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Biomedical subjects

J W Leer

Publications and source records attributed to J W Leer.

At least 19 recordsLinked to original sources
PubMed1992

Education in radiation oncology in Europe.

The outcome of an inventory among 22 European countries with respect to the radiotherapy facilities and the training of new radiation oncologists in each country is described. The radiotherapeutic profession, which mostly prescribes also cytostatics or hormones, has become well-regulated in the last 20 years. Most radiation oncologists are also involved in the diagnostic work-up and follow-up of the cancer patient. The numbers of radiotherapists and other staff, treatment capacities, and patients are given. The training for radiation oncologists is mostly taken at the university centers, but the curricula are rather diverse.

Europe↗
PubMed1992

Training in radiotherapy in The Netherlands.

The training in radiotherapy in The Netherlands is an example of a master apprentice system. In this overview we will discuss the organization and describe the official bodies involved in the Dutch training programs. Also the contents and the system of accreditation are presented.

Accreditation↗
PubMed1992

The prognostic value of hemoglobin and a decrease in hemoglobin during radiotherapy in laryngeal carcinoma.

An association between a low Hb-content and a poor response on radiation therapy has been established in previous years, especially in patients with squamous cell carcinomas. Whether this is linked with hypoxic conditions of the tumour or associated with tumour volume, blood loss or other conditions, is not yet known for certain. Patients with small head and neck tumours seem to form an interesting group to study this issue because several factors can be ruled out. Therefore, a retrospective analysis of 306 patients with glottic or supraglottic carcinoma was performed, to identify whether the Hb-value was of prognostic importance and whether this was linked to other patient characteristics. All patients were treated with primary radiotherapy with doses ranging from 60 to 70 Gy in 6-7 weeks. It appeared that in glottic carcinoma, the disease-free survival was significantly worse in patients with a Hb-value below normal at the start or/and at the end of therapy (p = 0.09, p = 0.0012, respectively). In patients with supraglottic carcinoma, the above mentioned difference approved only for a Hb-value below normal at the end of treatment (p = 0.05). A decrease in Hb-level of greater than or equal to 0.5 mmol/l during therapy, regardless whether the Hb-values were within or beyond normal range, reduced the disease-free survival in patients with glottic carcinoma (p = 0.0125). In a multivariate analysis, the Hb-value at the end of treatment proved to be an independent prognostic factor after T- and N-classification. There was no relationship with nutritional condition of the patient, nor with the Karnofsky Performance scale.(ABSTRACT TRUNCATED AT 250 WORDS)

Carcinoma, Squamous Cell↗
PubMed1992

The objective response of brain metastases on radiotherapy. A prospective study using computer tomography.

A prospective study was performed to establish the objective response of brain metastases after radiotherapy. Twenty-five patients with a total of 53 metastatic lesions were evaluated approximately 6 weeks after completing the treatment (30 Gy/2,5 weeks). Clinical response was seen more often than objective response, due probably to concomitant use of corticosteroids and to most patients having multiple metastases. Clinical response, although important for the patient, does not well reflect the objective response. In 48% of the cases there was agreement between the clinical and the radiodiagnostic findings. The tumor size was an important prognostic factor for prediction of complete response. The majority of patients who achieved complete remission of at least one of the metastatic lesions, did not show recurrence of the neurological symptoms.

Actuarial Analysis↗
PubMed1991

Should all patients with malignant astrocytoma have postoperative radiotherapy?

A retrospective analysis was carried out on 96 patients with malignant astrocytoma treated during the period 1977--1986 to evaluate the contribution of postoperative radiation treatment to survival. In this material the initial Karnofsky performance score, age and extent of resection appeared to be prognostic factors, on the basis of which suggestions are given for selection of patients for radiotherapy.

Adult↗
PubMed1991

In vitro assessment of cardiac performance after irradiation using an isolated working rat heart preparation.

The effect of irradiation on cardiac function was assessed using an isolated working rat heart preparation. The animals were given single doses of X-rays in the range 15-30 Gy to their hearts. Cardiac output (CO = aortic flow + coronary flow), heart weight and body weight were followed for a period of 10 months after treatment. Irradiation led to a decrease in cardiac function. This reduction was dose-dependent and progressive with time after treatment. The shape of the Frank-Starling curves constructed for irradiated hearts suggests a loss of contractile function of the myocardium. Coronary flow rates measured in 'working' hearts and in 'Langendorff' hearts were not significantly changed by the irradiation treatment. The isolated working rat heart preparation proved to be a simple and suitable animal model for the investigation of irradiation-induced cardiotoxicity.

Animals↗
PubMed1991

External radiotherapy and extrahepatic bile duct cancer.

The hospital records of patients with extrahepatic bile duct cancer who where treated surgically between 1968 and 1983 were reviewed. Of 55 patients, 16 (29%) received radiotherapy after surgery. The total dose given ranged from 40 to 60 Gy. Median follow-up time for analysis was 4.0 months and lasted until January 1988. The overall median survival was 4 months (range 0-36), that of the irradiated patients was 16 months (range 2-36), and that of the 39 patients who were not irradiated was 3 months (range 0-32). When the 13 post operative deaths were excluded the median survival was 4 months. Radiotherapy did not cause any severe complications. No firm conclusion about the role of radiotherapy can be drawn from these data because the patients were not randomly chosen to receive radiotherapy and selection was therefore biased. We conclude that most patients with extrahepatic bile duct cancer still die of locoregional disease. Effective adjuvant treatments are needed and should be evaluated in prospective randomized trials.

Adenocarcinoma↗
PubMed1990

[Radiation sickness; prospective study of incidence and course].

In a prospective inventory analysis of 169 irradiated patients concerning the incidence and course of Acute Radiation Sickness (fatigue, loss of appetite, nausea and vomiting), it was found that 2/3 of the patients had these complaints. The complaints started during the first week of treatment and mostly even within a few hours after each radiotherapy session. All complaints were progressive during the radiotherapy course, but disappeared spontaneously within one week after completion of the treatment. The possible occurrence of these symptoms soon after the start of radiotherapy should be kept in mind, especially since they can be reduced by simple regimens.

Adult↗
PubMed1990

Techniques applied for total body irradiation.

In this review, different techniques of total body irradiation are discussed with special attention to their advantages and disadvantages. The results of an EBMT questionnaire, which was sent out to the European TBI centres, are also presented. It turned out that there exists a great variety in techniques, total doses, and fractionation schedules used all over Europe. It was also clear that the documentation concerning dosimetry and the time factor in TBI still has some deficiencies. Therefore, a proposal is now made for reporting the technical and dosimetric aspects used in total body irradiation in an unambiguous manner.

Humans↗
PubMed1989

Rationality and antiemotionality as a risk factor for cancer: concept differentiation.

Control and repression of emotions may be coping styles or personality characteristics found more often in patients with cancer than in other patients and healthy subjects. Previous research indicated a possible relationship between high scores on a 'rationality and antiemotionality' scale and cancer. In the two studies reported, the psychometric properties of this scale and the meaning of the concept as a personality variable related to the control of emotions were investigated. It was found that the internal consistency of the scale could be improved by re-designing it into a personality inventory. Factor analysis repeatedly yielded more than one factor, indicating the complexity of the concept. 'Rationality and antiemotionality' seems related to the control, suppression or repression of anger. Our findings tentatively support the view that rationality and antiemotionality may be an important distinctive personality characteristic in patients with cancer.

Adult↗
PubMed1989

Treatment of locoregional recurrence of carcinoma of the cervix by radiotherapy after primary surgery.

Eighteen patients with locoregional recurrence after primary surgery for carcinoma of the cervix and treated by radiotherapy were analyzed. An overall complete response of 88%, 16 of 18, was achieved. Five of sixteen patients (31%) developed a second locoregional recurrence. Response to radiotherapy seemed to correlate strongly with tumor volume. The overall 5-year survival for all 18 patients was 44%, and the disease-free survival, 39%. Only 22%, 4 of 18, had distant metastases in the subsequent course of the disease.

Combined Modality Therapy↗
PubMed1989

Glottic and supraglottic carcinoma: a retrospective comparison of radiotherapy alone with sandwich therapy in 366 patients.

From 1971 through 1982, 442 patients with laryngeal carcinoma were seen at the Leiden University Hospital. They were treated either with radiotherapy alone, sandwich therapy (pre- and postoperative radiotherapy) or by surgery followed by postoperative irradiation. Three hundred and sixty-six patients with glottic or supraglottic tumours could be analysed with respect to two different treatments, complications of treatment and some prognostic factors. Two endpoints of analysis were used: disease-free interval and survival to cancer death. In patients with glottic or supraglottic carcinoma, the survival of patients with advanced disease, treated with radiotherapy only, was worse as compared to the survival of the same category of patients who were treated with sandwich therapy (p less than 0.005). In patients with small glottic tumours, radiotherapy alone was mostly used. In small supraglottic tumours, the survival with both therapy policies was equal. Persistent hoarseness in patients with small glottic tumours, treated with radiotherapy only, is of predictive value for the development of a recurrence (p less than 0.001). There was no influence on prognosis of histological differentiation of the tumour. It appeared that interruption of radiotherapy for more than two days had an adverse effect on survival in patients with glottic carcinoma (p = 0.0001). Finally, the occurrence of second malignancies was analysed. It was found that 19% had a second malignancy. Almost 60% of them were lung cancers.

Aged↗
PubMed1989

Locally advanced breast cancer: radiotherapy alone versus surgery and radiotherapy.

From 1976 through 1984 46 patients with locally advanced breast cancer were treated by either radiotherapy alone or by combination of surgery and postoperative radiotherapy. Eleven of the 21 patients treated by radiotherapy alone had a local or regional recurrence, while no recurrences occurred in the combined treatment group. From this study it was concluded that "locally advanced" breast cancer is a heterogeneous disease and that further study concerning the role of surgery is justifiable for a selected subgroup of patients with non-inflammatory resectable tumours (meeting the criteria of "locally advanced" breast cancer).

Adult↗
PubMed1988

Radiotherapy as an alternative to surgery in elderly patients with resectable lung cancer.

From 1978 to 1983, 50 patients with a peripherally located non-small cell tumor of the lung were irradiated with curative intent. These patients were not operated upon because of poor cardiac or pulmonary condition, old age or refusal to operate. Mean age was 74 years, 40 patients being over 70 years of age. All patients had T1-2 N0M0 tumors according to the AJC classification and received 60 Gy to the primary tumor only. The overall response rate was 90%, with 50% complete responses in tumors smaller than 4 cm. The crude overall survival rates were 56% at 2 years and 16% at 5 years, with a median survival of 27 months. Age did not influence survival. There was a strong correlation of survival to tumor size, with 5-year survival rates of 38, 22, 5 and 0% in tumors with diameters of less than or equal to 2, 2-3, 3-4 and greater than 4 cm respectively. Only 5 out of 20 complete responders had a local recurrence, the 5-year survival in this group was 42%. These results compared favorably to a group of 86 patients over 70 years of age who were selected for operation in the same hospital. The 2- and 5-year survival rates in these patients were 48 and 26% respectively, median survival being 23 months. We conclude that in patients over 70 years of age with resectable lung cancer, radiotherapy with curative intent should be offered as an alternative to operation, especially if the tumor is not larger than 4 cm.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

The effect of radiotherapy on dysphagia and survival in patients with esophageal cancer.

A group of 127 patients with esophageal cancer treated with radiotherapy at different dose levels was retrospectively analysed. It was found that 70.5% of the patients showed improvement of dysphagia and that 54% remained palliated with respect to food passage until their death. The two major prognostic variables with respect to the palliative effect on dysphagia as well as survival were the passage score and the radiation dose. Patients with severe dysphagia (PASS 0 or 1) had a median actuarial DFI and SURV of 3.7 and 6.4 months, respectively, in contrast to 16.0 and 8.7 months for patients who were able to use (semi)solid food (PASS 2 and 3). The median actuarial DFI and SURV of patients treated with a relatively low dose (less than 50 Gy in 5 weeks) were 2.5 and 4.8 months, respectively, compared to 10.1 and 8.3 months, respectively, for patients treated with a relatively high dose.

Adenocarcinoma↗
PubMed1987

Perioperative blood transfusion and cancer prognosis. Different effects of blood transfusion on prognosis of colon and breast cancer patients.

A detailed retrospective analysis was undertaken of the effect of perioperative blood transfusion on long-term survival of 113 patients with Dukes' Stages A, B and C1 cancer of the colon and 383 patients with invasive cancer of the breast who were treated in our institution between 1973 and 1978 and followed for 5 to 10 years. In the patients with colon cancer, a significant adverse effect of transfusion on long-term survival was seen. In this group there was a cumulative 5-year overall survival of 48% for the transfused and 74% for the nontransfused patients (P = 0.007, log-rank test). Perioperative blood transfusion was associated with a relative risk of 3.42 for all deaths (P = 0.005) and 4.25 for death due to cancer (P = 0.03), after adjustment for other important variables such as age, sex, stage, location of tumor, surgical procedure, and preoperative hemoglobin level. In contrast, in our study group of patients with breast cancers, who all underwent a modified radical mastectomy, no effect of blood transfusion on long-term survival was seen. Multivariate analysis adjusting for size of tumor, number of positive regional lymph nodes, menopausal status, estrogen receptor status and the addition or absence of chemotherapy, did not show any increased risk in all deaths or death due to cancer associated with blood transfusion. Although no definite explanation is available, our data show that there seems to be a difference in the relationship between perioperative blood transfusion and survival for colon and breast cancer patients.

Aged↗
PubMed1987

Irradiation of murine lip mucosa in combination with 5-fluorouracil, administered by single dose injection or continuous infusion.

The possible interaction of 5-fluorouracil (5-FU) and irradiation on mouse lip mucosa was studied, with special interest for the influence of the route of administration of the drug, either by single intraperitoneal (i.p.) injection or by 7 days continuous subcutaneous infusion. Apart from the possible modification by the drug of radiation-induced damage to the lip mucosa assessment was made of the systemic toxicity. No modification of the radiosensitivity of mouse lip mucosa nor of its repair capacity was observed with the use of 5-FU given either by i.p. injection or by continuous infusion. However, the combination of 5-FU and irradiation resulted in an increased systemic toxicity which was only seen when 5-FU was administered by an i.p. injection in close timing with irradiation. It is suggested that this increased systemic toxicity is caused by the combined effects of irradiation and 5-FU on the alimentary tract, although we could not demonstrate the mechanism of it.

Animals↗