AU756224B2 - Method for treating tumour growth - Google Patents

Description

A method for treating neoplasms Field of the invention This invention relates to medicine and may be useful in treating neoplasms, including malignant neoplasms, with optical, laser radiation.

Background A method for treating neoplasms with laser irradiation of tumor tissue, which is achieved by surface application of a light guide or insertion of said light guide into tumor tissue is disclosed in RU 20452298. The irradiation is performed using either impulse or continuous mode, or using a combination of the above modes. The impulse mode is used to produce a high level of power density (about 1 J/mm and short impulses of irradiation (about 10 3 Each of the above modes results in local destruction (coagulation or ablation) of tissues, and the impulse mode enhances this effect.

The above method is used in surgery, especially when parenchymatous organs are involved, and, also, in endoscopic surgery to stop bleeding and to reconstitute lumens in hollow organs. When the neoplasm is large in size, the implementation of this method is associated with the threat of massive bleeding and perforation of the wall of the respective organ. Moreover, the use of the above method is limited with regard to tumor localization (kidney and breast tumors etc.).

A method for treating neoplasms with optical, e.g. laser, irradiation, which method implies administration of photosensitization agents into the patient's body i iior to irradiation, is disclosed in B.B. CoKono6 u c)p. (PomocuHaMluqecK a mepaniw 3JnOKaqecmeeillblx onyxojeu OCNO6HbIX JRoKaJtu3atfuu C npenapamaMu (iomoeM u chomocenc. Bonpocbl OHKOOZ2UU, .N2. m. 41, c. 134. Sokolov, et al., Photodynamic therapy of localised tumor with photosensitization agents, Oncology, 1995, No. 2, Vol 41, p. 134).

Photosensitization agents treated with optical (laser) radiation initiate photochemical reactions in irradiated tissue when radiation wavelength ranging from 630 to 660 nm corresponds to one of optical absorbance maximi of the photosensitization agent chosen. The photochemical reaction results in tumor tissue damage and tumor regression. When a photosensitization agent is administered into a patient's body, a high sensitivity of the body to light develops, which makes it necessary to keep the patient in a dark room for a long time and to use individual protective means. When the light protecting regime is not followed, burns develop.

Besides, it should be noted that photosensitization agents do not always accumulate in tumor tissue to reach concentrations required to make a photochemical reaction effective. In a number of cases no selective accumulation of sensitization agent in tumor tissue occurs, which greatly reduces the efficacy of the method.

i" Summary of the invention This invention essentially provides for a solution to the problem of increasing the efficacy of neoplasm treatment and avoiding adverse bodily responses associated with the use of photosensitization agents.

According to the invention, the this effect is achieved by treating a neoplasm with optical, laser irradiation. The primary effect on the neoplasm is rendered by irradiation delivered at a dose ranging within 50-100 J/mm 2 and power density ranging within 0.1-10 W/cm 2 at which the size of the neoplasm is evaluated and, where it is found to have decreased, the above treatment with optical radiation at the bove dose is periodically repeated until the possibly maximum regress of the size of -3the neoplasm is achieved, whereas, if there has been no decrease in the size of the neoplasm after the primary irradiation, the dose of irradiation is gradually increased until a decrease in the size of the neoplasm is detected, whereupon the neoplasm is treated at the dose achieved.

Lower dosage limits of optical radiation and power density are determined by decreasing these parameters. Not only the therapeutic effect may cease to be observed but, moreover, blood vessel dilation may result in an improved nourishment of tissues, including tumor tissue, which promotes tumor growth.

The upper limit of the above parameters of the primary treatment of a tumor 1; 0 S. with optical radiation is determined by the necessity to ensure the avoidance of tissue coagulation and ablation and the adverse consequences of the above effects.

Where after the primary treatment of a neoplasm with optical radiation within said limits no regress of the neoplasm is observed, the radiation dose is gradually increased until a decrease of the volume of the neoplasm is observed. This is accompanied by monitoring the patient's bodily responses in order to avoid local i tissue destruction. Where the gradual increase of radiation dose results in a decrease of the neoplasm, subsequent treatment is conducted at the dose achieved until the maximal possible regression of the tumor occurs.

The method according to the present invention is implemented at wavelengths ranging from 700 to 1200 nm.

The applicant of the present invention is unaware, to the best of his knowledge, of any sources that disclose technical solutions identical to the present invention. Therefore, the applicant believes that the invention conforms to the novelty criterion.

Due to the distinct nature of this invention, an important effect is achieved, which is the elimination of the need to use photosensitization agents and the elimination of adverse affects associated with using such agents (high photosensitivity of patients and the absence of curative effects in cases when no selective accumulation of photosensitization agent occurs in tumor tissue compared with normal tissue).

When a tumor is treated with optical radiation at parameters and modes corresponding to those provided by the present investigation, a physical hyperthermia) rather than chemical response is evoked, which prevents effects that promote tumor growth as well as tissue damage.

*The applicant of the present invention has not found any information about the achievement of the above technical result by implementing features cited as distinctions of the present investigation. Therefore the applicant believes that the achieved progress conforms to the inventive level (IS) criterion.

g ::The preferred version of the invention i The examples below are intended to illustrate the optimal modes of using the method of this invention in particular situations.

EXAMPLE 1. Female patient S-va A.S. aged 46. Clinical diagnosis: T 3

NM,

breast cancer. The patient was hospitalized after three polychemotherapy courses.

Examination revealed a dense tumor node within the upper lateral quadrant of the left mammary gland, the node size being 5x7 cm. The patient complained about pain in the left mammary gland and about fatigue.

Ultrasound examination of the mammary gland revealed a 5x7-cm echonegative formation located 4 cm deep within the upper-lateral quadrant of the left r\ r ary gland.

The patient was subjected to laser therapy using a semiconductor laser.

Radiation characteristics: wavelength 800 nm; output power 1 W; primary dose J/cm 2 per field; field area 0.25cm After three days a decrease in tumor size was detected. The above mode of treatment was repeated 10 times. After the seventh treatment no further regress of the tumor occurred, so the course of treatment was discontinued after the tenth treatment.

EXAMPLE 2. Female patient S-na G.I. aged 32. Clinical diagnosis: left subscapular lymphosarcoma. The diagnosis was verified by knife biopsy.

Chemotherapy failed to be effective.

Examination of left subscapular area revealed a dense node with a 4-cm diameter. The patient complained about strong pain around the neoplasm area o* irradiated to the left side o the thorax. Ultrasound examination of the left subscapular area revealed an echo-negative body with a 3-cm diameter.

Irradiation parameters: wavelength 830 nm; output power 5 W; dose per one field 100 J/m 2 field area 0.5 cm 2 The tumor did not decrease in three days, whereupon the dose was increased up to 120 J/cm 2 This produced no effect during the next three days, and so the dose was further increased up to 140 J/cm 2 After another three days a decrease in tumor size was detected. The treatment with the last dose was repeated 15 times. Examination and ultrasound data provided evidence of a nearly complete regress of the pathological body substituted with cicatricial tissue.

EXAMPLE 3. Male patient V-v S.I. aged 56. Clinical diagnosis: malignant tumor of the right parotid gland with metastasis in left and right supraclavicular lymph nodes.

The patient complained about strong pain localized to the parotid area.

Ultrasound examination of the parotid gland revealed several amalgamated echonegative tumor nodes with a 5.5-cm diameter and uneven bumpy outline.

Irradiation parameters: wavelength 790 nm, output power 1 W; dose per one field 65 J/m 2 field area 10 cm 2 The above dose was used to perform 18 treatment sessions. Control examination and ultrasound data revealed that tumor diameter decreases down to 1.5 cm, tumor consistency became more dense, and the tumor outline became more clear. The pain syndrome significantly ameliorated.

Applicabiliy of the invention The implementation of the method provided by this invention is possible with technical means well known in the art, including semiconductor, gas, or solid-state laser and, also, mercury lamps, which allows to conclude that this invention conforms ito the industrial applicability (IA) criterion.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", or variations such as "comprises" or "cmpr,;csing", will h- iindtrtnAnd tn impnly the. inclusion of a stated integer or tenp or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that the prior art forms part of Scommon general knowledge in Australia.

Claims (3)

1. A method for treating neoplasms with optical radiation featuring primary treatment of a neoplasm at a dose ranging within 50-100 J/cm 2 and power density ranging within 0.1-10 W/cm 2 followed by checking the size of the neoplasms and, where size has been found to decrease, regular repetition of the treatment with optical radiation at the same dose until the maximal possible regression of the neoplasm is achieved, or, where no decrease of the size of the neoplasm occurs after the primary treatment, gradually increasing the dose of radiation until a decrease in the size of the neoplasm is detected, whereupon the treatment of the neoplasm is repeated at the dose achieved.

2. A method for treating neoplasms according to claim 1 wherein the optical radiation is laser radiation.

3. A method for treating neoplasms as herein described with reference to the examples. DATED THIS 11th day of November, 2002. ZAKRYTOJE AKTSIONERNOE OBSCHESTVO "POLUPROVODNIKOVYEPRIBORY" By Its Patent Attorneys -DAIES COLLISON CAVE