Tyrrell Jessica, Paterson Cheryl, Curnow Alison
European Centre for Environment and Human Health, University of Exeter Medical School, University of Exeter, Knowledge Spa, Royal Cornwall Hospital, Truro, Cornwall TR1 3HD, UK.
Cancers (Basel). 2019 Jan 10;11(1):72. doi: 10.3390/cancers11010072.
Photodynamic therapy (PDT) is a light activated drug therapy that can be used to treat a number of dermatological cancers and precancers. Improvement of efficacy is required to widen its application. Clinical protoporphyrin IX (PpIX) fluorescence data were obtained using a pre-validated, non-invasive imaging system during routine methyl aminolevulinate (MAL)-PDT treatment of 172 patients with licensed dermatological indications (37.2% actinic keratosis, 27.3% superficial basal cell carcinoma and 35.5% Bowen's disease). Linear and logistic regressions were employed to model any relationships between variables that may have affected PpIX accumulation and/or PpIX photobleaching during irradiation and thus clinical outcome at three months. Patient age was found to be associated with lower PpIX accumulation/photobleaching, however only a reduction in PpIX photobleaching appeared to consistently adversely affect treatment efficacy. Clinical clearance was reduced in lesions located on the limbs, hands and feet with lower PpIX accumulation and subsequent photobleaching adversely affecting the outcome achieved. If air cooling pain relief was employed during light irradiation, PpIX photobleaching was lower and this resulted in an approximate three-fold reduction in the likelihood of achieving clinical clearance. PpIX photobleaching during the first treatment was concluded to be an excellent predictor of clinical outcome across all lesion types.
光动力疗法（PDT）是一种光激活药物疗法，可用于治疗多种皮肤癌和癌前病变。需要提高其疗效以扩大其应用范围。在对172例有许可皮肤适应症的患者（37.2%为光化性角化病，27.3%为浅表基底细胞癌，35.5%为鲍恩病）进行常规甲基氨基酮戊酸（MAL）-PDT治疗期间，使用经过预先验证的非侵入性成像系统获取临床原卟啉IX（PpIX）荧光数据。采用线性回归和逻辑回归对可能影响照射期间PpIX积累和/或PpIX光漂白从而影响三个月临床结果的变量之间的任何关系进行建模。发现患者年龄与较低的PpIX积累/光漂白有关，然而，似乎只有PpIX光漂白的降低会持续对治疗效果产生不利影响。四肢、手和脚上的病变临床清除率降低，较低的PpIX积累和随后的光漂白对所取得的结果产生不利影响。如果在光照射期间采用空气冷却止痛，PpIX光漂白较低，这导致实现临床清除的可能性降低约三倍。得出结论，首次治疗期间的PpIX光漂白是所有病变类型临床结果的良好预测指标。
