A Study to Evaluate the Efficacy and Safety of Radion™-Pdt in Patients With Oral Precancerous Lesion

Inclusion Criteria: 1. Patients aged ≥20 years old; 2. Patient with oral verrucous hyperplasia (OVH) or oral erythroleukoplakia (OEL) lesions with histological evidence of oral precancerous lesions. Besides, patients should have at least one lesion whose size should not exceed 4 cm in the greatest diameter and the distance between two lesions should not less than 1 cm. 3. Patient who is willing and able to comply with study procedures and sign informed consent Exclusion Criteria: 1. Patients with history of hypersensitivity to any photosensitizer (including 5-aminolevulinic acid HCl or porphyrins), acute or chronic types of porphyria; 2. Record of previous unsuccessful treatment with photodynamic therapy; 3. Patients who have been diagnosed as having oral cancer or carcinoma in situ; 4. Patients who have a history or evidence of a medical condition that would expose them to an undue risk of a significant adverse event during the course of the trial, including but not limited to hepatic, renal, respiratory, cardiovascular, endocrine, immune, neurological, hematological, gastrointestinal or psychiatric disease as determined by the clinical judgment of the investigator; 5. Patients with impaired hepatic function (defined as AST and/or ALT \> 2× the upper limit of normal values), and/or impaired renal function (defined as serum creatinine \> 1.5 mg/dL); 6. Female patient of childbearing potential who: * is lactating; or * has positive urine pregnancy test at visit -1; or * refuses to adopt reliable method of contraception during the study; 7. Patient has received any other investigational agent within 28 days or 5 half-lives, whichever is longer, prior to the first photodynamic therapy; 8. Patient has a history of illegal substance abuse, drug addiction or alcoholism within 24 weeks prior to the study.