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G Gyenes

Publications and source records attributed to G Gyenes.

At least 19 recordsLinked to original sources
PubMed1998

Prediction of excess risk of long-term cardiac mortality after radiotherapy of stage I breast cancer.

BACKGROUND AND PURPOSE: Excess cardiac mortality has been reported in long-term follow up of breast cancer patients. Due to these findings it has been emphasized that radiotherapy techniques should be designed to minimize cardiac dose. The present study aims to provide risk figures of long-term excess cardiac mortality following radiotherapy for stage I breast cancer patients, using the relative seriality model. The impact of different modifications of the conventional irradiation technique on the calculated risk value is also analyzed. MATERIAL AND METHODS: One hundred consecutive left-sided stage I breast cancer patients were selected. All patients were treated with post-operative radiotherapy, using tangential 6 MV photon beams. The dose planning of each patient was done by means of a three-dimensional dose planning system. The prescribed mean tumor dose was 50 Gy, 2 Gy/fraction, 5 days a week. For each dose plan the differential heart and myocardium dose-volume histogram (DVH) were calculated. The excess risk of late cardiac mortality was predicted for each patient with the relative seriality model, using a parameter set previously determined. Different methods to decrease the risk of excess cardiac mortality (conventional collimation vs. multileaf collimation (MLC), partial blocking of the target in order to spare the heart and finally a general fluence modulation method) were analyzed. RESULTS AND CONCLUSIONS: The mean value of the calculated excess risk was 1.8%, having the heart as organ at risk, and 2.1% having the myocardium as organ at risk. However, a subgroup of patients where the risk increased up to about 9% (heart) and 12% (myocardium) was found. The risk could be substantially decreased either using an extended blocking of the target or applying the general fluence modulation method.

Breast Neoplasms↗
PubMed1998

Long-term cardiac morbidity and mortality in a randomized trial of pre- and postoperative radiation therapy versus surgery alone in primary breast cancer.

BACKGROUND AND PURPOSE: Some types of radiation therapy have been associated with an increased risk of cardiac mortality and morbidity in patients with early-stage breast cancer. A relationship has been observed between cardiac radiation dose-volume and the level of excess risk of cardiac mortality. However, relatively few data are available on the morbidity from myocardial infarction associated with adjuvant radiotherapy. PATIENTS AND METHODS: From 1971 to 1976, a total of 960 patients with operable breast cancer were randomly allocated to preoperative radiation therapy, postoperative radiation therapy or to surgery alone. A previous analysis of the cardiac dose-volumes with the treatment techniques used in the trial indicated that the irradiated patients could roughly be divided into three groups. Information on the number of myocardial infarctions was obtained through computerized record linkage with a population-based registry of myocardial infarctions in Stockholm County. Information on cause-specific mortality was obtained from the Swedish Cause-of-Death Registry. The median follow-up was 20 years (range 17-23 years). RESULTS: A total of 58 patients developed an acute myocardial infarction during the period of follow-up. The number of myocardial infarction cases was not significantly different between the three treatment groups. When analyzed according to estimated cardiac radiation dose-volumes, patients in the highest dose-volume subgroup exhibited a hazard of myocardial infarction of 1.3 (95% CI 0.7-2.6) relative to that of the surgical controls, whereas the corresponding relative hazard for the intermediate and low dose-volume subgroups was below unity. Data on death due to cardiovascular disease showed that patients in the high dose-volume group exhibited a hazard of 2.0 (95% CI 1.0-3.9, P = 0.04) relative to that of the surgical controls. Concerning death due to ischemic heart disease, the relative hazard for the same subgroup was 2.5 (95% CI 1.1-5.7, P = 0.03). The difference between the groups was established after 4-5 years. The cumulative incidence curves continued to diverge up to about 10-12 years. No further divergence appeared after 12 years, but the number of events was low. CONCLUSIONS: This analysis confirms and extends previous results from the trial. Cardiac mortality was positively correlated with the cardiac dose-volume. Patients receiving high dose-volumes exhibited an increased mortality of ischemic heart disease, but not of myocardial infarction, which implies another mechanism, e.g. radiation-induced microvascular damage to the heart.

Adult↗
PubMed1998

Radiation-induced ischemic heart disease in breast cancer--a review.

It is well established that adjuvant radiotherapy (RT) reduces loco-regional recurrences in breast cancer. The effect on overall survival, on the other hand, is a much-debated issue. Some old trials with a long follow-up as well as the first report on the overview of the randomized RT trials initiated before 1975 showed a reduced survival among irradiated patients compared with the surgical controls. In the update of the overview this proved to be due to cardiac deaths. In two more recent studies, adjuvant RT in the postmastectomy setting improved the survival of node-positive premenopausal patients who were also treated with chemotherapy. In one of these trials it was indicated that cardiac mortality was not increased. There are few data concerning the cardiac side effects of RT after conservative surgery. Some studies suggest that radiation-induced heart disease may be a potential problem also among these patients. Therefore, the search for both the causes of radiation-induced heart disease and preventive measures is crucial issues in breast cancer radiation oncology.

Breast Neoplasms↗
PubMed1997

Detection of radiation-induced myocardial damage by technetium-99m sestamibi scintigraphy.

A prospective study was initiated to assess the side-effects of postoperative adjuvant radiotherapy in patients with left-sided early breast cancer. Twelve patients with early breast cancer were examined before and a year after radiotherapy. Echocardiography, ECG and bicycle ergometry stress test with technetium-99m sestamibi myocardial perfusion scintigraphic were carried out to assess changes in regional myocardial blood flow. Six of the 12 patients had new fixed scintigraphic defects after radiotherapy (as compared with the preradiation examination). The localization of the defects corresponded well with the irradiated volume of the left ventricle. These defects were probably due to microvascular damage to the myocardium. Neither ECG changes nor left ventricular segmental wall motion abnormalities could be detected by echocardiography. To our knowledge this study is the first to show that radiation-induced micro-vascular damage to the myocardium may be detected by perfusion scintigraphy. This may limit the use of scintigraphy in diagnosing coronary artery disease in patients treated with thoracic radiotherapy. Long-term follow-up is necessary to assess whether the presence of microvascular damage is a prognostic sign for the development of radiation-induced coronary artery disease.

Breast Neoplasms↗
PubMed1997

Evaluation of irradiated heart volumes in stage I breast cancer patients treated with postoperative adjuvant radiotherapy.

PURPOSE: To quantify the proportion of heart volumes that received at least 25 Gy with tangential photon fields in patients with left-sided stage I (T1 NOMO) breast cancer treated with breast-conserving surgery. METHODS AND MATERIALS: The dose planning of 100 consecutive patients was reviewed. All were irradiated with tangential photon fields that covered the left breast only. A three-dimensional computed tomographic (CT)-based dose planning was made for each patient. The prescribed dose to the tumor was 50 Gy. For each patient, the proportion of the heart included in the 50% isodose was determined from the cumulative dose-volume histogram (DVH). The same volume determination was made for the left-sided breast cancer patients treated with tangential fields during the first Stockholm Breast Cancer Trial. RESULTS: The mean irradiated heart volume that received at least 25 Gy was 5.7% (SD = 4.5%) for the whole group and 11.9% (SD = 3.7%) in those with the highest volumes. The mean irradiated heart volume included in the 50% isodose for patients in the Stockholm Trial was 25% (SD = 11.9%). CONCLUSION: In this study, the majority of patients with left-sided T1NOMO breast cancer did not receive irradiation to substantial heart volumes. However, in 6% of all studied patients, the proportion of irradiated heart volume was close to the irradiated heart volumes with one of the treatment techniques used in the Stockholm Trial for patients with left-sided tumors. That technique has been associated with significantly increased cardiac mortality during long-term follow-up evaluation in a previous study. The CT-based three-dimensional treatment-planning system (TMS) represents a valuable tool in identifying such patients; thus, treatment may be conformed to reduce the irradiated heart volume.

Breast Neoplasms↗
PubMed1996

Myocardial damage in breast cancer patients treated with adjuvant radiotherapy: a prospective study.

PURPOSE: To look for early and late signs of cardiac side effects of postoperative radiotherapy in patients with left-sided breast cancer. METHODS AND MATERIALS: Seventeen left-sided primary (Stage I-III) breast cancer patients considered eligible were recruited. Their computer tomography-based dose planning showed a part of the heart's left ventricle irradiated with at least 85-95% of the total dose. Twelve patients were examined both before treatment and an average of 13 months later, at a first follow-up. In partially mastectomized patients tangential opposed photon fields were used to the breast tissue, while in patients with modified radical mastectomy electrons were given to the thorax. Echocardiography and a bicycle ergometry stress test with myocardial perfusion scintigraphy were carried out before and after radiotherapy to assess if any myocardial damage could be detected. RESULTS: Six of the 12 patients exhibited new fixed scintigraphic defects after radiotherapy indicating regional hypoperfusion. Four of them received treatment only to the breast after breast-conserving surgery. The localization of the defects corresponded well with the irradiated volume of the left ventricle. No deterioration in left ventricular systolic or diastolic function could be detected by echocardiography. CONCLUSIONS: In this study half of the patients exhibited new scintigraphic defects that indicate radiation-induced myocardial damage, probably affecting the microcirculation. There were no changes on electrocardiography or any deterioration of the left ventricular function at this stage. Long-term follow-up is necessary to assess whether this finding is a prognostic sign for developing radiation-induced coronary artery disease.

Adult↗
PubMed1994

[Heart disease caused by radiation].

The clinical forms of radiation-induced heart disease, its incidence and significance are reviewed from a practical point of view. Pathological and technical basis as well as prevention are also discussed.

Dose-Response Relationship, Radiation↗
PubMed1994

Morbidity of ischemic heart disease in early breast cancer 15-20 years after adjuvant radiotherapy.

PURPOSE: To assess the cardiac side effects, primarily the occurrence of ischemic heart disease in symptom-free patients with early breast cancer treated with radiotherapy. METHODS AND MATERIALS: Thirty-seven survivors of a former randomized study of early breast cancer were examined. Twenty patients irradiated pre- or postoperatively for left sided disease (study group patients) were compared with 17 controls who were either treated for right sided disease, or were nonirradiated patients. Radiotherapy was randomized in the original study; either tangential field 60Co, or electron-therapy was delivered. Echocardiography and bicycle ergometry stress test with 99mTc SestaMIBI myocardial perfusion scintigraphy were carried out and the patients' major risk factors for ischemic heart disease were also listed. RESULTS: Our results showed a significant difference between the scintigraphic findings of the two groups. Five of the 20 study group patients (25%), while none of the 17 controls exhibited some kind of significant defects on scintigraphy, indicating ischemic heart disease (p < 0.05). No deterioration in left ventricular systolic and/or diastolic function could be detected by echocardiography. CONCLUSION: Radiotherapy for left sided breast cancer with the mentioned treatment technique may present as an independent risk factor in the long-term development of ischemic heart disease, while left ventricular dysfunction could not be related to the previous irradiation. We emphasize the need to optimize adjuvant radiotherapy for early breast cancer by considering the dose both to the heart as well as the cancer.

Aged↗
PubMed1991

Pericardial irritation in breast cancer patients treated by curative postoperative radiotherapy--early results.

Authors prospectively examined 54 breast cancer patients treated by postoperative telecobalt, or electron therapy. They studied the cardiological side effects caused by ionizing radiation. ECG, echocardiography and measurement of systolic time intervals were performed before, immediately, six weeks, six months, one and 1.5 to two years after the completion of radiotherapy. 23 symptom-free patients were found to have signs of transitory pericardial irritation, more after telecobalt, than electron therapy (17/6). T-wave inversions were seen on the ECG of 20 patients. In six and three patients small amounts of pericardial effusion could be detected by echocardiography with, or without ECG alterations, respectively. Other side effects mentioned by the literature could not be found yet, further follow-up is recommended, however. In the authors' opinion the effect of ionizing radiation, mainly of telecobalt therapy is possibly a risk factor for cardiovascular disease, it is suggested to be considered at the planning of radiation therapy accordingly.

Adult↗
PubMed1990

[Cardiologic side effects of therapeutic irradiation of breast cancer--early results].

Authors prospectively examined 54 breast-cancer patients treated by postoperative telecobalt (28), or electron therapy (26). They studied the cardiological side-effects caused by ionizing radiation. ECG, echocardiography and measurement of the systolic time intervals were performed before, immediately, 6 weeks, 6 months, one and 1.5-2 yrs after the completion of radiotherapy. Twenty-three symptom-free patients were found to have signs of transitorial pericardial irritation, more after telecobalt, than electron therapy (17/6). T-wave inversions were seen on the ECG of twenty patients. In 5 and 3 patients small amounts of pericardial effusion could be detected by echocardiography with, or without ECG alterations, respectively. Other side-effects mentioned by the literature could not be found yet, further follow-up is recommended, however. In the authors' opinion the effect of ionizing radiation, mainly of telecobalt therapy is possibly a risk factor for cardiovascular diseases, it is suggested to be considered at the planning of radiation therapy accordingly.

Adult↗
PubMed1988

Radiotherapy alone or in combination with surgery in the management of stage III breast cancer.

239 women with stage III carcinoma of the breast were treated by primary radiation therapy from 1977 to 1985. Of them 212 had an objective response and 27 showed no response to irradiation. From the objective responders, 105 patients were subjected to mastectomy and axillary dissection and in 107 cases the radiotherapy was not followed by surgery. Patients of operated group had a 71% and the RT alone group had a 61% local-regional tumor control at 5 years. The analysis of local-regional recurrences revealed that none of the operated patients had axillary recurrence but 8 had in the RT alone group. Postirradiation surgery is recommended for patients who have residual disease especially in the axillary region. The 5-year survival rate of operated patients was significantly better, 58% vs. 35%. However, these results are not comparable since the incidence of less favourable cases was higher in the RT alone group. Chemotherapy was initiated for the 27 patients who failed to respond to RT, but results were unsatisfactory. None of them survived three years. Further studies are needed to explore the role of chemotherapy in this stage of breast cancer.

Adult↗
PubMed1987

Prognostic significance of residual disease after radiation therapy of stage III breast cancer.

239 Consecutive women with stage III carcinoma of the breast were treated by primary radiation therapy (RT) from 1977 to 1985. The response rate was 89%, the 5-year survival 40% and the local-regional tumor control (LTC) 59%. For the 27 non-responders, postirradiation chemotherapy was initiated but they died within 3 years. 105 Patients were subjected to mastectomy and axillary dissection after RT. In 107 cases, the RT was not followed by surgery. Systemic treatment consisted of hormonal therapy in both groups. The RT plus surgery group had better survival rate, 58% vs. 35% at 5 years. However, the incidence of less favorable cases was higher in the RT alone group. Histological findings in the operated group are analysed to determine prognostic significance of residual disease. No residual or only damaged microscopic disease was found in the breast in 36% of the cases. The axillary lymph nodes (ALN) were free of disease in 42% of the women. Patients with negative ALN after RT had significantly better 5-year survival (82% vs. 43%) and LTC (85% vs. 60%) rates. Decreased chest wall recurrence rate was associated with no residual or damaged microscopic disease in the breast (5% vs. 21%). The disease-free ALN were more common after 50-80 Gy telecobalt than after 40-50 Gy kV irradiation (51% vs. 33%). Primary tumor size (phi less than 5 cm vs. phi greater than 5 cm) had no significant impact on histological findings or on prognosis. Residual disease is mainly a marker of tumor-host relationship which indicates the biological aggressiveness of the disease.

Adult↗