[Different types of 199Tl chloride scintigraphic visualization of malignant tumors of the locomotor apparatus].

BACKGROUND: 201Tl chloride scintigraphy allows malignant tumors of the locomotor apparatus to be diagnosed. The capacities of scintigraphy with 199Tl chloride, a 201Tl chloride analog, in addition to routine visualization of malignant tumors of the locomotor apparatus, have revealed its untypical variants. OBJECTIVE: to study the specific features of 199Tl chloride scintigraphic visualization of malignant tumor processes in the locomotor apparatus. SUBJECTS AND METHODS: 199Tl chloride scintigraphy was performed in 85 patients having 107 foci of involvement presented with malignant (n = 57) and benign (n = 50) tumor processes. RESULTS: Malignant tumors were scintigraphically visualized in 98.1% of cases. Three types of their visualization were identified and studied; these included positive (82.4%) and rare: negative (7.8%), and mixed (9.8%) types associated with the specific features of the histological structure, metabolism, and blood supply of neoplasms and with the pharmacodynamic features of 199Tl chloride. The negative and mixed types, unlike metastatic neoplasms, were highly specific to primary or recurrent malignant tumors. CONCLUSION: Consideration of the negative and mixed types of scintigraphic visualization in addition to routine positive one permitted the sensitivity of diagnosis of malignant locomotor tumors to be increased from 90.4 to 98.1%, without reducing the specificity of 199Tl chloride scintigraphy.

[The comparative biochemical and morphological characteristics of chondrosarcoma and giant-cell tumor of the bone]. / Sravnitel'naia biokhimicheskaia i morfologicheskaia kharakteristika khondrosarkomy i gigantokletochnoi opukholi kosti.

Spectrometry has been employed to assess the levels of collagenase, catepsin D, trypsin-like proteinases and their inhibitors as well as bone acid and alkaline phosphatase both in the center and along the periphery of giant cell tumor of bone (GCTB) and chondrosarcoma. The levels of collagenase, trypsin-like proteinases and their inhibitors in the center of chondrosarcoma were much higher while those of alkaline phosphatase--lower than along tumor periphery. The catepsin D and acid phosphatase concentrations of the center and periphery of chondrosarcoma were similar. It was suggested that an extremely low concentration of trypsin-like inhibitors may contribute to degradation of the matrix in tissues adjacent to chondrosarcoma and, consequently, to tumor invasion development.

[Indices of proteolysis in evaluation of resorption in bone tumors]. / Pokazateli proteoliza v otsenke rezorbtsii pri opukholiakh kosti.

Activities of acid and alkaline phosphatases, collagenase, cathepsin D, trypsin-like proteinases, alpha(1)-proteinase inhibitor (alpha(1)-PI), alpha(2)-macroglobulin (alpha(2)-MG) were measured in blood plasma and tumor tissue of patients with giant-cell tumor of the bone (GCTB) and bone chondrosarcoma. These tumors differed by enzymatic activities. GCTB is characterized by increased activity of alkaline phosphatase, while in chondrosarcoma tissue the activities of collagenase and cathepsin D were the highest. Activities of acid phosphatase, collagenase, trypsin-like proteinases were increased in the plasma of patients with both tumors; alpha(1)-PI/alpha(2)-MG ratio was increased. Bone resorption parameters correlated with proteolysis inhibitors. Activities of collagenase and acid phosphatase were increased in tumor tissue and plasma in the presence of low activities of alpha(2)-MG and increased alpha(1)-PI/alpha(2)-MG index, which seems to require special attention during the postoperative period.

[The intraoperative irradiation of tumors]. / Intraoperatsionnoe obluchenie opukholei.

Intraoperative irradiation of tumor was performed in 40 patients with cancer of the lung, stomach, breast, bone and soft tissues. It included irradiation of the bed of tumor removed. Fast electron beam was produced by a small betatron (collimator size--5 x 6 cm and 8 x 12 cm) installed in the operating room. Radiation was given to a single or to multiple fields in a single dose of 10-20 Gy to each field. Location of the radioactive source in the operating room proved technically, economically and medically advantageous since it was cheaper, assured a shorter period of the treatment and delivered from patient transportation to a radiotherapy department and ensuing complications. The procedure did not interfere with postoperative period. The efficacy of the treatment modality will be evaluated as soon as sufficient end results have been obtained.

[Treatment tactics in giant cell tumor of the bone]. / Lechebnaia taktika pri gigantokletochnykh opukholiakh kostei.

The data on 76 patients treated for benign or malignant giant-cell tumor (GCT) of the bone are presented. Surgery involving bone reconstruction and endoprosthetics was the basic therapeutic procedure. Cases with lytic benign GCT received 36-40 Gy of radiation prior to surgery whereas whose with malignant tumors were subjected to complex treatment including preoperative irradiation, surgery and chemotherapy. Recurrence was observed in two patients with benign and in one--with malignant GCT. There were four fatalities. Five-year survival was 82%.

[Epithelioid sarcoma (clinico-morphological characteristics)]. / Epitelioidnaia sarkoma (kliniko-morfologicheskaia kharakteristika).

Epithelioid sarcoma is a relatively rare malignancy which possesses peculiar clinico-morphological characteristics. It is characterized by few symptoms and a comparatively long course; it tends to arise in distal parts of the extremities in the age range of 20-40 years. It reveals the following morphologic features: nodular pattern, involvement of tendons and fasciae, epithelium-like cells and central necroses. Recurrence was observed in 79% and dissemination-57% (metastases into lymph nodes-37.5% included). Extensive excision of tumor or amputation are a method of choice in treating epithelioid sarcoma.