[The reoxygenation of superficial tumors in fast-neutron therapy]. / Reoksigenatsiia poverkhnostno-raspolozhennykh opukholei pri terapii bystrymi neitronami.

The paper is concerned with the data on reoxygenation of superficial tumors in 38 patients exposed to densely and scarcely ionizing radiation. Tumor reoxygenation curves are presented. A tumor regression rate and reoxygenation of a tumor with respect to its original size showed correlation during fast-neutron therapy at 6.3 MeV.

[The reaction of tumors and normal tissues to therapy with fast neutrons from the U-120 cyclotron]. / Reaktion von Tumoren und Normalgeweben bei der Therapie mit schnellen Neutronen am Zyklotron U-120.

In the present information results of clinical studies are represented to show the effectiveness of therapy with 6.3 MeV fast neutrons in 45 patients with superficial tumors in head and neck area. The reaction of tumor and of normal tissue was studied in dependence on different physical and biological factors. Two variants of neutron therapy planning were estimated by means of mathematical models of a factor of time-dose-fractionation for neutron (TDFN) from clinical point of view. Results of changes in oxygen-tension within the tumor are represented in 20 patients with metastases in cervical lymph-nodes during neutron therapy. The obtained data show a correlation of regression and reoxygenation rate of the tumor to its initial volume. The reaction of the tumor in therapy with fast neutrons was studied in dependence on its morphological structure. Complete regression of epidermoid and nonepidermoid cancer types was seen in 42 or 89% of the cases. With corrections for adipose tissue and the extent of dose fraction of fast neutrons the clinical test of the mathematical model of TDFN-factor made discernible that the reaction of normal tissue can be prognosticated quite exactly by means of this model in neutron therapy.

[3 years' experience of radiation therapy with fast neutrons on the V-120 cyclotron]. / Trekhletnii opyt luchevoi terapii bystrymi netronami na tsiklotrone V-120.

The paper discusses the results of treatment of 128 patients with head and neck cancer in whom fast neutrons (Y-120; approximately 6.2 MeV) were used as a single procedure or in combination with surgery. Tumors of different histomorphologic structure displayed unequal sensitivity to fast neutrons. Mean disease-free survival in patients with complete regression of tumor was 24 months following neutron therapy alone, 18.5 months after combined neutron-photon treatment and 5.5 months only in controls. Relapse rates were 20 and 15% in patients with pre- and postoperative neutron treatment, respectively, as compared to 52% in controls.

[Local radiation reactions and injuries in neutron and combined therapy of tumors using the U-120 cyclotron]. / Mestnye luchevye reaktsii i povrezhdeniia pri neitronnoi i sochetannoi terapii opukholei na tsiklotrone U-120.

Early local radiation reactions and radiation damage during fast neutron therapy of head and neck tumors were studied. The frequency of moist epidermitis in a radical course of neutron therapy was 33%, that in combined neutron and photon irradiation was 21%. Mucosal reactions were observed in 30-35% of the patients with tumors of the oral mucosa. The most frequent radiation damage in a long-term period were fibrotic changes of the skin and subcutaneous connective tissue.

[Radiation-induced changes in normal tissues during neutron-photon therapy of recurrent cancer of the root of the tongue]. / Luchevye izmeneniia normal'nykh tkanei pri neitronno-fotonnoi terapii retsidiva raka kornia iazyka.

The paper is concerned with a case of a 2-year follow-up of a patient with recurrent cancer of the root of the tongue treated with fast neutrons on the Y-120 cyclotron. Medical history included a preoperative course of photon therapy at a dose of 40 Gy and operation. The total focal dose of fast neutrons of a repeated irradiation course was 11.2 Gy, that of photons--14 Gy corresponding to a total photon equivalent dose of 50 Gy. The authors provided the evidence of late radiation changes of the skin, temporomandibular articulation, pharynx, and the upper esophagus, and analyzed the causes of development of radiation complications.

[Neutron therapy of head and neck tumors]. / Neitronnaia terapiia opukholei golovy i shei.

The results of therapy of 55 head and neck tumor patients using fast neutrons of the Y-120 cyclotron of the Research Institute of Nuclear Physics, Tomsk Polytechnical Institute, were analyzed. For design of courses of neutron and combined neutron-photon therapy formulas of DMF calculation were used in cases of homogeneous and arrhythmic dose fractionation. The authors presented some data on methods of therapy with fast neutrons, dose fractionation schedules, a focal dose value, and time of treatment. Complete tumor regression was noted in 50-54% of cases using fast neutrons alone or in combination with photon radiation. A high sensitivity to neutron radiation of nonepidermoid carcinomas as compared to epidermoid cancer types was established with relation to tumor morphological structure.

[Preparation of patients with head and neck tumors for neutron teletherapy]. / Podgotovka bol'nykh s opukholiami golovy i shei distantsionnoi neitronnoi terapii.

The authors discuss some problems of preradiation preparation of patients with head and neck tumors for neutron teletherapy on the U-120 cyclotron of the Tomsk Polytechnical Institute in the Siberian Branch of the All-Union Cancer Research Center, AMS USSR. Some methods of the manufacture and employment technique of the fixing and forming devices for the optimization of neutron therapy are described.