Key factors for best control of the systemic leakage during hyperthermic isolated limb perfusion (HILP) in ECC. A critical synthesis of our experience.

The L-PAM-ILP procedures under true hyperthermal regime (41.5-41.8 degrees C) require both close control of the physical parameters of the treatment (temperatures profiles and time duration, artero-venous pressure, perfusate flow rate) and medical rationale (drug, dosage, fractioning, timing). All the above essential procedures must be supported by rigorous methodology, reliable operation of the medical devices and apparatus and real-time monitoring of the treatment parameters. Real-time monitoring is essential for proper trimming and modulation of the parameters during treatment. This paper delineates the technical improvements that we have implemented for drug leakage monitoring and control in the systemic circulation aimed at improving the therapeutic efficacy and at reducing the occurrence of unexpected complications.

Optimal procedure for thermal delivery in hyperthermic/chemotherapeutic treatments in the isolated perfusion of the the limbs.

Isolated locoregional limbs perfusion treatments of various malignancies have demonstrated synergistic efficacy when hyperthermia was associated with chemotherapy. This paper delineates the criteria, the technical provisions and the specifications that have been improved and implemented at our Institution. It is believed that, following the indications offered in this paper, several, apparently still unsolved problems of treatment planning and implementation will be overcome, offering closely controlled and highly reproducible procedures with a significant progress in the feasibility of reliable comparisons of the results among different research centres and in the reduction of the occurrence of controversial results or unexpected complications.

Control of the physical parameters in local electromagnetic hyperthermia.

The evaluation of the clinical results in experimental applications of local electromagnetic hyperthermia requires strict control of the physical parameters of the treatment and adhesion to close medical protocols. Development and application processes in close cooperation between physicians and electromagnetic experts are reported and discussed, on the basis of experimental and theoretical research work. Attention is concentrated on a 434 MHz apparatus, where the fundamental physical limits have been identified and the operating features in the clinical practice have been evaluated. The cases eligible for treatment were chosen according basically to the limitations posed by depth, volume and steep temperature gradients. Several cases are reported mainly in association with radiotherapy. Lines of technical improvement are suggested, mainly based on the development and optimization of lower-frequency applicators.

Exposure of workers to intense RF electric fields that leak from plastic sealers.

This paper presents the results of an environmental investigation in a plastic-ware industry using RF sealers. Environmental measurements have demonstrated the presence of strong electric fields the intensity of which: reaches significant levels from the health-protection point of view only in proximity to the applicators; often exceeds the maximal levels allowed by all standards (including the most permissive) for short duration exposures, especially in the region of the hands. Results of a cross-sectional study on the health of 63 female workers are related to the observed RF exposure. A statistically significant correlation was found to exist between RF exposure and some minor health effects--eye irritation, upper limb paresthesias, and vitreous body disorganization.

A radio-frequency monitor for protection against overexposure from RF heaters.

Extensive investigation on the various potentially polluting RF sources has led to the conclusion that the largest proportion of problems arising from possible RF hazards originates from industrial heating machines (short-wave). In particular, these turn out to require checks due to their intrinsic and induced instabilities. Through the analysis of RF leakage characteristics of these machines, the problem is simplified and the solution is presented in terms of an RF hazard monitor which can be used by non-specialized personnel. The monitor is also suitable for several other types of potentially dangerous apparatus in the medium- and short-wave range.

Measurement of enzymatic activation energy by continuous heating with microwaves.

A microwave heating method and an associated numerical method for computing the reaction velocities in a single experiment are proposed for rapid determination of the activation energy of enzymatic reactions. Application of this new technique to different enzymatic reactions is reported.

Analysis of the effects of microwave energy on enzymatic activity of lactate dehydrogenase (LDH).

Interactions between microwave energy (3 GHz) and the enzyme Lactate Dehydrogenase (LDH) have been analyzed by monitoring the enzymatic activity during irradiation in steady-state or dynamic conditions, by irradiating the sample with variable power levels (up to 6 W into the sample) and, finally, by knowing accurately the true specific absorption rate. No permanent or temporary changes can be induced when the energy absorption does not cause a temperature variation. For higher energy values, effects are purely thermal in nature. Furthermore the thermal activation of the reaction velocity, caused by microwave irradiation, is in itself sufficient to give a good fit with the experimental time evolution of the enzymatic reaction.