Effect of hyperthermia on the viability and proliferative activity of tumor cells

Introduction. Difficult diagnosis, aggressive progression, and absence of an increase in treatment effectiveness (especially in patients with osteosarcoma and Ewing sarcoma) make malignant tumors of the bones a significant medical problem. Use of traditional therapy methods is often associated with development of drug resistance and frequent recurrences. Therefore, there is a need for new treatment strategies and overcoming of the limitations of traditional methods through their improvement, combination or substitution to achieve higher survival, lower recurrence rate, and wider availability for patients with bone tumors.Aim. To present a clinical observation of the use of a new method of radical intraoperative thermal ablation for bone tumors, assess exposure tolerance, long-term oncological and functional results.Clinical observation. This article presents a clinical case of the use of a new radical treatment method for a patient with tibial osteosarcoma who underwent intraoperative thermal ablation using a new domestic complex of local hyperthermia “Phoenix-2”.Results. A session of intraoperative thermal ablation was performed in the operating room under anesthesia directly in the wound for 48 minutes. Access to the tumor-affected bone was performed with the standard oncological approach (en-block), the bone was not transected or removed. A constant heating mode of 90 °С was used, assuming a gradual increase in temperature. Thus, 60 °С reached 20 minutes, and the temperature at the end of high-temperature exposure was 78 °С (inside the medullary canal). The operation time was 2 hours 30 minutes. The postoperative period proceeded without complications. After 38 months of follow-up, examinations did not reveal any recurrence or progression in the patient.Conclusion. The technique of radical intraoperative thermal ablation using a local hyperthermia complex Phoenix-2 is effective and allows to widen the toolkit of treatment methods for patients with bone tumors. It can serve as an alternative or addition to organ-preserving surgical treatment without costly reconstruction stages.

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Experimental study of the temperature distribution in long tubular bones with a periossal arrangement of heaters

Pakhmurin

Pakhmurina

Anisenya

et al. 2023

Sib. onkol. ž.

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Purpose: to study the changes in the temperature outside and inside the long tubular bones of animals under the influence of different temperature regimes for a given time.Material and Methods. The experiments were conducted using fresh frozen pig long bones. The heating was carried out using surface heaters, the temperature of which was determined by the selected mode for 1 hour; fixation of temperature values was carried out every minute. Four heating modes were used: 3 modes of constant heating (60, 70, 80 °C) and the maximum heating mode, in which no special temperature limit was set, so heating was carried out up to 120 °C.Results. During the first 10 min of heating, a rapid rise in temperature occurred. The temperature increase rate on the outer surface outstripped the temperature increase rate on the inner surface of the bone, thus leading to a significant temperature difference. Further, there was a slowdown in the rate of temperature increase, which led to a gradual convergence of the temperature values inside and outside the bone, followed by temperature stabilization at a stable level (plateau), which was different for the studied areas. During this period, the temperature difference was 3.5–6 °C and it remained at this level until the end of the study. At a constant heating mode (60/70/80 °C), temperature stabilization occurred at the level of 55/61/70 °C in the center of the medullary canal and at the level of 58/67/75 °C under the heater, respectively. The period before reaching the stabilization temperature was 30–40 min. The stable temperature levels both inside and outside the bone were below the temperature stabilization level of the heater. Therefore, to achieve the planned temperature in the center of the bone to its outer surface, it is necessary to apply a high temperature, i.e., a downward temperature gradient is formed: the heater stabilization temperature – the temperature on the outer surface – the temperature inside the medullary canal. Increasing the exposure temperature can shorten the heating period, but increase the temperature difference during the heating period (up to 25 °C in the fifth minute of heating when using the maximum heating mode).Conclusion. To ensure reaching the required temperature (60°C) within a short time (15–20 min) while maintaining optimal temperature parameters, it was proposed to develop variable temperature modes that would combine the initial use of the maximum heating mode until reaching the desired temperature in medullary cavity, followed by switching to a constant temperature mode, which allowed maintaining the achieved temperature level during therapeutic exposure.

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Effect of hyperthermia on the viability and proliferative activity of tumor cells

Cited by 3 publications

References 1 publication

Experimental Basis for Optimal Regimnes of Hyperthermic Peritoneal Chemotherapy

Experimental Basis for Optimal Regimnes of Hyperthermic Peritoneal Chemotherapy

Radical intraoperative thermal ablation of osteogenic sarcoma: clinical observation

Experimental study of the temperature distribution in long tubular bones with a periossal arrangement of heaters

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