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PDT with PHOTOFRIN is a two-stage process requiring administration of both drug and light. The first stage of PDT is the intravenous injection of PHOTOFRIN at 2mg/kg. Illumination with laser light 40-50 hours following injection of PHOTOFRIN constitutes the second stage of therapy. A second laser light application may be given 96-120 hours after injection, preceded by gentle debridement of residual tumor. In clinical studies, debridement via endoscopy was required 2 days after the initial light application. Standard endoscopic techniques are used for light administration and debridement. Practitioners should be fully familiar with the patient's condition and trained in the safe and efficacious treatment of esophageal or endobronchial cancer using photodynamic therapy with PHOTOFRIN and associated light delivery devices.
Patients may receive a second course of PDT a minimum of 30 days after the initial therapy; up to three courses of PDT (each separated by a minimum of 30 days) can be given. Before each course of treatment, patients with esophageal cancer should be evaluated for the presence of a tracheoesophageal or bronchoesophageal fistula. In patients with endobronchial lesions who have recently undergone radiotherapy, sufficient time (approximately 4 weeks) should be allowed between the therapies to ensure that the acute inflammation produced by radiotherapy has subsided prior to PDT. All patients should be evaluated for the possibility that the tumor may be eroding into a major blood vessel.
PHOTOFRIN should be administered as a single slow intravenous injection over 3 to 5 minutes at 2 mg/kg body weight. Reconstitute each vial of PHOTOFRIN with 31.8mL of either 5% Dextrose Injection (USP) or 0.9% Sodium Chloride Injection (USP), resulting in a final concentration of 2.5 mg/mL. Shake well until dissolved. Do not mix PHOTOFRIN with other drugs in the same solution. PHOTOFRIN, reconstituted with 5% Dextrose Injection (USP) or 0.9% Sodium Chloride Injection (USP) has a pH in the range of 7 to 8. PHOTOFRIN has been formulated with an overage to deliver the 75 mg labeled quantity. The reconstituted product should be protected from bright light and used immediately. Reconstituted PHOTOFRIN is an opaque solution, in which detection of particulate matter by visual inspection is extremely difficult. Reconstituted PHOTOFRIN, however, like all parenteral drug products, should be inspected visually for particulate matter and discoloration prior to administration whenever solution and container permit.
Precautions should be taken to prevent extravasation at the injection site. If extravasation occurs, care must be taken to protect the area from light. There is no known benefit from injecting the extravasation site with another substance.
Initiate 630nm wavelength laser light delivery to the patient 40-50 hours following injection with PHOTOFRIN. A second laser light treatment may be given as early as 96 hours or as late as 120 hours after the initial injection with PHOTOFRIN. No further injection of PHOTOFRIN should be given for such retreatment with laser light. Before providing a second laser light treatment, the residual tumor should be debrided. Vigorous debridement may cause tumor bleeding. For endobronchial tumors, debridement of necrotic tissue should be discontinued when the volume of bleeding increases, as this may indicate that debridement has gone beyond the zone of the PDT treatment effect.
The laser system must be approved for delivery of a stable power output at a wavelength of 630 +/- nm. Light is delivered to the tumor by cylindrical OPTIGUIDE fiber optic diffusers passed through the operating channel of an endoscope/bronchoscope. Instructions for use of the fiber optic and the selected laser system should be read carefully before use. OPTIGUIDE cylindrical diffusers are available in serveral lengths. The choice of diffuser tip length depends on the length of the tumor. Diffuser length should be sized to avoid exposure of nonmalignant tissue to light and to prevent overlapping of previously treated malignant tissue.
Photoactivation of PHOTOFRIN is controlled by the total light dose delivered:
In the treatment of esophageal cancer, a light dose of 300 joules/cm of tumor length should be delivered. The total power output at the fiber tip is set to deliver the appropriate light dose using exposure times of 12 minutes and 30 seconds.
In the treatment of endobronchial cancer, the light dose should be 200 joules/cm of tumor length. The total power at the fiber tip is set to deliver the appropriate light dose using exposure times of 8 minutes and 20 seconds. For noncircumferential endobronchial tumors that are soft enough to penetrate, interstitial fiber placement is preferred to intraluminal activation, since this method produces better efficacy and results in less exposure of the normal bronchial mucosa to light. It is important to perform a debridement 2 to 3 days after each light administration to minimize the potential for obstruction caused by necrotic debris.
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©2007, Division of Thoracic Surgery at Brigham and Women's Hospital. All rights reserved.
Division of Thoracic Surgery
Brigham and Women's Hospital
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Boston, MA 02115
Phone: (617) 732-6824