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This update of the experience at the University of California at Irvine with laser photoradiation therapy (PRT) encompasses the period between May 1981 and June 1983. The results of treatment of 77 patients are reported (head and neck, 39; breast, 33, and lung 5). Head and neck cancer patients received treatment to 114 sites with a complete response (CR) in 28, partial response (PR) in 42, stable disease (SD) in three, and no response (NR) in 34, and an undetermined response in seven. Breast cancer patients were treated in 395 sites with CR in 222, PR in 74, SD in one, NR in 92, and undetermined response in six. The lung cancer patients in this series responded poorly, if at all. In addition to the above patient trials, we have investigated the interaction to laser hematoporphyrin derivative (HPD)- PRT with a chemotherapeutic agent, Cisplatin, against an experimental tumor (RIF-1) in an animal model. We have been unable to demonstrate an additive effect of laser HPD-PRT at total light doses of 25 j/cm2and 75j/cm2 with Cisplatin at a dose of 7 mg/kg. However, no additional toxicity was observed on combination therapy, suggesting that sequential application of laser HPD-PRT and Cisplatin may be safely employed in clinical situation. Another area of investigation has been the evaluation of the light-scattering characteristics of a lipid emulsion designed for laser HPD-PRT of bladder tumors. We have demonstrated that it is feasible to gain uniform illumination of the bladder surface with the use of this light-dispersing medium. We now believe that it is appropriate to begin clinical trials in which laser HPD-PRT is utilized as the initial form of therapy. Sites that appear most appropriate for this therapy are early cancers of the head and neck and early cancer of the bladder.

Visual function for ten patients undergoing HPD-PRT was tested using 1) the Graham Field Eye Chart for distance vision, 2) pseudo-isochromatic plates for color vision, and 3) Amsler grid for changes in macular function. Whereas some increases and decreases in ocular function were observed, no clear patterns or changes of significance were observed.

Systemically injected hematoporphyrin derivative (HPD) in combination with red laser light (630 nm) was used to treat a patient with intraepithelial neoplasia of the vulva. Since the patient had psoriasis in the mons pubis area this region also was exposed to the red light. The psoriasis treatment area was divided into two regions receiving 40 and 20 J/cm2. Both psoriatic zones responded vigorously to the HPD + light treatment, forming eschars by 1 week postirradiation. All three treatment zones (the neoplastic area and the two psoriatic areas) underwent normal reepithelialization by 17 days.

Two patients were treated at 20 different tumor sites by hematoporphyrin derivative (HPD) photoradiation therapy (PRT). An infrared detector was used to record changes in surface temperature during laser exposure. A temperature rise of up to 4.9 degrees C was recorded for a total energy of 15-30 J/cm2 and less than 150 mW/cm2. For 508 mW/cm2 and 15-20 J/cm2 a temperature rise of 7.0 degrees C was detected. The results suggest a possible role of hyperthermia in HPD-PRT.

A program of photoradiation therapy (PRT) of cancer employing the sensitizing agent Hematoporphyrin Derivative (HPD) was begun at UC, Irvine in May, 1981. We have used light obtained from a laser source to initiate the photochemical reaction required for tumor destruction. Initially a four-watt argon laser was used to pump a tunable dye laser emitting light at 630 nm. The system has been upgraded by adding a 12-watt argon laser (Spectra-Physics, Mt. View, CA).

Two sets of tables are presented that permit the rapid determination of (1) milliwatts per centimeter2 based upon known site diameter and power output from fiber optic and (2) time of exposure (minutes and seconds) based upon known site diameter and power output from fiber optic.