Thomsen A. R., Saalmann M. R., Nicolay N. H., Grosu A. L., Vaupel Peter
Department of Radiation Oncology, University Medical Center, University of Freiburg, Freiburg/Breisgau, Germany
German Cancer Consortium (DKTK) Partner Site Freiburg, German Cancer Research Center (DKFZ), Heidelberg, Germany
Efficacy of wIRA immediately followed by hypofractionated radiation in the treatment of locally recurrent breast cancer and other superficial tumors is documented. A prerequisite for the additive and synergistic radiosensitizing properties of hyperthermia is the assessment of resulting temperatures of tumors and normal tissues. To assess the role of hyperthermia in reversing tumor hypoxia through its effects on local blood flow, oxygen profiles in skin, subcutis, and superficial tumors have been additionally assessed during mild hyperthermia (39–43 °C). Upon wIRA-exposure, skin surface temperatures increased from 35 to 41.6 °C within 5–12 min. Maximum temperatures of 42 °C were found in subepidermal regions, with a steady decline in deeper layers reaching 40.1 °C at a depth of 20 mm. Heating was accompanied by increases in tissue oxygen tensions. Effective hyperthermia levels (≥ 39 °C) were established in depths up to 25 mm. Following wIRA exposure, tissue temperatures returned to pretreatment levels within a few minutes, with the decay time depending on tissue depths, while pO values remained on therapeutical levels for 30–60 min postheat, outlasting the period needed for subsequent radiotherapy. Monitoring in the upper dermis layer of skin and recurrent breast cancers confirmed the improved O status during wIRA exposure and outlasted the time needed for subsequent radiotherapy.
有文献记载，在局部复发性乳腺癌和其他浅表肿瘤的治疗中，温室内射频消融（wIRA）后立即进行低分割放疗具有疗效。热疗具有相加和协同的放射增敏特性的一个前提条件是评估肿瘤和正常组织的最终温度。为了评估热疗通过其对局部血流的影响在逆转肿瘤缺氧中的作用，在轻度热疗（39 - 43°C）期间还额外评估了皮肤、皮下组织和浅表肿瘤中的氧分布情况。在进行wIRA照射时，皮肤表面温度在5 - 12分钟内从35°C升高到41.6°C。在表皮下区域发现最高温度为42°C，在更深层温度稳步下降，在20毫米深度处达到40.1°C。加热伴随着组织氧张力的增加。在深度达25毫米处建立了有效的热疗水平（≥39°C）。wIRA照射后，组织温度在几分钟内恢复到预处理水平，衰减时间取决于组织深度，而pO值在热疗后30 - 60分钟内保持在治疗水平，超过了后续放疗所需的时间。对皮肤上层真皮层和复发性乳腺癌的监测证实，在wIRA照射期间氧状态得到改善，且持续时间超过了后续放疗所需的时间。
