12. Photodynamic Therapy for Squamous-Cell Cancer of the Head and Neck

Е.Ph.Stranadko, А.А.Radaev

Introduction

Over the last decade there has been a clear tendency in clinical oncology of using multi-component programs to treat malignant tumors of different localization. This has significantly been due to the fact that patients seek specialized help too late when they already have acute symptoms of a disease, and the process has become extensive. This is why the number of people with malignant neoplasms in the oropharyngeal area who live 5 years after a combined treatment including surgical operation and radiotherapy, makes 30 – 67 %, and with locally spread cancer in the oropharyngeal area after radiotherapy and a combined treatment including surgical operation, doesn’t make more than 56 %. If a cytostatic treatment is included into multi-component programs to treat squamous-cell cancer of the head and neck, complete tumor resorption is achieved in 20 – 25 % of patients. However, general survival time and qualitative life characteristics of patients remain unsatisfactory.

Currently, when making protocols of organ-preservation treatment of patients with locally spread inoperable tumors, there appears a necessity to combine radiotherapy and chemotherapy with modern methods of local destructive exposure on a tumor.

One of such modern methods of treatment is photodynamic therapy (PDT). Clinical applicability of a combined method which includes PDT was proven by experimental studies of a combined use of PDT and radiotherapy. The studies also showed that the efficiency of primary lesion recovery increased.

For the purpose of using PDT as a sparing, organ-preservation treatment, we worked out and performed in a clinic methods of combined and complex therapy of squamous-cell cancer of the head and neck. They are based on the use of PDT aimed at elimination of a primary tumor, and additional methods are used to prevent regional metastasis and generalization of the process.

Materials and methods

We tried to make schemes of combined and complex therapy of squamous-cell cancer of the head and neck, based on PDT of primary tumors with the use of additional methods to treat possible regional and distant metastasis. We also made a comparative analysis of the efficiency of PDT as a monotherapy and of PDT as a component of a combined and complex treatment.

PDT was performed in 76 patients with squamous-cell cancer in the oropharyngeal area (Table 1) with 87 lesions.

Table 1. Patient distribution depending on sex and type of tumor pathology

The age of patients varied from 26 to 88, the average age was 57. The males were 50 (65.8 %), the females were 26 (34.2 %). Stage I-IV primary cancer was diagnosed in 23 patients (30.3 %). Recurrent cancer after radiotherapy and a combined treatment was found in 46 patients (60.5 %) and residual tumors after radiotherapy – in 7 patients (9.2 %).

43 patients (Table 2) were diagnosed with tongue cancer, 13 – with cancer of the oral mucosa, 11 – with cancer of the lower lip, and 9 – with oropharyngeal cancer.

Table 2. Patient distribution depending on tumor localization and the treatment program with PDT

PDT was performed as a separate method of treatment in 50 patients, and as a basic component of a combined and complex treatment in combination with gamma-ray teletherapy (GRTT) and/or platinum- and 5-fluorouracil-based neoadjuvant polychemotherapy (PChT). GRTT was performed in the mode of multi-field irradiation and medium fraction with a single hot-spot dose of 3 Gray. The summary hot-spot dose was 33 – 38 Gray.

Two Russian medicines (Photohem – a hematoporphyrin derivative – at a dose of 1.5 – 5 mg/kg and Photosense – sulfonated aluminium phtalocyanine – at a dose of 0.5 - 1.5 mg/kg) were used as photosensitizers in the group of patients who had PDT as a separate method of treatment. Laser diode devices of the Crystal 2000 family (Russia) served as a light source, with wavelengths of 630 nm for Photohem and 675 nm for Photosense.

German Foscan (temoporfin) was used at a dose of 0.025 - 0.15 mg/kg for the group of patients who had a combined and complex treatment. PDT was performed by means of the Russian Crystal 2000 laser diode device with a wavelength of 662 nm.

Results

The evaluation of the treatment results was performed according to the WHO method in 2 months after PDT. Complete resorption (CR) of a tumor was diagnosed after complete disappearance of the tumor and negative results of morphological tests. Partial resorption (PR) is 50 % and more decrease of a tumor in size or detection of tumor cells in scrapes or biopsic material after clinically complete destruction of the tumor. If a tumor decreased less that 50 % in size, the treatment was considered to have no effect (NE).

Complete tumor resorption in the group of patients with squamous-cell cancer (Table 3) made 65.8 % (in 50 out of 76 patients), partial resorption was diagnosed in 23 out of 76 patients (30.3 %) and the treatment had no effect in 3 patients (3.9 %).

Table 3. Efficiency of PDT of squamous-cell cancer for different tumor localizations

CR – complete resorption; PR – partial resorption; NE – no effect

After PDT performed as a separate method of treatment, complete tumor resorption was found in 28 out of 50 patients (56 %) (Table 4) and partial resorption – in 19 out of 50 patients (38 %). The treatment had no effect in 3 patients (6 %).

Table 4. Efficiency of different treatment programs of squamous-cell cancer of the head and neck with PDT

CR – complete resorption

Radiotherapy and neoadjuvant PChT in combination with PDT allowed to raise the efficiency of treatment of locally spread squamous-cell cancer of the head and neck: complete tumor resorption rose from 65.8 % to 84.6 % (in 22 out of 26 patients), partial resorption made 15.4 % (in 4 out of 26 patients). All patients with cancer of the lower lip and oral mucosa showed complete resorption. Complete resorption was diagnosed in 14 out of 18 patients with tongue cancer (77.8 %), partial resorption – in 4 patients (22.2 %).

Conclusion

PDT of squamous-cell cancer of the head and neck as a separate method of treatment can be successfully used to treat both primary cancer and small early recurrent tumors after radiotherapy. The use of PDT in combination with GRTT and PChT in programs of combined and complex treatment broadens the spheres of application of this method in case with locally spread squamous-cell cancer of the head and neck, and raises the efficiency of treatment.