Localization and staging of cervical intraepithelial neoplasia using double ratio fluorescence imaging

Comparative study of topical 5-aminolevulinic acid photodynamic therapy and surgery for the treatment of vulvar squamous intraepithelial lesion

BACKGROUND

Vulvar squamous intraepithelial lesion (SIL) is a precursor lesion of vulvar squamous cell carcinoma. The current clinical treatments for vulvar SIL cause damage to the vulvar structure, chronic pain and psychological distress. Topical 5-aminolevulinic acid photodynamic therapy (ALA-PDT) is a novel, non-invasive therapy for intraepithelial lesions. The objective of this study was to compare the clinical efficacy and safety of ALA-PDT with local surgical resection for vulvar SIL.

METHODS

A total of 56 patients with vulvar SIL were enrolled in this retrospective study. Among them, 16 patients received local resection and 40 patients received ALA-PDT. HPV genotyping and ThinPrep cytologic test (TCT) were used to evaluate treatment efficacy. In addition, colposcopy-directed biopsy was performed in all patients at 3-month follow-up and in patients with positive high-risk human papillomavirus (HR-HPV) and/or abnormal TCT results during the follow-up.

RESULTS

At 3-month follow-up and in HSIL group the complete remission (CR) rate of the ALA-PDT group and surgery group was 90.6% (29/32) and 87.5% (14/16) (P = 1.000), respectively. The HPV clearance rate of the ALA-PDT group and surgery group was 45.2% (14/31) and 43.8% (7/16) (P = 0.927), respectively. The average numbers of ALA-PDT treatments were 5.34 for HSIL patients and 4.88 for LSIL patients, respectively. The CR rate of HSIL patients and LSIL patients was 90.6% (29/32) and 75.0% (6/8) (P = 0.550), respectively. The HPV clearance rate of HSIL patients and LSIL patients was 45.2% (14/31) and 37.5% (3/8) (P = 1.000), respectively. The ALA-PDT group showed similar clinical efficacy and milder adverse effects compared with the surgical group.

CONCLUSION

ALA-PDT showed similar clinical efficacy as surgery in the treatment of vulvar SIL, but with milder adverse effects and maintaining the integrity of the vulvar structure.

The Effect of Local Photodynamic Therapy with 5-aminolevulinic acid in the Treatment of Vaginal Intraepithelial Lesions with High-Risk HPV Infection

BACKGROUND

Recent data has shown increased rate of vaginal intraepithelial neoplasia (VAIN) in younger individuals. Traditional VAIN treatments exert adverse effects on the anatomy and functions of the vaginas. Topical 5-aminolevulinic acid photodynamic therapy (ALA-PDT) is a novel, non-invasive targeted therapy for intraepithelial lesions. Here, we aimed to investigate the efficacy and safety of ALA-PDT in VAIN with high-risk HPV (HR-HPV) infection.

METHODS

This study enrolled a total of 82 HR-HPV-positive women diagnosed with VAIN, who were receiving ALA-PDT. The effect of ALA-PDT was evaluated using HPV genotyping and Thinprep cytologic test (TCT). Besides, colposcopy directed biopsies were performed in all patients at 3-month follow-up, and in patients with positive HR-HPV and/or abnormal TCT results during the follow-up period.

RESULTS

Our data showed that the HPV clearance rate was 53.7% (44/82) at 6-month follow-up and 67.1% (55/82) at 12-month follow-up. Patients with HPV16/18 combined with other HR-HPV (HPV16/18 & other HR-HPV) infection, those with a history of hysterectomy and/or older age were had significantly lower HPV clearance rate. Besides, the lesion complete remission (CR) rate was 90.2% (74/82). These results show that HPV16/18 & other HR-HPV infection was associated with significantly lower CR rates. Throughout the follow-up, 2 cases had persistent lesions (2.4%), 6 cases had partial remission (7.3%), 2 cases recurred (2.7%) but none of the patients had disease progression.

CONCLUSIONS

Taken together, our data showed that ALA-PDT is an effective, safe, and alternative treatment for VAIN patients with HR-HPV infection. However, the ALA-PDT efficacy was relatively poor in patients with older age, HPV16/18 & other HR-HPV infection and/or those with a history of hysterectomy.

Effectiveness of photodynamic therapy with 5-aminolevulinic acid on HPV clearance in women without cervical lesions

BACKGROUND

High-risk HPV (hrHPV) not only increases the risk of cervical precancerous lesions and cervical cancer, but also adds psychological burden to HPV-positive women. 5-aminolevulinic acid photodynamic therapy (ALA-PDT) is a non-invasive and highly tissue-selective therapy. We aim to investigate the clinical efficacy of ALA-PDT for elimination of cervical hrHPV infection in HPV-positive women without cervical lesions.

METHODS

A total of 57 hrHPV-positive women without pathologically proved cervical lesions received three treatments of ALA-PDT in total. HPV DNA testing and pap cytology were performed in all patients. Patients with positive HPV16/18 or abnormal TCT results received colposcopic biopsy during the follow-up.

RESULTS

hrHPV clearance rate was 56.1 % (32/57) at 3-month follow-up and 68.1 % at 6-month follow-up. 100 % of HPV 18 and 87.5 % of HPV16 infections were cleared while the clearance rate was 48.8 % among those positive for 12 other high-risk types. Multivariate analysis showed HPV16/18 infection was associated with significantly higher clearance rate. HPV clearance rate in patients with multiple-type HPV infection was significantly lower than that in patients with single-type HPV infections.

CONCLUSIONS

ALA-PDT is effective on treating hrHPV infection in patients with no cervical lesions. HPV16/18 positive cases can benefit most from ALA-PDT. Multitype-infected women need more sessions of 5- ALA-PDT to eradicate hrHPV infection.

5-aminolevulinic-acid-based fluorescence spectroscopy and conventional colposcopy for in vivo detection of cervical pre-malignancy

Background

Sensitized fluorescence diagnostics are based on selective accumulation of photosensitizer in the tissue where carcinogenesis has started. The present study compared topical 5-aminolevulinic acid (5-ALA)-based fluorescence spectroscopy (FS) in vivo with conventional colposcopy for cervical intraepithelial neoplasia (CIN) detection.

Methods

We enrolled 48 patients who were referred for colposcopy because of high-grade changes in cervical cytology. Every inspected cervix was divided in to quadrants, and there were 174 quadrants included in the study. Each patient had a cytological smear, colposcopy, FS and histopathological analysis. For FS, 3% 5-ALA cream was used topically and after an average 135 min incubation, fluorescence spectra were recorded from the cervix in vivo. FS and colposcopy results were correlated with histopathology.

Results

All spectra were evaluated by a ratio of the protoporphyrin IX fluorescence intensity at 634 nm and autofluorescence intensity at 510 nm. For proper grouping of low-risk and high-risk cases, a threshold of 3.87 was calculated. Data per quadrant showed that FS had higher sensitivity than colposcopy (71.7% vs 67.4%) but specificity was greater for colposcopy (86.6% vs 75.6%). Combination of the methods showed higher sensitivity (88.0% vs 67.4%) but reduced specificity (88.0% and 69.5%), but it had the highest number of correctly identified high-risk changes and the highest (79.3%) accuracy. Data for each patient showed FS sensitivity of 91.2%, which was greater than for colposcopy (88.2%). Higher overdiagnosis resulted in decreased specificity for fluorescence methodology—71.4% versus 78.6% for colposcopy. In both cases, accuracy was 85.4% and effectiveness was >80%, which means that both methods can be used to determine high-risk cervical intraepithelial neoplasia. The diagnostic sensitivity of 97.1% for this complementary diagnosis indicates that it could be the best choice for detection of high-risk changes.

Conclusions

5-ALA-based FS is an objective method, requiring short-term administration for appropriate fluorescence measurements. FS is a promising diagnostic tool with similar accuracy as colposcopy but with the potential advantage of providing objective results.

Adjunctive colposcopy technologies for examination of the uterine cervix--DySIS, LuViva Advanced Cervical Scan and Niris Imaging System: a systematic review and economic evaluation

BACKGROUND

Women in England (aged 25-64 years) are invited for cervical screening every 3-5 years to assess for cervical intraepithelial neoplasia (CIN) or cancer. CIN is a term describing abnormal changes in the cells of the cervix, ranging from CIN1 to CIN3, which is precancerous. Colposcopy is used to visualise the cervix. Three adjunctive colposcopy technologies for examination of the cervix have been included in this assessment: Dynamic Spectral Imaging System (DySIS), the LuViva Advanced Cervical Scan and the Niris Imaging System.

OBJECTIVE

To determine the clinical effectiveness and cost-effectiveness of adjunctive colposcopy technologies for examination of the uterine cervix for patients referred for colposcopy through the NHS Cervical Screening Programme.

DATA SOURCES

Sixteen electronic databases [Allied and Complementary Medicine Database (AMED), BIOSIS Previews, Cochrane Database of Systematic Reviews (CDSR), Cochrane Central Register of Controlled Trials (CENTRAL), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Database of Abstracts of Reviews of Effects (DARE), EMBASE, Health Management Information Consortium (HMIC), Health Technology Assessment (HTA) database; Inspec, Inside Conferences, MEDLINE, NHS Economic Evaluation Database (NHS EED), PASCAL, Science Citation Index Expanded (SCIE) and Science Citation Index (SCI) - Conference Proceedings], and two clinical trial registries [ClinicalTrials.gov and Current Controlled Trials (CCT)] were searched to September-October 2011.

REVIEW METHODS

Studies comparing DySIS, LuViva or Niris with conventional colposcopy were sought; a narrative synthesis was undertaken. A decision-analytic model was developed, which measured outcomes in terms of quality-adjusted life-years (QALYs) and costs were evaluated from the perspective of the NHS and Personal Social Services with a time horizon of 50 years.

RESULTS

Six studies were included: two studies of DySIS, one study of LuViva and three studies of Niris. The DySIS studies were well reported and had a low risk of bias; they found higher sensitivity with DySIS (both the DySISmap alone and in combination with colposcopy) than colposcopy alone for identifying CIN2+ disease, although specificity was lower with DySIS. The studies of LuViva and Niris were poorly reported and had limitations, which indicated that their results were subject to a high risk of bias; the results of these studies cannot be considered reliable. The base-case cost-effectiveness analysis suggests that both DySIS treatment options are less costly and more effective than colposcopy alone in the overall weighted population; these results were robust to the ranges tested in the sensitivity analysis. DySISmap alone was more costly and more effective in several of the referral groups but the incremental cost-effectiveness ratio (ICER) was never higher than £1687 per QALY. DySIS plus colposcopy was less costly and more effective in all reasons for referral. Only indicative analyses were carried out on Niris and LuViva and no conclusions could be made on their cost-effectiveness.

LIMITATIONS

The assessment is limited by the available evidence on the new technologies, natural history of the disease area and current treatment patterns.

CONCLUSIONS

DySIS, particularly in combination with colposcopy, has higher sensitivity than colposcopy alone. There is no reliable evidence on the clinical effectiveness of LuViva and Niris. DySIS plus colposcopy appears to be less costly and more effective than both the DySISmap alone and colposcopy alone; these results were robust to the sensitivity analyses undertaken. Given the lack of reliable evidence on LuViva and Niris, no conclusions on their potential cost-effectiveness can be drawn. There is some uncertainty about how generalisable these findings will be to the population of women referred for colposcopy in the future, owing to the introduction of the human papillomavirus (HPV) triage test and uptake of the HPV vaccine.

The combination treatment using CO₂ laser and photodynamic therapy for HIV seropositive men with intraanal warts

BACKGROUND

We evaluate the effectiveness of combination treatment using photodynamic therapy after carbon dioxide laser in preventing the recurrence of condylomata acuminata for intraanal warts in HIV positive homosexual men. A retrospective survey of 41 patients referred to the STD clinic of the Fourth People's Hospital of Shenzhen for the treatment of intraanal warts among HIV positive homosexual men between Janurary 2009 and September 2011.

METHODS

The patients who accepted CO₂ laser monotherapy for the same diagnosis were used as the comparison group. After the confirmation of the diagnosis of HIV infection and intraanal warts, the patients were treated with the combination treatment using PDT with 5-ALA thermal gel immediately after CO₂ laser ablation of the warts. PDT was performed with irradiation of 100 J/cm² at an irradiance of 100-150 mW/cm² with a semiconductor laser, wavelength 635 nm. PDT therapy was repeated twice with 2 weekly intervals. Follow up examinations including an anoscopy every 4 weeks after the latest PDT.

RESULTS

After 3 cycles of PDT treatments, 39 cases of anoscopy examination showed no new or recurrent lesions. At the end of the sixth months, recurrence occurred in 12(29%) cases. HPV 11 was present in 6 (50%) of these recurrences. HPV 6/11 or 16/18 remains positive in 19 cases (46.3%) and HPV negative in 22 cases.

CONCLUSIONS

The combination treatment with CO₂ laser and PDT is much more effective in reducing the treatment cycles and the time intervals of the whole treatment for intraanal warts in HIV infected people.

Liposomes in topical photodynamic therapy

INTRODUCTION

Topical photodynamic therapy (PDT) refers to topical application of a photosensitizer onto the site of skin disease which is followed by illumination and results in death of selected cells. The main problem in topical PDT is insufficient penetration of the photosensitizer into the skin, which limits its use to superficial skin lesions. In order to overcome this problem, recent studies tested liposomes as delivery systems for photosensitizers.

AREAS COVERED

This paper reviews the use of different types of liposomes for encapsulating photosensitizers for topical PDT. Liposomes should enhance the photosensitizers' penetration into the skin, while decreasing its absorption into systemic circulation. Only few photosensitizers have currently been encapsulated in liposomes for topical PDT: 5-aminolevulinic acid (5-ALA), temoporfin (mTHPC) and methylene blue.

EXPERT OPINION

Investigated liposomes enhanced the skin penetration of 5-ALA and mTHPC, reduced their systemic absorption and reduced their cytotoxicity compared with free drugs. Their high tissue penetration should enable the treatment of deep and hyperkeratotic skin lesions, which is the main goal of using liposomes. However, liposomes still do not attract enough attention as drug carriers in topical PDT. In vivo studies of their therapeutic effectiveness are needed in order to obtain enough evidence for their potential clinical use as carriers for photosensitizers in topical PDT.

Successful photodynamic therapy with topical 5-aminolevulinic acid for five cases of cervical intraepithelial neoplasia

OBJECTIVES

Photodynamic therapy (PDT) is a minimally invasive treatment for cervical intraepithelial neoplasia. The purpose of this study was to assess the feasibility and effectiveness of PDT in patients with CIN and high-risk HPV infection.

METHODS

Five patients diagnosed CIN 2 or CIN 3 with human papillomavirus (HPV) infection were included. Each patient had gynecologic examination including cervical cytology, HPV DNA testing, colposcopy and biopsy. Two grams of 5-aminolevulinic acid (ALA) gel (118 mg/g) was topically applied to the cervix and covered with a special plastic cap for 3-4 h, followed by 20 min illumination of both ecto- and endo-cervical canal with red coherent light (wavelength 633 nm) using a PDT laser and a special light catheter. The PDT therapy was repeated with an interval of 1 week. Follow-up examination including biopsy and histology, colposcopy, HPV DNA testing were carried out after 3, 6 and 9 months.

RESULTS

Treatment could be accomplished in all cases and no severe side effect was encountered. All the CIN2 patients had a complete response for 9 months and one CIN3 HPV remained positive for 6 months after three or four treatments.

CONCLUSION

PDT seems to be a non-invasive, repeatable procedure for CIN and cervical HPV infection with minimal side effects and can be easily performed on outpatient basis.

In vivo quantification of fluorescent molecular markers in real-time by ratio imaging for diagnostic screening and image-guided surgery

Future applications of "molecular diagnostic screening" and "molecular image-guided surgery" will demand images of molecular markers with high resolution and high throughput (~ > or =30 frames/second). MRI, SPECT, PET, optical fluorescence tomography, hyper-spectral fluorescence imaging, and bioluminescence imaging do not offer such high frame rates. 2D optical fluorescence imaging can provide surface images with high resolution and high throughput. The ability to accurately quantify the fluorescence in vivo is critical to extract functional information of the disease state, however few methods are available. Here, a ratiometric 2D quantification method is introduced. Through mathematical modeling the performance was evaluated using optical properties that resembled biological tissues with the fluorescent marker Protoporhyrin IX. Experimentally the performance was evaluated in optical phantoms with different optical properties employing a novel prototype clinical imaging system. The clinical feasibility of real-time, image-guided surgery was demonstrated in patients undergoing prostatectomy. Discussed are the reasons why the introduced method leads to an increased quantification performance followed by modifications so it can be applied to novel fluorescent molecular markers as phthalocyanine 4 and dual-fluorescent markers. These offer additional advantages as these can provide a linear response to marker concentration and further minimize the dependence on autofluorescence and optical properties, as demonstrated through modeling.

Evaluation of BCECF fluorescence ratio imaging to properly measure gastric intramucosal pH variations in vivo

Our purpose is to evaluate intramucosal gastric pH video imaging by 2('),7(')-bis(carboxyethyl)-5,6-carboxyfluorescein (BCECF) fluorescence ratio techniques. We use a video endoscopic imaging system and BCECF as the pH fluorescent probe. Systemic in vivo pH variations are studied in 10 pigs: five in the control group and five with respiratory acidosis induced through rebreathing. The intramucosal pH of the gastric wall is measured every 5 s and the results demonstrate a good correlation (pearson correlation=0.832) between blood gases pH measurements and pH measured with the video endocopic imaging system. Our results confirm the feasibility of using BCECF fluorescence pH imaging to measure intramucosal pH in vivo.

Early neoplastic and metastatic mammary tumours of transgenic mice detected by 5-aminolevulinic acid-stimulated protoporphyrin IX accumulation

A photodynamic technique for human breast cancer detection founded upon the ability of tumour cells to rapidly accumulate the fluorescent product protoporphyrin IX (PpIX) has been applied to transgenic mouse models of mammary tumorigenesis. A major goal of this investigation was to determine whether mouse mammary tumours are reliable models of human disease in terms of PpIX accumulation, for future mechanistic and therapeutic studies. The haeme substrate 5-aminolevulinic acid (5-ALA) (200 mg kg⁻¹) was administered to mouse strains that develop mammary tumours of various histological subtypes upon expression of the transgenic oncogenes HRAS, Polyoma Virus middle T antigen, or Simian Virus 40 large T antigen in the mammary gland. Early neoplastic lesions, primary tumours and metastases showed consistent and rapid PpIX accumulation compared to the normal surrounding tissues, as evidenced by red fluorescence (635 nm) when the tumours were directly illuminated with blue light (380–440 nm). Detection of mouse mammary tumours at the stage of ductal carcinomain situ by red fluorescence emissions suggests that enhanced PpIX synthesis is a good marker for early tumorigenic processes in the mammary gland. We propose the mouse models provide an ideal experimental system for further investigation of the early diagnostic and therapeutic potential of 5-ALA-stimulated PpIX accumulation in human breast cancer patients.

The status of in vivo autofluorescence spectroscopy and imaging for oral oncology

Autofluorescence spectroscopy and imaging have been studied for the early detection and classification of (pre)malignancies of the oral mucosa. In the present review we will give an overview of the literature on autofluorescence imaging and spectroscopy for various clinical questions. From the studies performed so far we hope to conclude whether autofluorescence spectroscopy and imaging are helpful in the diagnosis of lesions of the oral mucosa, and if this is the case: for which clinical questions they are suitable. A strong emphasis is put on in vivo human studies of the oral mucosa.

Fluorescence spectroscopy accurately detects irreversible cell damage during hepatic radiofrequency ablation

BACKGROUND

A current limitation of hepatic radiofrequency ablation (RFA) is an inability to detect ablation margins in real time. Thermal injury from RFA alters the biochemical properties governing tissue fluorescence. We hypothesized that the changes in hepatic fluorescence measured during hepatic RFA could be used to detect irreversible hepatocyte damage accurately and to determine ablation margins in real time.

METHODS

RFA was performed on healthy pig livers and monitored in vivo simultaneously for fluorescence and temperature by a fiberoptic micro-interrogation probe connected to a spectroscopy system. Ablations were stopped based on previously established real-time fluorescence spectral data, not based on temperature or time. To determine where in the ablated tissue cell death occurred, biopsies for transmission electron microscopy were taken from 4 areas of 3 specimens: (1) nonablated liver, (2) hemorrhagic zone/normal liver interface, (3) hemorrhagic zone/coagulated zone interface, and (4) coagulated zone. In vitro fluorescence emission intensity was determined at each biopsy site.

RESULTS

Peak hepatic fluorescence intensity occurred at 470 nm and decreased as RFA progressed. Transmission electron microscopy evidence of irreversible hepatocyte damage occurred at the interface of the coagulation zone and the hemorrhagic zone and correlated with a 87.5% +/- 9% decrease in fluorescence emission intensity. Tissue fluorescent changes from thermal injury were unaffected by tissue cooling.

CONCLUSION

Fluorescence spectroscopy accurately detected hepatocellular thermal injury from RFA in real time and can detect irreversible cell damage during tissue thermal therapy.

Chronic UVB exposure enhances in vitro percutaneous penetration of 5-aminulevulinic acid in hairless mouse skin

BACKGROUND AND OBJECTIVES

(Pre)cancerous skin lesions accumulate more protoporphyrin IX (PpIX) upon topical application of 5-aminolevulinic acid (ALA) than the surrounding normal skin. This might be the result of a higher percutaneous penetration of ALA into (pre)cancerous skin.

STUDY DESIGN/MATERIALS AND METHODS

ALA penetration through (1) healthy skin with intact stratum corneum, (2) healthy skin with reduced stratum corneum (i.e. tape stripped skin) and (3) diseased skin with dysplastic and thickened epidermis (chronically UVB-exposed skin) was determined in an in vitro model with hairless mouse skin.

RESULTS

More ALA had penetrated through chronically UVB-exposed skin than through normal non-exposed skin after 8 hours ALA application. The amount of ALA penetrated through chronically UVB-exposed skin was smaller than through tape stripped skin.

CONCLUSIONS

The stratum corneum barrier function is less effective in chronically UVB-exposed skin than in normal non-exposed skin, but more effective than in tape stripped skin. A higher penetration rate of ALA into (pre)cancerous lesions may be (partly) responsible for the greater accumulation of PpIX in such lesions.

Autofluorescence characteristics of healthy oral mucosa at different anatomical sites

BACKGROUND AND OBJECTIVES

Autofluorescence spectroscopy is a promising tool for oral cancer detection. Its reliability might be improved by using a reference database of spectra from healthy mucosa. We investigated the influence of anatomical location on healthy mucosa autofluorescence.

STUDY DESIGN/MATERIALS AND METHODS

Spectra were recorded from 97 volunteers using seven excitation wavelengths (350-450 nm), 455-867 nm emission. We studied intensity and applied principal component analysis (PCA) with classification algorithms. Class overlap estimates were calculated.

RESULTS

We observed differences in fluorescence intensity between locations. These were significant but small compared to standard deviations (SD). Normalized spectra looked similar for locations, except for the dorsal side of the tongue (DST) and the vermilion border (VB). Porphyrin-like fluorescence was observed frequently, especially at DST. PCA and classification confirmed VB and DST to be spectrally distinct. The remaining locations showed large class overlaps.

CONCLUSIONS

No relevant systematic spectral differences have been observed between most locations, allowing the use of one large reference database. For DST and VB separate databases are required.