[Use of 4D-CT: Main technical aspects and clinical benefits]. / Utilisation de la scanographie quadridimensionnelle : principaux aspects techniques et intérêts cliniques.

The four-dimensional scannography, also called 4D-CT, was created in the early 2000s. This method enables the aquistion of CT-scans synchronised with the patient's breathing. It allows an anatomical observation depending on the time. Different systems have been marketed. They are commonly used in treatment planning. It allows to take into account respiratory motion, considering the changes of shape and position of the tumor and organs. In the age of new techniques and stereotactic irradiations, 4D-CT is a valuable tool for estimating the uncertainties associated with respiratory movements, This technique also presents some limitations, including artifacts. The quality of the examination can be degraded in some patients with irregular respiration. Here we propose a summary of this technique detailing its principle of operation, its advantages and its main limits.

Intraperitoneal chemohyperthermia for peritoneal carcinomatosis: original modeling, clinical tolerance and results study about 30 patients.

BACKGROUND/AIMS: The authors' objective is to report their experience of the intraperitoneal chemohyperthermia after a thermal modeling study which has allowed the optimization the intraperitoneal chemohyperthermia circuit and its running parameters and to evaluate the intraperitoneal chemohyperthermia tolerance. Intraperitoneal chemohyperthermia is considered more and more as an interesting therapeutic option in cases of some abdominal carcinomatosis, particularly of digestive origin. However, the main technical problem of this treatment is the homogenization of the temperature distribution in the abdominal cavity. METHODOLOGY: A thermal modeling has allowed us to finalize a reliable and well-tolerated intraperitoneal chemohyperthermia technique. The achievement of a physical model of the abdomen has allowed us to make an experimental study of the temperature distribution in a given liquid volume. Two steps were carried out. The first step was the characterization of the model with a thermal study carried out on the physical model and which has led to dynamic data about the heat balance leading to a knowledge model. The second step was the identification of a theoretical model of the thermal behavior which would correlate best with the experimental data. Between January 1995 and January 1998, 30 patients with peritoneal carcinomatosis were studied. Twenty-six patients underwent maximal cytoreductive surgery with abdominal evisceration, intraperitoneal chemohyperthermia. Intraperitoneal chemohyperthermia was carried out for 1 hour, at 42 degrees C, with a flow rate of 0.9 L/min in the 30 patients. The thermal modeling has shown the main purpose of a high flow rate of 0.9 L/min in the homogenization of temperature distribution. RESULTS: The 2 steps are shown to converge. This coherency between the 2 models proves that the thermal aspects of the process have been properly identified. Our initial results have shown that intraperitoneal chemohyperthermia was properly tolerated. Major intraoperative complications occurred for 1 patient. CONCLUSIONS: The experimental study with thermal modeling results should help to optimize the intraperitoneal chemohyperthermia circuit and its running parameters for human treatment, with an acceptable morbidity in 30 patients.

[Peritoneal carcinomatosis treated by cytoreductive surgery and intraperitoneal chemohyperthermia]. / Carcinoses péritonéales traitées par chirurgie de réduction tumorale et chimiohyperthermie intrapéritonéale.

STUDY AIM: The aim of this prospective non-randomized trial was to report a series of intraperitoneal carcinomatosis due to miscellaneous causes, treated by intraperitoneal hyperthermic perfusion (IPHP) and cytoreductive surgery. PATIENTS AND METHOD: From January 1995 to May 1999, 35 patients were treated by IPHP and 26 of them underwent maximal cytoreductive surgery. IPHP was performed for 60 minutes at an intraperitoneal temperature of 42 degrees C with Mitomycin C (10 mg/L) or cisplatinum (12 mg/L) at a flow rate of 0.9 L/min. RESULTS: There was one (2.8%) postoperative death due to respiratory complications on day 16. Three patients (8.5%) were admitted to the intensive care unit. A high morbidity rate (54%) was observed with intra-abdominal complications in 28.5% of patients, requiring reoperation in three patients. In patients with stages 1 and 2 peritoneal carcinomatosis (granulations less than 5 mm), the 12- and 24-month survival rates were 63.1% and 31.5%, respectively. In patients with advanced stage 3 (diffuse malignant nodules less than 2 cm) and stage 4 carcinomatosis (malignant nodules larger than 2 cm), the 12- and 24-month survival rates were 31.2% and 12%, respectively. Six patients survived for more than 30 months. CONCLUSION: IPHP appears to be an effective treatment for peritoneal carcinomatosis. IPHP combined with cytoreductive surgery is aggressive with a high morbidity rate. Rigorous patient selection is necessary. IPHP is still under evaluation. Prospective randomized trials with identical IPHP protocols are required.

[Modelling of intraperitoneal chemohyperthermia: experimental study and identification of certain thermal aspects]. / Modélisation de la chimiohyperthermie intrapéritonéale: étude expérimentale et identification de certains aspects thermiques.

Intraperitoneal chemohyperthermia is more and more considered as an interesting therapeutic option in cases of some abdominal cancers, particularly of digestive origin. However, many technical aspects of this treatment remain far from being mastered, particularly the homogeneous dispatch of temperatures within the abdomen cavity. This work consists, first of all, in an experimental study, which is being carried out on a physical "prototype" of the abdomen, on which different hot fluid flows and injection conditions (configurations) are investigated. The results of this experimental study are prospected in two ways. First, an a priori thermal model is proposed, based on physical equations (heat transfer, etc.). Then a "black box" model is identified from the measured temperatures evolutions, so as to obtain a model of the "system" behaviour. Finally, the two modelling approaches are being compared, and the results converge to a simple expression of a few parameters, either physical or identified. These modelling results have helped to optimize the injection circuit and its running parameters while applied to the human treatment.