title: Photodynamic therapy (PDT) for malignant brain tumors--where do we stand?
abstract: BACKGROUND
  What is the current status of photodynamic therapy (PDT) with regard to treating malignant brain tumors? Despite several decades of effort, PDT has yet to achieve standard of care.
  
  
  OBJECTIVE
  The questions we wish to answer are: where are we clinically with PDT, why is it not standard of care, and what is being done in clinical trials to get us there.
  
  
  METHODS
  Rather than a meta-analysis or comprehensive review, our review focuses on who the major research groups are, what their approaches to the problem are, and how their results compare to standard of care. Secondary questions include what the effective depth of light penetration is, and how deep can we expect to kill tumor cells.
  A measurable degree of necrosis is seen to a depth of about 5mm. Cavitary PDT with hematoporphyrin derivative (HpD) results are encouraging, but need an adequate Phase III trial. Talaporfin with cavitary light application appears promising, although only a small case series has been reported. Foscan for fluorescence guided resection (FGR) plus intraoperative cavitary PDT results were improved over controls, but are poor compared to other groups. 5-Aminolevulinic acid-FGR plus postop cavitary HpD PDT show improvement over controls, but the comparison to standard of care is still poor.
  
  
  CONCLUSIONS
  Continued research in PDT will determine whether the advances shown will mitigate morbidity and mortality, but certainly the potential for this modality to revolutionize the treatment of brain tumors remains. The various uses for PDT in clinical practice should be pursued.
authors.affiliation: Department of Neurology, Medical College of Wisconsin, Milwaukee, WI, United States.
authors.forename: Brendan J
authors.initials: BJ
authors.lastname: Quirk
authors.affiliation: Medical College of Wisconsin, Milwaukee, WI, United States.
authors.forename: Garth
authors.initials: G
authors.lastname: Brandal
authors.affiliation: Medical College of Wisconsin, Milwaukee, WI, United States.
authors.forename: Steven
authors.initials: S
authors.lastname: Donlon
authors.affiliation: Medical College of Wisconsin, Milwaukee, WI, United States.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Vera
authors.affiliation: Department of Oral and Maxillofacial Surgery, University at Buffalo, Buffalo, NY, United States.
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Mang
authors.affiliation: Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, United States.
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Foy
authors.affiliation: Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, United States.
authors.forename: Sean M
authors.initials: SM
authors.lastname: Lew
authors.affiliation: Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, United States.
authors.forename: Albert W
authors.initials: AW
authors.lastname: Girotti
authors.affiliation: Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, United States.
authors.forename: Sachin
authors.initials: S
authors.lastname: Jogal
authors.affiliation: Department of Radiology, Medical College of Wisconsin, Milwaukee, WI, United States.
authors.forename: Peter S
authors.initials: PS
authors.lastname: LaViolette
authors.affiliation: Department of Neurology, Medical College of Wisconsin, Milwaukee, WI, United States.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Connelly
authors.affiliation: Department of Neurology, Medical College of Wisconsin, Milwaukee, WI, United States. Electronic address: hwhelan@mcw.edu.
authors.forename: Harry T
authors.initials: HT
authors.lastname: Whelan
mesh_terms: D000622:Aminolevulinic Acid / Q000627:therapeutic use; D001932:Brain Neoplasms / Q000188:drug therapy*; D016923:Cell Death; D002986:Clinical Trials as Topic; D005453:Fluorescence; D017324:Hematoporphyrin Derivative / Q000494:pharmacology / Q000627:therapeutic use; D006801:Humans; D015192:Infratentorial Neoplasms / Q000188:drug therapy; D008652:Mesoporphyrins / Q000494:pharmacology / Q000627:therapeutic use; D009569:Nitric Oxide / Q000378:metabolism; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000494:pharmacology / Q000627:therapeutic use*; D011166:Porphyrins / Q000494:pharmacology / Q000627:therapeutic use; D015398:Signal Transduction; D025321:Surgery, Computer-Assisted
chemical_list: D008652:Mesoporphyrins; D017319:Photosensitizing Agents; D011166:Porphyrins; D009569:Nitric Oxide; D017324:Hematoporphyrin Derivative; D000622:Aminolevulinic Acid; C072269:temoporfin; C053434:Talaporfin
keywords: Malignant brain tumors; PDT light penetration; Photodynamic therapy