***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 There is no completely satisfactory treatment for  multiple actinic keratoses ( AKs ) .  OBJECTIVE To evaluate the efficacy of short incubation , broad-area application of delta-aminolevulinic acid followed by exposure to activating light-photodynamic therapy ( delta-ALA/PDT ) for treatment of AKs and background photodamage . The benefit of pretreatment with 40 % urea cream to enhance penetration and the use of topical 3 % lidocaine hydrochloride to decrease discomfort were also evaluated . METHODS Eighteen patients with at least 4 nonhypertrophic facial AKs and mild to moderate diffuse facial photodamage were enrolled in the study . For 7 days , 40 % urea cream or vehicle was applied to half of the treatment area , and then delta-ALA was applied to the entire area for 1 , 2 , or 3 hours . Lidocaine hydrochloride ( 3 % ) or vehicle cream was also applied to the entire area 45 minutes before exposure to 10 J/cm(2 ) of blue light . Pain , phototoxic reactions , AK counts , and photodamage improvement were evaluated 1 day , 1 week , and 1 month after treatment in all patients and after 5 months in 10 patients . RESULTS All patients experienced mild to moderate discomfort during treatment and moderate phototoxic effects for 1 week . At 1 and 5 months there was significant reduction in AKs in all groups and significant improvement of several photodamage parameters . Different delta-ALA application times and pretreatment with urea cream or lidocaine had no significant effect on the results . CONCLUSIONS This delta-ALA/PDT protocol is safe and effective for AK treatment as well as for improving photodamage . Further studies with a larger cohort , longer follow-up , and histologic confirmation of the clinical data would be of value This double-blind , vehicle-controlled , multicenter study evaluated the efficacy and safety of a new topical antineoplastic agent , masoprocol , in the treatment of  actinic keratoses of the head and neck . Of the 113 patients who applied topical masoprocol twice a day for 14 to 28 days , there was a mean decrease in actinic keratoses from 15.0 to 5.4 and a median percent reduction from baseline actinic keratosis count of 71.4 % at the 1-month follow-up visit . Comparable numbers for the vehicle-treated group were 13.4 to 11.1 actinic keratoses and 4.3 % median percent reduction . Irritation , as manifested by erythema or flaking , occurred in 61.5 % of topical masoprocol-treated patients versus 26.7 % of those treated with vehicle and did not correlate with clinical response . Topical masoprocol appears to be useful in the treatment of actinic keratoses The efficacy of photodynamic therapy ( PDT ) using broad area treatment with 5-aminolevulinic acid ( ALA ) has not been compared to topical 5-fluorouracil ( 5-FU ) in the treatment of actinic keratoses ( AK ) . The purpose of this study was to compare the efficacy and tolerability of PDT using short incubation time , broad area treatment with ALA plus activation with either blue light or laser light to topical 5-FU in the treatment of AK of the face and scalp . Thirty-six subjects with AK of either the face or scalp were r and omized to receive either application of ALA for 1 hour followed by activation with blue light or pulsed dye laser or topical 5-FU .  Efficacy was evaluated by grading AK lesions and photoaging signs . Tolerability was assessed by scoring crusting/erosions , erythema and stinging/burning . Treatment with PDT using ALA plus blue light was as effective as topical 5-FU in clearing AK . PDT using ALA plus laser light was the least effective treatment . All treatments made improvements in the signs of photoaging . Both PDT treatments were better tolerated than 5-FU . In conclusion , broad area PDT treatment with ALA plus activation with blue light appears to be as effective as 5-FU in the treatment of AK . ALA plus laser light is somewhat less effective than the above therapies . Efficacy could likely be improved with further study of laser parameters and incubation times Background . Organ transplant recipients on long-term immunosuppressive therapy are at increased risk of non-melanoma skin lesions . Repeated field photodynamic therapy using topical methyl aminolevulinate ( MAL ) may have potential as a preventive treatment . Methods . This open r and omized , intrapatient , comparative , multicenter study included 81 transplant recipients with 889 lesions ( 90 % actinic keratoses ( AK ) ] . In each patient , the study treatment was initially administered to one 50 cm2 area on the face , scalp , neck , trunk , or extremities ( n=476 lesions ) twice ( 1 week apart ) , with additional single treatments at 3 , 9 , and 15 months . On each occasion , the area was debrided gently and MAL cream ( 160 mg/g ) applied for 3 hr , before illumination with noncoherent red light ( 630 nm , 37 J/cm2 ) . The control , 50 cm2 area ( n=413 lesions ) received lesion-specific treatment ( 83 % cryotherapy ) at baseline and 3 , 9 , and 15 months . Additionally , all visible lesions were given lesion-specific treatment 21 and 27 months in both treatment and control areas . Results . At 3 months , MAL photodynamic therapy significantly reduced the occurrence of new lesions ( 65 vs. 103 lesions in the control area ; P=0.01 ) , mainly AK ( 46 % reduction ; 43 vs. 80 ; P=0.006 ) . This effect was not significant at 27 months ( 253 vs. 312 ; P=0.06 ) . Hypopigmentation , as assessed by the investigator , was less evident in the treatment than control areas ( 16 % vs. 51 % of patients ; P<0.001 ) at 27 months . Conclusion . Our results suggest that repeated field photodynamic therapy using topical MAL may prevent new AK in transplant recipients although further studies are needed Background Photodynamic therapy ( PDT ) is increasingly used for treatment of  actinic keratoses ( AKs ) but is a cumbersome procedure . A thin self‐adhesive patch ( PD P 506 A ) containing 5‐aminolaevulinic acid ( 5‐ALA ) was developed to facilitate PDT BACKGROUND Photodynamic therapy has been proved to be effective in skin rejuvenation . OBJECTIVE To evaluate clinical efficacy and side effects of photodynamic therapy using topical 5-methyl aminolevulinate and red light for photorejuvenation . METHODS A r and omized , prospect i ve , split-face comparison study of 10 white , adult patients with moderate photodamage , Fitzpatrick skin types 2 or 3 , and no occurrence of actinic keratosis was performed . Three treatments using topical methyl aminolevulinate cream , applied for 1 hour on one half of the face and 3 hours on the other half before illumination with red light . A blinded investigator prior to treatment and 2 months after the third treatment evaluated each side of the subject 's faces . RESULTS A moderate improvement in fine lines , tactile roughness , and skin tightness was observed in most of the patients , mostly on the 3-hour time side . There were no changes in mottled pigmentation or telangiectasias . Side effects were observed in all subjects ( erythema , edema , scaling ) mainly in the 3-hour incubation time side . LIMITATIONS The small number of patients and the lack of placebo group . CONCLUSION Methyl aminolevulinic-photodynamic therapy with red light can improve fine lines , tactile roughness and skin tightness in patients with moderate photoaging and no occurrence of actinic keratosis 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 r and omized 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 BACKGROUND Actinic keratoses are the most common actinic lesions on Caucasian skin .  Cryosurgery with liquid nitrogen is commonly used to treat actinic keratoses , but there have been few studies examining the true rate of cure in everyday dermatologic practice . AIM To determine prospect ively the true efficacy of cryosurgery as a treatment for actinic keratoses in everyday dermatologic practice . METHODS A prospect i ve , multicentered study ( a subsidiary study of a photodynamic therapy trial ) was performed . Patients with untreated actinic keratoses greater than 5 mm in diameter on the face and scalp were recruited . Eligible lesions received a single freeze-thaw cycle with liquid nitrogen given via a spray device and were review ed 3 months thereafter . Each center used their preferred freeze time . The only treatment criterion was complete freezing of actinic keratoses and a 1-mm rim of normal skin . Treated lesions were assessed as complete response or noncomplete response . The influence of the duration of freeze , cosmetic outcomes , and adverse events were examined . RESULTS Ninety adult patients from the community with 421 eligible actinic keratoses were recruited . The overall individual complete response rate was 67.2%[SEM = + /-3.5 % ; 95 % confidence interval ( CI ) = 60.4 - 74.1 % ] . Complete response was 39 % for freeze times of less than 5 s , 69 % for freeze times greater than 5 s , and 83 % for freeze times greater than 20 s. Cosmetic outcomes were good to excellent in 94 % of complete response lesions . The main adverse events were pain , stinging , and burning during treatment , and hypopigmentation after healing . CONCLUSIONS Cryosurgery is an effective treatment for actinic keratoses . The true complete response rate is significantly lower than that previously reported . The freeze duration influences successful treatment . Adverse events are mild and well tolerated BACKGROUND Actinic keratoses ( AKs ) are considered as in situ squamous cell carcinoma . Early and effective treatment is important . Objective To compare the efficacy , cosmetic outcome and patient preference of 5-aminolevulinic acid photodynamic therapy ( ALA-PDT ) with that of 5 % imiquimod ( IMIQ ) cream in patients with AKs on the dorsa of h and s and forearms . METHODS Subjects received two ALA-PDT treatment sessions and one or two courses of imiquimod ( three times per week for 4 weeks each ) . Treatments were r and omly allocated to alternate upper extremities . Assessment s included lesion response one and six months after treatment , cosmetic outcome evaluated by the investigators and patients ' preference 6 months after treatment . Efficacy end point included the individual AK lesion clearance rate . RESULTS Thirty patients with 256 lesions were included in the study . At the first follow-up , treatment with ALA-PDT result ed in significantly larger rate of cured lesions relative to 5 % IMIQ cream ( 70.16 % vs. 18.26 % ) . At the second follow-up both treatments showed a high rate of cured lesions ( 65.32 % for PDT vs. 55.65 % for IMIQ cream ) . Response rates obtained in grade I lesions were higher for both treatments ( 71.64 % for PDT vs. 72.13 % for IMIQ ) , while treatment with PDT result ed in a significant larger rate of cured grade II lesions ( 57.89 % for PDT vs. 37.03 for IMIQ ) . Difference in cosmetic outcome was not statistically significant . Results for subject preference favoured ALA-PDT . CONCLUSIONS Our study shows that ALA-PDT and 5 % IMIQ cream are both attractive treatment options for upper extremities AKs with comparable efficacy and cosmetic outcomes OBJECTIVE To examine clinical and molecular changes after topical fluorouracil treatment of photodamaged human facial skin for actinic keratoses .  DESIGN Nonr and omized , open-label 2-week treatment with fluorouracil cream , 5 % 
    Output:
    
AND RELEVANCE Photodynamic therapy has a 14%better chance of complete lesion clearance at 3 months after treatment than cryotherapy for thin AKs on the face and scalp