Simultaneous superficial hyperthermia and external radiotherapy: report of thermal dosimetry and tolerance to treatment
Simultaneous superficial hyperthermia and external radiotherapy: report of thermal dosimetry and tolerance to treatment
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DOI：
10.1080/026567399285639
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发表时间：
1999-07-01
影响因子：
3.1
通讯作者：
Taylor, ME
中科院分区：
文献类型：
--
作者：
Myerson, RJ;Straube, WL;Taylor, ME
背景资料：体外和动物研究表明，如果同时提供辐射（RT）和高温（HT），而不是顺序治疗，则维持41 ℃的中等温度约1小时将提供放射增敏作用。最低肿瘤温度为41摄氏度是一个更可行的目标比目标>42摄氏度所需的顺序treatment.Methods和材料：44例患者47复发浅表癌同时接受外照射放疗和浅表热疗连续IRE批准的I/II期研究。所有病灶既往治疗失败，35例既往接受过放疗（平均剂量52.7戈伊）。使用市售施源器，用915 MHz微波或1-3.5 MHz超声进行热疗。微波治疗的19个病灶的平均尺寸为4.7 x 3.6 x 1.7 cm，超声治疗的28个病灶的平均尺寸为8.0 x 6.1 x 2.9 cm。胸壁15例，头颈部21例。使用多传感器探头在平均六个肿瘤内位置监测温度。中位热疗次数为3次，中位辐射剂量为30戈伊。每部分的辐射剂量为4戈伊与热疗和2戈伊或4戈伊（取决于协议）在非热疗day.Results：六个不同的措施，最低监测温度和持续时间被发现是高度相关的。在41 ℃或以上的最小肿瘤时间（Min t41）和42 ℃的最小肿瘤Sapareto Dewey等效时间（Min teq 42）之间几乎是一一对应的。在四个疗程后，63%的病例在41 ℃下的平均Sapareto Dewey等效时间在所有监测的肿瘤位置超过60分钟。可评价病灶的完全缓解率和部分缓解率分别为21/41（51%）和7/41（17%），与部位（胸壁显示最佳缓解）相关性最好。毒性包括10/47例（21%）缓慢愈合的软组织溃疡，所有病例均愈合，但中位时间为7个月。最重要的预测慢性溃疡的累积辐射剂量>80戈伊和完整的反应treatment.Conclusions：最低肿瘤温度保持兼容的时间在体外与热放射增敏（如果RT和HT是同时交付）是临床上可行的和耐受的广泛的，但浅表病变适合外部应用超声或微波热疗。目前的内部方案正在评估超过四次热疗对整体热剂量分布和毒性的影响。
Background: In vitro and animal studies indicate that a moderate temperature of 41 degrees C maintained for similar to 1 h will provide radiosensitization if radiation (RT) and hyperthermia (HT) are delivered simultaneously, but not with sequential treatment. A minimum tumour temperature of 41 degrees C is a more feasible goal than the goal of >42 degrees C needed for sequential treatment.Methods and materials: Forty-four patients with 47 recurrent superficial cancers received simultaneous external beam radiotherapy and superficial hyperthermia on successive IRE approved phase I/II studies. All lesions had failed previous therapy, 35 were previously irradiated (mean dose 52.7 Gy). Hyperthermia was delivered with 915 MHz microwave or 1-3.5 MHz ultrasound using commercially available applicators. The average dimensions of 19 lesions treated with microwave were 4.7 x 3.6 x 1.7 cm and the average dimensions of 28 lesions treated with ultrasound were 8.0 x 6.1 x 2.9 cm. The most common sites were chest wall (15 cases) and head and neck (21 cases). Temperatures were monitored at an average of six intratumoral locations using multisensor probes. The median number of hyperthermia treatments was three and the median radiation dose 30 Gy. Radiation dose per fraction was 4 Gy with hyperthermia and 2 Gy or 4 Gy (depending on protocol) on non-hyperthermia days.Results: Six different measures of minimum monitored temperature and duration were found to be highly correlated with each other. There was nearly a one-to-one correspondence between minimum tumour time at or above 41 degrees C (Min t41) and minimum tumour Sapareto Dewey equivalent time at 42 degrees C (Min teq42). After four sessions 63% of cases had a per session average Sapareto Dewey equivalent time at 41 degrees C which exceeded 60 min in all monitored tumour locations. The complete and partial response rate in evaluable lesions were respectively 21/41 (51%) and 7/41 (17%) and were best correlated with site (chest wall showing best response). Toxicity consisted of 10/47 (21%) slow healing soft tissue ulcers which healed in all cases but required a median of 7 months. The most important predictors for chronic ulceration were cumulative radiation dose >80 Gy and complete response to treatment.Conclusions: Minimum tumour temperatures maintained for durations compatible in vitro with thermal radiosensitization (if RT and HT are delivered simultaneously) are clinically feasible and tolerable for broad but superficial lesions amenable to externally applied ultrasound or microwave hyperthermia. The current in-house protocol is evaluating the impact of more than four hyperthermia sessions on the overall thermal dose distribution and toxicity.