The effect of local photodynamic therapy with 5-aminolevulinic acid in treating different grades of cervical intraepithelial neoplasia

Advances and perspectives in use of semisolid formulations for photodynamic methods

Although nearly 30 years have passed since the introduction of the first clinically approved photosensitizer for photodynamic therapy, progress in developing new pharmaceutical formulations remains unsatisfactory. This review highlights that despite years of research, many recurring challenges and issues remain unresolved. The paper includes an analysis of selected essential studies involving aminolevulinic acid and its derivatives, as well as other photosensitizers with potential for development as medical products. Among various possible vehicles, special attention is given to gelatin, alginates, poly(ethylene oxide), polyacrylic acid, and chitosan. The focus is particularly on infectious and cancerous diseases. Key aspects of developing new semi-solid drug forms should prioritize the creation of easily manufacturable and biocompatible preparations for clinical use. At the same time, new formulations should preserve the primary function of photosensitizers, which is the generation of reactive oxygen species capable of destroying pathogenic cells or tumors. Additionally, the use of adjuvant properties of carriers, which can enhance the effectiveness of macrocycles, is emphasized, especially in chitosan-based antibacterial formulations. Current research indicates that many promising dyes and macrocyclic compounds with high potential as photosensitizers in photodynamic therapy remain unexplored in formulation and development work. This review outlines potential new and previously explored pathways for advancing photosensitizers as active pharmaceutical ingredients (APIs).

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.

5-aminolevulinic acid induced photodynamic reactions in diagnosis and therapy for female lower genital tract diseases

Since the patients suffering from female lower genital tract diseases are getting younger and younger and the human papilloma virus (HPV) infection is becoming more widespread, the novel non-invasive precise modalities of diagnosis and therapy are required to remain structures of the organ and tissue, and fertility as well, by which the less damage to normal tissue and fewer adverse effects are able to be achieved. In all nucleated mammalian cells, 5-Aminolevulinic acid (5-ALA) is an amino acid that occurs spontaneously, which further synthesizes in the heme biosynthetic pathway into protoporphyrin IX (PpIX) as a porphyrin precursor and photosensitizing agent. Exogenous 5-ALA avoids the rate-limiting step in the process, causing PpIX buildup in tumor tissues. This tumor-selective PpIX distribution after 5-ALA application has been used successfully for tumor photodynamic diagnosis (PDD) and photodynamic therapy (PDT). Several ALA-based drugs have been used for ALA-PDD and ALA-PDT in treating many (pre)cancerous diseases, including the female lower genital tract diseases, yet the ALA-induced fluorescent theranostics is needed to be explored further. In this paper, we are going to review the studies of the mechanisms and applications mainly on ALA-mediated photodynamic reactions and its effectiveness in treating female lower genital tract diseases.

Long-term follow-up of photodynamic therapy of cervical intraepithelial neoplasia grade 2 (CIN2)

BACKGROUND

To determine the long-term efficacy and safety of 5-aminolevulinic acid-based photodynamic therapy (ALA-PDT) for treating cervical intraepithelial neoplasia grade 2 (CIN2) as well as the suitability of ALA-PDT in treating of cervical lesions divided into cervical transformation zone type 3.

METHODS

We included 81 patients diagnosed with CIN2 at the Department of Gynecology of the Affiliated Hospital of Qingdao University with data collected between January 2019 and January 2021 following ALA-PDT. Furthermore, we analyzed the superiority of ALA-PDT in fertility preservation among women of childbearing age based on follow-up data from 11 patients with fertility requirements.

RESULTS

Our findings confirmed the long-term efficacy of ALA-PDT for CIN2 treatment, with an overall efficacy of 95.83 % (23/24) at follow-up of 25-36 months. Moreover, the cervical transformation zone type 3 improvement and human papillomavirus (HPV)-negative efficacy were 69.2 % (18/26) and 82.4 % (14/17), respectively. ALA-PDT is recommended for consenting patients with cervical transformation zone type 3. Additionally, women without primary infertility could experience natural pregnancy and full-term birth of more than one baby following ALA-PDT for CIN2 treatment, with a satisfaction rate of ≈100 %.

CONCLUSIONS

ALA-PDT is recommendable for treating high-grade squamous intraepithelial lesions, especially in patients with fertility requirements.

Comparative Study of 5-Aminolevulinic Acid-Mediated Photodynamic Therapy and the Loop Electrosurgical Excision Procedure for the Treatment of Cervical High-Grade Squamous Intraepithelial Lesions

The loop electrosurgical excision procedure (LEEP) is a common treatment for cervical intraepithelial neoplasia (CIN). Photodynamic therapy (PDT) mediated by 5-aminolevulinic acid (ALA) is a non-invasive modality that has been used for treating precancerous diseases and HPV infections. This comparative study evaluated the efficacy and safety of ALA PDT and the LEEP in the treatment of cervical high-grade squamous intraepithelial lesions (HSILs). Patient records were reviewed and HSIL patients with HPV infections (24-51 years old) who underwent PDT or LEEP treatment were selected. Efficacy was analyzed blindly based on HPV-DNA, cytology, and colposcopy-directed biopsy obtained at 6 months after treatment. Treatment-related discomfort and side effects were also analyzed. Cure rates of 88.1% and 70.0% were achieved for the PDT group and LEEP group (p < 0.05), respectively. HPV-negative conversion rates of 81.0% and 62.0% were achieved for the PDT group and LEEP group (p < 0.05), respectively. The overall lesion remission rate of the PDT group was 19% higher than that of the LEEP group. The incidence of side effects was much lower in the PDT group. These results show that ALA PDT is a feasible non-invasive treatment for cervical HSIL.

Successful treatment by a chlorin e6 derivative mediated photodynamic therapy combined holmium laser for cervical and vaginal giant condyloma acuminata and low-grade intraepithelial neoplasia:A case report

Photodynamic therapy (PDT) is proved effective for treating low-grade squamous intraepithelial lesions (LSIL) and condylomata acuminata (CA). 5-Aminolevulinicacid (5-ALA) is the most common applied photosensitizer, but high rate of unbearable pain and relative long incubation time were reported. Here, we report a 27-year-old woman suffering from cervical and vaginal giant CA with LSIL involving the whole right vaginal fornix, cervical surface, and vaginal wall. Holmium yttrium aluminum garnet (Ho: YAG) laser was first applied to remove the giant CA lesions. STBF, a derivative of chlorin e6 (Ce6) was then applied on suspicious lesions as a new photosensitizer for 1 h. Lesions were exposed to LED illumination with a wavelength of 630 nm and light dose of 200-284 J/cm2 for cervical canal and the vaginal surfaces, 100-150 J/cm2 for cervix surface. Vaginal giant CA and LSIL lesions got complete remission at 6-month follow-up. Mild tolerable adverse reactions were observed after STBF-PDT and relieved in 24 h. Thus, the combination of Ho: YAG laser and STBF-PDT may be a novel option for cervical and vaginal giant CA and LSIL, especially for special vaginal fornix areas.

Comparison of 5-ALA-PDT and LEEP of cervical squamous intraepithelial neoplasia (CIN2) with high-risk human papillomavirus infection in childbearing age women: A non-randomized controlled polit study

BACKGROUND

5-Aminolevulinic acid-mediated photodynamic therapy (5-ALA-PDT) is a possible minimally-invasive treatment for high-grade cervical intraepithelial neoplasia (HSIL). The present study was carried out to assess the effect of 5-ALA-PDT and loop electrosurgical excision procedure (LEEP) in cervical squamous intraepithelial neoplasia (CIN2) combined with high-risk human papillomavirus (HR-HPV) infection.

METHODS

In this study, 190 patients with CIN2 and HR-HPV infection were finally included. They were divided into the LEEP Group (n = 116) and PDT Group (n = 74) according to gynecologist's recommendation and patient's willingness. All patients were followed up at 4-6 months and 12 months after treatment, including HPV testing, cytology, and colposcopy examination.

RESULTS

(1) 4-6 months after treatment, the pathological regression rate was 97.30 % (72/74) in the PDT group and 98.28 % (114/116) in the LEEP group (P = 0.952). The HPV clearance rate was 81.08 % (60/74) in the PDT group and 80.17 % (93/116)in the LEEP group (P = 0.877). (2) 12 months after treatment, the pathological regression rate was 93.24 % (69/74) in the PDT group and 96.55 % (112/116) in the LEEP group (P = 0.486). The recurrence rate of CIN2 was 4.05 % (3/74) in the PDT group and 1.72 % (2/116) in the LEEP group (P = 0.608). The HPV clearance rate was 90.54 % (67/74) in the PDT group and 89.66 % (104/116)in the LEEP group (P = 0.843). The reinfection rate of HR-HPV was 5.41 % (4/74) in the PDT group and 1.72 % (2/116) in the LEEP group (P = 0.322). (3) The adverse reactions in the PDT Group were slightly lower than that in the LEEP Group (P = 0.4956), but the incidence of vaginal bleeding in the PDT group was lower than that in the LEEP group during follow-up.

CONCLUSIONS

The effectiveness of 5-ALA-PDT is similar to LEEP for CIN2 with less side effects. Therefore, 5-ALA-PDT, a non-invasive treatment, may be an effective method for CIN2 patients of childbearing age.

Photodynamic therapy of cervical cancer: a scoping review on the efficacy of various molecules

Background

Cervical cancer poses a considerable worldwide health issue, where infection with the human papillomavirus (HPV) plays a vital role as a risk factor. Photodynamic therapy (PDT) is a minimally invasive treatment for HPV-related cervical lesions, which uses photosensitizers and light to selectively destroy abnormal cells.

Objectives

Our objective is to present a comprehensive overview of the different types of molecules employed in PDT to reduce the occurrence and fatality rates associated with cervical cancer.

Design

Scoping review and bibliometric analysis.

Methods

The article explores clinical trials investigating the efficacy of PDT in treating low-grade squamous intraepithelial lesion and high-grade squamous intraepithelial lesion, as well as preclinical approaches utilizing various molecules for PDT in cervical cancer. Furthermore, the article sheds light on potential molecules for PDT enhancement, examining their properties through computer modeling simulations, molecular docking, and assessing their advantages and disadvantages.

Results

Our findings demonstrate that PDT holds promise as a therapeutic approach for treating cervical lesions associated with HPV and cervical cancer. Additionally, we observe that the utilization of diverse dye classes enhances the anticancer effects of PDT.

Conclusion

Among the various molecules employed in PDT, functionalized fullerene exhibits a notable inclination toward overexpressed receptors in cervical cancer cells, making it a potential candidate for intensified use in PDT. However, further research is needed to evaluate its long-term effectiveness and safety.

Additional role of ECC in the detection and treatment of cervical HSIL

Objective

To probe into the additional role of ECC in the detection of cervical HSIL. The primary objective was to risk-stratify HSIL patients according to ECC so as to provide clinical suggestions for subsequent treatment.

Methods

Retrospective analysis of medical records for patients with HSIL. All patients underwent both ECC and cervical biopsy. According to the results of colposcopic targeted biopsy and ECC, the patients were divided into three groups: (1) ECC negative group (those whose colposcopic targeted biopsy indicated HSIL, but ECC indicated LSIL or chronic inflammation); (2) Only the ECC positive group (those whose ECC suggested HSIL, but colposcopic targeted biopsy showed LSIL or chronic inflammation); (3) ECC and biopsy positive group (those whose ECC and targeted biopsy were both HSIL). Chi-square test was used to analyze the differences of lesion residue and biopsy results after LEEP amongst the three groups.

Results

A total of 1,146 medical records were analyzed. The diagnostic accuracy of ECC combined with colposcopic targeted biopsy for HSIL was higher than that of colposcopic biopsy alone (72.43% vs. 67.54%). When ECC indicated HSIL, the coincidence rate of ECC combined with colposcopic targeted biopsy and the histological pathology of LEEP was 86.25%, and the proportion of residual lesions after LEEP was 41.43%. When ECC and targeted biopsy both indicated HSIL, HSIL or worse lesions were confirmed in 90.68% of patients after surgery. Of these, 10.77% were confirmed as cervical invasive carcinoma. Moreover, the positive rate of LEEP resection margin and postoperative ECC in these patients was 43.48%.

Conclusion

ECC can improve the detection rate of cervical HSIL and reduce missed diagnosis. Also ECC can help clinicians predict the proportion of residual lesions after LEEP. This provides the gynecologists with a reference for the need to increase the depth of the procedure and the need to perform ECC for the residual cervical canal.