Comparative study of photodynamic therapy (PDT) of cervical low-grade squamous intraepithelial lesion (LSIL)

Background

Prevention of high-risk HPV (HR-HPV) infection and effective medical intervention of persistent HPV infection and precancerous lesions are critical for the prevention of cervical cancer.

Aims

The aim of this retrospective comparative study was to evaluate the outcomes of ALA PDT and observation only in the management of low-grade squamous intraepithelial lesions (LSIL).

Methods

In PDT Group (n = 138), ALA PDT was applied to patients with colposcopic biopsy confirmed cervical LSIL accompanied with HR-HPV infection longer than 1 year or HPV 16/18 subtype infection. Cervical LSIL only patients received 3 times of ALA PDT and those with concurrent cervical canal or vaginal lesions received 6 times ALA PDT. Control Group (n = 69) received observation only. Colposcopy, TCT and HPV typing were performed before and after treatment. Patients were followed up for up to two years.

Result

The observation group showed 26.1%, 34.8% and 53.6% HR-HPV negative conversion at 3-6, 12 and 24 months, respectively. LSIL regression rate of the observation group was 33.33%, 36.23% and 65.22% at 3-6, 12 and 24 months, respectively. There was 62.32%, 80.56% and 89.22% patients achieved HPV clearance at 3-6, 12 and 24 months after PDT treatment, respectively. The LSIL remission rate was 89.86%, 94.40% and 96.08% at 3-6, 12 and 24 months after ALA PDT, respectively. The abnormal TCT (≧ ASCUS) was reduced from 92% to 10.1%, 4.6% and 3.9% at 3-6, 12 and 24 months after ALA PDT, respectively. The patient age was not a factor affecting the clearance of HPV infection and the LSIL regression rate of PDT treatment.

Conclusions

This study demonstrates that the application of multiple ALA PDT treatments has added value in achieving both short-term and long-term HPV and lesion clearance.