Prevalence of gastrointestinal disorders in adult clients with pervasive developmental disorders.

BACKGROUND: In clients with pervasive developmental disorders (PDD), some authors have noticed the presence of gastrointestinal disorders and behavioural disorders. An augmented prevalence of different histological anomalies has also been reported. The aim of our study is to highlight the prevalence of gastrointestinal disorders in this adult with PDD sample and to demonstrate the importance of accurate evaluation of gastrointestinal disorders in clients with PDD. METHODS: The present comparative study involved 118 clients. Our research was motivated by the clinical observation that behavioural disorders sometimes disappeared with administration of anti-gastric acid or anti-ulcerous medications. It focused on two samples of clients with intellectual disability - those with associated PDD and those without. The presence of gastrointestinal disorders was assessed retrospectively on the basis of hospital records. RESULTS: The prevalence of gastrointestinal disorders reported in clinical files was 48.8% in clients with PDD, as compared with 8.0% in non-PDD clients (P < 0.00001). CONCLUSION: Gastrointestinal disorders, and especially gastro-oesophageal reflux, if neglected, may contribute to behavioural disorders in PDD clients. Moreover, gastrointestinal disorders may be considered as a feature of PDD. We highlight the fact that somatic disorders may coexist in persons with PDD.

The sliding slit test for dynamic IMRT: a useful tool for adjustment of MLC related parameters.

For treatments with dynamic intensity modulated radiotherapy (IMRT), the adjustment of multileaf collimator (MLC) parameters affecting both the optimization algorithm and dose distributions is crucial. The main parameters characterizing the MLC are the transmission (T) and the dosimetric leaf separation (DLS). The aim of this study is twofold: a methodology based on the 'sliding slit' test is proposed to determine (T, DLS) combinations inducing the best conformity between calculations and measurements. Secondly, the effects of the MLC adjustment on measured dose and on optimization are presented for different configurations as the chair test and for the patient dosimetric quality control (DQC). Tests were performed with a Varian 23EX linac operated at 20 MV and equipped with a 120 leaf Millenium dynamic collimator. The treatment planning system was CadPlan/Helios (version 6.3.6). Results demonstrated that the sliding width (SW) strongly depends on the (T, DLS) combinations, and the measured dose is a linear function of the SW. Different (T, DLS) combinations induced a good agreement between calculations and measurements. The influence of the MLC calibration was found to be particularly important on the 'sliding slit' test (11.8% for a gap change of 0.8 mm) but not so much on the chair test and on the DQC. To detect small variations in leaf adjustment and to ensure consistency between calculation and actual dose delivered to patients, a daily check called IMRT MU check is proposed.

[Constraints and dosage for prostate cancer patients treated with conformal radiotherapy and intensity modulated radiation therapy]. / Choix des contraintes et amélioration dosimétrique d'une radiothérapie conformationnelle du cancer de la prostate modulée en intensité pendant une partie du traitement.

PURPOSE: Intensity modulated radiation therapy (IMRT) is based on a methodology called inverse planning. Starting from dosimetric objectives, constraints of optimization are fixed and given to the inverse planning system, which in turn calculates the modulated intensity to apply to each beam. Since the algorithms allow the constraints to be violated, the results of optimization may differ from the initial dosimetric objectives. Consequently, the user is compelled to adapt the choice of the constraints according to the type of modulation and until satisfactory results are found. The purpose of this work is to present our experience in the choice of these constraints for prostate cancer treatments, as we moved from conformal radiotherapy to IMRT. Treatments were performed with a Varian 23EX linac and calculations were realized with the Varian CadPlan-Helios planning system. PATIENTS AND METHODS: The approach used for the first 12 patients treated at institut Curie with IMRT from June 2002 was analysed. The treatment always consisted of a combination of conformal radiotherapy with and without intensity modulation. RESULTS AND CONCLUSION: Results showed that, a larger fraction of the treatment performed with IMRT induced a better sparing of the organs at risk for the same homogeneous dose distribution to the target volume. Apart from the dose-volume constraint for the rectum, a fixed set of constraints, slightly more restrictive than the dosimetric objectives, could be used for all patients. Compared with conformal radiotherapy, the conformation factor for IMRT increased up to 16%. A specific study was undertaken in view of treatments completely performed with IMRT. The optimal technique consisted in performing separated IMRT plans for the two target volumes, the prostate volume and the prostate plus seminal vesicles volume respectively. Another satisfactory possibility was to define new constraints on two separated planning target volumes, prostate and seminal vesicles. This last approach is now routinely implemented for our IMRT patients.

[Upper aerodigestive tract cancers: clinical benefits of conformal radiotherapy and intensity modulation]. / Cancers des voies aérodigestives supérieures: bénéfices cliniques de la radiothérapie conformationnelle et de la modulation d'intensité.

The conformal radiotherapy approach, three-dimensional conformal radiotherapy (3DCRT) or intensity-modulated radiotherapy (IMRT), is based on modern imaging modalities, efficient 3D treatment planning systems, sophisticated immobilization systems and rigorous quality assurance and treatment verification. The central objective of conformal radiotherapy is to ensure a high dose distribution tailored to the limits of the target volume while reducing exposure of normal tissues. These techniques would then allow further tumor dose escalation. Head-and-neck tumors are some of the most attractive localizations to test conformal radiotherapy. They combine ballistic difficulties due to particularly complex shapes (nasopharynx, ethmoid) and problems due to the number and low tolerance of neighbouring organs like parotids, eyes, brainstem and spinal cord. The therapeutic irradiation of head-and-neck tumors thus remains a challenge for the radiation oncologist. Conformal radiotherapy does have a significant potential for improving local control and reducing toxicity when compared to standard radiotherapy. However, in the absence of prospective randomized trials, it is somewhat difficult at present to evaluate the real benefits drawn from 3DCRT and IMRT. The published clinical reports on the use of conformal radiotherapy are essentially dealing with dosimetric comparisons on relatively small numbers of patients. Recently, a few publications have emphasized the clinical experience of several precursor teams with a suitable follow-up. This paper describes the current state-of-the-art of 3DCRT and IMRT in order to evaluate the impact of these techniques on head-and-neck cancers irradiation.