***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND / PURPOSE A relatively long incubation time is needed for photosensitizer absorption in conventional photodynamic therapy ( PDT ) for actinic keratosis ( AK ) . The use of ablative CO2 fractional lasers ( AFXLs ) to increase drug delivery could shorten the incubation time . Here , we aim ed to compare the efficacy between AFXL-assisted PDT with a short incubation time and conventional PDT for AK . METHODS Patients with histopathologically confirmed facial AK were r and omly divided into two groups . The lesions were histopathologically classified into grade s I-III . In the AFXL-assisted PDT group , an ablative fractional laser was used for pretreatment , prior to the application of methyl aminolevulinate , with an incubation time of 90 min . Irradiation was performed with a 630-nm light-emitting diode . In the conventional PDT group , the incubation time was 180 min . All the patients received two rounds of PDT at 2-week intervals and underwent clinical or histological evaluation at 10 weeks after the first PDT course . RESULTS Twenty-two patients underwent conventional PDT and 24 patients underwent AFXL-assisted PDT . Thirty-four AKs were included in the conventional PDT group , and 35 AKs were included in the AFXL-assisted PDT group . The clearance rate was 64.7 % in the conventional PDT and 71.4 % in the AFXL-assisted PDT group ; no significant differences in the clearance rate were noted between the groups ( P = 0.55 ) . The clearance rates for each grade also did not significantly differ between the two groups . CONCLUSIONS The use of AFXL before PDT reduced the incubation time , but yielded similar treatment efficacy as compared to conventional PDT BACKGROUND Iontophoresis is a transdermal drug-delivery technique that enhances the transport of ionic species across membranes and may have significant benefit for the treatment of actinic keratosis ( AK ) by ablative fractional laser-primed photodynamic therapy ( AFL-PDT ) . The aims of this study were to compare the efficacy , recurrence rate , cosmetic outcome and safety of iontophoresis-assisted AFL-PDT with 2h of incubation vs. those of conventional AFL-PDT with 2- and 3-h incubation in patients with facial and scalp AK . METHODS Patients were r and omly assigned to iontophoresis-assisted AFL-PDT with a 2-h incubation time ( group A ) and conventional AFL-PDT with a 2-h ( group B ) and 3-h ( group C ) incubation time . All patients underwent  AFL-PDT  , and group A patients were assigned to treatment with iontophoresis after methyl-aminolevulinate ( MAL ) application . After 2 or 3h , MAL-applied lesions were irradiated using a red light . Patients were followed up at 1-week , 3 months and 12 months after treatment . Efficacy , cosmetic outcomes and adverse events were assessed . RESULTS In total , 41 patients ( 160 AK lesions ) completed the study and were evaluated . Efficacy was significantly higher in Group A ( 88.7 % ) than in Group B ( 73.2 % ) ; the efficacy of groups A and C ( 92.2 % ) at 3 months follow-up was comparable . The recurrence rates were not significantly different between the groups at 12 months ( P=0.841 ) . The three groups did not differ in terms of cosmetic outcomes and safety . CONCLUSIONS Iontophoresis-assisted AFL-PDT showed higher efficacy than AFL-PDT with short incubation time . Iontophoresis may effectively reduce the incubation time in AFL-PDT BACKGROUND Photodynamic therapy ( PDT ) with methyl aminolevulinate ( MAL ) is effective for treating multiple actinic keratoses ( AKs ) .  Ablative fractional laser ( FL ) creates vertical channels that may facilitate MAL delivery and improve PDT response . OBJECTIVE To evaluate the efficacy of FL-assisted PDT ( FL-PDT ) in treating facial AKs in Korean patients . METHODS A prospect i ve r and omized non-blinded trial initially evaluated 271 facial AKs in 45 patients . All patients underwent one session of MAL-PDT using a red light-emitting diode lamp at 37 J/cm(2 ) , and 23 patients with 135 AK lesions were r and omly assigned to pre-treatment with a 2940-nm ablative fractional erbium : Yag laser . Patients were followed up at 1 , 2 and 4 weeks and every month until 6 and 12 months post-treatment . Response , adverse events , cosmetic outcome and patient satisfaction were documented . Finally , a total of 236 facial AKs in 40 patients were enrolled and analysed in this study . RESULTS FL-PDT was significantly more effective than MAL-PDT at treating all AK grade s ( 86.9 % vs. 61.2 % ; P < 0.001 ) . The efficacy of FL-PDT was most pronounced in treating Olsen grade III AKs ( 69.4 % vs. 32.5 % ; P = 0.001 ) . FL-PDT also showed a lower lesion recurrence rate than MAL-PDT ( 9.7 % vs. 26.6 % ; P = 0.004 ) . Excellent or good cosmetic outcome was reported in > 90 % cases . Erythema and hyperpigmentation intensities were higher in the FL-PDT group ( P > 0.05 ) . Side-effects were more frequent in the FL-PDT group , but these were mild and well tolerated ( P > 0.05 ) . CONCLUSION FL-PDT is effective for treating AKs , especially moderate-to-thick lesions BACKGROUND Aminolevulinic acid ( ALA ) photodynamic therapy ( PDT ) is an established treatment option for actinic keratosis ( AK ) , and recently fractional carbon dioxide ( CO2 ) laser was shown to improve outcomes ; but studies of short incubation photosensitizer are lacking . OBJECTIVE Assess the efficacy of short incubation ALA followed by blue light PDT with and without previous fractional CO2 treatment for the treatment of AK . METHODS R and omized , paired split- design , controlled trial of fractional CO2 followed by ultrashort 15-minute versus 30-minute incubation ALA and blue light PDT for the treatment of AK on the face . RESULTS The complete clearance rates ( CRs ) at 8 weeks after ALA PDT with and without FxCO2 at 30- and 15-minute ALA incubation times were 89.78 % ( + FxCO2 ) versus 71.20 % CR ( −FxCO2 ) at 30′ , and 86.38 % ( + FxCO2 ) versus 69.23 % ( −FxCO2 ) at 15′ ALA incubation . All lesion improvements were statistically significant . CONCLUSION This r and omized , comparative paired group controlled clinical study demonstrates that ultrashort 15- and 30-minute incubation ALA PDTs are of limited efficacy for the treatment of AK . Pretreatment with fractional ablative resurfacing yields statistically significant greater AK clearance  with ALA-PDT at ultrashort ALA incubations followed by blue light 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 / MATERIAL S 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 BACKGROUND AND OBJECTIVE Photodynamic therapy ( PDT ) with 5-aminolevulinic acid ( ALA ) and intense pulsed light ( IPL ) is a relatively new combination for the treatment of actinic keratosis ( AK ) and photodamage . The objective of this study was to determine the effect of increasing the fluence of IPL on the outcome of patients with these skin conditions . METHODS Patients ( N = 24 ) were r and omly assigned to five treatment treatment groups : control ( IPL alone ) and ALA with 20 , 25 , 40 , and 50 J/cm(2 ) fluence of IPL . Each patient received a single treatment . ALA was applied twice and allowed to incubate 2 h before IPL irradiation . Results were evaluated 5 - 7 days and 8 weeks after treatment . Clearance of AK lesions was evaluated by counting lesions before and after treatment , and improvement in photodamage was assessed by comparing pre- and post-treatment photographs . Statistical evaluation was based at nonparametric tests with a cut-off level at p < 0.10 and a confidence interval at 95 % . RESULTS Responses to treatment were greatest in patients who received ALA and IPL fluences of 40 and 50 J/cm(2 ) . Responses were " marked " in 19 % of the patients receiving 50 J and " moderate " in 19 % of the patients receiving 40 J. Compared to the mean pre-treatment AK grade s , the mean post-treatment grade s were 56 % lower in the 50 J treatment group , 32 % lower in the 25 J group , 50 % lower in the 40 J group , 20 % lower in the 20 J group , and 7 % lower in the control group . Erythema , edema , crusts and erosion , and pain did not cause any patient to discontinue the study . CONCLUSION AK clearance , but not photorejuvenation , appears to improve with increasing fluence at the ALA PDT-IPL levels used in this study without serious adverse effects BACKGROUND Unmet needs exist in actinic keratosis ( AK ) treatment .  Daylight photodynamic therapy ( DL-PDT ) has shown good efficacy and safety results compared to conventional PDT ( c-PDT ) in a recent Phase III multi-centre r and omised controlled trial in Australia among 100 subjects with AKs . OBJECTIVES Demonstrate non-inferior efficacy and superior safety of DL-PDT compared to c-PDT in treating multiple mild and /or moderate facial/scalp AKs . METHODS Phase III , 12 week , multi-centre , r and omised , investigator-blinded , controlled , intra-individual study conducted at different latitudes in Europe . AKs of adult subjects were treated once with methyl aminolevulinate ( MAL ) DL-PDT on one side of the face and MAL c-PDT contralaterally . Endpoints for DL-PDT concerned efficacy ( non-inferiority regarding complete lesion response at week 12 ) and safety ( superiority regarding subject 's assessment of pain after treatment , on an 11-point numeric rating scale ) . Safety evaluation also included incidence of adverse events . Subject satisfaction was described using a question naire at baseline and last visit . RESULTS At week 12 , the total lesion complete response rate with DL-PDT was similar ( non-inferior ) to c-PDT ( 70 % vs. 74 % , respectively ; 95 % CI [ -9.5 ; 2.4 ] in PP analysis , confirmed in ITT analysis ) . In addition , efficacy of DL-PDT was demonstrated regardless of weather conditions ( sunny or cloudy ) . DL-PDT was nearly painless compared to c-PDT ( 0.7 vs. 4.4 , respectively ; P 
    Output:
    
Conclusion : Laser‐assisted PDT  is more efficient but not more painful  than PDT or laser treatment only