Photodynamic therapy for the treatment of metastatic lesions in bone: studies in rat and porcine models.
This study represents the first reported use of photodynamic therapy (PDT) for metastatic bone lesions and specifically, as a treatment for spinal metastases. A model of bone metastasis in rat confirmed the efficacy of benzoporphyrin derivative-monoacid-mediated PDT for treating lesions within the spine and appendicular bone. Fluorimetry confirmed the selective accumulation of drug into the tumor(s) at 3 h post-injection. 48 h post-light delivery into the vertebral body of the rat spine loss of bioluminescent signal and histological analyses of sectioned spine confirmed MT-1 tumor cell kill in vivo as previously confirmed in vitro using an established cell viability assay. Porcine vertebrae provided a model comparable to that of human for light propagation and PDT response. Histological examination of vertebrae 48 h post-PDT revealed a necrotic radius of 0.6 cm with an average fluence rate of 4.3 mW/cm2. Non-necrotic tissue damage was evident up to 2 cm out from the treatment fiber. Results support the application of PDT to the treatment of primary or metastatic lesions within bone.
Burch
S
S
Ontario Cancer Institute, University Health Network, 610 University Avenue, Toronto, Ontario, Canada M5G 2M9.
Bogaards
A
A
Siewerdsen
J
J
Moseley
D
D
Yee
A
A
Finkelstein
J
J
Weersink
Robert
R
Wilson
B C
BC
Bisland
S K
SK
D000818:Animals; D002470:Cell Survival; D006801:Humans; D010778:Photochemotherapy / Q000379:methods*; D011166:Porphyrins / Q000627:therapeutic use*; D011379:Prognosis; D051381:Rats; D011923:Rats, Nude; D013125:Spinal Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000556:secondary*; D013552:Swine; D016896:Treatment Outcome; D000077362:Verteporfin; D014930:Women
D011166:Porphyrins; D000077362:Verteporfin