PDF(Pubmed)
Abstract：
BACKGROUND: Hyperthermia treatment quality is usually evaluated by thermal (dose) parameters, though hyperthermic radiosensitization effects are also influenced by the time interval between the two modalities. This work applies biological modelling for clinical treatment evaluation of cervical cancer patients treated with radiotherapy plus hyperthermia by calculating the equivalent radiation dose (EQDRT, i.e., the dose needed for the same effect with radiation alone). Subsequent analyses evaluate the impact of logistics.
METHODS: Biological treatment evaluation was performed for 58 patients treated with 23-28 fractions of 1.8-2 Gy plus 4-5 weekly hyperthermia sessions. Measured temperatures (T50) and recorded time intervals between the radiotherapy and hyperthermia sessions were used to calculate the EQDRT using an extended linear quadratic (LQ) model with hyperthermic LQ parameters based on extensive experimental data. Next, the impact of a 30-min time interval (optimized logistics) as well as a 4‑h time interval (suboptimal logistics) was evaluated.
RESULTS: Median average measured T50 and recorded time intervals were 41.2 °C (range 39.7-42.5 °C) and 79 min (range 34-125 min), respectively, resulting in a median total dose enhancement (D50) of 5.5 Gy (interquartile range [IQR] 4.0-6.6 Gy). For 30-min time intervals, the enhancement would increase by ~30% to 7.1 Gy (IQR 5.5-8.1 Gy; p < 0.001). In case of 4‑h time intervals, an ~ 40% decrease in dose enhancement could be expected: 3.2 Gy (IQR 2.3-3.8 Gy; p < 0.001). Normal tissue enhancement was negligible (< 0.3 Gy), even for short time intervals.
CONCLUSIONS: Biological treatment evaluation is a useful addition to standard thermal (dose) evaluation of hyperthermia treatments. Optimizing logistics to shorten time intervals seems worthwhile to improve treatment efficacy.
METHODS: Biological treatment evaluation was performed for 58 patients treated with 23-28 fractions of 1.8-2 Gy plus 4-5 weekly hyperthermia sessions. Measured temperatures (T50) and recorded time intervals between the radiotherapy and hyperthermia sessions were used to calculate the EQDRT using an extended linear quadratic (LQ) model with hyperthermic LQ parameters based on extensive experimental data. Next, the impact of a 30-min time interval (optimized logistics) as well as a 4‑h time interval (suboptimal logistics) was evaluated.
RESULTS: Median average measured T50 and recorded time intervals were 41.2 °C (range 39.7-42.5 °C) and 79 min (range 34-125 min), respectively, resulting in a median total dose enhancement (D50) of 5.5 Gy (interquartile range [IQR] 4.0-6.6 Gy). For 30-min time intervals, the enhancement would increase by ~30% to 7.1 Gy (IQR 5.5-8.1 Gy; p < 0.001). In case of 4‑h time intervals, an ~ 40% decrease in dose enhancement could be expected: 3.2 Gy (IQR 2.3-3.8 Gy; p < 0.001). Normal tissue enhancement was negligible (< 0.3 Gy), even for short time intervals.
CONCLUSIONS: Biological treatment evaluation is a useful addition to standard thermal (dose) evaluation of hyperthermia treatments. Optimizing logistics to shorten time intervals seems worthwhile to improve treatment efficacy.
摘要：
背景：热疗治疗质量通常通过热（剂量）参数进行评估，尽管高热放射增敏作用也受两种方式之间的时间间隔的影响。这项工作通过计算等效辐射剂量（EQDRT，即，仅使用辐射即可达到相同效果所需的剂量）。随后的分析评估了物流的影响。
方法：对58例接受23-28分1.8-2Gy治疗的患者进行生物治疗评估，并每周进行4-5次热疗。测量的温度（T50）和记录的放疗和热疗之间的时间间隔用于使用扩展的线性二次（LQ）模型计算EQDRT，该模型具有基于大量实验数据的高温LQ参数。接下来,评估了30分钟时间间隔（优化物流）和4小时时间间隔（次优物流）的影响。
结果：测得的T50和记录的时间间隔的中值平均值为41.2°C（范围39.7-42.5°C）和79分钟（范围34-125分钟），分别,导致5.5Gy（四分位距[IQR]4.0-6.6Gy）的中值总剂量增强（D50）。对于30分钟的时间间隔，增强将增加~30%至7.1Gy(IQR5.5-8.1Gy;p<0.001)。在4小时的时间间隔的情况下，可预期剂量增强降低约40%:3.2Gy(IQR2.3-3.8Gy;p<0.001)。正常组织增强可忽略不计（<0.3Gy），即使是很短的时间间隔。
结论：生物治疗评估是对热疗治疗的标准热（剂量）评估的有用补充。优化后勤以缩短时间间隔似乎值得提高治疗效果。
方法：对58例接受23-28分1.8-2Gy治疗的患者进行生物治疗评估，并每周进行4-5次热疗。测量的温度（T50）和记录的放疗和热疗之间的时间间隔用于使用扩展的线性二次（LQ）模型计算EQDRT，该模型具有基于大量实验数据的高温LQ参数。接下来,评估了30分钟时间间隔（优化物流）和4小时时间间隔（次优物流）的影响。
结果：测得的T50和记录的时间间隔的中值平均值为41.2°C（范围39.7-42.5°C）和79分钟（范围34-125分钟），分别,导致5.5Gy（四分位距[IQR]4.0-6.6Gy）的中值总剂量增强（D50）。对于30分钟的时间间隔，增强将增加~30%至7.1Gy(IQR5.5-8.1Gy;p<0.001)。在4小时的时间间隔的情况下，可预期剂量增强降低约40%:3.2Gy(IQR2.3-3.8Gy;p<0.001)。正常组织增强可忽略不计（<0.3Gy），即使是很短的时间间隔。
结论：生物治疗评估是对热疗治疗的标准热（剂量）评估的有用补充。优化后勤以缩短时间间隔似乎值得提高治疗效果。
