A Study for Assessing the Efficacy and Safety of Tetrahydrobiopterin in Radiation-Induced Skin Injury

Inclusion Criteria:

1. Age: ≥ 18years old female patients.
2. The subjects of the study were pathologically diagnosed vulvar cancer patients, who needed postoperative supplemental radiotherapy, patients who received radical radiotherapy and chemotherapy (unresectable locally advanced tumors, including some stage II with tumor diameter \> 4 cm or tumor invading vagina, urethra, and anus), and early-stage patients with possible serious postoperative complications or serious complications, where in the option of undergoing a surgery was not appropriate.
3. The Eastern Cooperative Oncology GroupPerformance Status (ECOG PS) score: 0-1.
4. Expected survival ≥12 months.
5. The main organs functioned normally, which meant that they met the following criteria:

1\) Blood routine examination results:

* Hemoglobin (Hb) ≥90g/L. ② Absolute neutrophil count (ANC)≥1.5×109/L. ③ Platelet count (PLT) ≥50×109/L. 2) Biochemical examination results:
* Total bilirubin (TBIL)\<1.5×upper limit of normal (ULN).

  * Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST)\<2.5×ULN,for patients with liver metastasis\<5×ULN.

    ③ Blood urea nitrogen (BUN) and Creatinine ratio (CR) ≤1×ULN or Endogenous creatinine clearance≥50ml/min(by Cockcroft-Gault equation).

    6\. The subjects willingly participated inthe study, signed an informed consent form, were medication-compliant, and cooperated with the follow-ups.

Exclusion Criteria:

1. Patients with hypertension and could not control the blood pressure within the normal range after treating with antihypertensive medications (systolic blood pressure\>140 mmHg and diastolic blood pressure\>90 mmHg).
2. Patients with a history of severe cardiovascular diseases, including myocardial ischemia or myocardial infarction above grade II, poorly controlled arrhythmia (QTc interval ≥470 ms in women), grade III\~IV cardiac insufficiencyaccording to the New York Heart Association (NYHA) standards, orthe left ventricular ejection fraction (LVEF) \< 50%shown by the heart color Doppler ultrasound.
3. Patients with coagulation disorders (international normalized ratio (INR) \>1.5, activated partial thromboplastin time (aPTT) \>1.5 ULN), with bleeding tendency.
4. Patients with a history of psychotropic medication abuse and unable to quit, and patients with mental disorders.
5. Patients participatingin another drug trial.
6. Patients with concomitant diseases that seriously endangered the safety of the patient or affected the completion of the study from the investigators' opinion.
7. Not suitable for enrollment in the investigators' opinion.