Pretreatment with ablative fractional carbon dioxide laser improves treatment efficacy in a synergistic PDT protocol for actinic keratoses on the head

BACKGROUND

A recently proposed synergistic photodynamic therapy protocol (s-PDT) combining advantages of both conventional- and daylight-PDT proved to be an effective and almost painless treatment for patients with actinic keratoses (AKs). This study investigated the safety and efficacy of an additional ablative fractional CO2-laser (AFXL) pretreatment.

METHODS

28 patients with AKs on the head received s-PDT using 5-aminolevulinic acid. AFXL pretreatment was conducted using the following parameters: pulse energy 8 mJ, spot density 50 spots/cm², power 30 W, beam size 4-18 mm. Outcome was assessed by AK area and severity index (AKASI) and lesion count (LC) before and 3 months after treatment. Safety was monitored by blood pressure and pulse measurements. Intensity of pain was determined by use of a visual analog scale (VAS).

RESULTS

Most patients (96.4 %) showed a significant AKASI reduction (P < 0.0001) 3 months after PDT (median AKASI 1.6 [0-2.4]) compared to baseline (5.3 [4-7.75]). Median reduction rate was 75.5 % (61.3 %-100 %). Eleven patients (39.3 %) achieved AKASI 100, three (10.7 %) AKASI 75 and ten (35.7 %) AKASI 50. Blood pressure and pulse did not change significantly throughout treatment. Median VAS for pain during irradiation was 0 (0-0), 0 (0-2) and 0 (0-2) at the beginning, in the meantime and at the end, respectively. Compared to data without AFXL pretreatment, this study showed significantly higher AKASI and LC reduction rates (75.5 % vs. 63.7 % [P = 0.023] and 91.3 % vs. 80.4 % [P = 0.043]).

CONCLUSIONS

S-PDT with AFXL pretreatment represents a safe and almost painless treatment for patients with AKs on the head and improves treatment efficacy.

The conventional protocol vs. a protocol including illumination with a fabric-based biophotonic device (the Phosistos protocol) in photodynamic therapy for actinic keratosis: a randomized, controlled, noninferiority clinical study

BACKGROUND

Topical photodynamic therapy (PDT) using methyl aminolaevulinate is a noninvasive treatment option suitable to treat clinical and subclinical actinic keratosis (AK) over a large area (field cancerization). The most widely used, conventional protocol in Europe includes illumination with a red-light lamp. This illumination commonly causes pain, and patients often cannot complete the treatment.

OBJECTIVES

The aims of this paper are twofold. The first aim is to introduce a novel protocol, the Phosistos protocol (P-PDT), which includes illumination with a fabric-based biophotonic device. The second and major aim is to assess the noninferiority, in terms of efficacy for PDT of AK, of P-PDT compared with the conventional protocol (C-PDT).

METHODS

A randomized, controlled, multicentre, intraindividual clinical study was conducted. Forty-six patients with grade I-II AK of the forehead and scalp were treated with P-PDT on one area (280 AK lesions) and with C-PDT on the contralateral area (280 AK lesions). The primary end point was the lesion complete response (CR) rate at 3 months, with an absolute noninferiority margin of -10%. Secondary end points included pain scores, incidence of adverse effects and cosmetic outcome.

RESULTS

Three months following treatment, the lesion CR rate of P-PDT was noninferior to that of C-PDT (79·3% vs. 80·7%, respectively; absolute difference -1·6%; one-sided 95% confidence interval -4·5% to infinity). The noninferiority of P-PDT to C-PDT in terms of the lesion CR rate remained at the 6-month follow-up (94·2% vs. 94·9%, respectively; absolute difference -0·6%; one-sided 95% confidence interval -2·7% to infinity). Moreover, the pain score at the end of illumination was significantly lower for P-PDT than for C-PDT (mean ± SD 0·3 ± 0·6 vs. 7·4 ± 2·3; P < 0·001).

CONCLUSIONS

P-PDT is noninferior to C-PDT in terms of efficacy for treating AK of the forehead and scalp and resulted in much lower pain scores and fewer adverse effects. What's already known about this topic? Topical photodynamic therapy using methyl aminolaevulinate is effective for treating actinic keratosis. In Europe, the conventional protocol involves illumination with a red-light lamp. Unfortunately, pain is often experienced by patients undergoing this protocol. An alternative protocol that uses daylight illumination has recently been shown to be as effective as the conventional protocol while being nearly painless. However, this alternative protocol can be conducted only in suitable weather conditions. What does this study add? The Phosistos protocol is demonstrated to be as effective as the conventional protocol, nearly as painless as the daylight protocols and suitable year round for treatment of actinic keratosis.

Evaluation of two histological classifications for actinic keratoses - PRO classification scored highest inter-rater reliability

BACKGROUND

Actinic keratoses (AKs) can histologically be classified by the extent of atypical keratinocytes throughout the epidermis or their pattern of basal proliferation. Currently, no data on the inter-rater reliability of both scores is available.

OBJECTIVE

To evaluate the inter-rater reliability of the two classification schemes; histological grade (AK I-III) and basal proliferation (PRO I-III).

METHODS

Histological images of 54 AKs were classified by 21 independent dermatopathologists with regard to basal proliferation (PRO I-III), histological grade (AK I-III) and assumed risk of progression into invasive carcinoma.

RESULTS

Overall, of the 54 AKs 16.7% (9/54) were classified as AK I, 66.7% (36/54) as AK II, and 16.7% (9/54) as AK III. With regards to basal growth pattern, 25.9% (14/54) were classified as PRO I, 42.6% (23/54) as PRO II, and 31.5% (17/54) as PRO III. We observed a highly significant inter-rater reliability for PRO-grading (P < 0.001) which was higher than for AK-grading (Kendall's W coefficient: AK = 0.488 vs. PRO = 0.793). We found substantial agreement for assumed progression risk for AKs with worsening basal proliferation (k = 0.759) compared to moderate agreement (k = 0.563) for different AK-gradings.

CONCLUSIONS

Histological classification of basal growth pattern (PRO) showed higher inter-rater reliability compared to the established classification of atypical keratinocytes throughout epidermal layers. Moreover, experienced dermatopathologists considered basal proliferation to be more important in terms of progression risk than upwards directed growth patterns. It should be considered to classify AKs according to their basal proliferation pattern (PRO I-III).

A randomized split-scalp study comparing calcipotriol-assisted methyl aminolaevulinate photodynamic therapy (MAL-PDT) with conventional MAL-PDT for the treatment of actinic keratosis

BACKGROUND

Topical photodynamic therapy (PDT) is an approved treatment for actinic keratosis (AK). To enhance the efficacy of PDT for AKs, physical and chemical pretreatments have been suggested.

OBJECTIVES

To compare the efficacy and safety of the combination of topical calcipotriol (CAL) before methyl aminolaevulinate (MAL)-PDT for AKs of the scalp vs. conventional MAL-PDT in a randomized controlled clinical trial.

METHODS

Twenty patients with multiple AKs on the scalp were randomized to receive conventional MAL-PDT with previous curettage on one side of the scalp and CAL-assisted MAL-PDT once a day for 15 days before illumination on the other side. After 3 months, patients were evaluated for clearance of AKs, side-effects and histopathology before and after the procedure. Protoporphyrin IX (PpIX) fluorescence was measured before and after illumination on both sides.

RESULTS

All 20 patients completed the study. Overall AK clearance rates were 92·1% and 82·0% for CAL-PDT and conventional PDT, respectively (P < 0·001). Grade 1 AKs showed similar response rates for both sides (P = 0·055). However, grade II AKs showed more improvement on the CAL-PDT side (90%) than on the MAL-PDT side (63%) (P < 0·001). Before illumination, PpIX fluorescence intensity was higher on the CAL-assisted side (P = 0·048). The treatment was more painful on the CAL-PDT side, although well tolerated. The mean visual analogue scale score was 5·4 ± 1·4 on the CAL-PDT side and 4·0 ± 0·69 on the conventional MAL-PDT side (P = 0·001). Side-effects such as erythema (P = 0·019), oedema (P = 0·002) and crusts (P < 0·001) were more pronounced on the CAL-assisted side. Histopathological analyses were obtained from five patients and both sides showed improved keratinocyte atypia following PDT, with slightly more improvement on the CAL-assisted side.

CONCLUSIONS

CAL-assisted PDT proved to be safe and more effective than conventional MAL-PDT for the treatment of AKs on the scalp. CAL pretreatment increased PpIX accumulation within the skin and may have enhanced the efficacy in this first human trial.

Patient-reported health outcomes in patients with non-melanoma skin cancer and actinic keratosis: results from a large-scale observational study analysing effects of diagnoses and disease progression

BACKGROUND

Non-melanoma skin cancer (NMSC) and actinic keratosis (AK) are very common among fair-skinned individuals. A disease continuum from AK to squamous cell carcinoma (SCC) has been frequently postulated. AK and NMSC may influence quality of life (QL) of patients, and it can be suspected that disease progression entails a QL reduction. The purpose of this study was to document QL in patients with NMSC and AK using the health-outcome questionnaire EQ-5D-5L.

METHODS

The study was designed as a non-interventional, prospective, cross-sectional study. Patients with AK, SCC, basal cell carcinoma (BCC) or multiple diagnoses were enrolled in this study in 29 dermatological centres across Germany. Patients were asked to complete the EQ-5D-5L (compromising EQ Index and EQ VAS), and the dermatologists provided diagnosis, disease history and treatment data.

RESULTS

A total of 1184 patients were enrolled and diagnosed as follows: 73% AK, 49% BCC and 17% SCC. 66% had a single diagnosis, 28% two different diagnoses and 6% three different diagnoses. QL was strongly associated with patients' diagnosis. Patients with a single AK diagnosis had significantly higher mean EQ VAS (78) than patients with BCC (74), SCC (72), and BCC plus SCC (69), P < 0.050. When the effects of disease progression were calculated, patients with AK plus SCC reported significantly less mean EQ VAS (71) than patients with a single AK diagnosis (78), P < 0.011.

CONCLUSIONS

While rarely being imminently life-threatening, NMSC and AK have an impact on QL as quantified by the EQ-5D-5L. This impact is associated with diagnosis (AK vs. NMSC) and clinical progression (AK vs. AK plus SCC). Both lead to a clear decline in QL. This shows that disease progression is perceived and judged as detrimental by patients and that AK and NMSC should be diligently treated to preserve and restore QL.

Clinical, histopathological and immunohistochemical assessment of human skin field cancerization before and after photodynamic therapy

BACKGROUND

The field cancerization concept in photodamaged patients suggests that the entire sun-exposed surface of the skin has an increased risk for the development of (pre)-malignant lesions, mainly epithelial tumours. Topical photodynamic therapy (PDT) is a noninvasive therapeutic method for multiple actinic keratosis (AK) with excellent outcome.

OBJECTIVES

To evaluate the clinical, histological and immunohistochemical changes in human skin with field cancerization after multiple sessions of PDT with methyl-aminolaevulinate (MAL).

METHODS

Twenty-six patients with photodamaged skin and multiple AK on the face received three consecutive sessions of MAL-PDT with red light (37 J cm(-2)), 1 month apart. Biopsies before and 3 months after the last treatment session were taken from normal-appearing skin on the field-cancerized area. Immunohistochemical stainings were performed for TP-53, procollagen-I, metalloproteinase-1 (MMP-1) and tenascin-C (Tn-C).

RESULTS

All 26 patients completed the study. The global score for photodamage improved considerably in all patients (P < 0·001). The AK clearance rate was 89·5% at the end of the study. Two treatment sessions were as effective as three MAL-PDT sessions. A significant decrease in atypia grade and extent of keratinocyte atypia was observed histologically (P < 0·001). Also, a significant increase in collagen deposition (P = 0·001) and improvement of solar elastosis (P = 0·002) were noticed after PDT. However, immunohistochemistry showed only a trend for decreased TP-53 expression (not significant), increased procollagen-I and MMP-1 expressions (not significant) and an increased expression of Tn-C (P = 0·024).

CONCLUSIONS

Clinical and histological improvement in field cancerization after multiple sessions of MAL-PDT is proven. The decrease in severity and extent of keratinocyte atypia associated with a decreased expression of TP-53 suggest a reduced carcinogenic potential of the sun-damaged area. The significant increase of new collagen deposition and the reduction of solar elastosis explain the clinical improvement of photodamaged skin.

The use of photodynamic therapy in dermatology

In dermatology, topical photodynamic therapy (PDT) is a well established treatment modality which has mainly shown to be effective for dermato-oncologic conditions like actinic keratosis, Bowen's disease, in-situ squamous cell carcinoma and superficial basal cell carcinoma. However, a therapeutical benefit of PDT is also evident for inflammatory dermatoses like localized scleroderma, acne vulgaris and granuloma annulare as well as for aesthetic indications like photo aged skin or sebaceous gland hyperplasia. Recent work has been focused on the development and evaluation of topical photosensitizers like the hem precursor 5-aminolevulinic acid or its methyl ester inducing photosensitizing porphyrins. These drugs do not induce strong generalized cutaneous photosensitization like the systemically applied porphyrins or their derivatives. For dermatological purposes incoherent lamps or LED arrays can be used for light activation. Depending on the applied light dose and the concentration of the photosensitizer either cytotoxic effects resulting in tumor destruction or immunomodulatory effects improving the inflammatory conditions occur. Treating superficial oncologic lesions (tumor thickness < 2-3 mm) cure rates achieved by PDT are equal to the cure rates of the respective standard therapeutic procedure. The benefits of PDT are the low level of invasiveness and the excellent cosmetic results after treatment.

A clinical study comparing methyl aminolevulinate photodynamic therapy and surgery in small superficial basal cell carcinoma (8-20 mm), with a 12-month follow-up

OBJECTIVE

To compare the efficacy and cosmetic outcome (CO) of photodynamic therapy with topical methyl aminolevulinate (MAL-PDT) with simple excision surgery for superficial basal cell carcinoma (sBCC) over a 1-year period.

METHODS

In this multicentre, randomised, controlled, open study, patients were treated at baseline either with MAL-PDT (two sessions, 7 days apart, repeated 3 months later if incomplete clinical response) or surgery (at baseline). Primary endpoints were clinical lesion response (CR) 3 months after last treatment and CO assessed by the investigator 12 months after last treatment. Secondary endpoints were CR at 12 months (i.e. recurrence) and CO assessed by the investigator at 3 and 6 months and by the patient at 3, 6 and 12 months.

RESULTS

Overall, 196 patients were enrolled with 1.4 sBCC lesions on average per patient. Mean lesion count reduction at 3 months was 92.2% with MAL-PDT vs. 99.2% with surgery [per protocol (PP) population] confirming the non-inferiority hypothesis (95% confidence interval, -12.1, -1.9). A total of 92.2% lesions showed CR at 3 months with MAL-PDT vs. 99.2% with surgery (PP population). At 12 months, 9.3% lesions recurred with MAL-PDT and none with surgery. CO was statistically superior for MAL-PDT at all time points. At 12 months, 94.1% lesions treated with MAL-PDT had an excellent or good CO according to the investigator compared with 59.8% with surgery. This difference was confirmed with the patients' assessment. The proportion of excellent CO markedly improved with time with MAL-PDT unlike surgery.

CONCLUSIONS

MAL-PDT offers a similarly high efficacy and a much better CO than simple excision surgery in the treatment of sBCC.

Disappointing results and low tolerability of photodynamic therapy with topical 5-aminolaevulinic acid in psoriasis. A randomized, double-blind phase I/II study

BACKGROUND

Based on good results in the treatment of superficial skin tumours, since the early 1990s topical photodynamic therapy with aminolaevulinic acid (ALA PDT) has been used for disseminated, inflammatory dermatoses including psoriasis. However, there is still a lack of well-documented trials.

OBJECTIVE

A prospective randomized, double-blind phase I/II intrapatient comparison study was conducted in 12 patients to investigate whether topical ALA PDT is an effective treatment for chronic plaque-type psoriasis.

METHODS

In each patient three psoriatic plaques were randomly treated with a light dose of 20 J/cm(2) and 0.1%, 1% and 5% ALA, respectively. Treatment was conducted twice a week until complete clearance or for a maximum of 12 irradiations. Therapeutic efficacy was assessed by weekly determination of the psoriasis severity index (PSI).

RESULTS

The mean percentage improvement was 37.5%, 45.6% and 51.2% in the 0.1%, 1% and 5% ALA-treated groups, respectively. Irradiation had to be interrupted several times because of severe burning and pain sensation.

CONCLUSION

Topical ALA PDT did not prove to be an appropriate treatment option for plaque-type psoriasis due to disappointing clinical efficacy, the time-consuming treatment procedure and its unfavourable adverse event profile.

Towards a more specific therapy: targeting nonmelanoma skin cancer cells

Epithelial cancers of the skin, e.g. basal cell carcinoma and squamous cell carcinoma, are the most common tumours in humans with increasing incidence. Hence the development of new therapeutic strategies is of utmost interest. For many years the most often used conventional therapies for these diseases were surgical procedures such as curettage and electrodesiccation, excision or, with so far the best outcome in terms of remission rates, micrographic surgery. Other ablative treatment modalities are cryotherapy, radiation therapy or the use of lasers (Er:YAG, CO(2)). All those above-mentioned treatments have in common that they are quite unspecific and do not target the tumour itself or its environment, thus leading to unwanted effects in the surrounding tissue such as scar formation or other cosmetically disfiguring events. Therefore, the development of novel, more pathogenesis-based therapies such as the use of retinoids, cyclooxygenase inhibitors, topical immunomodulators, inhibitors of the sonic-hedgehog signalling pathway or photodynamic therapy are challenging new approaches.

Topical aminolaevulinic acid-based photodynamic therapy as a treatment option for psoriasis? Results of a randomized, observer-blinded study

BACKGROUND

Topical aminolaevulinic acid-based photodynamic therapy (ALA-PDT) has recently been tried in small open studies for several inflammatory dermatoses including psoriasis.

OBJECTIVES

The purpose of this randomized, within patient comparison study was to investigate whether topical ALA-based PDT using a range of light doses can induce a satisfactory response in localized psoriasis.

PATIENTS AND METHODS

Twenty-nine patients with chronic plaque type psoriasis were enrolled in the study. After keratolytic pretreatment three psoriatic plaques in each patient were randomly allocated to PDT with 1% ALA and a light dose of 5 J cm(-2), 10 J cm(-2) or 20 J cm(-2), respectively. Treatment was performed twice weekly until complete clearance or for a maximum of 12 irradiations. As a measure of clinical response the psoriasis severity index (PSI) of the three target plaques was assessed separately by an observer blinded to the treatment at baseline, before each PDT treatment and 3-4 days after the last irradiation.

RESULTS

Eight patients withdrew prematurely from the study. Keratolytic pretreatment alone reduced the baseline PSI in all three dose groups by about 25%. Subsequent PDT with 20 J cm(-2) resulted in a final reduction of PSI by 59%, PDT with the lower doses of 10 J cm(-2) and 5 J cm(-2) decreased the baseline PSI by 46% and 49%, respectively. The difference in clinical efficacy between 20 J cm(-2) and 10 J cm(-2) or 5 J cm(-2) was statistically significant (P = 0.003; P = 0.02), whereas no difference was found between 10 J cm(-2) and 5 J cm(-2) (P = 0.4). All patients reported some degree of PDT-induced stinging or burning during irradiation.

CONCLUSIONS

The unsatisfactory clinical response and frequent occurrence of pain during and after irradiation renders topical ALA-based PDT an inadequate treatment option for psoriasis.

Management of erosive lichen planus with topical tacrolimus and recurrence secondary to metoprolol

Metoprolol, a widely prescribed beta-adrenergic receptor blocker, has occasionally been associated with a diversity of cutaneous reactions. We present a 79-year-old male patient with erosive lichen planus (LP) on the feet and hands who was successfully treated with topical tacrolimus. Six months after the lesions had been cured the patient received the beta-receptor blocker metoprolol for the treatment of hypertonus. Within only 2 weeks of metoprolol intake the erosive lesions on the palms and feet recurred. After discontinuation of the drug and repetitive topical treatment with tacrolimus a complete remission of the lesions could be achieved. The recurrence of erosive LP probably secondary to metoprolol and the therapeutic success of topical tacrolimus in the treatment of LP are discussed.

Early detection of skin cancer (EDISCIM) through the use of non-invasive confocal imaging

In the past 15 years the number of malignant melanomas and non-melanoma skin cancer, (i.e. squamous cell carcinoma, basal cell carcinoma), have increased dramatically throughout the whole world, in particular among people with white skin. For example, in Germany the number of new cases of melanoma is about 10 to 12 per 100,000 people, (for basal cell carcinoma as a non-melanoma skin cancer 140 per 100,000), the absolute number of annual new cases of melanoma is an estimated 9,000 to 10,000, and the increasing rate is 5 to 10%. However, there are more than 40 differential diagnoses for skin cancer which makes it difficult even for expert dermatologists to give correct diagnosis, (estimated 75% correct diagnoses). This figure is even worse for doctors from other specialities. There is only a chance of high cure rates when skin tumours are detected at an early stage. The prognosis of skin cancer is dependent very much on the thickness, (as a sign of invasiveness), of the tumour and the number of mitotic figures in the tumour, (as a sign of proliferation activity). However, the final diagnosis of skin cancer is usually done by biopsy, the sample being investigated by a specialist. This is an invasive method, which is painful for the patient and might require several cuts and samples taken before being absolutely certain. Due to the potential risk of dissemination of tumour cells, taking an incisional biopsy is obsolete in malignant melanoma. Therefore the correct diagnosis of malignant melanoma can be made only after a total removal of the lesion and consecutive histopathological examination. The EDISCIM project intends to develop a system for the early diagnosis of skin cancer which uses confocal imaging for the non-invasive diagnosis of the upper layers of the skin that aids the physician in the analysis of the images and therefore with the diagnosis, allows for potential remote diagnosis by specialist dermatologists via tele-diagnosis if need be. The objectives of the system are Captures microscopic images of the skin by confocal imaging, Processes and records these images in real time, Compares these images against a knowledge base of known skin symptoms, Displays the results in a suitable interface to the physician performing the diagnosis, And supports the online telematic support by specialists.

Photodynamic therapy using topical methyl 5-aminolevulinate compared with cryotherapy for actinic keratosis: A prospective, randomized study

BACKGROUND

Actinic keratoses (AKs) are the most common premalignant tumors. Without treatment, a significant number of patients with AK will experience squamous cell carcinoma. Photodynamic therapy (PDT) using the new highly selective photosensitizer methyl 5-aminolevulinate is a promising new treatment modality for AK.

OBJECTIVE

We investigated the complete response rates, cosmetic outcome, and patient satisfaction after photodynamic therapy (PDT) using methyl 5-aminolevulinate (Metvix) versus cryotherapy in the treatment of AKs.

METHODS

Patients were randomized to receive either cryotherapy with liquid nitrogen spray or PDT using methyl 5-aminolevulinate cream 160 mg/g, 3 hours application time, and red light (75 J/cm(2)).

RESULTS

Efficacy results from 193 patients with 699 lesions (92% face/scalp and 93% thin/moderately thick) were analyzed. Overall complete response rates after 3 months were 69% for PDT and 75% for cryotherapy. Both treatments gave higher response rates in thin lesions (PDT 75%, cryotherapy 80%). PDT gave better cosmetic results and higher patient satisfaction than cryotherapy.

CONCLUSION

PDT using methyl 5-aminolevulinate is an attractive treatment option for patients with AK, with a response rate similar to that of cryotherapy, but with superior cosmetic results and high patient satisfaction.

[Cutaneous microdialysis. Use in dermatology]

The determination of concentrations of exogenous or endogenous substances in the dermis, e.g. for pharmacokinetic studies, is technically difficult. Performing skin biopsies or inducing suction blisters results in the disintegration of the tissue and allows only single measurements. Recently, cutaneous microdialysis, a new simple and minimally invasive technique for continuously measuring of substances in the dermis in vivo, has been introduced in dermatological research. According to the principle of dialysis, a semipermeable membrane is inserted in the dermis and due to a concentration gradient between the interstitial space and a perfusate, substances diffuse through the pores of the membrane and can be analyzed in the dialysate. Cutaneous microdialysis represents a useful technique for pharmacokinetic or pharmacodynamic studies as well as for investigations regarding cutaneous physiology and pathophysiology.

Role of lasers and photodynamic therapy in the treatment of cutaneous malignancy

Tumor therapy is not a common indication for the use of lasers, as it is in the treatment of benign vascular skin lesions, since many alternative treatment modalities exist. However, certain patients may benefit from laser therapy of premalignant and malignant skin tumors. Skin tumors can be treated by laser excision, laser coagulation, laser vaporization, or photodynamic therapy (PDT). For these purposes, the carbon dioxide laser, the neodymium:yttrium aluminum garnet laser and the argon laser are particularly suitable. PDT is a therapeutic approach based on the photosensitization of the target tissue by topical or systemic photosensitizers and subsequent irradiation with light from a laser or a lamp inducing cell death via generation of reactive oxygen species. Laser therapy and PDT have shown good results in the curative treatment of actinic keratoses, superficial basal cell carcinoma, Bowen's disease and cheilitis actinica. However, they are not recommended for primary malignant melanoma and invasive squamous cell carcinoma. In some patients, lasers and PDT might also be used effectively for the palliative treatment of cutaneous metastases. In selected patients, lasers and PDT may offer some advantages over routine procedures, e.g. reduction of scarring and better cosmetic results. However, when treating invasive tumors with curative intention, one has to bear in mind the lack of histologic control and the limited depth of tissue penetration of most laser and PDT therapies.

[Truss-induced macular amyloidosis]

A 80-year-old male presented with a long time history of a localized red-brown macule with superficial lichenification and slight scaling in the right groin. An earlier skin biopsy revealed the presence of amyloid deposits. The patient therefore had a complete internal checkup including a rectal biopsy for exclusion of systemic amyloidosis. However, the laboratory data did not reveal any specific abnormalities including immunoglobulins and Bence-Jones protein. The rectal biopsy was also nonspecific. After skin examination, a rebiopsy was performed at our department showing acanthosis and spongiosis of the epidermis with parakeratosis. A homogenous eosinophilic deposit was present in the upper dermis and stained positive with thioflavine. At the second visit the patient wore a truss for a right inguinal hernia, perfectly matching the area of the skin lesion. Thus, the diagnosis of a localized macular amyloidosis was confirmed very likely due to permanent local friction. The classification of localized cutaneous amyloidoses should include local trauma as a cause to avoid unnecessary and exhausting internal checkups to exclude systemic involvement.

[Cutaneous manifestations of graft-versus-host disease]

Graft-versus-host disease (GvHD) is a severe complication of allogeneic stem cell transplantation. GvHD can arise at various time points: acute GvHD occurs during the first 100 days after transplantation in up to 50% of graft recipients. Chronic GvHD develops less frequently in about 30% after the 3rd month following transplantation involving the skin, the liver, the gastrointestinal tract, the eyes, and the neuromuscular apparatus. Early diagnosis of GvHD can be difficult, as drug reactions, viral infections and cutaneous reactions to radiation therapy may have clinical and histological similarities. In this review, the various cutaneous manifestations of GvHD, the histopathologic features, prophylaxis, and therapies of acute and chronic GvHD are discussed according to the recent literature.

Phototherapy of psoriasis: comparative experience of different phototherapeutic approaches

BACKGROUND

Broad-band UVB alone or in combination with different topical drugs (anthralin, calcipotriol), systemic PUVA and bath-PUVA therapy are very effective and well-established treatment modalities for psoriasis.

OBJECTIVE

The aim of this retrospective study was to assess which of these routinely applied phototherapeutic modalities might be most effective and safe for the treatment of plaque-type psoriasis.

METHODS

Patients (n = 203) with moderate to severe (pretreatment Psoriasis Area and Severity Index score between 12 and 35) chronic plaque-type psoriasis treated between 1992 and 1998 at our department with either UVB (with/without anthralin or calcipotriol; n = 97), systemic PUVA (n = 19) or bath-PUVA therapy (n = 87) were evaluated for efficacy, duration of treatment, number of treatments necessary for complete remission (CR), cumulative light dose, side effects of therapy and duration of remission after therapy.

RESULTS

No statistically significant difference comparing the efficacy of bath-PUVA (CR in 72.4%), PUVA (CR in 89.5%) and UVB phototherapy (CR in 69.1%) was found. Although the duration of therapy was significantly longer for bath-PUVA (66 +/- 42 days) as compared to UVB treatment (50 +/- 27 days), the mean number of treatments did not differ significantly between bath-PUVA (28 +/- 12), UVB therapy (30 +/- 12) and PUVA (26 +/- 13). Significantly fewer side effects of phototherapy were observed with bath-PUVA (14.9%) therapy compared to UVB treatment (30.9%). Also, the duration of remission after successful therapy was significantly longer for bath-PUVA (8.4 +/- 3.5 months) as compared to UVB phototherapy (5.1 +/- 4.2 months).

CONCLUSION

Bath-PUVA therapy has some advantages over UVB phototherapy in the treatment of psoriasis: fewer UV-related acute side effects and a longer period of remission after therapy. However, the choice of treatment with either UVB, bath-PUVA or systemic PUVA should also be based on a history of previous response to treatment and patient considerations, including compliance and responsibility for following the precautions to avoid potential side effects.

[Treatment of therapy refractory verrucae vulgares with a ciclopirox-containing lacquer]

BACKGROUND AND OBJECTIVE

Anti-inflammatory actions of ciclopirox, an antifungal agent, have been described previously. We assessed the effectiveness of ciclopirox in the treatment of viral warts.

PATIENTS/METHODS

Twenty-three immunocompetent patients (age 9-61 years) with common warts at the hands, feet and in the face resistant to conventional therapy were treated. Following keratolysis with a salicylic acid-containing patch, an 8% ciclopirox lacquer was applied 1-2 times daily. At the beginning and the end of the treatment lesions were photographed and the time span (minimum 4 weeks) until complete resolution was documented.

RESULTS

In 7 patients complete remission, and in 12 patients partial remission was achieved. Only 4 patients did not show any effect under topical ciclopirox treatment (mean duration of therapy 3.2 +/- 2.1 months). The overall response rate was 82.6%. Local side effects like erythema or pruritus were not reported.

CONCLUSION

Our data suggest that a ciclopirox lacquer may be helpful in the treatment of common warts. However, the data have to be confirmed in a randomized controlled trial in the future.

[Photochemotherapy of cutaneous AIDS-associated Kaposi sarcoma with indocyanine green and laser light]

BACKGROUND AND OBJECTIVE

Indocyanine green (ICG) is a clinically approved dye for diagnostic purposes, which has an absorption peak in the near infrared and remains intravascular due to a high plasma protein binding. Its therapeutic potential in combination with a diode laser was studied for well vascularized cutaneous tumors.

PATIENTS/METHODS

Six male patients (mean age 49.2 years) with AIDS-related Kaposi sarcomas (n = 30) received ICG (2 x 2 mg/kg i.v.) followed directly by irradiation with a diode laser (lambda = 805 nm, 100 J/cm2, 3 W/cm2).

RESULTS

All macular and plaque-type lesions (n = 27) showed primarily blister- and crust formation and healed within 14 days. Only one out of the 3 nodular lesions treated showed complete remission. The only side effect recognized was a mild burning sensation during irradiation. Nineteen lesions resolved completely leaving a slight atrophic scar, in three lesions a transient postinflammatory hyperpigmentation occurred. Within the follow-up period of 2 years no recurrence was detected.

CONCLUSIONS

The ICG-mediated photochemotherapy is an effective palliative therapeutic modality with a low rate of side effects in the treatment of macular or plaque-type cutaneous Kaposi sarcomas.

Endoscopic fluorescence detection of low and high grade dysplasia in Barrett's oesophagus using systemic or local 5-aminolaevulinic acid sensitisation

BACKGROUND AND AIMS

Barrett's oesophagus is associated with an increased risk of cancer. As dysplasia is not visible during routine endoscopy, random biopsies in the four quadrants every 1-2 cm are recommended. Endoscopic fluorescence detection (EFD) after sensitisation with 5-aminolaevulinic acid (5-ALA) with different modes and concentrations was assessed to optimise the technique for detection of dysplasia or early cancers. 5-ALA is converted intracellularly to protoporphyrin IX which accumulates in malignant tissue and can be detected by typical red fluorescence after illumination with blue light.

METHODS

In 47 patients with Barrett's oesophagus, 10 with known dysplasia, 58 fluorescence endoscopies were performed after sensitisation with different concentrations of 5-ALA given orally (5, 10, 20, 30 mg/kg) or locally (500-1000 mg) by spraying the mucosa via a catheter. EFD was performed 4-6 hours after systemic and 1-2 hours after local sensitisation using a special light source delivering white or blue light. A total of 243 biopsies of red fluorescent (n=113) and non-fluorescent areas (n=130) were taken.

RESULTS

In three patients, two early cancers and dysplasia, not visible during routine endoscopy, were detected by EFD. Thirty three biopsies revealed either low or high grade dysplasia. Sensitivity for detection of dysplastic lesions ranged from 60% after local sensitisation with 500 mg to 80%, 100%, and 100% after systemic application of 5-ALA 10, 20, and 30 mg/kg, respectively. However, specificity was best for local sensitisation (70%) while systemic administration revealed values between 27% and 56%. Using 5 mg/kg, no red fluorescence in dysplastic lesions was found. No severe side effects were noted.

CONCLUSION

EFD is a promising tool to detect non-visible dysplastic lesions in Barrett's oesophagus using 5-ALA sensitisation. A randomised controlled study is now indicated to compare the efficacy of EFD with the standard technique of four quadrant random biopsies.

[Paraneoplastic Bazex acrokeratosis in adenocarcinoma of the stomach]

HISTORY AND EXAMINATION

A 58-year-old man presented with a sudden eruption of hyperkeratoses on hands and feet. Alcohol abuse had been present 10 years ago, together with a gastric ulcer. Physical examination was unremarkable, except for plantar bizarre hyperkeratoses especially at the sides of the feet as well as some rhagades with spread to the dorsum of the toes. Similar but less severe hyperkeratoses were found on the palms.

INVESTIGATIONS

Laboratory investigation was essentially normal. X-rays of the thorax and sinuses as well as a sonography of the stomach revealed, except for a fatty liver, no pathological findings. Gastroscopy revealed a chronic active gastritis on the small curvature of the stomach. Only a second gastroscopy and biopsy revealed an adenocarcinoma of the stomach.

DIAGNOSIS, THERAPY AND COURSE

According to the clinical presentation a paraneoplastic acrokeratosis (Bazex syndrome) was diagnosed. The patient was given high-dose chemotherapy with subsequent stem-cell transplantation and gastrectomy. The skin problems resolved after the first cycles of chemotherapy.

CONCLUSION

If clinically a paraneoplastic acrokeratosis is suspected extensive search for a malignancy has to be initiated, including a gastroscopy, because rarely, but as in the present case, a carcinoma of the stomach can be the underlying cause.

[Fluorescence-assisted biopsy of basal cell carcinomas]

BACKGROUND AND OBJECTIVE

The diagnosis of precancerous and cancerous skin lessons in pretreated or scarred skin can be difficult. The determination of the right biopsy site in a suspected area depends largely on the physician's experience.

PATIENTS/METHODS

The possibility of using a CCD-camera system and measuring tumor fluorescence following topical application of 5-aminolevulinic acid was employed in a single case to facilitate accurate choice of biopsy site.

RESULTS

An user-independent evaluation of the induced fluorescence intensity was achieved by means of the described optical system and digital imaging. The contrast of the acquired fluorescence images can be significantly enhanced and allows the determination of a threshold. As result an initial, clinically not visible basal cell carcinoma was detected and excised by a punch biopsy in toto.

CONCLUSIONS

Using the described optical system the early recognition of a superficial basal cell carcinoma and the determination of the exact biopsy site was achieved in pretreated skin. The routine employment of the system will be assessed in a prospective study.

[Therapy of onychomycosis]

BACKGROUND

Considering the increased rate of mycotic infections of the nail, various concepts in the treatment of onychomycosis have been developed looking for a successful therapeutic approach.

AIMS

An overview of the actual standards of topic and systemic treatment of onychomycosis depending on clinical findings, classification of onychomycosis and type of fungus will be presented.

RESULTS

Topical urea and bifonazole therapy was available in the past as well as systemic antimycotic therapy with just griseofulvin or ketoconazole. Nowadays a different spectrum of easily applicable, safe and effective therapeutic measures is on the physician's hands. Besides topical therapy with ciclopirox and amorolfine oral treatment with itraconazole, terbinafine and fluconazole is available. Combination therapy of terbinafine orally in addition with topical application of ciclopirox may possibly optimize the therapeutic approach considering the respective response rates however, no clinical study evaluating this hypothesis has been performed so far.

[Ectopic parotid tissue. An usual differential cervical cystic tumor diagnosis]

Cystic tumors of the neck are usually cysts, inflammatory masses, lymph nodes, benign and malignant tumors or metastases. Malformations are less common. Ectopic salivary tissue is a rather rare but clinically important malformation. Accessory and aberrant tissue can be identified histologically. There may be an association with lymphatic tissue. Possible complications include inflammation as well as the development of benign and in rare cases malignant salivary gland tumors. We report on two patients who underwent surgical treatment under the tentative diagnosis of epidermal cysts which histologically turned out to be ectopic parotid tissue.

No generalized skin phototoxicity after intravesical application of 5-aminolevulinic acid for fluorescence diagnosis of superficial bladder cancer

INTRODUCTION

A prospective monocenter open study was carried out to evaluate if generalized phototoxic skin reactions occur after intravesical application of 5-aminolevulinic acid (ALA) for fluorescence diagnosis of superficial bladder carcinomas.

PATIENTS AND METHODS

On 21 patients, skin phototoxicity was determined prior to as well as 4, 8 and 28 h after intravesical instillation of a 3% ALA solution by exposing small skin areas to a progressively graded series of defined UVA-light doses (n = 9; 5-80 J/cm(2)).

RESULTS

Prior to ALA instillation, erythema or pigmentation as signs of cutaneous phototoxicity occurred at an UVA-light dose of 28 +/- 1.5 J/cm(2) (mean +/- SEM). A reduction of the minimal phototoxic dose (MPD) was not detected 4 (28 +/- 1.9 J/cm(2)), 8 (28 +/- 1.6 J/cm(2)) and 28 h (28 +/- 1.5 J/cm(2)) after ALA instillation. Consequently phototoxic reactions were not observed.

CONCLUSIONS

A reduction of MPD for UVA was not detected. Therefore, it is not necessary to protect the skin of patients from ambient or daylight after intravesical instillation of ALA for fluorescence diagnosis.

Indocyanine green (ICG) and laser irradiation induce photooxidation

The cellular uptake and subcellular localization of indocyanine green (ICG; absorption band 700-850 nm), and cell survival and ultrastructural changes following ICG-mediated phototherapy were investigated in vitro in four different cell lines derived from human skin (SCL1 and SCL2 squamous cell carcinoma, HaCaT keratinocytes and N1 fibroblasts). The cellular uptake of ICG (1-50 microM, incubation times 1, 4, 24 h) was saturable, highly cumulative and could be inhibited by the addition of 250 microM bromosulphophthalein indicating the involvement of the organic anion transporting polypeptide (OATP). For HaCaT cells, the maximum cellular uptake (Vmax) and the Michaelis constant (K(m)) were 9.9 +/- 1.1 mM and 47 +/- 16 microM, respectively, following a 24-h incubation with ICG. Fluorescence microscopy revealed a cytoplasmic distribution of ICG, probably bound to glutathione S-transferase. Following irradiation with a cw-diode laser (805 nm, 80 mW/cm2) at doses of 24 or 48 J/cm2, the phototoxicity was determined using the MTT assay as a measure of cell viability. For all cell lines, ICG concentrations above 25 microM produced a significant phototoxic effect. The EC50, of ICG for HaCaT cells following irradiation at 24 J/cm2 was 20.1 +/- 3.9 microM. Growth curves showed that even HaCaT cells treated at the EC50 were killed within a week following treatment. Electron microscopy 1 h after ICG-mediated phototherapy revealed cytoplasmic vesiculation, dilation of the rough endoplasmic reticulum, the Golgi complex and the perinuclear cisternae and the beginning of chromatin condensation in the nucleus. These ultrastructural findings are not consistent with a photothermal action of ICG-mediated phototherapy. Taken together with those of previous studies by our group these results support photooxidation as a major cell-killing mechanism.

Simultaneous occurrence of folliculitis decalvans capillitii in identical twins

Folliculitis decalvans is a chronic purulent folliculitis resulting in permanent hair loss and follicular atrophy. We report 32-year-old identical female twins presenting with relapsing pruritic outbreaks on the scalp resulting in areas of permanent baldness. Staphylococcus aureus was detected in the lesions of both women. Histopathology confirmed the diagnosis of folliculitis decalvans. Immunological testing showed no alteration of the immune system. To our knowledge, this is the first report on folliculitis decalvans occurring in identical twins, suggesting a possible genetic component in this disease.

Does smoking influence the efficacy of bath-PUVA therapy in chronic palmoplantar eczema?

Bath-PUVA therapy has been described as successful treatment for palmoplantar eczema. However, our own observations showed that patients with palmoplantar eczema of the dyshidrotic or hyperkeratotic type responded only partially to bath-PUVA therapy. In order to evaluate environmental influences possibly having an impact on the efficacy of this therapy, smokers and non-smokers suffering from palmoplantar eczema treated with bath-PUVA therapy were compared. A retrospective study was conducted involving 62 patients, 39 non-smokers and 23 smokers, with palmar and/or plantar eczema resistant to local corticosteroids. Bath-PUVA therapy was performed according to the European standard regimen for oral PUVA therapy. The total number of treatments and the cumulative UVA-dose were similar in smokers and non-smokers (smokers 24+/-17.7 (mean+/-SD) and 67.6+/-51.3 J/cm2 vs. non-smokers 25.7+/-16.3 and 68.5+/-49.3 J/cm2). In the group of non-smokers, 31% showed complete remission (CR; 100% clearance), 33% partial remission (PR; more than 50% clearance) and 36% no change after treatment (NC; less than 50% clearance). In contrast, the group of smokers showed only 13% CR and 22% PR, whereas 65% exhibited NC. The differences regarding complete or partial remission between the groups were statistically significant (Student t-test for paired samples; P<0.05). Regarding the different type of eczema, bath-PUVA proved to be more successful in the dyshidrotic type of eczema as compared to the hyperkeratotic type in non-smokers (P<0.05). In the group of smokers no CR was achieved in patients suffering from the dyshidrotic form of eczema. Smoking is likely to be a reason for the failure of bath-PUVA therapy in the treatment of chronic palmoplantar eczema, in particular regarding smokers with eczema of the dyshidrotic type where no complete remission was achieved.

Topical photodynamic therapy for localized scleroderma

Therapy of localized scleroderma is unsatisfactory, with numerous treatments being used that have only limited success or considerable side-effects. The aim of this trial was to determine whether topical photodynamic therapy would be effective in patients with localized scleroderma. Five patients with progressive disease, in whom conventional therapies had failed, were treated by application of a gel containing 3% 5-aminolevulinic acid followed by irradiation with an incoherent lamp (40 mW/cm2, 10 J/cm2). The treatment was performed once or twice weekly for 3-6 months. In all patients the therapy was highly effective for sclerotic plaques, as measured by a quantitative durometer score and a clinical skin score. The only side-effect was a transient hyperpigmentation of the treated lesions. These cases document the beneficial effect of topical photodynamic therapy in localized scleroderma. Controlled trials are now necessary to confirm these preliminary results.

Long-pulse dye laser for photodynamic therapy: investigations in vitro and in vivo

BACKGROUND AND OBJECTIVE

Continuous wave lasers or incoherent lamps are used effectively for photodynamic therapy (PDT). As the mechanism of action of pulsed lasers in PDT is not known, we investigated the efficacy of PDT with 5-aminolevulinic acid (ALA) using a long-pulse (1.5 ms) tunable flashlamp-pumped pulsed dye laser (LPDL) in vitro and in vivo.

STUDY DESIGN/MATERIALS AND METHODS

HaCaT human keratinocytes were incubated with ALA (3 mmol/l) and irradiated (0-50 J/cm(2)) using the LPDL at 585 nm, 595 nm, or 600 nm vs. an incoherent light source (580-740 nm). Topical ALA-PDT was performed on 24 patients with actinic keratoses (AK) on the head (n = 200) after incubation with a 20% ALA emulsion and irradiation by either an incoherent light source (160 mW/cm(2), 60-160 J/cm(2)) or the LPDL (585 nm, 18 J/cm(2)).

RESULTS

Maximal cytotoxic effects in vitro were achieved using the LPDL at 585 nm or the incoherent lamp (50 J/cm(2)). Sodium azide, a quencher of singlet oxygen, significantly reduced cell killing, suggesting that the cytotoxic effects are mainly mediated by singlet oxygen. This is supported by an increase of lipid peroxides as determined by malondialdehyde after adding D(2)O. Complete remission was achieved in 79% of 100 AK treated by ALA and the LPDL and in 84% of 100 AK treated by ALA and the incoherent lamp. Pain during light treatment was significantly reduced by using the LPDL. Control lesions (LPDL without ALA) did not clear.

CONCLUSION

These results show the in vitro and in vivo efficacy of ALA-PDT using a pulsed light source mediated by singlet oxygen.

Active and higher intracellular uptake of 5-aminolevulinic acid in tumors may be inhibited by glycine

Topical 5-aminolevulinic acid is used for the fluorescence-based diagnosis and photodynamic treatment of superficial precancerous and cancerous lesions of the skin. Thus, we investigated the kinetics of 5-aminolevulinic acid-induced fluorescence and the mechanisms responsible for the selective formation of porphyrins in tumors in vivo. Using amelanotic melanomas (A-Mel-3) grown in dorsal skinfold chambers of Syrian golden hamsters fluorescence kinetics were measured up to 24 h after topical application of 5-aminolevulinic acid (1%, 3%, or 10%) for 1 h, 4 h, or 8 h by intravital microscopy (n = 54). Maximal fluorescence intensity in tumors after 1 h application (3% 5-aminolevulinic acid) occurred 150 min and after 4 h application (3% 5-aminolevulinic acid) directly thereafter. Increasing either concentration of 5-aminolevulinic acid or application time did not yield a higher fluorescence intensity. The selectivity of the fluorescence in tumors decreased with increasing application time. Fluorescence spectra indicated the formation of protoporphyrin IX (3% 5-aminolevulinic acid, 4 h; n = 3). The simultaneous application of 5-aminolevulinic acid (3%, 4 h) and glycine (20 microM or 200 microM; n = 10) reduced fluorescence in tumor and surrounding host tissue significantly. In contrast, neither decreasing iron concentration by desferrioxamine (1% and 3%; n = 10) nor inducing tetrapyrrole accumulation using 1, 10-phenanthroline (7.5 mM; n = 5) increased fluorescence in tumors. The saturation and faster increase of fluorescence in the tumor together with a reduction of fluorescence by the application of glycine suggests an active and higher intracellular uptake of 5-aminolevulinic acid in tumor as compared with the surrounding tissue. Shorter application (1 h) yields a better contrast between tumor and surrounding tissue for fluorescence diagnosis. The additional topical application of modifiers of the heme biosynthesis, desferrioxamine or 1,10-phenanthroline, however, is unlikely to enhance the efficacy of topical 5-aminolevulinic acid-photodynamic therapy at least in our model.

Photo-oxidative killing of human colonic cancer cells using indocyanine green and infrared light

Despite of the approval of Photofrin in various countries, chemically defined sensitizers for photodynamic therapy (PDT) are still needed for the absorption of light in the infrared spectrum, which provides a maximal penetration of light into tissue. Therefore, both the efficacy and the mechanism of action of the clinically approved dye indocyanine green (ICG) and laser irradiation were investigated in vitro. For the investigation of phototoxic effects, HT-29 cells were incubated 24 h prior to irradiation by using different concentrations of ICG (10-500 microM). In each experiment, cells were irradiated using a continuous wave (cw)-diode laser (lambda(ex) = 805 nm, 30 J cm(-2), 40 mW cm(-2)). After laser irradiation, cell viability of dark control and of cells incubated with 500 microM ICG was 1.27+/-0.11 or 0.28+/-0.05 respectively. Using 100 microM ICG and D2O, cell viability was further decreased from 0.46+/-0.03 (H2O) to 0.11+/-0.01 (D2O). Using D2O and 100 microM ICG, the concentration of malondialdehyde, a marker of lipid peroxidation, increased from 0.89+/-0.10 nmol 10(-6) cells to 11.14+/-0.11 nmol 10(-6) cells. Using 100 microM ICG and laser irradiation sodium azide or histidine (50 mM), quenchers of singlet oxygen reduced the cell killing significantly. In contrast, when using mannitol, a quencher of superoxide anion and hydroxyl radical, cell killing was not inhibited. According to the present results, photoactivated ICG seems to kill colonic cancer cells due to the generation of singlet oxygen and the subsequent formation of lipid peroxides. Therefore, ICG might present a promising photosensitizer for PDT; first clinical results confirm these findings.

Epidermodysplasia verruciformis treated using topical 5-aminolaevulinic acid photodynamic therapy

We describe a 65-year-old woman who had had wart-like lesions on the hands, lower arms and forehead for about 45 years. She had already had several basal cell carcinomas excised. Histological study, electron microscopy and in situ hybridization [human papilloma virus (HPV)-types 5/8/12/14/19-23/25/36] of skin biopsies confirmed a diagnosis of epidermodysplasia verruciformis (EV). Photodynamic therapy (PDT) was performed using a 20% 5-aminolaevulinic acid ointment applied for 6 h to the lesions and irradiating using an incoherent light source (lambda = 580-740 nm, 160 mW/cm2, 160 J/cm2). Following PDT, blistering and crusting of the lesions occurred, but these healed completely within 2-3 weeks without scarring, and the cosmetic result was excellent. Six months after PDT a skin biopsy was taken. In situ hybridization was positive for HPV type 8 in skin which was clinically and histologically normal. Twelve months after PDT a few lesions had recurred on the hands. Although permanent cure of EV cannot be achieved by any therapy at present and single lesions continue to appear in this patient, topical PDT might result in better control of HPV-induced lesions.

Treatment of digital mucous cysts with a carbon dioxide laser

Digital mucous cysts are common tumours of the distal interphalangeal joint, causing pain, cosmetic disfigurement and nail deformities. This study describes six patients suffering from digital mucous cysts, some of which recurred after surgery. Carbon dioxide laser vaporization was performed under local anaesthesia, resulting in complete remission in four out of six patients. In two patients, the mucous cyst recurred within 3 weeks and 11 months, respectively, after laser therapy. Although complete remission cannot be achieved in all patients, carbon dioxide laser vaporization of mucous cysts is fast and easy to perform. No side-effects of therapy, such as nail deformities, pain or infection, occurred. For this reason, more aggressive treatments, such as radical excision of the cyst, could be restricted to cases in which carbon dioxide laser therapy fails.

Photosensitization of human skin cell lines by ATMPn (9-acetoxy-2,7,12,17-tetrakis-(beta-methoxyethyl)-porphycene) in vitro: mechanism of action

9-Acetoxy-2,7,12,17-tetrakis-(beta-methoxyethyl)-porphycene (ATMPn) is a promising new photosensitizer characterized by high absorption around 640 nm and high singlet oxygen yield. To study the mechanism of action in vitro we have investigated uptake, intracellular localization, cell survival and ultrastructural changes following photodynamic treatment in human cell lines derived from the skin (SCL1 and SCL2, squamous cell carcinoma; HaCaT keratinocytes; N1 fibroblasts). Using flow cytometry we have determined the cellular fluorescence as a marker for the uptake of ATMPn after incubation for 60 min. Co-staining with ATMPn and fluorescent dyes specific for cell organelles reveals an intracellular localization of ATMPn in lysosomes. Following irradiation using an incoherent light source (580-740 nm) and a light fluence of 24 J cm-2, phototoxicity is determined by means of the 3-4.5 dimethylthiazol-2,5 diphenyl tetrazolium bromide (MTT) assay. For all cell lines ATMPn concentrations above 15 nM yield a significant phototoxic effect. The 50% effective concentration, EC50, for SCL1 cells is 11.2 +/- 2.9 nM ATMPn. ATMPn uptake and phototoxicity are more effective for HaCaT and SCL1 as compared to SCL2 and N1 cells. Growth curves confirmed the results of the MTT assay. Because of the high lysosomal accumulation of ATMPn, already low photosensitizer concentrations without dark toxicity yield a high photodynamic effect. Immunofluorescence and electron microscopy reveal damage to tonofilaments, plasma membrane and mitochondria, indicating a mechanism unrelated to apoptosis. A dose yielding complete cell killing, as needed for oncological indications, might lead to necrosis, whereas lower sub-lethal doses result in induction of apoptosis.

Simulations on the selectivity of 5-aminolaevulinic acid-induced fluorescence in vivo

The knowledge of the exact time course of a photosensitizer in tumour and surrounding host tissue is fundamental for effective photodynamic therapy (PDT) and fluorescence-based diagnosis. In this study the time course of porphyrin fluorescence following topical application of 5-aminolaevulinic acid (ALA) using different formulations, concentrations and incubation times has been measured in amelanotic melanomas (A-Mel-3) (n = 54) grown in transparent dorsal skinfold chambers of Syrian golden hamsters and in human basal cell carcinomas (BCCs) (n = 40) in vivo. To simulate the accumulation of ALA-induced protoporphyrin IX (Pp IX), a three-compartment model has been developed and rate constants have been determined. The kinetics of both the A-Mel-3 tumours and the BCCs show a significantly higher fluorescence intensity in tumour as compared to normal surrounding host tissue. Maximal fluorescence intensity in A-Mel-3 tumours as a percentage of the reference standard used occurs 150 min post incubation (p.i.) using a 1, 3 or 10% (vol.) ALA solution buffered to pH 7.4 and 1 h incubation time. After a 4 h incubation time maximal fluorescence intensity in tumour is measured shortly p.i. A concentration of 10% ALA does not increase the fluorescence intensity as compared to 3% ALA following 4 h incubation, but either 3 or 10% ALA yields a significantly higher fluorescence after 4 h incubation time as compared to 1 h. The fluorescence intensity following an 8 h incubation reaches its maximum directly p.i. for all concentrations and then decreases exponentially. The fluorescence intensity in the surrounding host tissue shows no statistically significant difference regarding concentration or incubation time. At least during the first hour p.i., the fluorescence intensity measured in the surrounding tissue is lower as compared to that in the tumour in all groups. 24 h after topical application hardly any fluorescence is detectable in tumour or surrounding host tissue in all experimental groups. Incubating human BCCs with a 20% ALA cream (water-in-oil emulsion) or a 20% ALA gel (containing 40% dimethyl sulfoxide) for approximately 2 h yields a similar fluorescence intensity directly after incubation for either cream or gel. However, while yielding a maximum 120 min p.i. with cream, the fluorescence intensity increases for a longer time (about 2-3 h p.i.) and up to higher values using the gel formulation. In surrounding normal skin, cream as well as gel formulation yields a similar fluorescence intensity directly after incubation. Afterwards the fluorescence intensity decreases slowly using the cream whereas a further increase of the fluorescence intensity is measured in the normal skin with a maximum 240 min p.i. using the gel formulation. The results of the proposed three-compartment model indicate that the observed selectivity of accumulated porphyrins following topical application of ALA is mainly governed by an increased ALA penetration of the stratum corneum of the skin, an accelerated ALA uptake into the cell and a higher porphyrin formation in tumour as compared to normal skin tissue, but not by a reduced ferrocheletase activity.

Photostability and thermal stability of indocyanine green

The photo-fading of the S0-S1 absorption band of the infrared dye indocyanine green sodium iodide (ICG-NaI) has been studied by cw laser excitation to the S1 band. Monomeric solutions in water, heavy water, aqueous sodium azide, human plasma, methanol and dimethyl sulfoxide (DMSO) as well as J-aggregated solutions in H2O and D2O have been investigated. A leucoform of indocyanine green seems to be formed by photodegradation. The degradation slows down with exposure time. The initial degradation yield, phi D,0, is determined. In monomeric and dimeric water, heavy water and sodium azide solutions the initial photostability is of the order of phi D.0 approximately 10(-3), in the organic solvents methanol and DMSO it is of the order of phi D.0 approximately 10(-5), and in human plasma it is phi D.0 approximately 2 x 10(-6). J-aggregates at high concentration are very stable. The thermal stability of the ICG-NaI solutions at room temperature in the dark is compared with their photostability. The thermal degradation time of monomeric and dimeric ICG-NaI in water, heavy water and sodium azide solutions is t(th) approximately 10 days, while no thermal degradation is observed for ICG-NaI J-aggregates and ICG-NaI in methanol, DMSO and human plasma.

Photosensitization of skin-derived cell lines by Dimegin [2,4-di-(alpha-methoxyethyl)-deuteroporphyrin IX] in vitro

The deuteroporphyrin-IX derivative Dimegin [2,4-di-(alpha-methoxyethyl)-deuteroporphyrin IX] was investigated with respect to cellular uptake, intracellular localization and cell survival following photodynamic treatment in human cell lines derived from the skin (SCL1 and SCL2, squamous cell carcinoma; HaCaT keratinocytes; N1 fibroblasts). Using flow cytometry, we determined the cellular fluorescence as a marker of the uptake of Dimegin after incubation for 24 h. The intracellular localization of Dimegin was analysed using fluorescence microscopy and co-staining with fluorescent dyes specific for cell organelles. Following irradiation with an incoherent light source (580-740 nm) using a light dose of 24 J/cm2, phototoxicity was determined by means of trypan blue dye exclusion, MTT assays and growth curves. The relative Dimegin fluorescence of the different cell lines declined as follows: SCL1 > HaCaT > N1 > SCL2. Intracellular localization of Dimegin was found in the mitochondria. For all cell lines Dimegin concentrations above 15 microM yielded a significant phototoxic effect. The EC50 for SCL1 cells was 8.9 +/- 2.0 microM Dimegin. The EC50 for the cell lines increased as follows: SCL1 < HaCaT < N1 < SCL2, thus correlating with the cellular fluorescence of Dimegin. The results of the MTT assay were confirmed by trypan blue dye exclusion assay and growth curves. In conclusion, the study shows that Dimegin is an effective photosensitizer with a rapid mechanism of action in vitro, resulting in an immediate loss of plasma membrane integrity following irradiation.

[Photodynamic diagnosis of gastrointestinal precancerous lesions after sensitization with 5-aminolevulinic acid. A pilot study]

BASIC PROBLEM AND OBJECTIVE

Endoscopic diagnosis of gastrointestinal precancerous and cancerous lesions is difficult, often even impossible. This study was undertaken to find out whether premalignant or suspected malignant tumors can be diagnosed by preceding sensitization with 5-aminolaevulinic acid (ALA), which in tumors is transformed in increased amounts into photosensitizing protoporphyrin IX, the latter being recognized by its characteristic red fluorescence on exposure to blue light.

PATIENTS AND METHODS

20 patients with known mild or moderately severe dysplasias (Barrett's esophagus, n = 8; colorectal adenoma, n = 3; ulcerative colitis n = 2, and gastric polyps or mucosal changes suspicious of malignancy, n = 5. Two patients with squamous-cell carcinoma, who after radio- and chemotherapy were endoscopically free of tumor, were sensitized with different concentrations of ALA (orally: 5-30 mg/kg; or locally: 3 g in 100 ml 0.9% NaCl). Photodynamic diagnosis (PDD) took place 4-8 h after oral and ca. 1-2 h after local sensitization with blue light (D-light, Storz, Tuttlingen, Germany).

RESULTS

Definite red fluorescence with demonstration of dysplasia was found in three of four patients with Barrett's esophagus. Biopies from nonfluorescent areas were free of dysplasia. Two gastric adenomas (10 mg/kg ALA with high-grade dysplasia were definitively endoscopically by their red fluorescence. In one patient mild dysplasia was found in a non-fluorescent area after radio- and chemotherapy of an esophageal carcinoma. Dysplasias were also seen in the rectal biopsy after local applications.

CONCLUSIONS

PDD makes it possible for the first time to visualize precancerous lesions of the gastrointestinal tract after preceding ALA sensitization. PDD is a highly promising method for monitoring patients with gastrointestinal disease and an increased risk of cancer, and for clarifying the diagnosis of mucosal changes suspicious of malignancy.

[Allopurinol in treatment of cutaneous sarcoidosis]

Several reports more than ten years ago provided evidence that allopurinol may be effective for cutaneous sarcoidosis. We therefore treated two patients with histologically confirmed scar sarcoidosis and two with nodular sarcoidosis. A daily dosage of 300 mg allopurinol was given over a period of 4-7 months as single drug therapy. In both patients with scar sarcoidosis, the skin manifestations completely regressed while in the patients with nodular sarcoidosis there was significant improvement. The concomittant pulmonary involvement in two patients was unpredictable, in one patient improved while the other was deteriorated, The mode of action is still unclear but because of the positive results and the low rate of side effects, allopurinol seems a reasonable agent for treating cutaneous sarcoidosis.

Indocyanine green and laser light for the treatment of AIDS-associated cutaneous Kaposi's sarcoma

Indocyanine green (ICG) is clinically approved for the determination of liver function, cardiac output and plasma volume. In this pilot study, ICG was used as photosensitizer in combination with a diode laser to treat AIDS-associated Kaposi's sarcoma (KS) in three patients. Directly and up to 50 min after intravenous administration of ICG (2-4 mg kg(-1) body weight), KS (n=57), mainly plaque-type, were irradiated using a diode laser (lambda em=805 nm, 100 J cm[-2], 0.5-5 W cm[-2]) matching the absorption maximum. Complete remission of KS (n=16) was achieved when irradiated 1-30 min after injection of the second dose of ICG (2 x 2 mg kg(-1) b.w., 30 min apart) with 3-5 W cm(-2) and 100 J cm(-2). Biopsies (n=3) revealed necrosis of the tumour 24 h and complete remission 4 weeks after therapy. In general, systemic side-effects were not observed and cosmetic results were very good. However, hyperpigmentation occurred temporarily in lesions located on the lower extremities. These findings show that AIDS-associated KS can be effectively treated after photosensitization with ICG and subsequent irradiation with an appropriate diode laser. However, additional investigations need to elucidate the exact mechanism of action of ICG-mediated phototherapy and have to show the efficacy for the treatment of other highly vascularized solid tumours.