ABSTRACT
A detector (MOPI) has been developed for the online monitoring of the beam at the Centro di AdroTerapia e Applicazioni Nucleari Avanzate (CATANA), where shallow tumours of the ocular region are treated with 62 MeV protons. At CATANA the beam is passively spread to match the tumour shape. The uniformity of the delivered dose depends on beam geometrical quantities which are checked before each treatment. However, beam instabilities might develop during the irradiation affecting the dose distribution. This paper reports on the use of the MOPI detector to measure the stability of the beam profile during the irradiation in the clinical practice. The results obtained in the treatment of 54 patients are also presented.
Subject(s)
Eye Diseases/radiotherapy , Laboratories , Proton Therapy , Radiotherapy, Computer-Assisted/methods , HumansABSTRACT
The therapeutic use of protons and ions, especially carbon ions, is a new technique and a challenge to conform the dose to the target due to the energy deposition characteristics of hadron beams. An appropriate treatment planning system (TPS) is strictly necessary to take full advantage. We developed a TPS software, ANCOD++, for the evaluation of the optimal conformal dose. ANCOD++ is an analytical code using the voxel-scan technique as an active method to deliver the dose to the patient, and provides treatment plans with both proton and carbon ion beams. The iterative algorithm, coded in C++ and running on Unix/Linux platform, allows the determination of the best fluences of the individual beams to obtain an optimal physical dose distribution, delivering a maximum dose to the target volume and a minimum dose to critical structures. The TPS is supported by Monte Carlo simulations with the package GEANT3 to provide the necessary physical lookup tables and verify the optimized treatment plans. Dose verifications done by means of full Monte Carlo simulations show an overall good agreement with the treatment planning calculations. We stress the fact that the purpose of this work is the verification of the physical dose and a next work will be dedicated to the radiobiological evaluation of the equivalent biological dose.
Subject(s)
Heavy Ion Radiotherapy , Radiotherapy Planning, Computer-Assisted , Software , Biophysics , Brain Neoplasms/radiotherapy , Carbon/therapeutic use , Glioblastoma/radiotherapy , Humans , Imaging, Three-Dimensional , Meningioma/radiotherapy , Monte Carlo Method , Orbital Neoplasms/radiotherapy , Programming Languages , Proton Therapy , Tomography, X-Ray Computed/statistics & numerical dataABSTRACT
This study was developed in an attempt to estimate the prevalence of hepatitis B and C virus markers in the sanitary personnel from dentistry clinics which represents a high risk group concerning both contamination and transmission of the infection. The results of the study showed a higher contamination by virus B than virus C. The distribution of contamination depending upon the position held by the staff members revealed a higher contamination incidence among medium level personnel than among high level personnel. The need to initiate this study is due to the high incidence of contamination with hepatitis B virus which calls for the implementation of prophylaxis measures to protect both the medical personnel and the patients.
Subject(s)
Dentistry , Hepatitis B/epidemiology , Hepatitis C/epidemiology , Occupational Exposure , Adult , Female , Hepatitis B/transmission , Hepatitis B Surface Antigens/blood , Hepatitis C/transmission , Hepatitis C Antibodies/blood , Humans , Male , Middle Aged , PrevalenceSubject(s)
Duodenal Ulcer/complications , Peptic Ulcer Hemorrhage/etiology , Peptic Ulcer Perforation/etiology , Pyloric Stenosis/etiology , Duodenal Ulcer/surgery , Emergencies , Hemostasis, Surgical , Humans , Peptic Ulcer Hemorrhage/surgery , Peptic Ulcer Perforation/surgery , Pyloric Stenosis/surgery , RecurrenceABSTRACT
In view of providing hepatic assistance, and for conservation aims in attempts at transplantation conditions have been investigated for achieving extracorporeal normothermal perfusion of the liver isolated from pig and dog. A total of 33 experiments have been performed. The preparations and the devices used allow to apply the method in a patient only after stabilisation of the perfusion, and frees the medical team from a series of technical problems. The duration and the quality of the perfusion are especially influenced by the collecting technique. In the dog the liver should be removed 3--5 hours, and in the pig 7--8 hours before perfusion is started. The functional condition of the liver can be assessed at 45 minutes after the start of the perfusion by evaluating the following criteria: the macroscopic aspect of the liver, the blood flow, the biliary flow, the ascitis fluid, TGP and oxygen consumption. Adequate installations and a permanent involvement of the laboratory team are essential conditions for the application of this method to the treatment of acute severe hepatic failure.
