[Dosimetric comparison between the intensity modulated radiotherapy with fixed field and Rapid Arc of cervix cancer]. / Comparaison dosimétrique des radiothérapies conformationnelles avec modulation d'intensité par faisceaux statiques et RapidArc(®) des cancers du col.

PURPOSE: Concurrent radiochemotherapy is the standard treatment for locally advanced cervical cancer. This treatment is responsible for bowel and hematologic toxicities. The use of intensity-modulated radiotherapy (IMRT), in static beams, allows a decrease of this toxicity. The technique of RapidArc(®) IMRT could lower the dose delivered to the organs at risk and improve the homogeneity of the planning target volume coverage, while decreasing the processing time. PATIENTS AND MATERIALS: For 20 patients, treatment plans performed with IMRT and RapidArc(®) were compared. The target volumes were: the clinical target volume (gross tumour volume, uterus, upper third of the vagina, the hypogastric, iliac and presacral nodal regions), and the planning target volume (clinical target volume+1cm). The delineated organs at risk were: rectum, bladder, bowel and bone marrow. The dose was 45 Gy in 25 fractions. IMRT were delivered with five beams and RapidArc(®) with two arcs. The comparisons were made by the non-parametric test of Wilcoxon. RESULTS: Medium coverage of the planning target volume was better with RapidArc(®) (P=0.01). It was also better regarding the sparing of bowel (P=0.01) and IMRT was better regarding the sparing of bladder (P=0.01) and rectum (P=0.05). The total volume receiving 20 Gy was less important with RapidArc(®) (P<0.001). RapidArc(®) allowed to decrease the treatment time (3 versus 12 minutes with IMRT) and the number of monitor units (MU) (376.5 versus 962.2, on average, P=0.0001). CONCLUSION: The technique of RapidArc(®) seems to obtain better dosimetric results compared to RCMI, with fewer MU, and a significant decrease in treatment time.

[Intensity-modulated radiation therapy for anal carcinoma]. / Radiothérapie conformationnelle avec modulation d'intensité des cancers de l'anus.

Anal canal carcinoma are highly curable by irradiation, combined with chemotherapy in locally advanced disease, with preservation of sphincter function. The clinical target volume for the nodes is extended, often including the inguinal nodes, which is not usual for other pelvic tumours. Acute and late effects are correlated with the volume and dose delivered to organs at risk, i. e. small bowel, bladder and increased by concomitant chemotherapy. Intensity modulated irradiation (IMRT) makes it possible to optimize the dose distribution in this "complex U shaped" volume, while maintaining the dose distribution for the target volumes. The conversion from conformal irradiation to IMRT necessitates good knowledge of the definition and skills to delineate target volumes and organs at risk, including new volumes needed to optimize the dose distribution. Dosimetric and clinical benefits of IMRT are described, based on early descriptions and evidence-based publication. The growing development of IMRT in anal canal radiotherapy must be encouraged, and long-term benefits should be soon published. Radiation oncologists should precisely learn IMRT recommendations before starting the technique, and evaluate its early and late results for adverse effects, but also for long-term tumour control.

[Curative salvage treatment of mediastinal and pleuropulmonar metastatis from anal canal cancer]. / Chimioradiothérapie de rattrapage pour métastases médiastinales et pleuropulmonaires d'un cancer du canal anal.

This case report presents a 57 years-old woman treated for a squamous cell carcinoma of the anal canal by radiochemotherapy and brachytherapy. The particularity of this case lays on the fact that she presented a mediastinal and pleural metastatic evolution three years later, which was also treated by radiochemotherapy, leading to a complete remission of 50 months. This observation is interesting for its curative treatment in metastatic cancer of the anal canal. It also illustrates the radiosensibility of anal canal cancers, including metastatic situations, and raises the contribution of PET-scanner to evaluate the response to treatment and detect a recurrence.

[Long-term results and prognostic factors of squamous cell carcinoma of the anal canal treated by irradiation]. / Résultats à long terme et facteurs pronostiques des carcinomes épidermoïdes du canal anal traités par irradiation.

PURPOSE: To analyze the prognostic factors of loco regional control (LRC), specific survival (SS) and sphincter conservation (SC) of patients treated by curative and conservative irradiation for an epidermoid cancer of anal canal in our institution. PATIENTS AND METHODS: From 1976 to 2005, 286 patients (pts) were treated by exclusive radiotherapy (180 pts) or chemo-radiotherapy (106 pts) followed by a brachytherapy boost (233 pts) or external beam radiotherapy boost (24 pts). Forty-three pts were stage I, 154 stage II, 31 stage IIIA and 53 stage IIIB. RESULTS: The mean follow-up was 65 months (range: 1.3-250 months). The 5-years-overall survival and SS rates were 66.4% and 78.1% respectively. In multivariate analysis, tumor size (>or=40 mm) [RR=2.1], node involvement (RR=2.4), and poor response (<75%) to first course irradiation [RR=1.9], local relapse (RR=4.5) and distant metastases were factors of poor prognosis for SS. Five-years-LRC were 71.5% (88% for stage I, 69% for stage II, 77%, for stage IIIA and 60% for stage IIIB). Prognosis factors of LCR were tumor size (RR=2.5), response to first course of irradiation (RR=2.9). SC was 71% at 5 years. Prognosis factors of SC were tumor size (RR=1.9) and response to first course of irradiation (RR=2.4). CONCLUSION: The results of this series are similar to those of the literature. As well as initial tumor extension, response to first course of irradiation was found as prognostic factor on LCR, SS, SC. Our results are similar to other series and brachytherapy seems not to be deleterious. Its impact to local control remains to be evaluated.