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Biomedical subjects

W A van Daal

Publications and source records attributed to W A van Daal.

At least 19 recordsLinked to original sources
PubMed2000

Informed consent in palliative radiotherapy: participation of patients and proxies in treatment decisions.

Informed consent is regularly discussed, but little attention has been paid to the daily practice of the patient participation in treatment decisions regarding palliative care. Therefore, an exploratory study was conducted into shared decision making between radiation oncologists and patients and proxies in interviews where decisions regarding palliative radiotherapy have to be made. Interviews of 6 radiation oncologists with 26 outpatients were recorded on audiotape. Each verbal utterance was coded with the aid of the Roter Interaction Analysis System (RIAS). Results indicated that in over 75% of the interviews, patients and proxies were not asked for their opinion regarding treatment decisions. Other treatment options or the option of abstaining from treatment were discussed in 46% of the interviews. In conclusion, in this sample informed consent was not a natural part of the daily practice of palliative radiotherapy. The question remains to what extent informed consent in palliative radiotherapy is realistic.

Aged↗
PubMed1998

A randomized controlled clinical trial on the efficacy of radiation therapy in the control of subfoveal choroidal neovascularization in age-related macular degeneration: radiation versus observation.

BACKGROUND: The results of several pilot studies concerning radiation therapy for age-related subfoveal choroidal neovascularization (CNV) have been published recently. Although positive treatment results have been described, it is not known whether this therapy alters the natural course of eyes with neovascular age-related macular degeneration (AMD). A randomized controlled clinical trial was conducted in which radiation therapy was compared with observation in patients with subfoveal neovascular AMD. METHODS: Seventy-four patients with a recent drop in central vision due to subfoveal age-related CNV were randomized to either radiation treatment or observation. Patients with either classic, occult or mixed type CNV were included. Eyes in the treatment group received a radiation dose of 24 Gy in four fractions of 6 Gy. Evaluation of data concerning visual acuity (VA) and fluorescein angiography occurred at 3, 6 and 12 months after inclusion. RESULTS: At 12 months of follow-up 52.2% of the observation group versus 32.0% of the irradiation group had lost 3 or more lines of VA (P = 0.03, log rank test). More severe visual decline, 6 lines or more, was observed in 40.9% of the observation versus 8.8% in the irradiation group (P = 0.002 using log rank test). At 12 months 39.6% of the observation group and 20.0% of the treatment group had VA of less than 0.1 (P = 0.08, log rank test). The size of the CNV membrane doubled in 25.2% of eyes in the observation group versus 20.0% in the treatment group at least 12 months (P = 0.5, log rank test). No side effects were observed. CONCLUSION: Preservation of VA was significantly better in the treatment group compared with the control group at 12 months. Nevertheless we noted a drop in central vision of 3 or more lines in a substantial proportion of the treatment group. Radiation therapy does not prevent visual loss in all patients with age-related subfoveal CNV, and whether the treatment benefit at 12 months will persist has to be awaited.

Aged↗
PubMed1998

Accelerated radiotherapy with carbogen and nicotinamide (ARCON) for laryngeal cancer.

BACKGROUND AND PURPOSE: Tumor hypoxia and tumor cell repopulation are known factors determining radiation response. Accelerated radiotherapy as a method to counteract cellular repopulation was combined with carbogen (95% O2 + 5% CO2) breathing and oral administration of nicotinamide as a means to improve tumor perfusion and oxygenation. The feasibility, toxicity and clinical effectiveness of this approach as a voice-preserving treatment for carcinoma of the larynx was assessed in a prospective study. PATIENTS AND METHODS: Sixty-two patients with stage III-IV laryngeal carcinoma were treated with a schedule of accelerated radiotherapy. The total radiation dose to the primary tumor was 64 Gy and that to the metastatic nodes was 68 Gy delivered in fractions of 2 Gy over 35-37 days. Radiotherapy was combined with carbogen breathing in the initial 11 patients and with both carbogen and nicotinamide administration in the subsequent 51 patients. RESULTS: After a median follow-up of 24 months, the actuarial local control rate at 2 years was 92%. This is higher than any previous report in the literature for this category of patients. Five patients had a local tumor recurrence and underwent laryngectomy. There was one regional recurrence. Including salvage surgery the loco-regional control rate was 100%. Four patients developed distant metastases and died. The actuarial overall survival rate at 2 years was 85%. Toxicity was increased relative to conventional radiotherapy but was considered as acceptable. One patient underwent laryngectomy for radiation-induced cartilage necrosis. CONCLUSION: These preliminary results indicate that advanced laryngeal cancer can be controlled in a high proportion of patients when treated with accelerated radiotherapy combined with carbogen and nicotinamide. This approach offers excellent possibilities for larynx preservation.

Actuarial Analysis↗
PubMed1997

[Vascularization and perfusion of tumors as target in cancer therapy].

Many tumours depend on the formation of an own vascular system to support progressive tumour growth. This is accomplished through induction of vessel growth from pre-existing vessels, a process called neo-angiogenesis. Therefore, inhibiting neo-angiogenesis and modulating tumour perfusion constitute attractive possibilities for tumour therapy, combined, of course, with treatment aimed at the tumour cells themselves. By now many angiogenesis inhibitors have been developed, but their use is mostly still experimental. They inhibit endothelial proliferation and migration (fumagillin derivates, angiostatin, suramin) or prevent proteolytic degeneration of the extracellular matrix by products of the tumour (metalloproteinase inhibitors). Improving tumour oxygenation and perfusion by carbogen inhalation and nicotinamide or vasoactive agents (flunarizine, verapamil, nicotinamide) enhances the effects of radiotherapy and improves delivery of chemotherapeutic agents to the tumour. Research is currently in progress into the efficacy of accelerated radiotherapy in combination with carbogen inhalation and administration of nicotinamide in tumours of the head and neck, bladder, bronchi and brain.

Angiogenesis Inducing Agents↗
PubMed1997

Infrastructure for radiotherapy in The Netherlands: development from 1970 to 2010.

In 1993 the radiotherapy advisory committee of the Dutch Health Council published its report on the developments of infrastructure for radiotherapy in The Netherlands during the last 10 years and the prognosis for future needs until 2010. Based on demographic trends, the expected incidence of cancer, the role of radiotherapy in the treatment of cancer, and the workload assessment in a model department, two scenarios are presented for the development of infrastructure. According to the committee, the Quality Scenario would be the most appropriate.

Cancer Care Facilities↗
PubMed1997

Administration of nicotinamide during a five- to seven-week course of radiotherapy: pharmacokinetics, tolerance, and compliance.

BACKGROUND AND PURPOSE: Nicotinamide was administered daily as a liquid formulation to head and neck cancer patients receiving a 5- to 7-week course of radiotherapy. The pharmacokinetics, compliance, and tolerance of this drug formulation were studied. MATERIALS AND METHODS: Blood samples were drawn and nicotinamide levels determined in 40 head and neck cancer patients. On the first treatment day serial samples were obtained followed by daily samples at the time of irradiation during the first and last full weeks of the treatment. Side-effects of nicotinamide were monitored. RESULTS: In all patients peak concentrations greater than 700 nmol/ml could be obtained 0.25-3 h (mean 0.83 +/- 0.73 h) after drug intake. During the first week of treatment plasma levels at the time of irradiation were adequate in 82% of the samples. This decreased to 59% in the last week of treatment which can be partly attributed to reduced compliance. The most important side-effect of nicotinamide was nausea with or without vomiting occurring in 65% of the patients. Severe side-effects were associated with high plasma concentrations over subsequent days. Tolerance improved after a 25% reduction of dose in six of seven patients but plasma levels at the time of irradiation fell below 700 nmol/ml in four out of six of these patients. CONCLUSIONS: Peak plasma concentrations above the 700 nmol/ml level were obtained in all patients but these concentrations could not be reproduced during the entire course of the treatment in a significant portion of the subjects. Side-effects of nicotinamide are associated with plasma concentrations and tolerance can be improved by a moderate reduction of dose.

Adult↗
PubMed1995

Radiation therapy for age-related subfoveal choroidal neovascular membranes. A pilot study.

In this pilot study the effect of radiation therapy on subfoveal CNV membranes associated with age-related macular degeneration was evaluated. Four groups of 10 patients were treated with external beam radiotherapy (16 MV photons) on an area of 1 cm2 (macular region) using a lens-sparing technique and total dose of 8 to 24 Gy. The first group received 8 Gy in a single fraction. In this group only 30% had a stable visual acuity and a stable FA after 18 months follow-up. In 50% of patients in group 2 (12 Gy) and 40% of patients in group 3 (18 Gy) the visual acuity and FA appearance remained stable after 18 months of follow-up. In the last group (24 Gy) 80% of patients had a stable visual acuity and FA appearance after 12 months follow-up. Comparison of these findings with the natural history data of subfoveal age-related CNV, suggests a beneficial effect of radiation therapy with a total dose of 12 Gy or more on the progression of CNV membranes.

Aged↗
PubMed1995

Radiotherapy with carbogen breathing and nicotinamide in head and neck cancer: feasibility and toxicity.

The feasibility and early toxicity of radiotherapy with carbogen breathing and nicotinamide was tested in 74 head and neck cancer patients. Forty patients with laryngeal and hypopharyngeal tumors were treated with an accelerated schedule combined with carbogen alone (16) or with carbogen and nicotinamide (24). Thirty-four patients with far advanced unresectable tumors of the oral cavity and oropharynx received conventional radiotherapy with carbogen [16] or with carbogen and nicotinamide (18). Some enhancement of skin reaction was observed with nicotinamide but this remained well within limits of tolerance. With the accelerated regimen there was increased severity of mucosal damage expressed as confluent mucositis in 95% of patients which required healing times of 3-4 months in four patients. Eventually restoration of the mucosal lining was complete in all cases. Nausea and vomiting are the most frequent side effects of nicotinamide and were reported by 60% and 36% of the subjects, respectively. In 26% this was reason to discontinue drug intake. Severe renal dysfunction was associated with nicotinamide intake in two patients of this study and in one other patient who presented later. It is our conclusion that radiotherapy combined with carbogen and nicotinamide is a safe treatment with manageable side effects. We recommend not to give nicotinamide concomitantly with nephrotoxic medication or to patients who have impaired renal function. Preliminary tumor control rates are encouraging and clinical testing will be continued.

Administration, Inhalation↗
PubMed1995

Personality traits of women with breast cancer: before and after diagnosis.

The aim of this study was to investigate the extent to which the diagnosis of breast cancer influences the self-assessment of personality traits by patients. In 1989 and 1990, all female inhabitants of Nijmegen aged 43 years and over were invited to participate in a population screening for breast cancer and were asked to complete a personality questionnaire. During 1989-1992, 25 women who were diagnosed as having breast cancer were psychologically assessed for a second time 1 1/2 years after diagnosis. A control group of 822 healthy women also completed the questionnaire twice. A statistically significant decrease in scores on three scales (Rationality, Emotional Expression-out, and Emotional-Control) was reported by the patient group compared to the control group.

Adult↗
PubMed1994

Radiation therapy for subfoveal choroidal neovascular membranes in age-related macular degeneration. A pilot study.

BACKGROUND: The natural course of the visual acuity of age-related subfoveal choroidal neovascularisation (CNV) membranes is poor. Laser photocoagulation of subfoveal CNV is recommended if the patient is willing to accept a large decrease in visual acuity immediately after treatment. A large proportion of patients with subfoveal CNV do not meet the Macular Photocoagulation Study Group (MPS) guidelines for laser photocoagulation. The fact that so few patients meet these criteria makes further research into new treatment techniques warranted. Ionising radiation may prevent the proliferation of endothelial cells of newly formed subretinal capillaries and may induce obliteration of the aberrant new vessels. METHODS: In this study, the effect of radiation therapy on subfoveal CNV membranes was evaluated. Four groups of ten patients were treated with external beam radiotherapy (16-MV photons) on an area of 1 cm2 (macular region) using a lens-sparing technique and total doses of 8-24 Gy. The first group received 8 Gy in one fraction. The second, third and fourth groups received 12 Gy in 2 fractions, 18 Gy in three fractions and 24 Gy in four fractions respectively. The studied parameters included best-corrected visual acuity and membrane size and leakage on the fluorescein angiogram. We included 17 occult and 23 classic CNV membranes as defined by the MPS, with a duration of less than 5 weeks at presentation. Complete ophthalmic examination including fluorescein angiography was performed before and 3, 12 and 18 months after radiation treatment. We analysed the angiogram using a standard overprojection sheet. The results concerning the visual acuity and fluorescein angiography (FA) were compared with the extensively published, natural course data. RESULTS: The first group (including three cases of occult CNV) received 8 Gy in a single fraction. In this group only four of ten patients had stable visual acuity and stable FA appearance after 21 months follow-up. The visual acuity and FA remained stable after 13.6 months follow-up in seven of the patients in group 2 (12 Gy in two fractions, four occult CNV). The third group (18 Gy in three fractions, seven occult CNV) contained six patients with stable visual acuity, although two of them had CNV deterioration on the FA (11.1 months follow-up). In the last group (24 Gy in four fractions, three occult CNV), with a short follow-up of 5.6 months, eight patients had stable visual acuity and FA appearance. We did not note any regression of the CNV membrane on the angiogram. The visual acuity in groups 2, 3 and 4 decreased to 0.1 or worse in only three cases, three cases and one case respectively after at least 6 months follow-up. CONCLUSION: Comparison of these findings with the natural history data of subfoveal age-related CNV suggests a beneficial effect of radiation therapy with a total dose of 12 Gy or more on the progression of CNV. To date no negative side effects have been observed.

Aged↗
PubMed1992

Yearly chest radiography in the early detection of lung cancer following laryngeal cancer.

In a retrospective study of 556 patients (505 men, 51 women) with laryngeal cancer the incidence and prognosis of lung malignancies was studied in patients who were examined yearly by chest radiography. In 69 patients (12.4%) a lung malignancy was diagnosed, with 28 having a histologically confirmed second primary malignancy. All of these 69 patients were men. The incidence of radiologically detected lung malignancies, both second primary and metastatic cancer, is higher and more prolonged following supraglottic carcinoma than following glottic carcinoma. In 47 patients (68%) without symptoms, the lung malignancy was detected by routine annual chest radiography. The survival rate in patients with lung cancer detected by the yearly radiography was significantly higher than in patients diagnosed after symptoms (median survival 10 and 4 months, respectively). However, taking into account the lead time between early radiologic diagnosis and the time a tumor would have been diagnosed following symptoms, the observed survival benefit of yearly radiography was much lower, or even nil.

Actuarial Analysis↗
PubMed1992

Accelerated fractionation radiotherapy for laryngeal cancer, acute, and late toxicity.

The acute toxicity of an accelerated radiotherapy scheme was compared with a conventional schedule. Eighteen patients with squamous cell carcinoma of the larynx were treated with accelerated fractionation radiotherapy. An average reduction of overall treatment time of 11 days was accomplished by giving 2 fractions a day during the last part of the treatment. Total dose and fraction dose were left unchanged. Acute reactions of skin and mucosa in these patients were compared with those in 40 patients treated with a conventional fractionation scheme, that is, 2 Gy per fraction, 5 fractions per week, to a total dose of 64-70 Gy. Acute reactions were maximal between 5 and 7 weeks after the start of treatment. Complete healing occurred within 3 months in all patients. Mucosal reactions and, as a consequence, dysphagia were clearly increased in those patients treated with accelerated fractionation. For confluent mucositis an ED50 of 66 Gy was calculated compared to 69 Gy for conventional fractionation. To a lesser degree, skin toxicity was also enhanced in the patients treated with the accelerated schedule. Severe edema of the laryngeal mucosa occurred only in patients treated to a total dose of 68 or 70 Gy and was somewhat more frequent with accelerated fractionation (4/10) than with conventional fractionation (4/24). One patient in the accelerated fractionation group underwent laryngectomy for persistent edema and laryngeal necrosis. No severe late skin reactions were observed. It can be concluded that the fractionation schedule tested in this study is feasible. Further shortening of overall treatment time without reduction of total dose will likely lead to unacceptable acute and, possibly, also late toxicity.

Carcinoma, Squamous Cell↗
PubMed1991

[Postoperative irradiation in grade III and IV astrocytoma].

The aim of this paper is to contribute to the discussion on the value of postoperative radiotherapy in patients with astrocytoma grade III-IV. One hundred and fifteen of the 243 patients with histologically proven astrocytoma grade III-IV received postoperative radiotherapy at the St. Radboud University Hospital Nijmegen. According to the protocol all patients with a fairly good performance status were irradiated. The extent of surgery consisted of biopsy alone in 11%, subtotal tumour resection in 85% and macroscopically complete tumour removal in 4%. All patients received a whole brain irradiation of 40 Gy with a boost of 10-15 Gy in the tumour. Patients with grade III who underwent surgical resection had a median survival of 2.1 months, those with grade IV 2.7 months. Patients who underwent surgical resection and radiotherapy had a median survival of 12 months (grade III) and 8.6 months (grade IV). The extent of surgery and grade of malignancy were the only prognostic factors. Because of the selection of patients this study produces no additional arguments in favour of postoperative radiotherapy. However, we continue our treatment strategy to irradiate patients with grade III-IV tumours because the median survival obtained with this strategy is high in comparison with data from literature.

Adolescent↗
PubMed1991

The contribution of routine follow-up mammography to an early detection of asynchronous contralateral breast cancer.

The role of routine mammography was assessed in the early detection of asynchronous contralateral breast cancer (ACBC). The breast cancer patient populations of two cities, Nijmegen and Eindhoven, The Netherlands, which were subjected to a well-defined follow-up program, were compared. The program consisted of regular physical examination and annual mammography in Nijmegen and physical examination only in Eindhoven. From 1975 until 1987, 24 ACBC patients were detected within a group of 880 breast cancer patients in Nijmegen (3%) and, from 1971 until 1984, 14 ACBC patients within a group of 411 patients in Eindhoven (3%). In Nijmegen, eight of the 23 evaluable patients (35%) had a contralateral tumor with a histologic size smaller than 10 mm or an in situ carcinoma, compared with one of the 14 of the Eindhoven patients (7%), whereas 18 of the 24 (75%) versus eight of the 14 patients (57%) were node-negative. Thus annual mammography is very likely a contribution in the early detection of contralateral breast cancer as compared with follow-up by regular physical examination only.

Breast Neoplasms↗
PubMed1991

Breast-conserving treatment or mastectomy in early breast cancer: a clinical decision analysis with special reference to the risk of local recurrence.

A clinical decision analysis was performed to judge the impact of local recurrences after breast-conserving treatment (BCT) on the (quality-adjusted) life expectancy of breast cancer patients. A life-long follow-up of two patient groups, one of which had undergone mastectomy and one BCT, was simulated by a Markov model of medical prognosis. Data used in the model originated from the literature. Since results in the source papers were not split according to stage, we performed two analyses: one with data from all source studies (T1 and T2) and one with data from source studies, concerning only T1 patients. In both analyses, the conclusion was that BCT yields better quality-adjusted life expectancy than mastectomy. Sensitivity analysis, however, identified subgroups of patients who should preferably undergo mastectomy. These subgroups are: patients preferring mastectomy to BCT, patients with a high risk of local recurrence, young patients and patients at high age, if they also have a high local recurrence risk. For these groups, patient preferences should play a major role in recommending treatment.

Adult↗
PubMed1990

[Utility assessment in clinical decision making].

In clinical decision analysis a quantitative value is attached to a longevity or a life quality by means of utility assessment. The actual value of the utility can determine the result of the decision analysis. In this article utility theory is briefly discussed. Four kinds of utility tests (direct scaling methods, the basic reference gamble, the time trade-off test and additive conjoint measurement) are introduced on the basis of an example and their pros and cons are discussed. It is concluded that additive conjoint measurement has the best formal infrastructure, but that the test method is not always easily applicable.

Choice Behavior↗