***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 
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    Input: PURPOSE Vascular targeted photodynamic therapy with WST11 ( TOOKAD ® Soluble ) is a form of tissue ablation that may be used therapeutically for localized prostate cancer . To study dosing parameters and associated treatment effects we performed a prospect i ve , multicenter , phase I/II trial of WST11 vascular targeted photodynamic therapy of prostate cancer . MATERIAL S AND METHODS A total of 30 men with unilateral , low volume , Gleason 3 + 3 prostate cancer were enrolled at 5 centers after local institutional review board approval .  Light energy , fiber number and WST11 dose were escalated to identify optimal dosing parameters for vascular targeted photodynamic therapy hemi-ablation . Men were treated with photodynamic therapy and evaluated by posttreatment magnetic resonance imaging and biopsy . Prostate specific antigen , light dose index ( defined as fiber length/desired treatment volume ) , toxicity and quality of life parameters were recorded . RESULTS After dose escalation 21 men received optimized dosing of 4 mg/kg WST11 at 200 J energy . On posttreatment biopsy residual prostate cancer was found in the treated lobe in 10 men , the untreated lobe in 4 and both lobes in 1 . At a light dose index of 1 or greater with optimal dosing in 15 men 73.3 % had a negative biopsy in the treated lobe . Six men undergoing retreatment with the optimal dose and a light dose index of 1 or greater had a negative posttreatment biopsy . Minimal effects were observed on urinary and sexual function , and overall quality of life . CONCLUSIONS Hemi-ablation of the prostate with WST11 vascular targeted photodynamic therapy was well tolerated and result ed in a negative biopsy in the treated lobe in the majority of men . Dosing parameters and the light dose index appear related to tissue response as determined by magnetic resonance imaging and biopsy . These parameters may serve as the basis for further prospect i ve studies Purpose : We assessed the midterm oncologic outcomes of vascular targeted photodynamic therapy with padeliporfin for low risk prostate cancer treatment . Material s and Methods : We prospect ively assessed all patients treated with vascular targeted photodynamic therapy for low risk prostate cancer at our center . Patients were followed every 6 months . All patients underwent prostate biopsies 6 months after treatment or when there was biological or clinical progression . The primary end point was progression‐free survival . Secondary end points were absent clinical ly significant cancer in the treated lobes , radical therapy and the prostate specific antigen rate . Variables were compared with the chi‐square , Mann‐Whitney or Wilcoxon test . Progression‐free survival is reported with Kaplan‐Meier curves . Results : A total of 82 men were treated with vascular targeted photodynamic therapy . Median followup was 68 months ( range 6 to 89 ) . Median progression‐free survival was 86 months ( 95 % CI 82–90 ) . Median prostate specific antigen decreased significantly by 41 % 6 months after treatment and it remained stable during followup ( p < 0.001 ) . A total of 115 lobes were treated and absent clinical ly significant cancer was achieved in 94 ( 82 % ) . Of the 82 patients 20 ( 24 % ) underwent radical therapy , including radical prostatectomy in 18 and brachytherapy in 2 , at a median of 22 months ( range 6 to 86 ) . Study limitations include a single arm design , small population size and midterm followup . Conclusions : Padeliporfin vascular targeted photodynamic therapy for low risk prostate cancer achieved an 82 % rate of absent clinical ly significant cancer in treated lobes and 76 % of patients avoided radical therapy at a median followup of 68 months . However , longer followup is required to determine long‐term outcomes Low-risk prostate adenocarcinoma is classically managed either with active surveillance or radical therapy ( such as external radiotherapy or radical prostatectomy ) , but both have significant side effects . Vascular-targeted photodynamic therapy ( VTP ) is a focal therapy proposed as an alternative approach for localized , low-volume , and low-Gleason score ( ≤6 ) carcinomas . We report histological modifications observed in prostate biopsies of 56 patients , performed 6 months after VTP using the photosensitizer TOOKAD ® Soluble ( WST11 ) and low-energy laser administered in the tumor area transperineally by optic fibers .  In 53 patients , we observed sharply demarcated hyaline fibrotic scars , with or without rare atrophic gl and s , sometimes reduced to corpora amylacea surrounded by giant multinuclear macrophages . Mild chronic inflammation , hemosiderin , and coagulative necrosis were also observed . When residual cancer was present in a treated lobe ( 17 patients ) , it was always located outside the scar , most often close to the prostate capsule , and it showed no therapy-related modification . Histopathological interpretation of post-WST11 VTP prostate biopsies was straightforward , in contrast with that of prostate biopsies after radio or hormonal therapy , which introduces lesions difficult to interpret . VTP result ed in complete ablation of cancer in the targeted area To report on the efficacy of TOOKAD ® ( WST 09 ; NegmaLerads , Magny‐Les‐Hameaux , France ) vascular‐targeted photodynamic therapy ( VTP ) as a method of whole‐prostate ablation in patients with recurrent localized prostate cancer after the failure of external beam radiotherapy ( EBRT ) BACKGROUND AND OBJECTIVES Interstitial photodynamic therapy ( PDT ) is an emerging modality for the treatment of solid organ disease . Our group at the University of Pennsylvania has performed extensive studies that demonstrate the feasibility of interstitial PDT for prostate cancer . Our pre clinical and clinical experience is herein detailed . STUDY DESIGN / MATERIAL S AND METHODS We have treated 16 canines in pre clinical studies , and 16 human subjects in a Phase I study , using  motexafin lutetium-mediated PDT for recurrent prostate adenocarcinoma . Dosimetry of light fluence , drug level and oxygen distribution for these patients were performed . RESULTS We demonstrate the safe and comprehensive treatment of the prostate using PDT . However , there is significant variability in the dose distribution and the subsequent tissue necrosis throughout the prostate . CONCLUSIONS PDT is an attractive option for the treatment of prostate adenocarcinoma . However , the observed variation in PDT dose distribution translates into uncertain therapeutic reproducibility . Our future focus will be on the development of an integrated system that is able to both detect and compensate for dose variations in real-time , in order to deliver a consistent overall PDT dose distribution BACKGROUND AND OBJECTIVES Prostate cancer is increasing in incidence , but current treatments including surgery and radiotherapy have significant side effects . This pilot study was design ed to assess the potential of photodynamic therapy ( PDT ) using meso tetra hydroxy phenyl chlorin ( mTHPC ) for organ confined prostate cancer . STUDY DESIGN / PATIENTS AND METHODS Six men with organ confined prostate cancer were photosensitised with mTHPC ( 0.15 mg/kg ) . Between 2 and 5 days later , red light ( 652 nm ) was delivered to areas of biopsy proven cancer via fibres inserted through transperineal needles ( 50 - 100 J per site ) . RESULTS After 8 of 10 PDT sessions , the prostate specific antigen ( PSA ) fell by up to 67 % . Early MRI scans showed oedema and patchy necrosis , which resolved over 2 months . Biopsies of treated areas revealed necrosis and fibrosis at 1 - 2 months . CONCLUSIONS PDT for primary prostate cancer appears safe and can reduce PSA levels . As this was a phase I study , no attempt was made to treat the whole prostate ; this or targeted tumour ablation could be attempted in a phase II study with an increased number of fibres . This technique merits further investigation in early prostate cancer To determine the optimal drug and light dose for prostate ablation using WST11 ( TOOKAD ® Soluble ) for vascular‐targeted photodynamic ( VTP ) therapy in men with low‐risk prostate cancer It is desirable to quantify the distribution of the light fluence rate , the optical properties , the drug concentration , and the tissue oxygenation for  photodynamic therapy ( PDT ) of prostate cancer . We have developed an integrated system to determine these quantities before and after PDT treatment using motorized probes . The optical properties ( absorption ( micro(a ) ) , transport scattering ( micro(s ' ) , and effective attenuation ( micro(eff ) ) coefficients ) of cancerous human prostate were measured in-vivo using interstitial isotropic detectors . Measurements were made at 732 nm before and after motexafin lutetium ( MLu ) mediated PDT at different locations along each catheter . The light fluence rate distribution was also measured along the catheters during PDT . Diffuse absorption spectroscopy measurement using a white light source allows extrapolation of the distribution of oxygen saturation StO2 , total blood volume ( [Hb]t ) , and MLu concentration . The distribution of drug concentration was also studied using fluorescence from a single optical fiber , and was found to be in good agreement with the values determined by absorption spectroscopy . This study shows significant inter- and intra-prostatic variations in the tissue optical properties and MLu drug distribution , suggesting that a real-time dosimetry measurement and feedback system for monitoring these values during treatment should be considered in future PDT studies Locally recurrent prostate cancer after treatment with radiation therapy  is a clinical problem with few acceptable treatments . One potential treatment , photodynamic therapy ( PDT ) , is a modality that uses laser light , drug photosensitizer , and oxygen to kill tumor cells through direct cellular cytotoxicity and /or through destruction of tumor vasculature . A Phase I trial of interstitial PDT with the photosensitizer Motexafin lutetium was initiated in men with locally recurrent prostate cancer . In this ongoing trial , the primary objective is to determine the maximally tolerated dose of Motexafin lutetium-mediated PDT . Other objectives include evaluation of Motexafin lutetium uptake from prostate tissue using a spectrofluorometric assay and evaluation of optical properties in the human prostate . Fifteen men with biopsy-proven locally recurrent prostate cancer and no evidence of distant metastatic disease have been enrolled and 14 have been treated . Treatment plans were developed using transrectal ultrasound images . The PDT dose was escalated by increasing the Motexafin lutetium dose , increasing the 732 ran light dose , and decreasing the drug-light interval . Motexafin lutetium doses ranged from 0.5 to 2 mg/kg administered IV 24 , 6 , or 3 hr prior to 732 ran light delivery . The light dose , measured in real time with in situ spherical detectors was 25 - 100 J/cm2 . Light was delivered via optical fibers inserted through a transperineal brachytherapy template in the operating room . Optical property measurements were made before and after light therapy . Prostate biopsies were obtained before and after light delivery for spectrofluorometric measurements of photosensitizer uptake . Fourteen patients have completed protocol treatment on eight dose levels without dose-limiting toxicity . Grade I genitourinary symptoms that are PDT related have been observed . One patient had Grade II urinary urgency that was urinary catheter related . No rectal or other gastrointestinal PDT-related tox-icities have been observed to date . Measurements of Motexafin lutetium demonstrated the presence of photosensitizer in prostate tissue from all patients . Optical property measurements demonstrated substantial heterogeneity in the optical properties of the human prostate gl and which supports the use of individualized treatment planning for prostate PDT PURPOSE Photodynamic therapy , using a photosensitizing drug activated by red light , can destroy localized areas of cancer with safe healing and without the cumulative toxicity associated with ionizing radiation . We used photodynamic therapy in a phase I-II study to treat patients with locally recurrent prostate cancer after radiotherapy .  MATERIAL S AND METHODS Patients with an increasing prostate specific antigen ( PSA ) and biopsy proven local recurrence after radiotherapy  were offered photodynamic therapy . Three days after intravenous administration of the photosensitizer meso-tetrahydroxyphenyl chlorin , light was applied using optical fibers inserted percutaneously through perineal needles positioned in the prostate with imaging guidance . Patients were followed with PSA measurements , prostate biopsies , computerized tomography or magnetic resonance imaging and question naires on urinary and sexual function . RESULTS Photodynamic therapy was given to 14 men using high light doses in 13 . Treatment was well tolerated . PSA decreased in 9 patients ( to undetectable levels in 2 ) and 5 had no viable tumor on posttreatment biopsies . After photodynamic therapy , contrast enhanced computerized tomography or magnetic resonance imaging showed necrosis involving up to 91 % of the prostate cross section . In 4 men stress incontinence developed ( troublesome in 2 and mild in 2 ) which is slowly improving . Sexual potency was impaired in 4 of the 7 men able to have intercourse before photodynamic therapy , which did not improve . There were no rectal complications directly related to photodynamic therapy , but in 1 patient a urethrorectal fistula developed following an ill-advised rectal biopsy 1 month after therapy . CONCLUSIONS Photodynamic therapy is a new option that could 
    Output:
    
Conclusions The meta- analysis results shows that PDT for patients with prostate cancer can be considered as effective based on single-arm clinical trials .
Meanwhile , this study reveals that there are not only low levels of side effect rates but also insignificant effect on both urinary and erectile function .