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Photodynamic therapy

Photodynamic therapy

Cancer is revealed in about 8 million people in the world annually, and over 5 million die from this disease. In Russia about half-million malignant tumor are diagnosed every year. The technique of oncologic patients’ treatment is known: radio- and chemotherapy, surgery. But today photodynamic therapy becomes perspective instrument, helping to eliminate cancer.

Photodynamic therapy (PDT) is a nonsurgical method of tumour treatment. It is based on selective accumulation of a certain light-absorbing preparations (photosensitizer) in the tumor tissue, and following pathological tissue destruction after irradiation by light of a certain wavelength. A photosensitiser is administered to the patient, usually by injection. The photosensitiser alone is harmless and has no effect on either healthy or abnormal tissue. However, when light (often from a laser) is directed onto tissue containing the drug, the drug becomes activated and the tissue is rapidly destroyed, but only precisely where the light has been directed. Necrosis of tumor tissue develops, pathological tissue resorbs, and is gradually replaced by connecting tissue.

PDT procedure

Photodynamic therapy offers a number of advantages over traditional techniques for malignant tumors (such as surgical operation, radiotherapy, and chemotherapy). First, PDT is highly selective and targeted in action. Second, it is free of surgical risks, serious damages, and systemic complications. Third, PDT sessions can be repeated as many times as needed. Fourth, a single PDT procedure enables both the treatment and fluorescent diagnosis. Finally, most patients exhibit tumor resolution after a single PDT cure, which can be performed under outpatient conditions.

In our practice, we use the second – generation drug “Radachlorin”, produced by RADAPHARMA Co ( as a photosensitizer. Radachlorin &® is a derivative of the well-known green pigment chlorophyll ?. Initial raw material for this drug is Spirulina platensis microalga. This drug substance represents an aqueous solution of three chlorins, including sodium chlorin e6 (90-95%) sodium chlorin p6 (5-7%), and a third chlorin t (1-5%). Generally, chlorin constituents (called "chlorin active substance") of the drug are 98% of its dry weight. Thus, Radachlorin® is a complex natural drug, accumulating and efficiently destroying tumors upon photoirradiation (662 nm).

The drug is administered intravenously and within a period of 0.5-3 hours, selectively concentrates in diseased cells or pathologically altered tissues while largely clearing from normal tissues. Radachlorine remains inactive until exposed to laser light. When applied, the laser energy, delivered to the relevant site, activates the drug. The cumulative action destroys the tumor, however, does not inflict hurt to the normal tissues. After the treatment a decomposition of tumor (necrosis) takes place for up to 2-3 weeks, followed by regeneration of the wholeness of the normal tissue with an excellent cosmetic effect

Chlorin photosensitizers produced radical changes in the PDT of malignant tumors. The application of the most of other photosensitisers relies on a long-term treatment under inpatient conditions, whereas the application of Radachlorin avoids this stage. Instead, the patient receives a one-day or outpatient treatment. A tumor is irradiated 3 hours after the photosensitizer injection.

Radachlorin treatment does not demand major anesthesia, it can be applied in elderly patients with an accompanying somatic disease. Photodynamic therapy does not affect healthy tissues , in contrast with radiotherapy, so it may be applied repeatedly for bulk tumors or relapses.

One more advantage of the given method is the fine cosmetic result of treatment, so important for the great number of women and men. Despite of the obvious positive features, the new technique is not a magic elixir for all occasions. The success of therapy depends on the stage of disease. The treatment of extensive tumours with Radachlorin is not radical; in such cases photodynamic therapy can improve quality of patient’s life, restore the patency of hollow organs (recanalization of esophagus, rectum, trachea, etc.), but the tumour is not removed completely.


This method was introduced into practice of CSMA Clinic of General surgery under the direction of professor Privalov V.A.We applied it in more then 100 patients aged from 10 to 93 years with tumours of skin, lower lip, tongue, oral cavity mucous, larynx, lung, bladder, gastrointestinal tract, genitalias and other localizations.

The irradiation was performed under local or intravenous anaesthesia. At external irradiations (cancers of skin, lip, and so on) no anaesthesia was required as a rule. For a day after irradiation patients stayed in black-out rooms without TV to avoid light reactions of skin and eyes because of some presence of Radachlorin. Then patients were free in respect to light and TV.

18 patients underwent PDT because of contraindications to traditional treatments (age, concomitant diseases). 19 patients had recurrent tumours (30 tumors) after standard methods of treatment (surgery, radiotherapy, chemo- and cryotherapy). In these patients, photodynamic therapy was carried out not earlier than one month after radiotherapy or drug therapy. 22 patients entered the hospital with IV stage of disease, 56 patients had I-II stage tumors, mainly basaliomas. In 12 cases there were primary-multiple tumors.

The PDT efficiency was estimated by visual, endoscopic, radiological, ultrasonic and cytomorphological researches. Follow-up terms were from 3 to 36 months. Local photodynamic reaction developed in a few minutes after the beginning of irradiation. By the end of irradiation, the tumour and surrounding skin became anemic, and "halo" of hyperemia appeared around. Surface of the tumor became violet or black, because of hemorrhagic necrosis in 2-3 hours. Final results of were estimated as complete tumour regress, partial regress (decrease of the tumour by 50 %) and absence of effect (decrease of the tumour less than 50 %).

Clinical researches have shown the high efficiency of PDT with Radachlorin for treatment of cancer of various localizations. Complete regress of the tumor was achieved in 68 %, partial in 32 % of cases. The absolute (100 %) result was received in treatment of skin basal cell carcinoma. We managed to improve life quality of 7 incurable patients with advanced malignancies of different localizations by recanalization of obturated hollow organs in 5 cases (esophagus, rectum, bronchial tube) and by elimination of inflammatory complications caused by tumor decay in 2 cases.


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