ESTRO 2024 - Abstract Book

S263

Brachytherapy - Gynaecology

ESTRO 2024

Statistical analysis: chi-square test for comparing proportions and Kaplan Meier for survival analysis and log-rank for curve comparison.

Results:

After a median follow-up of 24 months (5-48), 3-year overall survival (OS), 3-year disease-free survival (DFS), 3-year local relapse-free survival (LRFS) and 3-year nodal relapse-free survival (NRFS) were 71.8 %, 77.3%, 97.8% and 91.9 %, respectively. Three-year metastases disease-free survival (MDFS) was 80%. Median High Risk Clinical Target Volume (HRCV): 31.6 cc (12-111.6), median D90-HRCTV: 90.8Gy (78.4-94), median D90-IRCTV: 71.8Gy (58.3-75.7), median D98-IRCTV: 65.6Gy (55-70) and median T-score: 4 (2-9). Intracavitary/interstitial brachytherapy ws combine in 32p. Median needles: 4 (0-8). T-score >4 not correlated with larger IGABT target volume (HRCTV) (31.4cc vs 34.4cc, pNS): However T-score >4 was correlated with the use of interstitials needles (81% vs 18.7% for T-score>4; p=0.05). There was no correlation between HRCTV>30cc and T score>4 and survival analysis. However, there was a non-significant trend toward worse 3y-MDFS and T-score >4 (70.4% vs 93.8% for T-score>4; p=NS) (Figure 1). The mean D2cc in rectum, bladder, sigmoid and bowel were 63.1Gy (46.9-72), 77Gy (63-87), 64.05Gy (45-76) and 56.2Gy (43.2-72.8), respectively. Rectal morbidity (diarrhoea, proctitis and/or bleeding), was observed in 19 p: G1: 10 p (19.6%), G2: 8 p (15.6%) and G3: 1 p (0.02%). Two-year G2-3 proctitis toxicity-free survival (PTFS) and G2- 3 rectal bleeding-free survival (RBFS) were 85.4 % and 86.6%, respectively. In relation to dosimetric parameters, there were more rectal toxicity in patients with D2cc >65Gy, although differences were not significant; D2cc >65Gy was associated with more incidence of 2-y G2-3 PTFS (68.6% vs 90% (p: 0.06)) and 2-y G2-3 RBFS (71.6% vs 100%, (p: 0.06)). Urinary morbidity (urgency, incontinence, cystitis and/or haematuria) was observed in 10 p: G1: 9 p (17.6%) and G2: 1 p (0.02%). No evidence of urinary toxicity G3. In relation to vaginal toxicity, vaginal atrophy: 20p (39%), telangiectasia: 14p (27.5%) and partial vaginal cleisis (upper third of vagina): 15p (29%). No sacrum fracture was observed. There was no correlation between HRCTV>30cc and T-score>4 and 2-y G2-3 morbidity-free survival (rectal, urinary or sexual toxicity).

Conclusion: