Blant S A, Woodtli A, Wagnières G, Fontolliet C, van den Bergh H, Monnier P
Department of Otolaryngology Head and Neck Surgery, CHUV Hospital, Lausanne, Switzerland.
Photochem Photobiol. 1996 Dec;64(6):963-8. doi: 10.1111/j.1751-1097.1996.tb01862.x.
Several parameters affect clinical trials in photodynamic therapy and influence the therapeutic outcome. Beside drug dose, light dose, drug-light interval and other variables, the fluence rate is a parameter that can influence the therapeutic results. In this study we have evaluated the fluence rate effect with a second-generation photosensitizer, tetra(m-hydroxyphenyl)chlorin (mTHPC) using a 7,12-dimethylbenz(a)anthracene induced early squamous cell carcinoma of the Syrian hamster cheek pouch as a tumor model. Following injection of 0.5 mg/kg of mTHPC, irradiation tests were performed at two drug-light intervals, 4 and 8 days. Wavelength and light dose were adapted from those applied routinely in clinical trials. Irradiations at 652 nm were carried out with fluences ranging from 8 to 20 J/cm2 delivered at fluence rates of 15 and 150 mW/cm2. Similar tests were also performed at 514 nm with a fluence of 80 J/cm2 delivered at fluence rates ranging from 25 to 125 mW/cm2. At both wavelengths and drug-light intervals for a given fluence, the higher fluence rates resulted in less tissue damage in tumor and healthy mucosae. However, the lower fluence rates yielded slightly less therapeutic selectivity. This study confirms that the fluence rate is of major importance in clinical PDT.
有几个参数会影响光动力疗法的临床试验并影响治疗结果。除了药物剂量、光剂量、药物 - 光间隔和其他变量外，能量通量率也是一个会影响治疗结果的参数。在本研究中，我们使用7,12 - 二甲基苯并(a)蒽诱导的叙利亚仓鼠颊囊早期鳞状细胞癌作为肿瘤模型，评估了第二代光敏剂四(间 - 羟基苯基)氯卟啉(mTHPC)的能量通量率效应。注射0.5 mg/kg的mTHPC后，在4天和8天这两个药物 - 光间隔进行照射测试。波长和光剂量采用临床试验中常规应用的参数。在652 nm处以15和150 mW/cm²的能量通量率进行8至20 J/cm²的照射。在514 nm处也进行了类似测试，以25至125 mW/cm²的能量通量率进行80 J/cm²的照射。在给定通量下的两个波长和药物 - 光间隔中，较高的能量通量率导致肿瘤和健康黏膜中的组织损伤较小。然而，较低的能量通量率产生的治疗选择性略低。本研究证实能量通量率在临床光动力疗法中至关重要。
