Neurosurgery of intracranial tumors, especially of glial origin, is a non-trivial task due to their infiltrative growth. In recent years, optical methods of intraoperative navigation have been actively used in neurosurgery. However, one of the most widely used approaches based on the selective accumulation of fluorescent contrast medium (5-ALA-induced protoporphyrin IX) by the tumor cannot be applied to a significant number of tumors due to its low accumulation. On the contrary, Raman spectroscopy, which allows analyzing the molecular composition of tissues while preserving all the advantages of the method of fluorescence spectroscopy, does not require the use of an exogenous dye and may become a method of choice when composing a system for intraoperative navigation or optical biopsy. This work presents the first results of using the principal component method to classify Raman spectra of human glioblastoma with intermediate processing of spectra to minimize possible errors from the fluorescence of both endogenous fluorophores and photosensitizers used in fluorescence navigation. As a result, differences were found in the principal component space, corresponding to tissue samples with microcystic components, extensive areas of necrosis, and foci of fresh hemorrhages. It is shown that this approach can serve as the basis for constructing a system for automatic intraoperative tissue classification based on the analysis of Raman spectra.

The authors consider the possibilities of pain management during photodynamic therapy (PDT) of visible tumors based on the observation of 102 patients. Of the total number of patients, 62 had verified basal cell skin cancer, 10 people - squamous cell skin cancer, another 10 - oral and oropharynx mucosa cancer, 8 - oral leukoplakia and dysplasia, in 6 - lower lip cancer, in 4 - breast cancer, in 2 - other localizations of neoplasms. In 15 patients, nonsteroidal anti-inflammatory drugs (NSAID) were used as pain management, in 69 - a combination of NSAID with tramadol, in 14 - nerve block anesthesia, in 4 - PDT was performed under general anesthesia. The intensity of pain syndrome during laser irradiation of the tumor was assessed on the verbal rating scale (VRS). The absence of pain was recorded in 9% of cases. Mild pain was noted by 58% of patients, moderate pain - 20%, severe pain - 10%, very severe pain was noted by 3% of patients.

The degree of expression of pain syndrome during PDT depends on the incidence of a lesion, histological form of tumor, and method of anesthesia. NSAID alone, or in combination with an opioid analgesic, allows effective control of pain syndrome in PDT of basal cell skin cancer in 89%, in PDT of squamous cell skin cancer in 66% of observations. Nerve block anesthesia allows stoping pain syndrome during PDT of oropharyngeal tumors.

Phototherapy has shown its effect on cell stimulation and inhibition based on Arndt-Schulz model. Even though this therapeutic method has apparent effect, but it has limitations for epithelial application due to limitations on light penetration. Hence, with the ideology of fully overcoming this limitation, phosphorescent powder (strontium aluminate) is proposed as the potential light source that emitting photon from inside the body for phototherapy purposes. The strontium aluminate powder used in the experiment has the highest peak absorption at wavelength around 650 nm and lowest at around 350 nm. According to FESEM images, the powder has the particle size varies from 10 to 50 μm at cubic phase. The assessment is done by studying the effect on erythrocyte after blood plasma is irradiated by strontium aluminate powder’s photon. The powder luminesces with a maximum at 491.5 nm when pumped with 473 nm laser at 100 mW in fixed amount of 0.005±0.001 g. Later, it is mixed with  centrifuged blood plasma for a predetermined time period (5, 10, 15, and 20 minutes). From this study, it shows that 5 minutes irradiation is the optimum  period for erythrocyte in term of morphology enhancement and increase of UV-visible absorption spectrum with at least 21% in comparing  with control blood. While the significant increment located at wavelengths 340 nm and 414 nm with both increased by 54% and 41%, respectively. However, for 10 minutes and beyond, the irradiation leads to morphology deterioration while the UV-visible spectrum decrement starts at 15 minutes and beyond. In conjunction, a comparison between blood plasma that either interacted with powder emitting photon or powder with no emission shows that photon emission plays a role in the phototherapy effect.

This review article discusses the key aspects of the use of laser technologies, namely, laser vaporization (LV) and photodynamic therapy (PDT), in the treatment of patients with cervical intraepithelial neoplasia (CIN). The authors analyzed and systematized the foreign experience of these methods of treatment, their indications and contraindications, as well as the advantages over traditional approaches to the treatment of this pathology. The main advantages of the LV are the possibility of complete evaporation of the pathological focus, visual control over the depth of tissue destruction, the absence of prolonged edema and cicatricial deformities, which allows maintaining the integrity of the cervix and its reproductive function. Despite the low trauma and low frequency of adverse reactions, the data on the effectiveness of LV are quite contradictory and, according to various authors, vary from 50% to 98%. To date, there is a significant amount of accumulated experience in the use of PDT with various photosensitizing agents (5-aminolevulinic acid (5-ALA), hematoporphyrin and chlorin and their derivatives) in the treatment of patients with CIN. The main advantages of the PDT are minimal toxicity to the surrounding normal tissues due to the selective accumulation of photosensitizer in pathological tissues, a low risk of severe pain syndrome, the absence of mechanisms of primary and acquired resistance, the possibility of an outpatient treatment session, the possibility of combining with other methods of therapeutic action, the absence of limiting cumulative doses of photosensitizers and light exposure, the possibility of multiple repetitions of the session, good cosmetic results and the possibility of implementing an organ-preserving method of treatment. The obtained results indicate good tolerability of the method (no severe adverse reactions) and a fairly high efficiency of PDT: the frequency of complete regressions varies from 30% to 67% - for application forms of 5-ALA and from 90% to 98.1% - for hematoporifirin and chlorin photosensitizers. Thus, LV and PDT can be considered safe and effective treatment options for patients with CIN.