The relationship between technical parameters of external beam radiation therapy and complications for localized prostate cancer. (65/2648)

BACKGROUND: This study was performed to review retrospectively the clinical course of chronic rectal bleeding as a complication of external beam radiation therapy for localized prostate cancer and to analyze the relationship between technical parameters of radiation therapy and the complications. METHODS: Seventy-one patients with stages A2, B and C were treated with local-field radiotherapy (total dose 52.5-66 Gy, daily dose 2.0-3.28 Gy, field area 30-81 cm2, number of fields 3-15 ports, planning simulations X-ray or CT-based) between 1989 and 1998 at three institutions. The protocols were consistent during this same period at these institutions. RESULTS: Multivariate analysis revealed pretreatment PSA and Gleason sum to be statistically significant predictors of 5 year prostatic specific antigen (PSA) relapse-free rates in a median follow-up period of 42 months (range 12-119 months). The significant risk factors for higher grading of acute morbidity were a biological equivalent dose, alpha/beta = 10(BED10) > or =65 Gy, dose per fraction > or =3.0 Gy, field area > or =42 cm2, fewer ports and X-ray planning simulation. However, no parameter was associated with higher grading of late morbidity. Eleven patients (15.4%) experienced a late GI complication: grade 1 (4.2%), grade 2 (9.8%), grade 3 (1.4%). The median time to occurrence of rectal bleeding was 12 months after radiotherapy and the mean duration of morbidity was 11 months. CONCLUSIONS: Higher total dose and dose per fraction, larger field area, fewer ports and X-ray simulation increased the grades of acute morbidity. A majority of chronic rectal bleedings were transient and responded to conservative treatment.  (+info)

Causes of interruption of radiotherapy in nasopharyngeal carcinoma patients in Taiwan. (66/2648)

BACKGROUND: Nasopharyngeal cancer (NPC) is now curable with early diagnosis and radiotherapy treatment. In the past several decades, few studies have investigated why some patients fail to complete the recommended full course of radiotherapy. METHODS: A total of 3273 nasopharyngeal carcinoma patients were treated at the Radiation Oncology Department of Linkou Chang Gung Memorial Hospital in a span of 18 years from 1979 to 1996. Among these patients, 276 did not complete the full course of treatment of radiation therapy. The medical records of these patients were reviewed to determine the factors contributing to treatment interruption. RESULTS: Of the 276 patients whose treatment was interrupted, 120 (43.5%) were unable to endure the acute side effects of radiation therapy and were afraid of the possible complications resulting from the treatment; 57 (20.7%) had doubts about the diagnosis or had the subjective perception that the treatment offered would be ineffective in view of the severity of their disease; 50 (18.1%) resorted to folk prescriptions; 17 (6.2%) were faced with socioeconomic problems; 15 (5.4%) sought treatment at another hospital owing to transport considerations; 10 (3.6%) stopped radiation therapy and switched to chemotherapy for palliative management; seven (2.5%) resorted to praying, god worshipping and taking incense powder and magic elixirs because their families were against any established therapy. CONCLUSIONS: The acute side effects and complications caused by radiation therapy were the major factors influencing patients' decisions to discontinue treatment. This finding suggests that more attention should be paid to providing care with regard to the acute side effects of radiotherapy and to reinforcing pretreatment education.  (+info)

Radiotherapy for subfoveal neovascularisation associated with pathological myopia: a pilot study. (67/2648)

BACKGROUND/AIM: Limited treatments are available for this disease process. A pilot study was performed to determine the toxicity and efficacy of external beam radiotherapy for subfoveal neovascular membranes and subretinal haemorrhage associated with pathological myopia. METHODS: A randomised, prospective study was carried out on 39 patients with subfoveal neovascularisation associated with high myopia. 20 patients underwent radiotherapy and the remaining 19 were observed as a randomised comparison group. All patients were followed up for at least 24 months. Subfoveal choroidal neovascular membranes (CNVMs) were treated with a single lateral 6 MV photon beam to a dose of 10 Gy in five fractions over 5-7 days. Post-treatment measurements included corrected visual acuity, area of CNVM, and occurrence of radiotherapy related complications, and adverse reactions. To assess changes of area of CNVM, the initial (pretreatment) size of the CNVM was set to 100%, and all post-treatment measurements were normalised relative to the initial size. RESULTS: No significant acute morbidity was noted. There was no significant difference in age, sex, refractive error, visual acuity, and area of CNVM at baseline between the treatment group and control group. The mean change of the size of the CNVM for 2 years was 155% (SD 156%) in the treatment group and 249% (124%) in the control group. The increase in the size of CNVM in the treatment group was significantly smaller than that in the control group (p = 0.0452). In the treated eyes, the visual acuity before and 1 and 2 years after radiotherapy were 0.111 (22.2/200), 0.091 (18.2/200), and 0.086 (19.2/200), respectively. In the control eyes, visual acuity before and 1 and 2 years after the start of the follow up were 0.141 (34.2/200), 0.089 (17.8/200), and 0.063 (12.6/200). The patients in the treatment group showed no significant change for 2 years, and those in the control group showed a significant decrease in the visual acuity (p = 0.0033). The changes of logMAR of visual acuity for 2 years after the start of the follow up were +0.019 (0. 443) in the treatment group and +0.347 (0.374) in the control group. There was a statistically significant difference between them (p = 0. 0173). Multiple regression analysis on the treatment group showed that the most significant predictive variable for the visual acuity 2 years after the treatment was the combination of pretreatment visual acuity and refractive error. CONCLUSIONS: Radiotherapy appeared to have a favourable treatment effect in eyes with subfoveal neovascular membranes and haemorrhage associated with pathological myopia. Further investigation is needed to evaluate the efficacy of radiotherapy for subfoveal neovascularisation associated with pathological myopia.  (+info)

Brady-tachycardia syndrome after radiotherapy for lung cancer. Assessment by computed tomography and carbon-11 methionine positron emission tomography. (68/2648)

A 74-year-old male who had received radiotherapy (total 54 Gy) for right lung cancer 7 months earlier developed a symptomatic brady-tachycardia syndrome requiring the implantation of a permanent pacemaker. Chest CT showed a pulmonary tumor of 2-cm diameter in the right lower lobe with direct extension into the surrounding tissue, suggesting the possibility of cardiac invasion. Carbon-11 methionine positron emission tomography (PET) indicated the absence of visible invasion of the heart with lung cancer. The bradytachycardia syndrome, therefore, was considered to be associated with sinus node injury due to radiation. Carbon-11 methionine PET metabolic imaging might play an important role in evaluating noninvasively the cause of the arrhythmia in this patient.  (+info)

Radiotherapy-associated anemia: the scope of the problem. (69/2648)

The impact of anemia on cancer patients undergoing chemotherapy is well established, but only recently has the prevalence of anemia in patients receiving radiotherapy received much attention. Many cancer patients present with anemia prior to radiotherapy, and even more experience anemia or a worsening of anemia at some point during treatment. However, the problem of anemia is often ignored because patients may experience only functional anemia, defined as a hemoglobin level less than 12 g/dl. Unless physiologic anemia (hemoglobin = 8 g/dl) is discovered, efforts to correct anemia are often not made. Because hemoglobin levels <12 g/dl seem to be associated with tumor hypoxia and poorer outcomes of radiotherapy in a number of patient populations, ignoring even modest anemia can result in decreased locoregional control, overall survival, and quality of life (QOL). Because increasing hemoglobin levels 1-2 g/dl is usually easily accomplished, there exists the potential for improving outcomes by paying greater attention to this problem. This article focuses on the prevalence of anemia, particularly functional anemia, and discusses the impact of anemia on locoregional control, overall survival, and QOL.  (+info)

Impact of anemia in patients with head and neck cancer. (70/2648)

Head and neck squamous cell carcinoma, which is comprised of a heterogeneous group of tumors arising from the epithelial lining of the oral cavity, pharynx, and larynx, is a locoregional disease. Tumor hypoxia and anemia are known to adversely effect the efficacy of radiation therapy, a local treatment modality. Therefore, head and neck cancers represent an ideal model for assessing the impact of anemia following treatment with radiation therapy. Various treatment strategies aimed at increasing tumor oxygenation in head and neck cancer patients (including hyperbaric oxygen and hypoxic cell radiosensitizers) have been studied. These studies have been fueled by evidence that hypoxia adversely effects the radiosensitivity of cells. Although the exact mechanism of action of the oxygen effect is not known, in vitro studies with conventional photon radiation therapy under normoxic conditions have shown an effectiveness of 2.5-3.0 times greater than that achieved under anoxic conditions. Recent studies, including large retrospective analyses, have demonstrated the dramatic adverse impact of anemia upon locoregional tumor control and survival. These studies, which have revealed hemoglobin levels as a powerful prognostic factor, provide compelling evidence for the value of reversing anemia and hence tumor hypoxia in head and neck cancer patients.  (+info)

Selection of patients for bone marrow transplantation in severe aplastic anemia. (71/2648)

Despite androgens and intensive supportive care, satisfactory survival in severe aplastic anemia remains at 20% or less. Histocompatible bone marrow transplantation can restore normal hematopoiesis in approximately 40% of similarly severe individuals. Delay of transplantation for 3 wk after diagnosis allows time for proper evaluation and for many spontaneous recoveries. Further delay increases risks of fatal complications and decreases chances for successful transplantation while the incidence of spontaneous remission declines. When available, early histocompatible bone marrow transplantation may be the treatment of choice for severe aplastic anemia.  (+info)

Genetic and hormonal risk factors in breast cancer. (72/2648)

Breast cancer poses a serious public health problem, and it is hoped that identification of genetic and environmental factors that contribute to the development of breast cancer will enhance prevention efforts. Two breast cancer susceptibility genes (BRCA1 and BRCA2) have been identified, and germline mutations in these genes are thought to account for between 5% and 10% of all breast cancer cases. Current findings suggest that mutations in other highly penetrant genes may play an important role in breast cancer susceptibility, and studies aimed at the isolation of these genes are under way. In addition, common variants in a number of gene classes are thought to act as low-penetrance susceptibility alleles, and efforts to identify and characterize these variants are under way. This review discusses the genetic components of susceptibility to breast cancer from the standpoint of both human genetics and rat models.  (+info)