Спектроскопические методы и увеличительная эндоскопия в дифференциальной диагностике патологии толстой кишки

The review of recent development in diagnosis of premalignancy and early cancer in colon is represented. The results of several diagnostic methods which are supplemental for convenient colonoscopy, are described. Thus, NBI system (narrow spectrum endoscopy) and FICE combined with system for magnifying endoscopy significantly improve sensitivity and specifity of diagnostic method. However, the serious disadvantage is coloration of intestinal contents into different shades of red, impeding visualization of small structures and lesions. For detection of dysplasia of different degree in patients with colon polyps high levels of sensitivity and specifity were shown in the methods of magnifying and zoom-endoscopy (93.8% and 64.6%, respectively), confocal laser endomicroscopy (81% and 82%, perspectively), and optic coherent tomography (92% and 84%, respectively). The one of the most recent method – immunophotodiagnosis, showed high efficiency for detection of dysplasia and early cancer in patients with colon polyps: the sensitivity was 78.6%, specifity – 100%. Autofluorescence and fluorescence diagnostics with exogenous photosensitizers. The studies showed that autofluorescence diagnosis was valuable method for differential diagnosis of colon tumors (sensitivity was 85%, specifity – 81%).

Интраоперационная фотодинамическая терапия при неорганных забрюшинных опухолях

The results of treatment in 17 patients with morphologically confirmed resectable primary or recurrent retroperitoneal tumor using intraoperative photodynamic therapy with photogem (5 patients), radaсhlorin (7 patients) and photodithazine (5 patients). The drugs were administered intravenously in following regimen: photogem 48 h before surgery in dose 2.5–3.0 mg/kg, radaсhlorin and photodithazine – 0.7 and 0.7–1.0 mg/kg, respectively, 2–3 h before resection. Irradiation was performed to tumor bed after complete radical removal from one or several positions depending on tumor localization. The light dose accounted for 30 J/cm2, duration of treatment session depended on area of irradiation. Two patients with recurrent tumor had two reoperations with session of photodynamic therapy. One patient had repeated recurrence requiring third surgery with photodynamic therapy. Thus, 17 patients underwent 25 sessions of intraoperative photodynamic therapy. There were no intraoperative complications. One patient had an early post-operative complication in the form of pancreonecrosis which could be associated with extended resection. The recurrence rate was 17.6%. The results showed safety of the method and affinity of utilized photosensitizers to retroperitoneal tumors of different histological types (sarcoma, gastrointestinal stromal tumor and others).

Фотодинамическая активность производного тетраазахлорина в экспериментах in vivo

The results of investigation for photodynamic activity of new tetraazachlorin derivate – tetramethyltribenzotetraazachlorin, synthesized in Research Institute of Organic Intermediates and Dyes. The study was performed on female mice of СВА line. The tumor model was transferred solid ascetic sarcoma S-37. The samples of photosensitizer, previously solubilized in 10% aqueou s solution ofCremophor EL, injected to mice intravenously on the 7th day of tumor growth in dose of 1–2 mg/kg. Two hours later the irradiation of sensitized tumor using light emitting diode device in a maximal wavelength of 755 nm (light power density – 50 mW/cm2, maximal total light dose – 300 J/cm2) was performed. The efficacy of photodynamic therapy was assessed by growth inhibition rates in the study group comparing with control group. The study showed that photodynamic therapy with investigated sample in dose of 2 mg/kg and light dose of 300 J/cm2 significantly inhibited the tumor growth (inhibition rate of 70–80% within 20 days), indicating prospectivity of subsequent investigations of tetraazachlorin as photosensitizer for photodynamic therapy of malignant tumors.

Фотодинамическая терапия больных ранним центральным раком легкого

The results of photodynamic therapy (PDT) for early central lung cancer are represented in the article. The study included 37 patients (52 tumor lesions). For 52 lesions pre-invasive cancer (carcinoma in situ) was determined in 6 cases, squamous cell cancer with invasion within mucosal and submucosal layers of bronchial wall – in 46 cases. 51 tumors were primary lesion, 1 – residual after radiotherapy. 17 of 37 patients underwent previous surgical or combined modality treatment for cancer in other anatomical sites. For PDT we used photosensitizers photogem, photosens and radachlorine. The treatment response was assessed 1 months later by data of endoscopy and morphological study, CT, US and endosonography. Complete regression was achieved in 86,5% of cases, partial regression – in 13,5%. The efficacy of PDT was depended on tumor size. For lesion up to 1 cm in size complete regression was in 100% of cases, from 1.5 cm to 2.0 cm – in 28.6%, for tumors more than 2 cm the complete regression was not achieved. The recurrence of tumor was diagnosed in 2 patients in the period from 1 to 5 years with following successful repeated courses of PDT. Adverse effects included inflammation changes in mucosa at the PDT region with transient (up to 6-7 days) local fibrinous endobronchitis with obturation of segmental bronchial lumen by fibrin membranes (7 patients), scar stenosis of segmental bronchus (2 patients). All patients had increased sensitivity to sun exposure, mild skin burns at exposed areas of body were in 2 patients. The results showed that method was highly efficient and applicable for pre-invasive central lung cancer and in patients with multiple primary bronchial lesions and high risk of surgical complications.