaginal brachytherapy (VBT) schedules in postoperative endometrial carcinoma (PEC) patients considering vaginal-cuff relapses (VCR), late toxicities, dosimetry analysis and vaginal dilator use. MATERIAL ANDMETHODS:
110 PEC patients were treated with exclusive high-dose-rate VBT using two schedules. Group-144-patients received 6 Gy×3fractions (September-2011-April-2014); Group-266-patients were treated with 7.5 Gy×2fractions with a dose limit of equivalent total doses in 2-Gy fr (EQD2(α/ß=3)) of 68 Gy in the most exposed 2 cm3 of clinical target volume (CTV) (July-2015-November-2021). The dose was prescribed at 5 mm from the applicator surface. Were evaluated the overall radiation dose delivered to 90% of the CTV (D90), the CTV receiving 100% of the prescription dose (V100) and the EQD2(α/ß=3) received in the most exposed 2 cm3 to dose in CTV. Late toxicity was prospectively assessed using RTOG scores for bladder and rectum and objective LENT-SOMA criteria for late vaginal toxicity (LVT). STATISTICS Descriptive analysis, Chi-square, Student's t-tests and Kaplan and Meier method.RESULTS:
The median follow-up was 60 months (15.9-60). There were no VCR or late toxicities in bladder or rectum. LVT ≥ G1 appeared in 26/44 (59.1%) in Group-1 and 25/66 (37.9%) in Group-2. The mean EQD2(α/ß=3) received by the most exposed 2 cm3 of CTV was 63.7 Gy ± 10.0 in Group-1 and 60.5 Gy ± 3.8 in Group-2 (p = 0.063). There were no differences in adherence to vaginal dilator use ≥9 months, overall D90 and V100.CONCLUSION:
Considering the lack of vaginal relapses and similar LVT over time, 7.5 Gy×2fractions seem more efficient in terms of patient comfort, workload, and cost. This is the first study using dosimetry parameters to compare effectivity of schedules. Larger series are needed to confirm the present results.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Brachytherapy
/
Endometrial Neoplasms
Limits:
Female
/
Humans
Language:
En
Journal:
Radiother Oncol
Year:
2023
Document type:
Article