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Natural killer cell activity in Hodgkin's disease patients undergoing radiation therapy or chemotherapy and radiation therapy.

Natural killer (NK) cell activity in peripheral blood mononuclear cells (PBMCs) from patients with Hodgkin's disease was studied using 4 h 51Cr release assay and K562 cells as sensitive targets. PBMCs were obtained from 15 previously untreated patients at different stages of their disease. PBMCs were also obtained from 46 patients treated by radiation therapy or combined chemotherapy and radiation therapy. Twenty healthy age-matched volunteer donors were used as controls to the treated patients. For these normal donors the mean cytotoxicity was 24.8 +/- 5.67% at a 100:1 effector-target cell ratio; and 43.7 +/- 12.1% for the treated cancer patients. Fifteen healthy age-matched volunteer donors were used as controls to the untreated patients. The mean cytotoxicity for these normal donors was 20.8 +/- 3.61% at a 100:1 effector-target cell ratio; and 37.6 +/- 6.65% for the previously untreated cancer patients. The mean cytotoxicity for all 35 normal donors was 23.1 +/- 5.22% at a 100:1 effector-target cell ratio. Most treated patients (93.5%) had a complete response to therapy and a significant difference was found between the mean cytotoxicity of the whole group (46 treated patients), compared with controls (P < 0.001). A significant difference (P < 0.05) was also observed when the same 11 patients were studied before and after treatment.

Adult↗

Occupational exposure to ionizing radiation has no effect on T- and B-cell total counts or percentages of helper, cytotoxic and activated T-cell subsets in the peripheral circulation of male radiation workers.

PURPOSE: To investigate changes in immune cell subsets in the peripheral circulation of a male population occupationally exposed to ionizing radiation. MATERIALS AND METHODS: Peripheral blood samples were taken from 194 male workers with cumulative exposures of >200 mSv (mean exposure 331.5 mSv, mean age 51 years) and from a reference population of 131 male workers with cumulative exposures of <27.5 mSv (mean exposure 13.9 mSv, mean age 47 years). Samples were analysed by flow cytometry for T- and B-cell total counts and for the T-cell subset percentages of CD4+ (helper T-cells), CD8+ (cytotoxic T-cells) and CD3+/HLA-DR+ (activated T-cells). RESULTS: Comparison of the >200 and <27.5 mSv exposure groups using linear regression analysis showed no statistically significant differences between the two groups for T-cell total count, B-cell total count or for percentages of the T-cell subsets CD4+, CD8+ or CD3+/HLA-DR+ and CD4+:CD8+. However, statistically significant increases in both T- and B-cell total counts were observed within the two exposure groups and data pooled from both groups when non-smokers (never and ex-smokers) were compared with current smokers. For pooled data T-cell total count increased in smokers by 35% (p=0.0001) and B-cell total count increased by 37% (p=0.0004). CONCLUSIONS: No significant immunological effects were observed in male radiation workers with cumulative exposures of >200 mSv when compared with a reference population with cumulative exposures of <27.5 mSv, although highly significant increases in both T- and B-cell total counts were observed in smokers compared with non-smokers.

Adult↗

Randomized trial of radiation therapy versus concomitant chemotherapy and radiation therapy for advanced-stage oropharynx carcinoma.

BACKGROUND: We designed a randomized clinical trial to test whether the addition of three cycles of chemotherapy during standard radiation therapy would improve disease-free survival in patients with stages III and IV (i.e., advanced oropharynx carcinoma). METHODS: A total of 226 patients have been entered in a phase III multicenter, randomized trial comparing radiotherapy alone (arm A) with radiotherapy with concomitant chemotherapy (arm B). Radiotherapy was identical in the two arms, delivering, with conventional fractionation, 70 Gy in 35 fractions. In arm B, patients received during the period of radiotherapy three cycles of a 4-day regimen containing carboplatin (70 mg/m(2) per day) and 5-fluorouracil (600 mg/m(2) per day) by continuous infusion. The two arms were equally balanced with regard to age, sex, stage, performance status, histology, and primary tumor site. RESULTS: Radiotherapy compliance was similar in the two arms with respect to total dose, treatment duration, and treatment interruption. The rate of grades 3 and 4 mucositis was statistically significantly higher in arm B (71%; 95% confidence interval [CI] = 54%-85%) than in arm A (39%; 95% CI = 29%-56%). Skin toxicity was not different between the two arms. Hematologic toxicity was higher in arm B as measured by neutrophil count and hemoglobin level. Three-year overall actuarial survival and disease-free survival rates were, respectively, 51% (95% CI = 39%-68%) versus 31% (95% CI = 18%-49%) and 42% (95% CI = 30%-57%) versus 20% (95% CI = 10%-33%) for patients treated with combined modality versus radiation therapy alone (P =.02 and.04, respectively). The locoregional control rate was improved in arm B (66%; 95% CI = 51%-78%) versus arm A (42%; 95% CI = 31%-56%). CONCLUSION: The statistically significant improvement in overall survival that was obtained supports the use of concomitant chemotherapy as an adjunct to radiotherapy in the management of carcinoma of the oropharynx.

Adult↗

"Compensated" split-course versus continuous radiation therapy of carcinoma of the tonsillar fossa. Final results of a prospective randomized clinical trial of the Radiation Therapy Oncology Group.

The Radiation Therapy Oncology Group conducted a prospective comparison of a compensated split course radiotherapy technique (300 cGy x 10, 3 weeks rest, 300 cGy x 10), versus continuous radiotherapy (200-220 cGy up to 6000-6600 cGy), in 137 evaluable patients. The complete response (CR) was 57% in 63 patients, treated with the split-technique vs 61% in 74 patients submitted to continuous course radiotherapy. The completion of therapy as planned was better in the split-technique, but acute and late tissue reactions were the same. Locoregional control of tumor at 5 years was 25% for split and 28% for continuous therapy. At 7 years this was 25% and 24%, respectively. Absolute survival in the split-course patients tended to be lower than in the continuous group, but when the sample of patients was enlarged by the addition of cases from similar trials of nasopharynx and base of tongue lesions, the survival difference was eliminated. On the basis of the results of this study we conclude that the stated compensated split-course technique gives equal clinical results as conventional continuous therapy, with the advantage of requiring fewer radiation fractions, and less burden on the patient and therapy facilities.

Aged↗

The effect of ultra-violet and visible radiation on CaSO4:Dy in Teflon discs used for personnel gamma-radiation monitoring.

The influence of ultra-violet and visible radiation (UV/VIS) on the read-out obtained from the main dosimetry peak of CaSO4:Dy in Teflon discs exposed to the gamma-radiation levels measured by a personnel-monitoring service has been studied as a function of wavelength, irradiance and radiant exposure. The results have been explained by the net effect of three separate factors, namely (i) an inherent response, (ii) a phototransfer and (iii) an optical bleaching. The response obtained from unirradiated discs illuminated with fluorescent room lighting became saturated after 16 hrs at a value corresponding to 0.33 microC kg-1 whilst gamma-irradiated discs faded to 90% of their initial exposure for the same illumination period.

Calcium Sulfate↗

Accelerated growth of intestinal tumours after radiation exposure in Mlh1-knockout mice: evaluation of the late effect of radiation on a mouse model of HNPCC.

Mlh1-knockout mice have been developed as a useful model of hereditary non-polyposis colorectal cancer (HNPCC). In this study, we analyzed the pathology of gastrointestinal tumours (GIT) in these mice in detail and examined the possible effects of ionizing radiation on the induction of intestinal tumours to evaluate the late response to radiotherapy in HNPCC. Mlh1-/- mice spontaneously developed GIT and thymic lymphomas by 48 weeks. GIT included not only well differentiated adenocarcinomas but also poorly differentiated and mucinous adenocarcinomas, suggesting that this mouse is a good model for HNPCC. In contrast to colon cancers from HNPCC patients, however, carcinomas of Mlh1-/- mice expressed p53 and showed a lack of transforming growth factor (TGF)-betaRII mutation, which resulted in the expression of TGF-betaRII protein. Irradiation of 10-week-old Mlh1-/- mice accelerated GIT development but had little effect at 2 weeks. Mlh1+/- and Mlh1+/+ mice were not susceptible to spontaneous or radiation-induced thymic lymphomas and GIT until 72 weeks after birth. The development and pathology of GIT in Mlh1-/- mice suggest that this mouse is a good model for HNPCC, although tumour-related responsible genes might be different from HNPCC. As X-ray exposure promoted carcinogenesis of GIT in adult Mlh1-/- mice, an increased risk of secondary cancers after radiotherapy for HNPCC patients should be taken into consideration.

Adaptor Proteins, Signal Transducing↗

Ultraviolet radiation induces a change in cell membrane potential in vitro: a possible signal for ultraviolet radiation induced alteration in cell activity.

The regulation of a transmembrane ionic gradient, reflected by the cellular membrane potential, has been shown in several cell systems to be involved in the regulation of cell function. This investigation presents evidence that biologically relevant doses of ultraviolet radiation (UVR) will alter the membrane potential of keratinocytes in vitro. Estimation of the relative change in the steady-state membrane potential of the murine keratinocyte cell line PAM 212, the murine myelomonocytic cell line P388D1, and normal human keratinocytes in culture, were made through the use of the lipophilic cationic membrane potential sensitive probe; triphenylmethylphosphonium. Our observations indicate that UVR composed primarily of UVB (280-320 nm) radiation at doses as low as 100 J/m2 can induce a depolarization in the murine cell lines and a hyperpolarization in human keratinocytes. Evidence suggests that this difference in the direction of the membrane potential response reflects a difference in Na+/K+ ATPase activity following UVR. These results suggest a possible mechanism for modulation of keratinocyte activity induced by UVR.

Cells, Cultured↗

The influence of photosynthetically active radiation on the effects of ultraviolet-B radiation on Arabidopsis thaliana.

Ultraviolet-B (UVB; 280-320 nm) radiation is a small but biologically significant portion of the solar spectrum reaching the earth's surface. Research interests have been fostered because UVB has been increasing in recent years due to depletion of stratospheric ozone. Ultraviolet-B that penetrates into plant tissue may damage important cellular macromolecules. Although there has been considerable research on the effects of UVB on plants, the influence of the level of photosynthetically active radiation (PAR; 400-700 nm) on effects of UVB requires further definition as a prelude to studies of UVB sensitivity and defense mechanisms. Arabidopsis thaliana wild-type ecotype Landsberg erecta (LER), which is relatively insensitive to UVB, and the relatively sensitive LER-based mutant transparent testa-5 (tt5), were grown under 100 or 250 mumol m-2 s-1 PAR and then exposed to (zero) or 7 kJ m-2 day-1 UVBBE under these PAR levels. Plants exposed to UVB had reduced dry weight and leaf area and higher levels of UV-absorbing compounds in leaf tissue. The level of PAR did influence the effects of UVB, with the higher level of PAR prior to UVB exposure reducing sensitivity of LER to UVB. In contrast to other studies, higher PAR supplied simultaneously with UVB increased rather than decreased sensitivity of both genotypes to UVB. These results demonstrate the importance of controlling and comparing PAR levels when undertaking studies of UVB sensitivity, as effects of UVB on plants are influenced by the PAR levels plants are growing under prior to and during exposure to UVB.

Arabidopsis↗

MOSFET dosimetry for microbeam radiation therapy at the European Synchrotron Radiation Facility.

Preclinical experiments are carried out with approximately 20-30 microm wide, approximately 10 mm high parallel microbeams of hard, broad-"white"-spectrum x rays (approximately 50-600 keV) to investigate microbeam radiation therapy (MRT) of brain tumors in infants for whom other kinds of radiotherapy are inadequate and/or unsafe. Novel physical microdosimetry (implemented with MOSFET chips in the "edge-on" mode) and Monte Carlo computer-simulated dosimetry are described here for selected points in the peak and valley regions of a microbeam-irradiated tissue-equivalent phantom. Such microbeam irradiation causes minimal damage to normal tissues, possible because of rapid repair of their microscopic lesions. Radiation damage from an array of parallel microbeams tends to correlate with the range of peak-valley dose ratios (PVDR). This paper summarizes comparisons of our dosimetric MOSFET measurements with Monte Carlo calculations. Peak doses at depths <22 mm are 18% less than Monte Carlo values, whereas those depths >22 mm and valley doses at all depths investigated (2 mm-62 mm) are within 2-13% of the Monte Carlo values. These results lend credence to the use of MOSFET detector systems in edge-on mode for microplanar irradiation dosimetry.

Animals↗

Materials for thermoluminescent dose detectors and photon radiation energy detectors intended for intercomparison procedures of radiation therapy units.

Composite thermoluminescent (TL) materials characterized by different TL sensitivity to energy of photon radiation, namely, double-component mixtures of finely dispersed ingredients: thermoluminescent phosphor (LiF or CaSO4:Dy) and nonluminescent material (salts with various Zeff values) have been described. The TL sensitivity of such TL composites was demonstrated to depend upon Zeff values inherent to separate components and upon their concentration ratio in the mixture. Within the range of x-ray energy values from 10 to 120 keV, the LiF-based materials containing Li2CO3 as nonluminescent material were dosimetrically equivalent to soft tissues. The availability of powder-like TLD materials containing 65% LiF + 35% Li2CO3 can definitely serve the basis for extending the application area for the well-known procedure adopted by IAEA/WHO for comparative testing of x-ray therapy units with HVL < 0.5 mm Cu and for starting the intercomparison of units intended for superficial x-ray therapy. The use of the dose detectors based on TLD of 35% LiF + 65% Li2CO3 composition in orthovoltage x-ray therapy units excludes the necessity for introducing corrections for the dependence of detector's readings on energy levels. LiF- and CaSO4:Dy-based TL materials containing PbSO4 as a nonluminescent material are, by a factor of 10, more sensitive to energy variations than other known thermoluminescent phosphors. With the application of TLD based on above materials into two-detector systems intended for determining Eeff values of x-ray radiation, the ambiguity of readings in low-energy region has been eliminated, whereas the range of measurement appeared to be significantly expanded.

Biophysical Phenomena↗

Monte Carlo modeling of radiation dose distributions in intravascular radiation therapy.

Radiation dose distributions are developed for balloon and wire sources of radioactivity within coronary arteries. The Monte Carlo codes MCNP 4B and EGS4 were used to calculate dose distributions for photons and electrons at discrete energies around such sources, with and without the presence of a high-density atherosclerotic plaque. An interactive computer program was developed which then calculates dose distributions for many radionuclides by applying the emission spectra to the discrete energy grids calculated by the Monte Carlo codes, weighting appropriately for electron energy and abundance. Results for Re-186 and Re-188 balloon sources are shown in comparison to an Ir-192 wire source. The program provides dose distributions as well as estimates of activity levels needed to deliver prescribed doses to the vessel wall at selected distances from the lumen in a selected time interval. In addition, dose calculations are presented in this paper for other organs in the body, from photon radiation as well as from possible loss of liquid activity into the bloodstream in the case of a balloon rupture. These results, especially the interactive computer program permitting easy comparison of various radionuclides and their physical characteristics, will greatly facilitate the comparison process and aid in the selection of the best candidate(s) for clinical use.

Biophysical Phenomena↗

Phase III study comparing three cycles of infusional carmustine and cisplatin followed by radiation therapy with radiation therapy and concurrent carmustine in patients with newly diagnosed supratentorial glioblastoma multiforme: Eastern Cooperative Oncology Group Trial 2394.

PURPOSE: This phase III Eastern Cooperative Oncology Group-Southwest Oncology Group intergroup study was conducted to determine whether three 72-hour infusions of carmustine (BiCNU) and cisplatin administered monthly before external-beam radiotherapy would improve the survival of patients with newly diagnosed glioblastoma multiforme. The control arm consisted of radiation with standard adjuvant BiCNU. PATIENTS AND METHODS: A total of 223 patients were accrued from 1996 to 1999. Of these, 219 patients were eligible; 109 were randomly assigned to the experimental arm, and 110 were randomly assigned to the control arm. Randomization was stratified by age, performance status, and extent of resection. RESULTS: The median age of the patients was 55 years; 55% were male, 93% were white, 26% had a biopsy only, and 84% were ambulatory. Treatment arms were well balanced with respect to baseline characteristics. Median follow-up time of the 15 patients still alive at the time of analysis was 3.3 years (range, 2 to 5 years). Median survival times for the standard and experimental arms were 11.2 and 11.0 months (P =.33, two-sided log-rank test), and survival at 1 year was 45% versus 44%, respectively. Fifty-six percent of patients received all three cycles of BiCNU/cisplatin, 12% received two cycles, and 31% received only one cycle. Toxicity was primarily hematologic and was more common in the experimental arm (P <.01). CONCLUSION: This study demonstrates that 72-hour infusions of BiCNU and cisplatin followed by radiation do not improve median survival, survival at 1 year, or time to progression. Furthermore, this treatment requires more time in the hospital and is associated with more serious toxicities than standard therapy.

Adult↗

Randomized trial comparing iridium implant plus external-beam radiation therapy with external-beam radiation therapy alone in node-negative locally advanced cancer of the prostate.

PURPOSE: To determine if iridium implant (IM) and external-beam radiation therapy (EBRT) is better than standard EBRT in locally advanced prostate cancer. METHODS: Patients with T2 and T3 prostate cancer with no evidence of metastatic disease were randomly assigned to EBRT of 66 Gy in 33 fractions during 6.5 weeks or to IM of 35 Gy delivered to the prostate during 48 hours plus EBRT of 40 Gy in 20 fractions during 4 weeks. The primary outcome consisted of biochemical or clinical failure (BCF). BCF was defined by biochemical failure, clinical failure, or death as a result of prostate cancer. Secondary outcomes included 2-year postradiation biopsy positivity, toxicity, and survival. RESULTS: Between 1992 and 1997, 51 patients were randomly assigned to receive IM plus EBRT, and 53 patients were randomly assigned to receive EBRT alone. The median follow-up was 8.2 years. In the IM plus EBRT arm, 17 patients (29%) experienced BCF compared with 33 patients (61%) in the EBRT arm (hazard ratio, 0.42; P = .0024). Eighty-seven patients (84%) had a postradiation biopsy; 10 (24%) of 42 in the IM plus EBRT arm had biopsy positivity compared with 23 (51%) of 45 in the EBRT arm (odds ratio, 0.30; P = .015). Overall survival was 94% in the IM plus EBRT arm versus 92% in the EBRT arm. CONCLUSION: The combination of IM plus EBRT was superior to EBRT alone for BCF and postradiation biopsy. This trial provides evidence that higher doses of radiation delivered in a shorter duration result in better local as well as biochemical control in locally advanced prostrate cancer.

Adenocarcinoma↗

Effects of electromagnetic radiation (bright light, extremely low-frequency magnetic fields, infrared radiation) on the circadian rhythm of melatonin synthesis, rectal temperature, and heart rate.

Electromagnetic spectra reduce melatonin production and delay the nadirs of rectal temperature and heart rate. Seven healthy men (16-22 yrs) completed 4 permuted sessions. The control session consisted of a 24-hours bedrest at < 30 lux, 18 degrees C, and < 50 dBA. In the experimental sessions, either light (1500 lux), magnetic field (16.7 Hz, 0.2 mT), or infrared radiation (65 degrees C) was applied from 5 pm to 1 am. Salivary melatonin level was determined hourly, rectal temperature and heart rate were continuously recorded. Melatonin synthesis was completely suppressed by light but resumed thereafter. The nadirs of rectal temperature and heart rate were delayed. The magnetic field had no effect. Infrared radiation elevated rectal temperature and heart rate. Only bright light affected the circadian rhythms of melatonin synthesis, rectal temperature, and heart rate, however, differently thus causing a dissociation, which might enhance the adverse effects of shiftwork in the long run.

Adolescent↗

Response of canine soft tissue sarcomas to radiation or radiation plus hyperthermia: a randomized phase II study.

Sixty-four dogs with spontaneous soft tissue sarcomas without evidence of metastases were stratified by tumour volume and randomized to receive graded doses of radiotherapy (XRT) alone or radiotherapy plus hyperthermia (HT). An improvement in duration of local control was achieved with the addition of hyperthermia as compared with XRT alone (Wilcoxon, p = 0.040; log rank, p = 0.064). Overall frequency of late complications was not different for the two treatment arms when comparing across equivalent XRT dose groups. Frequency of distant metastases after therapy completion was not significantly different for the two treatment arms at 1 year (7.4% for XRT versus 20% for HT plus XRT) or 2 years (11.5% for XRT versus 25% for HT plus XRT) post therapy. These results suggest that a therapeutic gain was achieved for this group of tumour-bearing animals. Uni- and multivariate analyses were performed to examine the potential for various factors to influence treatment outcome. Patient related variables included tumour stage, histologic subtype and grade and tumour site. Treatment related variables included total radiation dose and 15 descriptors of temperature distributions achieved during hyperthermia. When considering patient related factors, tumour histology, grade and location were important predictors of time to minimum volume, but only tumour location influenced time to tumour regrowth. When considering treatment related factors, radiation dose was not significantly correlated with time to minimum volume or time to local regrowth, but it was correlated with probability for late normal tissue damage in the XRT alone group (p = 0.005). For the hyperthermia treatments, 13 of 15 tumour temperature distribution descriptors were correlated with time to minimum volume, but none were correlated with time to local regrowth. These results suggest that caution should be used in interpreting the value of temperature distribution descriptors in predicting for long-term local control after hyperthermia and radiotherapy, based on analysis of short-term responses.

Animals↗

Response of 145 spontaneous canine head and neck tumours to radiation versus radiation plus microwave hyperthermia: results of a randomized phase III clinical study.

The results of a phase III, clinical trial of local microwave hyperthermia (target = 2 x 44 degrees C for 30 min) and megavoltage radiation (4 x 9 Gy fractions) in the treatment of 145 naturally occurring canine head and neck cancers are reported. Patients were re-examined at regular intervals following treatment until death. The median follow up time was 90 weeks. Tumour response, patient survival and normal tissue toxicity were analysed by treatment allocation. There was no significant difference in best tumour response nor patient survival between the two treatment groups. There was no difference in acute normal tissue toxicity but there was a suggestion that patients receiving RT and HT may suffer a higher incidence of late skin reactions. Histological type and tumour volume were of prognostic significance with smaller tumours and carcinomas showing higher response rates. There were also positive associations between minimum tumour dose and best tumour response and percentage of tumour heated and best tumour response. The results of this study must be interpreted in the knowledge of limitations on the dose and fractionation schedule for radiation therapy, the small number of hyperthermia treatments applied and the variation in tumour type and size that is inevitable in a clinical study. It is concluded that the quality of hyperthermia in terms of intra-tumour temperatures and the uniformity of heating is of paramount importance in governing response to adjuvant hyperthermia.

Animals↗

[Bases for allowable norms of infrared radiation exposure in accordance with the radiation spectrum].

Specification of norms is the most radical protective means in a system of activities reducing harmful influence on human health. For effective work of norms, the authors specified hygienic classification covering industrial sources of infrared radiation. The classification is based on biologic effect peculiarities depending on maximal energy in the radiation spectrum. Requirements to measuring devices and measurement procedures were specified as well. Nowdays production of sensitive devices measuring the spectrum energy is launched in Ukraine, so it is time to put the novelties into practice.

Adaptation, Physiological↗

[Current status of radiation therapy--evidence-based medicine (EBM) of radiation therapy. Breast cancer].

Evidenced-based medicine(EBM) is undergoing rapid acceptance as a principle of decision making in radiation oncology clinics. Adjuvant therapy for breast cancer is one of the most actively researched areas, and there is a great deal of clinical evidence of high-quality treatment of breast cancer. The case of 47-year-old premenopausal woman who underwent consultation for postmastectomy radiotherapy (PMRT) is presented, and the course of practice using EBM is described. Because she had one positive axillary lymph node, she received systemic chemotherapy with doxorubicin, cyclophosphamide, and paclitaxel. She is also receiving trastuzumab and tamoxifen. She underwent immediate reconstruction with a TRAM flap. Existing guidelines point out that PMRT significantly reduces the risk of local recurrence; however, none of them recommend PMRT for a patient with < 4 positive lymph nodes because of the lack of firm evidence for improvement of overall survival. There is also some evidence that PMRT after immediate reconstruction reduces the cosmetic result and that paclitaxel might increase the risk of radiation pneumonitis even in sequential administration. She chose PMRT, although our recommendation was not to do so. Expertise in the area of breast cancer as well as high-level evidence developed in Japan is essential to effectively implement EBM.

Breast Neoplasms↗