Optimisation des techniques de radiothérapie dans le cadre de la prise en charge des patientes traitées par radiochimiothérapie d'un cancer du col de l'utérus

Contexte : En février 1999 la publication de 4 essais randomisés incite le NCI à recommander la radiochimiothérapie chez les patientes traitées pour un cancer du col utérin de stade avancé. Objectif : Le but de notre étude était de comparer nos résultats en terme de survie globale, de toxicité aiguë et tardive à ceux de la littérature, et de déterminer si l'augmentation du volume irradié en curiethérapie (V60) et en radiothérapie externe était prédictif de complications, chez les patientes de stade >= IB2 traitées par radiochimiothérapie. Matériels et Méthodes : 97 patientes d'âge moyen 49,4 ans atteintes de cancers du col utérin de stade >= IB2 (17 IB2, 12 IIA, 21 IIB, 1 IlIA, 34 IIIB, 4 IVA et 8 IVB), ont été incluses dans notre étude rétrospective. Toutes les patientes ont reçu une chimiothérapie à base de sel de platine (CDDP-5FU ou Carbo-5FU ou CDDP hebdo) de manière concomitante à la radiothérapie, 94 patientes ont eu une curiethérapie et 55 patientes ont bénéficié d'une chirurgie. Résultats : Le suivi moyen des patientes était de 34,2 mois. Les patientes dont la V60 était supérieur à 70 cm3, avaient plus de toxicités tardives (grade 2, 3,4) 61,7% que les patientes dont la V60 était inférieur à 70 cm3, 33,3% (p=0,02). La taille des champs de radiothérapie externe, ainsi que le protocole de chimiothérapie ne modifiaient pas le taux de complications tardives ni aiguës. La réalisation d'une chirurgie augmentait les toxicités tardives (grade 3, 4), 11,3% en cas de chirurgie vs 0% en l'absence de chirurgie (P=0,02). La survie actuarielle à 5 ans est de 63,6%. La survie sans événement est de 83% à 2 ans. Conclusion : Nos résultats sont comparables à ceux de la littérature en terme de survie sans récidive, de survie globale et de taux de complications aiguës et tardives. Notre étude met en évidence une relation entre le volume de curiethérapie et le taux de complications tardives. Des travaux récents ont montré une augmentation du contrôle local lorsque la dose de curiethérapie augmente, les curiethérapies devront à l'avenir être réalisées avec optimisation de la répartition de dose.The aim of our study was to compare our results in term of survival, acute and late toxicity to those of the literature, and to determine if increase in the volume irradiated in brachytherapy (V60) and in extemal radiotherapy were predictive complications, in the patients of stage >= IB2 treated by radiochemotherapy.Materials and Methods : 97 patients of average age 49,4 years reached of cancers of the cervix cancer of stage >= IB2 (17 IB2, 12 lIA, 21 IlB, 1 IlIA, 34 I1IB, 4 IV A and 8 IVB), were included in our retrospective study. All the patients received a chemotherapy containing platinum salt (CDDP-5FU or Carbo-5FU or CDDP weekly) in a concomitant way to the radiotherapy, 94 patients had brachytherapy and 55 patients profited from a surgery. Results : The average follow-up of the patients was 34,2 months. The patients whose V60 was higher than 70 Cm3, had more late toxicities (rank 2,3,4) 61,7% that the patients whose V60 was lower than 70 Cm3, 33,3% (p=0,02). Size of the fields of extemal radiotherapy, as weil as the protocol of chemotherapy did not modify the rate of late complications nor acute. The surgery increased late toxicities (rank 3, 4), II,3% in the event of surgery vs 0% in the absence of surgery (p=0,02). Survival at 2 years is 86%. Survival without event is 83% to 2 years. Conclusion: Our results are comparable with those of the literature in term of survival without repetition, total survival and rate of acute and late complications. Our study highlights a relation between the volume of brachytherapy and the rate of late complications. Recent work showed an increase in local control when the amount of c brachytherapy increases, the brachytherapy will have in the future to be completed with optimization of the distribution of amount.NANCY1-SCD Medecine (545472101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Dosimetric analysis of radiation therapy oncology group 0321: The importance of urethral dose

PurposeRadiation Therapy Oncology Group 0321 is the first multi-institutional cooperative group high-dose-rate (HDR) prostate brachytherapy trial with complete digital brachytherapy dosimetry data. This is a descriptive report of the data and an analysis of toxicity.Methods and materialsPatients are treated with external beam radiation therapy at 45 Gy and 1 HDR implant with 19 Gy in 2 fractions. Implants are done with transrectal ultrasound guidance, and computed tomography (CT)-compatible nonmetallic catheters. HDR planning is done on ≤3-mm-thick CT slices. The "mean DVH" (dose-volume histogram) of the planning target volume (PTV), implanted volume (IP), and organs at risk are calculated. This includes the mean and standard deviation (SD) of the volume at 10-percentage-point intervals from 10% to 200% of the prescribed dose. The conformal index (COIN), homogeneity index (HI), catheters per implant, and patients per institution are calculated. Multivariate analysis and hazard ratios calculation of all the variables against reported grade ≥2 (G2+) genitourinary (GU) adverse events (Common Terminology Criteria for Adverse Events, version 3) are performed.ResultsDosimetry data are based on 122 eligible patients from 14 institutions. The mean of PTV, IP, catheters per implant, and patients per institution are 54 cc, 63 cc, 19 and 9, respectively. The mean of %V100PTV, V80Bladder, V80Rectum, and V120Urethra were 94%, 0.40 cc, 0.15 cc, and 0.25 cc, respectively. There are too few G2+ gastrointestinal adverse event (GI AE) for correlative analysis; thus, the analysis has been performed on the more common G2+ GU AE. There are positive correlations noted between both acute and late G2+ GU AE and urethral dose at multiple levels. Positive correlations with late AE are seen with PTV and IP at high-dose levels. A negative correlation is seen between HI and acute AE. A higher patient accrual rate is associated with a lower rate of G2+ acute and late AE.ConclusionsHigher urethral dose, larger high-dose volumes, and lower dose homogeneity are associated with greater toxicities. A mean dose-volume histogram comparison at all dose levels should be used for quality control and future research comparison

Impact of dosimetric parameters on local control for patients treated with three-dimensional pulsed dose-rate brachytherapy for cervical cancer

International audienceTo investigate the impact of dose-volume histograms parameters on local control of three-dimensional (3D) image-based pulsed dose-rate brachytherapy (BT).METHODS AND MATERIALS:Within a French multicentric prospective study, the data of the 110 patients treated for cervical cancer with external beam radiotherapy followed by 3D image-based and optimized pulsed dose-rate BT were analyzed. Delineation procedures were performed on magnetic resonance imaging in a minority of cases and on CT for the majority of cases, adapted from the Gynaecological Groupe Européen de Curiethérapie-European Society for Therapeutic Radiology and Oncology recommendations. Optimization procedure was left to the discretion of the treating center.RESULTS:At 2 years, local control rate reached 78%. Dose to Point A, total reference air kerma, and intermediate-risk clinical target volume (IR-CTV) V60 were predictive factors for local control (p = 0.001, p = 0.001, and p = 0.013, respectively). Patients with IR-CTV V60 <75% had a relative risk of local recurrence of 3.8 (95% confidence interval, 1.4-11.1). There was no correlation found between the high-risk clinical target volume dosimetric parameters and local control.CONCLUSIONS:This multicentric study has shown that 3D image-based BT provides a high local control rate for cervical cancer patients. The V60 for IR-CTV was identified as an important predictive factor for local control