Efficacy of 5-aminolevulinic acid and LED photodynamic therapy in cervical intraepithelial neoplasia: A clinical trial

Efficacy and Safety of 5-Aminolevulinic Acid Photodynamic Therapy for Treating Cervical and Vaginal Intraepithelial Neoplasia

Persistent HPV infections may cause cervical and vaginal intraepithelial neoplasia (CIN and VaIN). Traditional methods might destroy the structure and function of the cervix. 5-aminolevulinic acid photodynamic therapy (ALA-PDT) is a non-invasive targeted therapy. This study aims to evaluate the efficacy and safety of ALA-PDT for CIN and VaIN and the clearance of HPV. A retrospective study of 303 patients who confirmed CIN or VaIN and received ALA-PDT was conducted. All the patients were followed up at six and twelve months after treatment and then annually thereafter. The effect was evaluated through HPV genotyping, a cytology test, and colposcopy-directed biopsy if necessary. After ALA-PDT, the remission rates for CIN 2, CIN 3, VaIN 2, and VaIN 3 were 90.6%, 88.5%, 87.3%, and 77.8%. For CIN 1, the remission rate at the six-month follow-up was 93.1%. The total HPV clearance rates were 72.5% at the six-month follow-up and 85.7% at the 12-month follow-up. The most common adverse event was vaginal discharge. No severe adverse effect was observed. ALA-PDT is an effective and safe treatment for all grades of CIN and VaIN and is helpful in clearing HPV with minimal side effects. This treatment may not influence fertility and delivery.

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.

Evaluation of the effectiveness and safety of photodynamic therapy in the treatment of precancerous diseases of the cervix (neoplasia) associated with the human papillomavirus: A systematic review

This study provides an overview of the effectiveness and safety of PDT for the treatment of HPV-associated precancerous cervical conditions and contains recent findings from relevant research studies. A comprehensive literature search of MEDLINE/PubMed, Cochrane Central Library, and Google Scholar was conducted, including analytic epidemiological studies, and 11 papers were included. The narrative synthesis approach was used to summarize the results of the included studies. Studies were critically appraised using The Joanna Briggs Institute (JBI) tool for assessing the risk of bias. The results of the study demonstrate that CRR for HPV remission ranges from 66.7 % to 92.73 %, whereas for CIN1 it fluctuates from 57.1 % to 83.3 %. The frequency of recurrence of the disease ranged from 3.3 % to 8.9 % during the follow-up period of up to 2 years. Adverse events were observed in 8 (66 %) studies and the most common were cervical stenosis, abdominal pain, vaginal pain, and focal edema. Five types of topical and intravenous applications along with lasers of various wavelengths and intensities were mostly used. However, all studies demonstrated relatively similar results. According to the results, PDT has demonstrated favorable outcomes, but no impressive effect on the treatment of CIN. It should be emphasized, that the effectiveness of PDT for the treatment of HPV-associated CIN may vary depending on some variables, including the kind of PDT agent used, the dosage, duration and frequency of PDT administration, the severity and location of the lesions, and the host immunological response.

A comparative study of treatment of cervical low-grade squamous intraepithelial lesions (LSIL)

BACKGROUND AND AIMS

Low-grade squamous intraepithelial lesion (LSIL) is one of two categories of cervical intraepithelial lesions. Given that controversy exists regarding its management, this comparative study aimed to evaluate the effect of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) in treating LSIL of the high-risk human papillomavirus (HR-HPV)-infected cervix.

METHODS

A total of 218 patients (25-45 years old) with cervical LSIL associated with HR-HPV who underwent ALA-PDT, loop electrosurgical excision procedure (LEEP), or observation only were included. The clearance rates of cervical LSIL and HR-HPV between the ALA-PDT, LEEP, and observation groups were compared at 6 and 12 months follow-up. Adverse reactions were also compared. The factors affecting the clearance on ALA-PDT of cervical LSIL were evaluated.

RESULTS

There were no statistically significant differences in lesion and HR-HPV clearance rates between the ALA-PDT and LEEP groups at 6 and 12 months. However, the lesion and HR-HPV clearance rates were significantly higher in the ALA-PDT group than that in the observation group. The adverse reaction rate was significantly lower in the ALA-PDT group than in the LEEP group.

CONCLUSION

For patients with cervical LSIL, the lesion and HR-HPV clearance rates after ALA-PDT were close to those after LEEP and significantly higher than in the observation group. Moreover, the adverse reaction rate for ALA-PDT was much lower than that for LEEP. Therefore, ALA-PDT provides a new option for the minimally invasive treatment of cervical LSIL.

Recent advancement of nanomedicine-based targeted delivery for cervical cancer treatment

Cervical cancer is a huge worldwide health burden, impacting women in impoverished nations in particular. Traditional therapeutic approaches, such as surgery, radiation therapy, and chemotherapy, frequently result in systemic toxicity and ineffectiveness. Nanomedicine has emerged as a viable strategy for targeted delivery of therapeutic drugs to cancer cells while decreasing off-target effects and increasing treatment success in recent years. Nanomedicine for cervical cancer introduces several novel aspects that distinguish it from previous treatment options such as tailored delivery system, precision targeting, combination therapies, real-time monitoring and diverse nanocarriers to overcome the limitations of one another. This abstract presents recent advances in nanomedicine-based tailored delivery systems for the treatment of cervical cancer. Liposomes, polymeric nanoparticles, dendrimers, and carbon nanotubes have all been intensively studied for their ability to transport chemotherapeutic medicines, nucleic acids, and imaging agents to cervical cancer cells. Because of the way these nanocarriers are designed, they may cross biological barriers and preferentially aggregate at the tumor site, boosting medicine concentration and lowering negative effects on healthy tissues. Surface modification of nanocarriers with targeting ligands like antibodies, peptides, or aptamers improves specificity for cancer cells by identifying overexpressed receptors or antigens on the tumor surface. Furthermore, nanomedicine-based techniques have made it possible to co-deliver numerous therapeutic drugs, allowing for synergistic effects and overcoming drug resistance. In preclinical and clinical investigations, combination treatments comprising chemotherapeutic medicines, gene therapy, immunotherapy, and photodynamic therapy have showed encouraging results, opening up new avenues for individualized and multimodal treatment regimens. Furthermore, the inclusion of contrast agents and imaging probes into nanocarrier systems has enabled real-time monitoring and imaging of treatment response. This enables the assessment of therapy efficacy, the early diagnosis of recurrence, and the optimization of treatment regimens.

Unleashing the potential of 5-Aminolevulinic acid: Unveiling a promising target for cancer diagnosis and treatment beyond photodynamic therapy

The therapeutic properties of 5-aminolevulinic acid (5-ALA) have been extensively studied for cancer detection and treatment using photodynamic therapy (PDT). When administered externally, 5-ALA is converted to protoporphyrin IX (PpIX) in cancer cells, which generates reactive oxygen species (ROS) upon exposure to light. This process enables targeted cell death induction and cancer detection. Given the highly conserved nature of heme biosynthesis over billions of years, we hypothesized that natural mechanisms might exist to prevent excessive accumulation of PpIX or heme resulting from 5-ALA overload. Therefore, we anticipated alterations in protein expression profiles upon exogenous administration of 5-ALA. To understand cellular responses to 5-ALA, we investigated protein expression changes and identified OR1B1 as a promising target in bladder, prostate, lung, and cervical cancer cells. OR1B1 expression was observed only with 5-ALA and ferrous chloride, highlighting the central role of heme in this discovery. Immunofluorescence and electron microscopy confirmed OR1B1's sub-cellular localization. These findings suggest that 5-ALA transformation in cancer cells and OR1B1 expression have potential for enhancing cancer detection and developing alternative treatments, including immunotherapy. This approach overcomes the limitations of PDT and opens new avenues for effective and targeted cancer interventions.

A pilot study of repeated 5-aminolevulinic acid photodynamic therapy for cervical intraepithelial neoplasia by a newly developed intravaginal irradiation system

The pilot study was performed to assess the usefulness of a newly developed patientand physician-friendly intravaginal irradiation system for photodynamic therapy with 5-aminolevulinic acid (5-ALA PDT) for cervical intraepithelial neoplasia (CIN). We used an intravaginal balloon applicator to make the cervix upright and to adjust the position and direction of the laser source in the vagina, resulting in minimal patient discomfort and minimal effort required by the physician during irradiation. Ten outpatients of CIN2 or 3 with high-risk human papillomavirus (HPV) infection without a history of HPV vaccination were treated by 5-ALA PDT. Each patient underwent PDT four times every two weeks. Nine patients showed pathological improvement, and the HPV clearance rate was 80%, and no recurrence was observed at two-years follow-up. Serum anti-HPV16 antibodies were detected in seven patients, and the antibody levels of three patients were high, equivalent to those acquired after HPV vaccination. Our newly developed irradiation system enabled easy repeat 5-ALA PDT in the outpatient clinic resulting in the improvement of CIN lesions and HPV clearance. Our results also suggested that repeated 5-ALA PDT might enhance HPV antibody production in CIN patients.

Feasibility study of 5-aminolevulinic acid mediated photodynamic therapy of persistent vaginal high-risk HPV infection of post-hysterectomy patients

BACKGROUND

Patients after hysterectomy are at higher risk for developing VaIN. However, there are no standard treatments for HPV infection and VaIN after hysterectomy and relative studies are limited. Thus we aim to evaluate the feasibility of 5-aminolevulinic acid photodynamic therapy (5-ALA-PDT) for the treatment of persistent vaginal infection with high-risk HPV (HR-HPV) in post-hysterectomy patients.

METHODS

Thirty-eight patients aged 43-70 years old with persistent vaginal stump HR-HPV infection with or without histological vaginal intraepithelial neoplasia (VaIN1) during follow-up after hysterectomy were recruited. Twenty patients received three times of ALA-PDT (PDT Group). Eighteen patients did not receive any treatments (Control Group). HPV testing, cytology, and colposcopy were performed in all patients 4-6 months and 12 months after treatment.

RESULTS

HR-HPV remission rates of the PDT Group were 40% (8/20) and 66.67% (12/18) at the 4-6 month and 12-month follow-up, respectively, both were significantly higher than that of the Control Group (11.11% (2/18) and 6.23% (1/16), respectively; P < 0.05). For the PDT Group, the regression rate of VaIN1 was 100% (7/7) at 4-6 months, while VaIN1 recurred in two cases (28.6%) at the 12-month due to persistent HR-HPV infection. No persistence or progression of VaIN1 was noted. For the Control group, the spontaneous regression rate of VaIN1 was 50% (3/6) at 4-6 months and one patient progressed into VaIN2. At the 12-month follow-up point, one patient reccurred and the disease regression, persistence and recurrence rates were 40% (2/5), 40% (2/5) and 20% (1/5), respectively. Adverse reactions were mild after PDT treatment.

CONCLUSION

5-ALA-PDT is a safe, non-invasive, and effective option for post-hysterectomy patients who have persistent HR-HPV infection.

Efficacy of photodynamic therapy with 5-aminolevulinic acid for the treatment of cervical high-grade squamous intraepithelial lesions with high-risk HPV infection: A retrospective study

BACKGROUND

The current principle of clinical management of cervical high-grade squamous intraepithelial lesion(HSIL) is surgical excision. However excisional procedures of the uterine cervix may have a negative impact on fertility. Topical photodynamic therapy(PDT) is a non-invasive and selective tissue destruction. We investigated the clinical efficacy of PDT for cervical HSIL with high-risk human papilloma virus(HPV) infection.

METHODS

A retrospective study consisting of 96 patients aged 20-50 years with a histologically confirmed cervical HSIL with high-risk HPV infection from July 2018 to June 2022 was carried out. Patients were treated with six times of 20% 5-aminolevulinic acid photodynamic therapy (5-ALA PDT) at intervals of 7-14 days. Three months after treatment, the effect was evaluated through HPV typing and colposcopy directed biopsy. Six and twelve months after treatment, TCT and HPV tests were carried out.

RESULTS

Three months after 5-ALA PDT treatment, among 96 HSIL with high-risk HPV infection patients, the total lesion regression rate was 89.58%(86/96), and the HPV clearance rate was 79.17 % (76/96) at 3 months follow-up. At 6 and 12 months follow-up, the patients who was HSIL pathological regression and negative HPV at 3 months follow-up continued negative results in both TCT and HPV. All patients with ineffective 5-ALA PDT treatment had persistent HPV infections. There was no significant difference in the HSIL regression rate and HPV clearance rate among different age groups. The main side effects of PDT were abdominal pain and increased vaginal secretions. Univariate analysis showed that the different severity of cervical cytology was associated with lesion regression rate in 5-ALA PDT treatment. The HSIL regression rate of TCT<ASC-H was higher than that of TCT≧ASC-H(94.59% vs 72.72%; P<0.01).Multicentric lesions,the proportion of visible lesion size in ectocervical size≥24.59%, size of visible lesion ≥1.23cm² and maximum linear length of visible lesion ≥0.90cm were risk factors of HSIL persistence after 5-ALA PDT treatment (P<0.05).

CONCLUSION

5-ALA PDT can be a safe and efficient treatment for cervical HSIL who wish to preserve fertility. 5-ALA PDT did not appear to create cervical damage and have negligible side effects. But we need evaluate the type of transformation zone, the visible lesion size, the location of lesion,baseline status of TCT and histological results before 5-ALA PDT treatment.

Chinese Expert Consensus on the Clinical Applications of Aminolevulinic Acid-Based Photodynamic Therapy in Female Lower Genital Tract Diseases (2022)

INTRODUCTION

With the younger onset age of female lower genital tract diseases, there are increasing demands for protecting organ and tissue structures to preserve fertility and, therefore, effective fertility-sparing treatments that cause minimal normal tissue damage and less adverse reactions are urgently needed.

OBJECTIVE

This study is aimed at reviewing information and achieving consensus on recommendations on the clinical applications of aminolevulinic acid-based photodynamic therapy (ALA-PDT) in female lower genital tract diseases.

METHODS

Members of the expert panel held online and in-person meetings to discuss and revise drafts created by the steering committee based on the literature review and the clinical experiences of the expert panel. Opinions of the experts were transcribed and discussed in detail to ensure that the consensus statement best reflects the current advances in the field and the experts' view.

RESULTS

After numerous rounds of meetings, experts unanimously agreed on the importance of ALA-PDT in the treatment of cervical squamous intraepithelial lesions (SIL), vaginal SIL, vulvar SIL, vulvar lichen sclerosus (VLS), and condyloma acuminatumon (CA). Experts also reached consensus on the recommended treatment regimen and treatment methods.

CONCLUSION

This consensus aimed to provide practical basis and guidance for the clinical applications of ALA-PDT in female lower genital tract diseases in China. Of note, this is the only expert consensus prepared by board-certified specialists in gynecology and obstetrics in China. More evidence-based clinical studies should be made to update and expand the current recommendations.

The effect of high-risk HPV E6/E7 mRNA on the efficacy of topical photodynamic therapy with 5-aminolevulinic acid for cervical high-grade squamous intraepithelial lesions

BACKGROUND

E6 and E7 high-risk human papillomavirus (HR-HPV) oncoproteins are closely associated with the initiation and progression of cervical cancer (CC) and pre-cancerous lesions. Cervical high-grade squamous intraepithelial lesions (HSIL), as pre-cancerous lesions, have a 5% chance of progressing to invasive cancer. Topical 5-aminolevulinic acid photodynamic therapy (ALA-PDT) is a novel non-invasive targeted therapy for intraepithelial lesions. Herein, we analyzed the effect of HR-HPV E6/E7 mRNA on ALA-PDT for cervical HSIL.

METHODS

A retrospective analysis of 148 HR-HPV-positive patients diagnosed with cervical HSIL and receiving ALA-PDT was carried out. ALA-PDT was performed with 20% ALA thermosensitive gel, and irradiation at wavelength of 635 nm and density of 80-100 J/cm² for 20-30 min. The therapeutic instruments of LED and semiconductor laser were applied for cervical lesions and lesions in endocervical canal, respectively. All patients were tested for HPV E6/E7 mRNA before and after PDT, and then followed up at 3, 6, and 12 months after treatment, and every six months thereafter.

RESULTS

At the 6-month follow up, the complete remission (CR) rate of patients' lesions was 86.5% (128/148), whereas the total HPV clearance rate was 72.3% (107/148). It was evident that positive E6/E7 mRNA before treatment had a significant effect on HPV clearance rate (66.3% VS 81.4%, P=0.045) and CR rate (80.9% VS 94.9%, P=0.015). The E6/E7 mRNA associated with HPV16/18 and HPV16/18 combined with other HR-HPV (HPV16/18 and other HR-HPV) affected HPV clearance (P=0.035) and lesions CR (P=0.039), respectively. Moreover, persistently positive E6/E7 mRNA after treatment was closely associated with poor efficacy (HPV clearance rate: P=0.000, CR rate: P=0.000). Throughout the follow up period, two cases recurred but none of the patients progressed.

CONCLUSIONS

This study has shown that ALA-PDT is an effective, safe, and alternative treatment for cervical HSIL, especially for the patients of childbearing age. However, its efficacy is relatively poor in patients with persistently positive E6/E7 mRNA before and after treatment, who are insensitive to ALA-PDT.

Phototheranostics of Cervical Neoplasms with Chlorin e6 Photosensitizer

Simple Summary

Neoplasms of the cervix are the most common types of oncological pathology. Photodynamic therapy with intravenous administration of the photosensitizer chlorin e6 shows high efficiency in the treatment of precancerous lesions of the cervix with complete eradication of the human papillomavirus. The treatment method can reduce deaths from cervical cancer and preserve fertility in patients. Spectral and video fluorescence diagnostics allows intraoperatively assessing the degree of photosensitizer accumulation and photobleaching and visualizing the boundaries of pathologically altered tissues.

Abstract

(1) Purpose: Improving the treatment effectiveness of intraepithelial neoplasia of the cervix associated with human papillomavirus infection, based on the application of the method of photodynamic therapy with simultaneous laser excitation of fluorescence to clarify the boundaries of cervical neoplasms. (2) Methods: Examination and treatment of 52 patients aged 22 to 53 years with morphologically and cytologically confirmed mild to severe intraepithelial cervix neoplasia, preinvasive, micro-invasive, and squamous cell cervix carcinoma. All patients were carriers of human papillomavirus infection. The patients underwent photodynamic therapy with simultaneous laser excitation of fluorescence. The combined use of video and spectral fluorescence diagnostics for cervical neoplasms made it possible to control the photodynamic therapy process at all stages of the procedure. Evaluation of the photodynamic therapy of intraepithelial cervical neoplasms was carried out with colposcopic examination, cytological conclusion, and morphological verification of the biopsy material after the photodynamic therapy course. The success of human papillomavirus therapy was assessed based on the results of the polymerase chain reaction. (3) Results. The possibility of simultaneous spectral fluorescence diagnostics and photodynamic therapy using a laser source with a wavelength of 660 nm has been established, making it possible to assess the fluorescence index in real-time and control the photobleaching of photosensitizers in the irradiated area. The treatment of all 52 patients was successful after the first photodynamic therapy procedure. According to the PCR test of the discharge from the cervical canal, the previously identified HPV types were not observed in 48 patients. Previously identified HPV types were absent after repeated PDT in four patients (CIN III (n = 2), CIS (n = 2)). In 80.8% of patients, regression of the lesion was noted. (4) Conclusions. The high efficiency of photodynamic therapy with intravenous photosensitizer administration of chlorin e6 has been demonstrated both in relation to eradication therapy of human papillomavirus and in relation to the treatment of intraepithelial lesions of the cervix.

Phthalocyanine and Its Formulations: A Promising Photosensitizer for Cervical Cancer Phototherapy

Cervical cancer is one of the most common causes of cancer-related deaths in women worldwide. Despite advances in current therapies, women with advanced or recurrent disease present poor prognosis. Photodynamic therapy (PDT) has emerged as an effective therapeutic alternative to treat oncological diseases such as cervical cancer. Phthalocyanines (Pcs) are considered good photosensitizers (PS) for PDT, although most of them present high levels of aggregation and are lipophilic. Despite many investigations and encouraging results, Pcs have not been approved as PS for PDT of invasive cervical cancer yet. This review presents an overview on the pathophysiology of cervical cancer and summarizes the most recent developments on the physicochemical properties of Pcs and biological results obtained both in vitro in tumor-bearing mice and in clinical tests reported in the last five years. Current evidence indicates that Pcs have potential as pharmaceutical agents for anti-cervical cancer therapy. The authors firmly believe that Pc-based formulations could emerge as a privileged scaffold for the establishment of lead compounds for PDT against different types of cervical cancer.

Long-term outcomes of photodynamic therapy for a positive resection margin after conization for cervical intraepithelial neoplasia grade 3

BACKGROUND

Positive resection margins after conization or loop electrosurgical excision procedure (conization/LEEP) are associated with increased risks of recurrence or residual cervical intraepithelial neoplasia (CIN). Herein, we investigated the long-term outcomes of photodynamic therapy (PDT) for incomplete excision of CIN3.

METHODS

We retrospectively reviewed the medical charts of 73 patients treated with PDT between 2000 and 2011. Patients who underwent conization/LEEP before PDT within 6 months were included. The primary outcomes were the complete response (CR) rate after 1 year and human papillomavirus (HPV) eradication rate at 6 months after PDT.

RESULTS

A total of 34 patients with positive resection margins were finally enrolled. The median patient age was 33 years. Carcinoma in situ was diagnosed in 25 patients and CIN3 in 7 patients. The CR rate was 97.1% after 1 year. Except for one case of a persistent disease, there was no recurrence or newly developed disease during the median follow-up of 84 months (range, 12-224 months). The HPV eradication rate of PDT following conization/LEEP after 6 months was 96.9% (31/32). Photosensitivity was identified in five patients and cervical stenosis in one patient.

CONCLUSIONS

In conclusion, PDT could be an effective therapeutic option for patients with a positive resection margin after conization/LEEP for CIN3. It could reduce the residual or recurrence rate of CIN lesions with tolerable adverse events.

Efficacy of photodynamic therapy in women with HSIL, LSIL and early stage squamous cervical cancer: a systematic review and meta-analysis

BACKGROUND

We sought to conduct a systematic review and meta-analysis of randomized and non-randomized clinical trials to assess the efficacy of photodynamic therapy (PDT) in cervical epithelial neoplasia (CIN) and early-stage cervical cancer. Additionally, according to the results, we tried to consider which stage of CIN is more sensitive to PDT.

METHODS

A systematic search was conducted using electronic databases including PubMed, ClinicalTrials.gov, the Cochrane Library, and Google Scholar.

INCLUSION CRITERIA

all patients had confirmed low-grade squamous intraepithelial lesion (LSIL), high-grade squamous intraepithelial lesion (HSIL), or an early-stage cervical cancer - the cancer is less than 3 mm deep into the cervix -IA; type of photosensitizer and any type of wavelength.

EXCLUSION CRITERIA

women who were previously treated with PDT; Risk of bias assessment was carried out for each study included in the systematic review using the Cochrane Handbook for Systematic Reviews of Interventions: RoB-2 was used to assess the risk of bias in randomized studies, while ROBINS-I - in non-randomized ones.

RESULTS

We identified 2213 publications, but only 6 met the inclusion criteria and were included in the synthesis. PDT is most effective when patients have CIN 2 or photosensitizer is administered intravenously.

CONCLUSION

Based on our systematic review and meta-analysis, it could be concluded that photodynamic therapy may be a practical approach in CIN (LSIL) regression compared with placebo. Nevertheless, we need more evidence and long-term follow-up to answer all questions thoroughly.

Efficacy and safety of photodynamic therapy mediated by 5-aminolevulinic acid for the treatment of cervical intraepithelial neoplasia 2: A single-center, prospective, cohort study

BACKGROUND

Photodynamic therapy (PDT) mediated by 5-aminolevulinic acid (5-ALA) is a minimally-invasive treatment for cervical intraepithelial neoplasia (CIN). The present study was carried out to investigate the effect of 5-ALA-PDT on CIN2 and the factors influencing outcome of 5-ALA-PDT.

METHODS

Patients diagnosed as CIN2 who met the inclusion criteria were enrolled in this study sequentially from January 2019 to April 2020. Patients were treated by PDT or cryotherapy according to their intentions. The primary endpoint was pathological regression. The secondary endpoint was HPV clearance. Affecting factors of the efficacy of PDT and adverse events were also assessed during treatment.

RESULTS

A total of 210 patients were enrolled, including 97 patients in PDT group and 101 patients in cryotherapy group, with 12 patients excluded. There was no statistical difference in population characteristics. The pathological regression rate in PDT group was 92.0% (80/87), compared with 81.4% (79/97) in cryotherapy group (P < 0.05). The HPV clearance rate was 64.4% (56/87) in PDT group and 57.8% (56/97) in cryotherapy group (P = 0.36). The main side effects of PDT were abdominal pain (24.1%, 21/87) and increased vaginal secretions (23.0%, 20/87). On univariate analysis, the risk for lesions persisting at 6 months after PDT was increased by recurrent genital tract inflammation (P = 0.004), smoking or passive smoking (P = 0.020), and multicentric lesions (P = 0.020).

CONCLUSION

PDT can be a safe and efficient treatment for CIN2. Risk factors for persisting HSIL after PDT include recurrent genital tract inflammation, smoking or passive smoking, and multicentric lesions.

Light delivery device modelling for homogenous irradiation distribution in photodynamic therapy of non-spherical hollow organs

SIGNIFICANCE

Photodynamic therapy (PDT) is a useful treatment for select cancers. Homogeneous illumination is a key factor in the successful application of PDT treatment of tumours in hollow organs. Over illumination may damage normal tissue while under illumination may not ablate the target.

BACKGROUND

There have been many approaches to provide homogeneous irradiation for PDT treatment of hollow organs, including light-scattering medium and isotropic emitter to diffuse light, a balloon filled with solution to expand the organ wall, and shaped fibres. In most studies, the organ is assumed to be spherical. However, many hollow organs treated by PDT are non-spherical, and the uniformity of azimuthal irradiation remains an unsolved problem for cylindrical light sources.

OBJECTIVE

Find a design principle for homogeneous irradiation in a non-spherical cavity for PDT treatment.

METHOD

A PDT light delivery device is modeled by a series of sub light sources placed along the longitudinal axis of an ellipsoid. In order to achieve a homogeneous azimuthal irradiation distribution on the elliptical arc, a cost function is solved by adding modulation coefficient to the emission profile. The coefficient of variation of uniformity (U_cov) describes the statistical dispersion of the variation in irradiation over the ellipsoid to the average value. U_cov is used to evaluate the homogeneity of the azimuthal irradiation distribution.

RESULT

By minimizing the cost function, we found that the truncated Gaussian function can be chosen as the emission profile to generate homogeneous irradiation profile within an ellipsoid cavity model. The emission profile can be tailored to generate U_cov of 96.7 %. Further discussion shows that the light distribution could be generated practically by a side-emitting optical fibre, a LED array, or moving an isotropic emitter successively. The impact of emission angle of light sub-source is analysed and the irradiation profile from discrete longitudinal emissions is calculated.

CONCLUSION

Theory analysis and simulation indicate that a cylindrical emitter with a non-uniform longitudinal emission profile (truncated Gaussian functions) results in an approximate homogeneous irradiance profile within an ellipsoidal cavity.