Embed Size (px)
Citation preview
Impact of overall treatment time and dose escalation on local control in locally advanced cervical cancer
treated by chemo-radiation and image-guided adaptive brachytherapy
Renaud Mazeron# 57608 (abstract 1827)DPD 06. Digital Poster Discussion - GYN
GUSTAVE ROUSSY Mazeron R ASTRO GYN PD6
Background
Image-guided adaptive brachytherapy (IGABT) is becoming a standard in the treatment of locally advanced cervical cancer
Local control rates reported in monocentric series are high, about 90% (Pötter et al., Nomden et al., Mazeron et al.)
Objective: Identifying the prognosis factors for local control in a cohort a patients treated with concomitant chemo-radiation followed by IGABT
2
GUSTAVE ROUSSY Mazeron R ASTRO GYN PD6
Material and Methods
Consecutive patientsLocally advanced cervical cancer (IB2-IVA)Curative intentGEC-ESTRO recommendations appliedAt the beginning of our experience, patients with
stage I-II lesions went throughout post radiation hysterectomy. For them, local failure was considered in case of macroscopic remnant (1 cm in width) or in case of local relapse during their follow-up.
In patients treated with definitive radiotherapy, local failure was defined as any relapse in the cervix, vagina, parametium, or uterus during the follow-up.
3
GUSTAVE ROUSSY Mazeron R ASTRO GYN PD6
Note: Post radiation hysterectomy
Patients included to warrant consecutive patientsTreated at the beginning of our experience, with
doses lower than nowadays. Important to study dose-response effect.
1cm as cutoff: strong prognosis factor reported in the literature
Prognostic factors were analyzed using a linear regression model. Additional dose / effect correlations were done using the logit model.
4
Statistics
GUSTAVE ROUSSY Mazeron R ASTRO GYN PD6
Results
Tumor width at diagnosis (> 5 cm), initial tumor volume (>50 cm3), D90% of the HR-CTV (high risk, > 85 Gy), the HR-CTV volume (> 30 cm3) and overall treatment time (OTT, > 55days) appeared significantly correlated with local control in univariate analysis, but treatment duration remained the only significant factor in multivariate analysis (p=0.022, odds ratio=2.44).
Logit models: positive for OTT, D90 HR and IR-CTV
5
GUSTAVE ROUSSY Mazeron R ASTRO GYN PD6
Figure 1
6
GUSTAVE ROUSSY Mazeron R ASTRO GYN PD6 7
GUSTAVE ROUSSY Mazeron R ASTRO GYN PD6
Take home messages
OTT remains important with a loss of 0,5% of local control probability beyond 55 days
This is less than reported 10 years ago (1%) but significant
A dose-response for both HR-IR CTV has been shown similar to that demonstrated by Dimopoulos et al. for HDR brachytherapy, supporting the dose escalation concept (see oral presentation by Kari Tanderup)
8
