Nonsmall-cell lung cancer treated with PDT
Lung cancer is the leading cause of cancer-related deaths in the US, and about 85 percent of lung cancers are the nonsmall-cell type. Surgery is currently the main treatment, but about half of newly diagnosed cases are inoperable. Of patients who do receive surgery, many experience recurrences of the disease that usually are treated with radiotherapy and/or chemotherapy.
Photodynamic therapy (PDT) has proved a successful alternative treatment for small-cell cancers because it can treat sites that cannot be reached by surgery, and it can selectively treat cancer cells without causing much harm in surrounding tissues. Also, unlike radiation therapy, PDT can be used again and again. However, not much is known about its effect on nonsmall-cell lung cancer.
Dr. Luigi Corti from the department of radiotherapy at Istituto Oncologico Veneto-Istituto di Ricovero e Cura a Carattere Scientifico (IOV-IRCCS) in Padua, Italy, and his colleagues tested the efficacy of PDT in treating early inoperable or recurrent nonsmall-cell lung cancer.
As reported in the June issue of Lasers in Surgery and Medicine, 40 patients with inoperable or recurrent nonsmall-cell lung cancers (50 cancers total) were treated with PDT. Twenty-four of the patients received the light therapy with a Carl Zeiss Meditec 630-nm argon dye laser at 200 to 300 J/cm2, and 16 received it with a Diomed 630-nm diode laser at 100 to 200 J/cm2. The lasers were kept between 1 and 1.5 cm away from the surface of the lesions. Patients received endoscopy follow-up about 40 days after the treatment to see how well they responded to the PDT.
A total of 72 percent (36/50) of the treated lesions appeared gone at an endoscopy follow-up. Twenty percent showed partial response to the treatment, and 6 percent had no response. Twelve patients suffered a relapse of the cancer after the initial PDT treatment. None of the patients experienced any adverse effects.
The researchers concluded that PDT can be effective in treating early or recurrent nonsmall-cell lung cancers. They believe that further investigation is needed on how it compares with other therapies and on how it can be used in conjunction with radiotherapy and brachytherapy.
- photodynamic therapy (pdt)
- A medical technology that uses lasers or other light sources in combination with photosensitizing drugs to treat cancerous tumors.
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