TLD postal dose intercomparison for megavoltage units in Poland.

The aim of the TLD pilot study was to investigate and to reduce the uncertainties involved in the measurements of absorbed dose and to improve the consistency in dose determination in the regional radiotherapy centres in Poland. The intercomparison was organized by the SSDL. It covered absorbed dose measurements under reference conditions for Co-60, high energy X-rays and electron beams. LiF powder type MT-N was used for the irradiations and read with the Harshaw TLD reader model 2000B/2000C. The TLD system was set up and an analysis of the factors influencing the accuracy of absorbed dose measurements with TL-detectors was performed to evaluate and minimize the measurement uncertainty. A fading not exceeding 2% in 12 weeks was found. The relative energy correction factor did not exceed 3% for X-rays in the range 4-15 MV, and 4% for electron beams between 6 and 20 MeV. A total of 34 beams was checked. Deviation of +/- 3.5% stated and evaluated dose was considered acceptable for photons and +/- 5% for electron beams. The results for Co-60, high energy X-rays and electron beams showed that there were two, three and no centres, respectively, beyond acceptance levels. The sources of errors for all deviations out of this range were thoroughly investigated, discussed and corrected, however two deviations remained unexplained. The pilot study resulted in an improvement of the accuracy and consistency of dosimetry in Poland.

[Evaluation of the usefulness of measuring the serum and urine levels of light chain immunoglobulins in multiple myeloma and Waldenström's macroglobulinemia]. / Ocena przydatnosci oznaczania stezenia lekkich lancuchów immunoglobulinowych w surowicy krwi i moczu chorych na szpiczaka plazmocytowego i makroglobulinemie Waldenströma.

Quantitative determinations were carried out of light immunoglobulin chains by the method of ring precipitation in the serum and urine of 117 patients with plasmocytic myeloma and 16 with Waldenström's macroglobulinemia. The method was found useful for the identification of the light chain of the monoclonal proteins of IgG, and IgD classes. In the case of the lambda-type light chain disease the method is helpful in the identification of the M-component of the serum. Quantitative determination of light chains of immunoglobulins by ring precipitation is not essentially superior to other immunological and electrophoretic methods of protein analysis in monitoring treatment of cases of this myeloma.

[Therapeutic plasmapheresis in patients with multiple myeloma]. / Plazmafereza lecznicza u chorych na szpiczaka plazmocytowego.

The effectiveness of therapeutic plasmaphereses with antineoplastic chemotherapy was evaluated in 25 cases of plasmocytic myeloma in stage III of progression of the proliferative process. The indication to plasmapheresis was hypergelification of serum with clinical symptoms of central nervous system disturbances, renal failure in various stages of progression, intensification of coronary symptoms, bleeding tendency. Good effects with reduced level of total protein and monoclonal protein in serum by 30-80% with regression of clinical symptoms caused by serum hypergelification were obtained in 11 cases. In the remaining patients clinical improvement of varying degree was noted when the level of total and monoclonal protein in the serum fell by 10-29%.

[Chemotherapy and immunomodulating treatment of patients with multiple myeloma]. / Chemioterapia i leczenie immunomodulacyjne u chorych na szpiczaka plazmocytowego.

Prospective studies were carried out on the effectiveness of various treatment methods in 208 patients with plasmocytic myeloma. In 102 patients induction therapy was based exclusively on melphalan, in 106 cases polychemotherapy was used including vincristine, melphalan, carmustine, cyclophosphamide and prednisone. The differences in the per cent of patients with good response to treatment and in the survival time after treatment beginning were statistically not significant between these groups which suggests that polychemotherapy begun from the diagnosis of the disease is justified in patients with large mass of the neoplasm and poor prognostic factors. In 45 patients chemotherapy was supported by administration of immunomodulatory agents, including calf thymus extract in 25 cases, levamisole in 18 and interferon in 2. It was observed that maintenance of remission with chemotherapy and with immunomodulatory agents calf thymus extract or levamisole prolonged the survival of the patients. In cases of leucopenia the use of calf thymus extract facilitated chemotherapy by stimulation of myelopoiesis.

[Clinical and laboratory analysis of the cases of multiple myeloma with over 5-year survival time from the beginning of the antineoplastic treatment]. / Analiza kliniczna i laboratoryjna przypadków szpiczaka plazmocytowego z czasem przezycia powyzej 5 lat od rozpoczecia leczenia przeciwnowotworowego.

Out of 436 studied patients with plasmocytic myeloma 67 (15.0%) survived over 5 years from the beginning of antineoplastic treatment, and 18 survived over 10 years from the first symptom of the proliferative process. The patients with long survival were younger at the time of diagnosis than the whole studied group and had normal creatinine and calcium levels in the serum. Nearly half these patients had I or II stage of clinical progression and IgG monoclonal protein. Treatment with melphalan only was given to 17 patients, 33 were treated with melphalan, followed by vincristine, cyclophosphamide, BCNU, prednisone and doxorubicin. Polychemotherapy was given from the time of the diagnosis to 13 patients, and 4 received radiotherapy or 60Co irradiation besides chemotherapy. In 81% of the analysed cases a good response was obtained. Thirteen patients are alive. In 5 cases myeloid leukaemia, in 1 case bronchogenic carcinoma and in 1 case liver carcinoma were the causes of death.

[IgM monoclonal gammopathy in plasmacytic neoplasms]. / Gammapatia monoklonalna IgM w nowotworach plazmocytowych.

In 331 patients with the diagnosis of multiple myeloma in 4 cases proliferation of plasma cells was associated with synthesis of a monoclonal IgM. In 3 of these cases coexistence was noted of features typical of multiple myeloma and Waldenström's macroglobulinaemia. In the clinical picture in two of these cases sings of blood hyperviscosity prevailed. These patients showed impairment of plasma clotting factors. The count of T and B cells in blood and the adherence and phagocytic activity of monocytes were not abnormal. The ultrastructural pattern of plasma cells in bone marrow was similar to that observed in classical cases of IgG or IgA multiple myeloma. In one case of lymphoplasmocytic proliferation with leucocytosis over 100 x 10(9)/l immunoelectroscopic examination of bone marrow cells demonstrated a formidable accumulation of the heavy chain of mu immunoglobulin in the cytoplasm of lymphoplasmacytes. In the serum and urine no monoclonal protein was found. In this case compression of vertebral bodies Th7 and L2 occurred.

[Clinical usefulness of serum beta2-microglobulin determination in patients with multiple myeloma]. / Ocena przydatnosci klinicznej oznaczania stezenia beta 2-mikroglobuliny w surowicy krwi chorych na szpiczaka plazmacytowego.

Serum concentrations of beta 2-microglobulin (beta 2M) were determined in 73 patients with various forms of multiple myeloma and in various phases of the proliferative process. These determinations showed that beta 2M may be a useful indicator of changes in tumour mass and proliferation activity, and also an important prognostic factor. In patients with active proliferation the serum beta 2M concentration was significantly higher than in the group with stable proliferative process, and particularly in remission. A correlation was found between the serum concentration of monoclonal protein and beta 2M concentration. In the group with the secretory form of myeloma significant differences were showed in the length of survival which depended on beta 2M concentration in serum. The median survival of patients with beta 2M concentration in serum below 5.0 mg/l was 52 months and that in those with this concentration above 8.0 mg/l was 24 months.