Publications (6)17.39 Total impact

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    ABSTRACT: Respiration-gated radiotherapy offers a significant potential for improvement in the irradiation of tumor sites affected by respiratory motion such as lung, breast and liver tumors. An increased conformality of irradiation fields leading to decreased complications rates of organs at risk (lung, heart…) is expected. Respiratory gating is in line with the need for improved precision required by radiotherapy techniques such as 3D conformal radiotherapy or intensity modulated radiotherapy. Reduction of respiratory motion can be achieved by using either breath-hold techniques or respiration synchronized gating techniques. Breath-hold techniques can be achieved with active techniques, in which airflow of the patient is temporarily blocked by a valve, or passive techniques, in which the patient voluntarily holds his/her breath. Synchronized gating techniques use external devices to predict the phase of the respiration cycle while the patient breaths freely. This work summarizes the different experiences of the centers of the STIC 2003 project. It describes the different techniques, gives an overview of the literature and proposes a practice based on our experience.
    No preview · Article · Jun 2007 · Cancer/Radiothérapie
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    ABSTRACT: Background and PurposeThe goal of our study was to quantify the limits of the EUD models for use in score functions in inverse planning software, and for clinical application.Materials and MethodsWe focused on oesophagus cancer irradiation. Our evaluation was based on theoretical dose volume histograms (DVH), and we analyzed them using volumetric and linear quadratic EUD models, average and maximum dose concepts, the linear quadratic model and the differential area between each DVH.ResultsWe evaluated our models using theoretical and more complex DVHs for the above regions of interest. We studied three types of DVH for the target volume: the first followed the ICRU dose homogeneity recommendations; the second was built out of the first requirements and the same average dose was built in for all cases; the third was truncated by a small dose hole. We also built theoretical DVHs for the organs at risk, in order to evaluate the limits of, and the ways to use both EUD(1) and EUD/LQ models, comparing them to the traditional ways of scoring a treatment plan. For each volume of interest we built theoretical treatment plans with differences in the fractionation.ConclusionWe concluded that both volumetric and linear quadratic EUDs should be used. Volumetric EUD(1) takes into account neither hot–cold spot compensation nor the differences in fractionation, but it is more sensitive to the increase of the irradiated volume. With linear quadratic EUD/LQ, a volumetric analysis of fractionation variation effort can be performed.
    No preview · Article · Apr 2007 · Physica Medica
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    ABSTRACT: The European Organization for Research and Treatment of Cancer (EORTC) phase II study No. 22953 demonstrated the feasibility of reducing the overall treatment time of chemoradiation, delivering mitomycin C twice rather than once and fluorouracil during the whole treatment. We tested the feasibility of chemoradiation in anal carcinoma with mitomycin and cisplatin in a phase II study. Twenty-one patients with locally advanced anal carcinoma (15 women, 6 men) were treated. The first sequence of radiotherapy consisted of 36 Gy over four weeks. After a gap interval of 16 days, a second sequence of radiotherapy was given, delivering 23.4 Gy over 2.5 weeks. Mitomycin C was delivered at 10 mg/m(2) day 1 of each sequence and cisplatin was delivered at 25 mg/m(2)/week of each sequence. The compliance rates for the first sequence with radiation, mitomycinm, and cispaltin (dose and timing) were 100 percent. The median duration gap was 16 days (14-30 days). The compliance rates for the second sequence with radiation, mitomycin, and cisplatin (dose and timing) were 100, 76.2, and 85.7 percent, respectively. Grade > or = 2 acute toxicities of 62, 29, 25, and 5 percent were observed for skin, diarrhea, hematologic, and renal toxicities, respectively. Nineteen patients were in complete response (90.5 percent). Combining radiation with mitomycin and cisplatin in patients with locally advanced anal cancer is feasible. The results are promising. The EORTC is currently comparing this combination with mitomycin and 5-fluorouracil in a large phase II-III trial.
    No preview · Article · Feb 2007 · Diseases of the Colon & Rectum
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    ABSTRACT: The currently used tumor-node metastasis (TNM) staging method is generally not applicable to patients with unresectable esophageal carcinomas. There is a need for both an efficient, easy-to-perform clinical classification and for identification of pretherapeutic prognostic factors that would be useful for oncologists, one of which is tumor volume. Records of 148 patients, admitted to hospital during the period January 1993 to December 2001, were evaluated retrospectively. Median age was 65.7 years (range, 35.5-85.5 years). Most patients had SCC (84.5%). Using the computed tomography (CT) scan classification, tumors were recorded as follows: 1 T1, 42 T2, 93 T3, 6 T4, 2 Nx, 72 N0, 74 N1. Tumor volume from the CT scans was determined as the sum of 2 opposed truncated cones. Median tumor volume was 57.5 cm3 (range, 0.6-288 cm3). Median follow-up was 15.1 month (range, 0.3-82.8 months). Survival rates at 1, 2, and 3 years were 42.5%, 21.6%, and 8%, respectively. Prognostic factors identified by univariate analysis were: dysphagia grade > or =2, other histology than squamous cell, tumor location below the carina, age <65 years and tumor volume > or =100 cm3. Prognostic factors identified with multivariate analysis were: dysphagia grade > or =2 (P = 0.013), weight loss > or =10% (P = 0.047), tumor location below the carina (P = 0.002), and tumor volume > or =100 cm3 (P = 0.041). For patients that the TNM staging system is not applicable, tumor volume is a new powerful determinant of survival. Further clinical trials need to be carried out to validate this prospectively.
    Full-text · Article · Dec 2006 · American journal of clinical oncology
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    ABSTRACT: To evaluate esophageal tumor and OAR movement during the respiratory cycle in order to obtain optimal values for ITV and PRV. To correlate tumor motion with chest wall displacement - information of value in the free-breathing gating system. Inclusion criteria were: histologically proven squamous-cell carcinoma (SCC) or adenocarcinoma at stage T3 - T4 NX or TX N1 M0 according to the UICC 1997 classification. Two spiral scans were performed with breath-hold respiration under spirometric control: one at end expiration (EBH) and the other at end inspiration (IBH). Displacements between exhalation and inhalation were calculated according to ICRU report 42 recommendations. For the correlation study, CT-scan acquisition was performed at the isocenter over a 20 - 40 s period. After Fourier Transform, frequency spectra for amplitude and phase of tumor and chest wall motions were performed for each patient. Cumulative distribution of CTV motion in absolute values showed that 95% of data ranged from 0 to 1 cm. Cumulative distribution of GTV motion in absolute values showed that 95% of data ranged from 0 to 0.8 cm. The correlation study demonstrated no specific relationship between respiratory and esophageal motions. The ITV margin for 3D conformal radiotherapy in esophageal cancer was 1 cm when 95% of motions were taken into account in this clinical study involving eight patients. Before using a free-breathing gating system, the correlation between external markers and target displacement during irradiation must be established for each patient.
    No preview · Article · Oct 2006 · Radiotherapy and Oncology
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    ABSTRACT: The objective of this paper is to study the dosimetric impact of respiratory gated radiotherapy in locally advanced esophageal carcinomaand to define the optimal respiratory phase for this treatment. The study included 8 consecutive patients with squamous-cell carcinoma (SCC) or histologically proved adenocarcinoma, for both at least T3-T4 NX or TX N1 M0 stage. Informed consent was obtained before beginning the study. Three spiral scans were performed in breath-hold respiration: one acquisition in end expiration (EBH), one in end inspiration (IBH) and one in deep inspiration breathhold (DIBH); and one acquisition was performed in Free Breathing (FB). A 3 mm-margin was defined as Internal Target Volume (ITV) on FB CT-scan. No ITV was applied on EBH, IBH and DIBH CT-scan. Target volumes were analyzed and we performed dosimetric comparisons on DVH data of each CT-scan for PTV and Organs at Risk (OAR) (Conformity Index, V(dose), D(mean), Equivalent Uniform Dose). DIBH and IBH correlated with a 32% (p=0.77) and 20% (p=0.52) decrease in lung V(20) respectively as compared to FB (13.5%and 15.6% respectively versus 19.9%). DIBH and IBH correlated with a 25% (p=0.25) and 17% (p=0.39) decrease in cardiac V(40) respectively, as compared with FB (16.9% and 18.9% respectively versus 22.7%). For spinal cord irradiation, the minimum dose was obtained in IBH (36.5 Gy). Conformal radiotherapy with respiratory gating for esophageal cancer decreases the irradiated dose to OAR. We suggest that DIBH technique should be used when irradiation is performed using the spirometric system. In the Tidal Volume, the inspiration phase is the most favourable and should be chosen for irradiation with a free breathing gating system.
    No preview · Article · Oct 2006 · Physica Medica