Vascular function and the probability of skin necrosis after photodynamic therapy: an experimental study.
The clearance of an intradermally-injected solution of 133Xenon in 0.9% saline has been used to study the impairment and recovery of blood flow in mouse tail for 5 days following photodynamic therapy (PDT) with 2mg TPPS i.v. per mouse and a range of doses of white light. Impairment of blood flow was observed within 10 min of light exposure. Blood flow increased between day 1 and day 5 at light doses less than 151J cm-2 and had returned to control levels by day 5 at light doses less than 129J cm-2. In mice treated with a light dose that caused a 50% incidence of necrosis, there was no significant difference in the initial xenon clearance half-time (measured at 10 min and 1 day after PDT) between those mice which developed tail necrosis and those which healed. However, the latter showed significantly greater improvement in vascular function on days 2, 3 and 4. This suggests that the timing and extent of recovery of blood flow determined the risk of necrosis in individual mice.
Benstead
K
K
Paterson Institute for Cancer Research, Christie Hospital and Holt Radium Institute, Manchester, UK.
Moore
J V
JV
D000818:Animals; D004307:Dose-Response Relationship, Radiation; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009336:Necrosis; D010778:Photochemotherapy / Q000009:adverse effects*; D012039:Regional Blood Flow / Q000528:radiation effects; D012867:Skin / Q000098:blood supply* / Q000473:pathology; D013623:Tail; D013997:Time Factors; D014980:Xenon Radioisotopes
D014980:Xenon Radioisotopes