Assessment of tissue perfusion changes in port wine stains after vascular targeted photodynamic therapy: a short-term follow-up study

Devices and Methods for Dosimetry of Personalized Photodynamic Therapy of Tumors: A Review on Recent Trends

Significance: Despite the widespread use of photodynamic therapy in clinical practice, there is a lack of personalized methods for assessing the sufficiency of photodynamic exposure on tumors, depending on tissue parameters that change during light irradiation. This can lead to different treatment results. Aim: The objective of this article was to conduct a comprehensive review of devices and methods employed for the implicit dosimetric monitoring of personalized photodynamic therapy for tumors. Methods: The review included 88 peer-reviewed research articles published between January 2010 and April 2024 that employed implicit monitoring methods, such as fluorescence imaging and diffuse reflectance spectroscopy. Additionally, it encompassed computer modeling methods that are most often and successfully used in preclinical and clinical practice to predict treatment outcomes. The Internet search engine Google Scholar and the Scopus database were used to search the literature for relevant articles. Results: The review analyzed and compared the results of 88 peer-reviewed research articles presenting various methods of implicit dosimetry during photodynamic therapy. The most prominent wavelengths for PDT are in the visible and near-infrared spectral range such as 405, 630, 660, and 690 nm. Conclusions: The problem of developing an accurate, reliable, and easily implemented dosimetry method for photodynamic therapy remains a current problem, since determining the effective light dose for a specific tumor is a decisive factor in achieving a positive treatment outcome.

Non-invasive efficacy assessment of pulsed dye laser and photodynamic therapy for port-wine stain

Port wine stain (PWS) is a congenital vascular malformation that commonly occurs on the face and neck. Currently, the main treatments for port wine stain are pulsed dye laser (PDL) and photodynamic therapy (PDT). However, the efficacy evaluation of PWS mostly relies on the subjective judgement of clinicians, and it is difficult to accurately respond to many small changes after treatment. Therefore, some non-invasive and efficient efficacy assessment methods are also needed. With the continuous development of technology, there are currently many visualisation instruments to evaluate PWS, including dermoscopy, VISIA-CR™ system, reflectance confocal microscopy (RCM), high-frequency ultrasound (HFUS), optical coherence tomography (OCT), Photoacoustic imaging (PAI), laser speckle imaging (LSI) and laser Doppler imaging (LDI). Among them, there are simple and low-cost technologies such as dermoscopy and the VISIA-CR™ system, but they may not be able to observe the deeper structures of PWS. At this time, combining techniques such as HFUS and OCT to increase penetration depth is crucial to evaluate PWS. In the future, the combination of these different technologies could help overcome the limitations of a single technology. This article provides a systematic overview of non-invasive methods for evaluating treatment efficacy in port wine stains and summarises their advantages and disadvantages.

Effect of Hemoporfin-mediated photodynamic therapy in the treatment of facial port-wine stains on intraocular pressure

BACKGROUND

Photodynamic therapy (PDT) is a potential treatment for port-wine stains (PWS), but its effects on intraocular pressure (IOP) have not been reported. This study evaluated the efficacy of PDT for facial PWS and analyzed the changes in IOP before and after treatment.

METHODS

Data from 32 patients with facial PWS who underwent single PDT treatment at our department were collected. The patients were divided into three groups based on the location of the PWS. Group A (15 cases) involved the eyelid of the eye being measured; Group B (10 cases) was located near the eyes but did not involve the measured eyelid; and Group C (7 cases) was situated on the face but not near the eyes. IOP measurements were taken before and after treatment, and the efficacy and changes in IOP were analyzed.

RESULTS

The overall efficacy rates of single PDT were 84.37 %, demonstrating superior efficacy for the pink type, age < 6 years, and skin lesions < 10 cm2 (P < 0.05). The higher IOP was observed on the side with eyelid involvement of PWS (P < 0.001). The IOP of the affected side in Group A decreased by 2.13 ± 2.10 mmHg on average after treatment, which was statistically significant compared with the other two groups (P<0.05).

CONCLUSIONS

Eyelid involvement in PWS increases the risk of elevated IOP. Hemoporfin-mediated PDT can reduce the IOP in patients with PWS involving the eyelid within a safe range. PDT for facial PWS is considered to be safe and effective.

Analysis of urethral blood flow by high-resolution laser speckle contrast imaging in a rat model of vaginal distension

OBJECTIVE

To investigate the feasibility of laser speckle contrast imaging (LSCI) for monitoring urethral blood flow (UBF).

MATERIALS AND METHODS

In this study, 18 healthy, virgin female Sprague-Dawley rats aged 8-week-old were used. The animals were divided into the sham group (n = 9) and the vaginal distension (VD) group (n = 9). The sham group underwent one catheterization of the vagina without distension and the VD group underwent one VD. Following the VD or sham treatment for one week, LSCI assessment of urethral blood flow was performed during bladder filling and leak point pressure (LPP) process.

RESULTS

During the LPP process, in the VD group, the mean LPP was significantly lower than in the sham group (p < 0.05) and the mean UBF level was also significantly lower than in the sham group (p < 0.05) in the LPP condition. The mean relative change of UBF (Δ Flow) was significantly different between the sham group and VD group. The value was 0.646 ± 0.229 and 0.295 ± 0.19, respectively (p < 0.05). During the bladder filling process, the VD group had a significant lower mean UBF level than the sham group under full bladder conditions (p = 0.008). The mean ΔFlow was also significantly lower than in the sham group. The value was 0.115 ± 0.121 and 0.375 ± 0.127, respectively (p = 0.016).

CONCLUSIONS

The results confirmed that LSCI was able to determine UBF in female rats. The VD group had lower baseline UBF and lower increases in UBF during bladder filling and LPP process compared with the sham group.

Multi-level optical angiography for photodynamic therapy

Blood flow imaging is widely applied in photodynamic therapy (PDT) to provide vascular morphological and statistical parameters. This approach relies on the intensity of time-domain signal differences between blood vessels and background tissues; therefore, it often ignores differences within the vasculature and cannot accommodate abundant structural information. This study proposes a multi-level optical angiography (MOA) method for PDT. It can enhance capillaries and image vessels at different levels by measuring the signal frequency shift associated with red blood cell motion. The experimental results regarding the PDT-induced chorioallantoic membrane model showed that the proposed method could not only perform multi-level angiography but also provide more accurate quantitative information regarding various vascular parameters. This MOA method has potential applications in PDT studies.

Efficacy of photodynamic therapy in the treatment of port wine stains: A systematic review and meta-analysis

Background

Port wine stains (PWS) often cause cosmetic effects and psychological distress. Pulsed dye lasers (PDL) and photodynamic therapy (PDT) are the most commonly used treatments. PDL is still the "gold standard" of therapy to date. However, its shortcomings have become apparent as clinical applications have increased. PDT has been proven as an alternative to PDL. Patients with PWS still lack enough evidence about PDT to make informed treatment decisions.

Objective

The purpose of this systematic review and meta-analysis was to assess the safety and effectiveness of PDT for PWS.

Methods

The online datasets, comprising PubMed, Embase, Web of Science, and the Cochrane Library, were searched for meta-analysis-relevant publications. Two reviewers separately evaluated the risk of bias in each listed study. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was used to assess the treatment and safety outcomes.

Results

Our search retrieved 740 hits and only 26 studies were finally included. Among the 26 studies included, 3 were randomized clinical trials, and 23 were prospective or retrospective cohort investigations. Based on a gathered assessment, the percentage of individuals achieving a 60% improvement was estimated to be 51.5% [95% confidence interval (CI): 38.7-64.1; I ² = 83.8%] and a ≥75% improvement was 20.5% (95% CI: 14.5-26.5; I ² = 78.2%) after 1-8.2 treatment sessions (GRADE score: very low). Due to the statistical diversity of the meta-analysis, a subgroup assessment was performed to determine the sources of diversity. The collected findings indicated that the impact of PDT on enhancing the medical effectiveness of PWS was significant in different treatment sessions, different types of ages, different locations of PWS, and different types of PWS. Pain and edema occurred in most patients. Hyperpigmentation was present in 7.9-34.1% of the patients in 17 studies. Photosensitive dermatitis, hypopigmentation, blister, and scar were infrequently reported, with 0-5.8% incidences.

Conclusion

Photodynamic therapy is recommended as a safe and effective treatment for PWS based on the current evidence. However, our findings are based on poor-quality evidence. Therefore, comparative investigations of a large scale and high quality are necessary to support this conclusion.

A proposed scoring system for facial port-wine stain evaluation: Facial port-wine stain area and severity index

BACKGROUND

Port-wine stain (PWS) is a congenital capillary malformation that often occurs on the face. Feasible and quantitative evaluation of facial port-wine stain (FPWS) can significantly impact its clinical management and aid in future research.

AIM

To develop and validate an easy-to-use scoring system for FPWS evaluation.

METHODS

A facial port-wine stain area and severity index (FSASI) scoring system was proposed. To determine the FSASI score, the face was divided into four regions: forehead, right malar, left malar, and perioral. The severity of FPWS in each region was evaluated by three factors: percentage of the area affected, lesion color, and thickness. To evaluate the intra- and inter-rater reliability of FSASI, two separate FSASI assessments on 111 clinical pictures were conducted by each rater in a one-week interval, and the results from 6 independent raters at different time points were compared. Validity of the FSASI scores was assessed by comparing it with physician global assessment (PGA) and traditional classification data. Validity of the area and color elements of FSASI was also determined. The changes in FSASI scores after vascular-targeted photodynamic therapy (V-PDT) were analyzed to evaluate the treatment effect.

RESULTS

The FSASI scoring system showed good intra- and inter-rater reliability (ICC >0.75, p < 0.001) and was found to be comparable to PGA scores (Spearman's r = 0.752-0.907, p < 0.001) and traditional classification data (Spearman's r = 0.426-0.662, p < 0.001). Efficacy analysis indicated that FSASI scores decreased after V-PDT treatment.

CONCLUSION

The results of this study demonstrated the reliability and validity of FSASI, which may be applied to assess the severity of FPWS and to evaluate treatment effects in clinical practice and research.

Therapeutic Strategies for Untreated Capillary Malformations of the Head and Neck Region: A Systematic Review and Meta-Analyses

Background

Capillary malformations of the head and neck region often cause psychological and physical burden. As the effectiveness of modern laser and light therapies is still suboptimal, patients often seek different therapeutic strategies. Other recognized, but not routinely proposed therapies include cosmetic camouflage, surgery, and medical tattooing. Information on therapeutic outcomes is currently lacking for patients to adequately participate in the treatment decision-making process.

Objective

The objective of this systematic review was to review the effectiveness and safety of recognized therapies for untreated capillary malformations of the head and neck: laser and light treatment modalities, photodynamic therapy, cosmetic camouflage, medical tattooing, and surgery.

Methods

PubMed, Embase, and the Cochrane Central Register of Controlled Trials were searched up to 16 December, 2020 for observational and experimental studies examining recognized therapies for untreated capillary malformations of the head and neck. Two reviewers independently evaluated the risk of bias of included studies. Predefined treatment and safety outcomes of pooled data were scored using the Grading of Recommendations Assessment, Development and Evaluation (GRADE).

Results

We included 48 observational and three randomized studies (totaling 3068 patients), evaluating nine different therapies. No studies on surgery or cosmetic camouflage matched our inclusion criteria. The pooled proportion of patients reaching a ≥75% clearance was 43% (95% confidence interval 24–64%; I² = 55%) for the pulsed dye laser after three to eight treatment sessions (GRADE score: very low). Other therapies were less effective. Hyperpigmentation was most frequently described after the pulsed dye laser (incidences up to 40%). Pain was most common after photodynamic therapy, yet the intensity was unreported. Substantial heterogeneity among studies as to patient characteristics and outcomes limited pooling and data comparisons.

Conclusions

The pulsed dye laser seems preferable for treatment-naive capillary malformations of the head and neck region, yet demonstrates greater hyperpigmentation rates compared with other therapies. Our results are, however, based on low-quality evidence. Future studies using uniform outcome measures and validated metrics are warranted for study comparability. Based on this systematic review, clinicians and patients should be aware of the limited evidence about the available options when making (shared) treatment decisions for capillary malformations.

Trial Registration

Review registration number PROSPERO database: CRD42020199445.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40257-021-00616-5.

Quantitative Evaluation of Retinal Vessel Density in Central Serous Chorioretinopathy after Half-dose Photodynamic Therapy

PURPOSE

To determine vessel changes in retinochoroid with optical coherence tomographic angiography (OCT angiography) and spectral-domain OCT (SD-OCT) of patients with central serous chorioretinopathy (CSC) after half-dose photodynamic therapy (hd-PDT).

METHODS

A prospective observational study of 62 eyes of 58 patients undergoing hd-PDT was followed for 3 months. Fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA) were performed at baseline; best-corrected visual acuity (BCVA), fundus photography, OCT angiography and SD-OCT were performed at baseline, 1-month, and 3-month follow-up visits.

RESULTS

The mean vessel density of inner retina (VDIR) layer was 50.72 ± 3.17 at baseline, then decreased to 48.97 ± 4.34 at 1-month follow-up (p < .001), and partially recovered to 49.00 ± 4.28 at 3-month follow-up (p < .001); the mean area of foveal avascular zone (FAZ) was 0.303 ± 0.107 mm² at baseline, and then increased to 0.339 ± 0.121 mm² and 0.342 ± 0.125 mm² at 1-month and 3-month follow-up after hd-PDT (p < .001, p < .001). The mean diameters of choroidal big vessels (DCV) were 309.66 ± 72.24 microns at baseline, then decreased to 300.13 ± 69.38 microns at 1-month and 293.39 ± 69.92 microns at 3-month after treatment (p < .001, p < .001).

CONCLUSIONS

Currently common applied hd-PDT for patients with CSC has significantly impact on both retinal and choroidal vessels. The retinal capillary flow decreased, therefore optimizing PDT parameters for treating CSC may still be necessary in the future.

Monitoring perfusion and oxygen saturation in port-wine stains during vascular targeted photodynamic therapy

Background

Vascular targeted photodynamic therapy (V-PDT) is a safe and effective therapeutic modality for port-wine stains (PWS) by targetedly damaging the dilated and malformed blood vessels. This study aims to monitor and quantify the changes in oxygen saturation (StO₂), blood volume fraction (BVF) and perfusion in PWS lesions before and during V-PDT.

Methods

Microvascular parameters (i.e., StO₂ and BVF) and skin perfusion were measured noninvasively by using diffuse reflectance spectroscopy (DRS) and laser Doppler imaging (LDI), respectively. The change in StO₂, BVF and perfusion that occurred in the PWS lesions of 26 patients were monitored and investigated before and during V-PDT in vivo with the systematic administration of the porphyrin-based photosensitizer HiPorfin.

Results

The mean StO₂ (P<0.05), BVF (P<0.05), and perfusion (P<0.001) in PWS lesions of all subjects significantly increased by 6%, 34%, and 113%, respectively, 3 min after the initiation of V-PDT. The StO₂ increased first and fluctuated during V-PDT. The overall trend of BVF change was consistent with the perfusion change. The BVF and the perfusion of PWS lesions increased after the initiation of V-PDT, and then gradually decreased.

Conclusions

V-PDT is an effective therapeutic modality in treating PWS. Results showed that LDI and DRS permitted the noninvasive monitoring of the changes in StO₂, BVF, and perfusion in PWS lesions during V-PDT, and these methods can be useful in facilitating our understanding of the basic physiological mechanisms during V-PDT.

Removing Subcutaneous Microvessels Using Photo-Mediated Ultrasound Therapy

BACKGROUND AND OBJECTIVES

We have developed a novel anti-vascular technique, termed photo-mediated ultrasound therapy (PUT), which utilizes nanosecond duration laser pulses synchronized with ultrasound bursts to remove the microvasculature through cavitation. The objective of the current study is to explore the potential of PUT in removing subcutaneous microvessels.

STUDY DESIGN/MATERIALS AND METHODS

The auricular blood vessels of two New Zealand white rabbits were treated by PUT with a peak negative ultrasound pressure of 0.45 MPa at 0.5 MHz, and a laser fluence of 0.056 J/cm2 at 1064 nm for 10 minutes. Blood perfusion in the treated area was measured by a commercial laser speckle imaging (LSI) system before and immediately after treatment, as well as at 1 hour, 3 days, 2 weeks, and 4 weeks post-treatment. Perfusion rates of 38 individual vessels from four rabbit ears were tracked during this time period for longitudinal assessment.

RESULTS

The measured perfusion rates of the vessels in the treated areas, as quantified by the relative change in perfusion rate, showed a statistically significant decrease for all time points post-treatment (P < 0.001). The mean decrease in perfusion is 50.79% immediately after treatment and is 32.14% at 4 weeks post-treatment. Immediately after treatment, the perfusion rate decreased rapidly. Following this, there was a partial recovery in perfusion rate up to 3 days post-treatment, followed by a plateau in the perfusion from 3 days to 4 weeks.

CONCLUSIONS

This study demonstrated that a single PUT treatment could significantly reduce blood perfusion by 32.14% in the skin for up to 4 weeks. With unique advantages such as low laser fluence as compared with photothermolysis and agent-free treatment as compared with photodynamic therapy, PUT holds the potential to be developed into a new tool for the treatment of cutaneous vascular lesions. Lasers Surg. Med. © 2020 Wiley Periodicals, LLC.

In vivo assessment of vascular-targeted photodynamic therapy effects on tumor microvasculature using ultrahigh-resolution functional optical coherence tomography

Vascular-targeted photodynamic therapy (VTP) is an emerging treatment for tumors. The change of tumor vasculatures, including a newly-formed microvascular, in response to VTP, is a key assessment parameter for optimizing the treatment effect. However, an accurate assessment of vasculature, particularly the microvasculature's changes in vivo, remains challenging due to the limited resolution afforded by existing imaging modalities. In this study, we demonstrated the in vivo imaging of VTP effects on an A431 tumor-bearing window chamber model of a mouse with an 800-nm ultrahigh-resolution functional optical coherence tomography (UHR-FOCT). We further quantitatively demonstrated the effects of VTP on the size and density of tumor microvasculature before, during, and after the treatment. Our results suggest the promising potential of UHR-FOCT for assessing the tumor treatment with VTP in vivo and in real time to achieve an optimal outcome.

Clinical outcome measures and scoring systems used in prospective studies of port wine stains: A systematic review

BACKGROUND

Valid and reliable outcome measures are needed to determine and compare treatment results of port wine stain (PWS) studies. Besides, uniformity in outcome measures is crucial to enable inter-study comparisons and meta-analyses. This study aimed to assess the heterogeneity in reported PWS outcome measures by mapping the (clinical) outcome measures currently used in prospective PWS studies.

METHODS

OVID MEDLINE, OVID Embase, and CENTRAL were searched for prospective PWS studies published from 2005 to May 2020. Interventional studies with a clinical efficacy assessment were included. Two reviewers independently evaluated methodological quality using a modified Downs and Black checklist.

RESULTS

In total, 85 studies comprising 3,310 patients were included in which 94 clinician/observer-reported clinical efficacy assessments had been performed using 46 different scoring systems. Eighty-one- studies employed a global assessment of PWS appearance/improvement, of which -82% was expressed as percentage improvement and categorized in 26 different scoring systems. A wide variety of other global and multi-item scoring systems was identified. As a result of outcome heterogeneity and insufficient data reporting, only 44% of studies could be directly compared. A minority of studies included patient-reported or objective outcomes. Thirteen studies of good quality were found.

CONCLUSION

Clinical PWS outcomes are highly heterogeneous, which hampers study comparisons and meta-analyses. Consensus-based development of a core outcome-set would benefit future research and clinical practice, especially considering the lack of high-quality trials.

Clinical applications of laser speckle contrast imaging: a review

When a biological tissue is illuminated with coherent light, an interference pattern will be formed at the detector, the so-called speckle pattern. Laser speckle contrast imaging (LSCI) is a technique based on the dynamic change in this backscattered light as a result of interaction with red blood cells. It can be used to visualize perfusion in various tissues and, even though this technique has been extensively described in the literature, the actual clinical implementation lags behind. We provide an overview of LSCI as a tool to image tissue perfusion. We present a brief introduction to the theory, review clinical studies from various medical fields, and discuss current limitations impeding clinical acceptance.

Blood flow index as an indicator of successful sciatic nerve block: a prospective observational study using laser speckle contrast imaging

BACKGROUND

Laser speckle contrast imaging allows real-time, non-invasive, quantitative measurements of regional blood flow. The objectives of this prospective observational study were to use laser speckle contrast imaging to evaluate blood flow changes after sciatic nerve block, and to determine whether this novel optical technique can evaluate block success.

METHODS

This observational study included 63 adult patients undergoing elective lower limb surgery with sciatic nerve block. Blood flow images and blood flow index (BFI) values of toes were recorded using laser speckle contrast imaging 5 min before nerve block and at 5 min intervals until 30 min after sciatic block. The sensitivity, specificity, and cut-off value of laser speckle contrast imaging for predicting successful sciatic block were determined by receiver operator characteristic (ROC) curve analysis.

RESULTS

The BFI values of toes were significantly increased at each time point after successful sciatic block, compared with the baseline value obtained 5 min before nerve block; in failed sciatic block, there were no significant differences. For successful sciatic block, the highest increase of BFI value was at the big toe. BFI increase of the big toe at 10 min after sciatic block has great potential as an indicator of block success. The area under the ROC curve was 0.954 at a cut-off value of 8.48 perfusion units (PU) with a sensitivity of 89% and a specificity of 100%.

CONCLUSIONS

Laser speckle contrast imaging might be an early, objective, quantitative, and reliable indicator of successful sciatic block. BFI increase of the big toe not reaching 8.48 PU within 10 min after sciatic block indicates block failure.

CLINICAL TRIAL REGISTRATION

NCT03169517.

The Role of Laser Speckle Imaging in Port-Wine Stain Research: Recent Advances and Opportunities

Here, we review our current knowledge on the etiology and treatment of port-wine stain (PWS) birthmarks. Current treatment options have significant limitations in terms of efficacy. With the combination of 1) a suitable preclinical microvascular model, 2) laser speckle imaging (LSI) to evaluate blood-flow dynamics, and 3) a longitudinal experimental design, rapid preclinical assessment of new phototherapies can be translated from the lab to the clinic. The combination of photodynamic therapy (PDT) and pulsed-dye laser (PDL) irradiation achieves a synergistic effect that reduces the required radiant exposures of the individual phototherapies to achieve persistent vascular shutdown. PDL combined with anti-angiogenic agents is a promising strategy to achieve persistent vascular shutdown by preventing reformation and reperfusion of photocoagulated blood vessels. Integration of LSI into the clinical workflow may lead to surgical image guidance that maximizes acute photocoagulation, is expected to improve PWS therapeutic outcome. Continued integration of noninvasive optical imaging technologies and biochemical analysis collectively are expected to lead to more robust treatment strategies.

Intraoperative monitoring of blood perfusion in port wine stains by laser Doppler imaging during vascular targeted photodynamic therapy: A preliminary study

OBJECTIVE

The objective of this study was to monitor blood perfusion dynamics of port wine stains (PWS) during vascular targeted photodynamic therapy (V-PDT) with laser Doppler imaging (LDI).

METHODS

The PWS lesions of 30 facial PWS patients received V-PDT, while the normal skins on the forearm of 5 healthy subjects were treated as light-only controls for comparison. Furthermore, two different PWS lesions in the same individual from each of 3 PWS patients successively received laser irradiation only and V-PDT, respectively. LDI was used to monitor intraoperative blood perfusion dynamics.

RESULTS

During V-PDT, the blood perfusion (278±96 PU) in PWS lesions for 31 of 33 PWS patients significantly increased after the initiation of V-PDT treatment, then reached a peak (638±105 PU) within 10min, followed by a slow decrease to a relatively lower level (515±100 PU). Furthermore, the time for reaching peak and the subsequent magnitude of decrease in blood perfusion varied with different patients. For light-only controls, an initial perfusion peak at 3min followed by a nadir and a secondary increase were found not only in normal skin, but also in PWS lesions.

CONCLUSION

The preliminary results showed that the LDI permits non-invasive monitoring blood perfusion changes of PWS lesions during V-PDT. There was a clear trend in blood perfusion responses during V-PDT and laser irradiation. The blood perfusion changes during treatment were due to V-PDT effects as well as local temperature increase induced by laser irradiation.

Relationship between the blood perfusion values determined by laser speckle imaging and laser Doppler imaging in normal skin and port wine stains

OBJECTIVE

Laser Doppler imaging (LDI) and laser speckle imaging (LSI) are two major optical techniques aiming at non-invasively imaging the skin blood perfusion. However, the relationship between perfusion values determined by LDI and LSI has not been fully explored.

METHODS

8 healthy volunteers and 13 PWS patients were recruited. The perfusions in normal skin on the forearm of 8 healthy volunteers were simultaneously measured by both LDI and LSI during post-occlusive reactive hyperemia (PORH). Furthermore, the perfusions of port wine stains (PWS) lesions and contralateral normal skin of 10 PWS patients were also determined. In addition, the perfusions for PWS lesions from 3 PWS patients were successively monitored at 0, 10 and 20min during vascular-targeted photodynamic therapy (V-PDT). The average perfusion values determined by LSI were compared with those of LDI for each subject.

RESULTS

In the normal skin during PORH, power function provided better fits of perfusion values than linear function: powers for individual subjects go from 1.312 to 1.942 (R(2)=0.8967-0.9951). There was a linear relationship between perfusion values determined by LDI and LSI in PWS and contralateral normal skin (R(2)=0.7308-0.9623), and in PWS during V-PDT (R(2)=0.8037-0.9968).

CONCLUSION

The perfusion values determined by LDI and LSI correlate closely in normal skin and PWS over a broad range of skin perfusion. However, it still suggests that perfusion range and characteristics of the measured skin should be carefully considered if LDI and LSI measures are compared.

Intraoperative, real-time monitoring of blood flow dynamics associated with laser surgery of port wine stain birthmarks

BACKGROUND AND OBJECTIVE

Port-wine stain (PWS) birthmarks affect ∼22 million people worldwide. After several treatment sessions, complete disappearance of the PWS occurs in only ∼10% of treated patients. There is a need to develop a new strategy to improve the efficacy of each treatment session and the overall treatment outcome. The study objective was to determine how intraoperative measurements of blood flow correlate with treatment response assessed several weeks post treatment.

STUDY DESIGN/MATERIALS AND METHODS

We employed Laser Speckle Imaging (LSI) to measure intraoperative blood-flow dynamics. We collected data from 24 subjects undergoing laser therapy for facial PWS birthmarks. Photographs were taken before treatment and at a follow-up visit, and analyzed by two expert observers.

RESULTS

Intraoperative LSI enables real-time monitoring of blood-flow dynamics in response to laser treatment and can inform clinicians on the need for focused re-treatment. The degree of PWS blanching achieved is positively correlated with the log-transformed acute blood-flow reduction (P = 0.022).

CONCLUSION

LSI is a simple, intraoperative monitoring tool during laser therapy of PWS birthmarks. LSI provides a single value for blood flow that correlates well with the degree of blanching achieved with laser therapy.