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E Van Limbergen

Publications and source records attributed to E Van Limbergen.

At least 19 recordsLinked to original sources
PubMed2001

Survey of the use of the ICRU 38 in recording and reporting cervical cancer brachytherapy.

BACKGROUND: A survey on the practice of reporting intracavitary cervix cancer brachytherapy (LDR and HDR) in clinical practice (CP) and in literature (LIT) was performed on the occasion of a workshop, 'ICRU 38: The Basis for a Revision', which took place at the Annual GEC ESTRO meeting in Naples in 1998. MATERIALS AND METHODS: The answers (n=85) to a specific questionnaire which had been sent to all ESTRO members (n=1600), were evaluated. In parallel, a systematic survey on the literature reporting cervix cancer brachytherapy since 1985 was performed using the MEDLINE database. The main recommendations for reporting as given in the ICRU 38 were addressed for both surveys: technique; total reference air kerma (TRAK); dose specification to the target volume '60 Gy reference volume', to organs at risk 'ICRU rectum and bladder point' and other reference points and time-dose pattern. In addition, some other items were investigated such as mg h, Point A, B, and in vivo dosimetry in bladder and rectum. RESULTS: Issues related to technique (source, machine and applicator type) and to time-dose pattern are reported in the majority of patients in CP and LIT. The same applies for the following parameters: Point A is indicated in 76% (LDR) to 89% (HDR) in CP, in 60% (LDR) to 96% (HDR) in LIT. Rectum and bladder ICRU points are recorded in 55% (HDR) to 90% (LDR) and 58% (HDR) to 84% (LDR), respectively, in CP. On the other hand, TRAK is given in 14% (HDR) to 43% (LDR) in CP, in 0% (HDR) to 10% (LDR) in LIT. '60 Gy reference volume' is recorded in 18% (HDR) to 51% (LDR) in CP, in 0% (HDR) to 17% (LDR) in LIT. Rectum and bladder ICRU points are reported in 18% (LDR) to 28% (HDR) and 14% (HDR) to 29% (LDR), respectively, in LIT. Other reference points and in vivo dosimetry measurements are given in a low percentage. Dose rate and overall treatment time is reported in 10-44%. CONCLUSION: Recording and reporting in CP and in LIT meets the recommendations as given in ICRU 38 to different degrees. Specific items such as TRAK and the 'Reference volume' have only limited penetration into CP and LIT, which applies in particular to centers using HDR brachytherapy. The discrepancies between CP and LIT may be due to the well-known delay between change in CP and its translation into LIT. In order to arrive at a more common language for the better exchange of clinical results, it seems to be necessary to adapt some terms and recommendations. In particular, comprehensive concepts are needed for reporting dose to points and volumes in the target and in critical organs, according to the new potential from imaging and computer technology and from modern radiobiological insights, bridging the gap between LDR and HDR brachytherapy.

Brachytherapy↗
PubMed2001

Quality control in interstitial brachytherapy of the breast using pulsed dose rate: treatment planning and dose delivery with an Ir-192 afterloading system.

BACKGROUND AND PURPOSE: In the Radiotherapy Department of Leuven, about 20% of all breast cancer patients treated with breast conserving surgery and external radiotherapy receive an additional boost with pulsed dose rate (PDR) Ir-192 brachytherapy. An investigation was performed to assess the accuracy of the delivered PDR brachytherapy treatment. Secondly, the feasibility of in vivo measurements during PDR dose delivery was investigated. MATERIALS AND METHODS: Two phantoms are manufactured to mimic a breast, one for thermoluminescent dosimetry (TLD) measurements, and one for dosimetry using radiochromic films. The TLD phantom allows measurements at 34 dose points in three planes including the basal dose points. The film phantom is designed in such a way that films can be positioned in a plane parallel and orthogonal to the needles. RESULTS: The dose distributions calculated with the TPS are in good agreement with both TLD and radiochromic film measurements (average deviations of point doses <+/-5%). However, close to the interface tissue-air the dose is overestimated by the TPS since it neglects the finite size of a breast and the associated lack of backscatter (average deviations of point doses -14%). CONCLUSION: Most deviations between measured and calculated doses, are in the order of magnitude of the uncertainty associated with the source strength specification, except for the point doses measured close to the skin. In vivo dosimetry during PDR brachytherapy treatment was found to be a valuable procedure to detect large errors, e.g. errors caused by an incorrect data transfer.

Brachytherapy↗
PubMed2000

The influence of patient, tumor and treatment factors on the cosmetic results after breast-conserving therapy in the EORTC 'boost vs. no boost' trial. EORTC Radiotherapy and Breast Cancer Cooperative Groups.

PURPOSE: To analyze the influence of different patient, tumor, and treatment parameters on the cosmetic outcome after breast-conserving therapy at 3-year follow-up. A subjective and an objective cosmetic scoring method was used and the results of both methods were compared. PATIENTS AND METHODS: In EORTC trial 22881/10882, 5569 early-stage breast cancer patients were treated with tumorectomy and axillary dissection, followed by tangential fields irradiation of the breast to a dose of 50 Gy in 5 weeks, at 2 Gy per fraction. A total of 5318 patients, having a microscopically complete tumorectomy, were randomized between no further treatment and a boost of 16 Gy to the primary tumor bed. The cosmetic result at 3-year follow-up was assessed by a panel for 731 patients, and by digitizer measurements, measuring the displacement of the nipple, for 1141 patients. Univariate and multivariate analyses were used to evaluate the correlation between various patient, tumor, and treatment factors and cosmesis. RESULTS: The factors associated with a worsened cosmesis according to the panel evaluation were: an inferior tumor location, a large excision volume, the presence of postoperative breast complications, and the radiotherapy boost. According to the digitizer measurements, a central/superior tumor location, a large excision volume, an increased pathological tumor size, an increased radiation dose inhomogeneity, and an increased bra cup size resulted in an increased asymmetry in nipple position. It appeared that the evaluation of the nipple position (whether by panel or by digitizer) is only moderately representative of the overall cosmetic outcome. CONCLUSION: To achieve a good cosmesis, it is necessary to excise the tumor with a limited margin, to avoid postoperative complications, to assess the need for a boost in the individual patient, and to give the radiation dose as homogeneously as possible. As far as the method of evaluation is concerned, the panel evaluation is the most appropriate method for giving an overall impression of the cosmetic result after breast-conserving therapy (BCT). The use of the digitizer is recommended for comparing the cosmetic outcome of two different approaches to BCT or for analyzing cosmetic changes over time.

Adult↗
PubMed2000

Brachytherapy with iridium-192 for bladder cancer.

OBJECTIVE: Patients with invasive bladder cancer often need radical cystectomy with its implications on quality of life. Bladder preservation combining surgery and radiotherapy could maintain quality of life without compromising tumor control. STUDY DESIGN: Twenty-eight selected patients with different stages of invasive bladder cancer were treated with preoperative external beam radiotherapy in a dosage depending on the tumor stage. Subsequently they underwent surgical exploration with or without partial cystectomy and insertion of source carrier tubes for afterloading with iridium-192. A close follow-up consisted of 3-monthly urine cytology, cystoscopy and yearly CT scan. RESULTS: Sixteen patients (57%) are alive with no evidence of disease. Five patients (18%) have died of non-cancer-related causes without evidence of recurrent tumor. Tumor progression was seen in 7 patients (25%). CONCLUSIONS: Interstitial radiation can result in long-term complete remission in patients with small solitary invasive bladder tumors. The afterloading technique is safe and effective. The selection of patients is the most relevant key to success.

Adult↗
PubMed2000

Coronary radiation therapy with liquid rhenium-186: a first clinical experience.

BACKGROUND: Coronary radiation therapy (CRT) is a new, attractive approach for the treatment and prevention of restenosis after percutaneous coronary interventions (PCI). The RadioCath device consists of a standard balloon dilatation catheter that can be charged with a solution of sodium 186Re perrhenate, a predominant beta emitter. The safety and performance of this new device was evaluated in a pilot trial. METHODS AND RESULTS: Thirty-three patients with a de novo lesion in a native coronary artery were treated with the RadioCath device after successful angioplasty. The average dwell time to deliver a dose of 20 Gy at 0.5 mm into the vessel wall was 418+/-64 seconds. The treatment was well tolerated by most of the patients. In 79%, only one inflation cycle was required to deliver the prescribed dose. There were two procedural device-related complications (5.9%) and three minor procedural related in-hospital complications (9%). CONCLUSIONS: CRT using a balloon catheter device, charged with a sodium 186Re perrhenate solution, seems feasible and safe. Clinical and angiographic 6-month follow-up data are pending.

Angioplasty, Balloon, Coronary↗
PubMed1999

Validation of the methods of cosmetic assessment after breast-conserving therapy in the EORTC "boost versus no boost" trial. EORTC Radiotherapy and Breast Cancer Cooperative Groups. European Organization for Research and Treatment of Cancer.

PURPOSE: To evaluate both qualitative and quantitative scoring methods for the cosmetic result after breast-conserving therapy (BCT), and to compare the usefulness and reliability of these methods. METHODS AND MATERIALS: In EORTC trial 22881/10882, stage I and II breast cancer patients were treated with tumorectomy and axillary dissection. A total of 5318 patients were randomized between no boost and a boost of 16 Gy following whole-breast irradiation of 50 Gy. The cosmetic result was assessed for 731 patients in two ways. A panel scored the qualitative appearance of the breast using photographs taken after surgery and 3 years later. Digitizer measurements of the displacement of the nipple were also made using these photographs in order to calculate the breast retraction assessment (BRA). The cosmetic results after 3-year follow-up were used to analyze the correlation between the panel evaluation and digitizer measurements. RESULTS: For the panel evaluation the intraobserver agreement for the global cosmetic score as measured by the simple Kappa statistic was 0.42, considered moderate agreement. The multiple Kappa statistic for interobserver agreement for the global cosmetic score was 0.28, considered fair agreement. The specific cosmetic items scored by the panel were all significantly related to the global cosmetic score; breast size and shape influenced the global score most. For the digitizer measurements, the standard deviation from the average value of 30.0 mm was 2.3 mm (7.7%) for the intraobserver variability and 2.6 mm (8.7%) for the interobserver variability. The two methods were significantly, though moderately, correlated; some items scored by the panel were only correlated to the digitizer measurements if the tumor was not located in the inferior quadrant of the breast. CONCLUSIONS: The intra- and interobserver variability of the digitizer evaluation of cosmesis was smaller than that of the panel evaluation. However, there are some treatment sequelae, such as disturbing scars and skin changes, that can not be evaluated by BRA measurements. Therefore, the methods of cosmetic evaluation used in a study must be chosen in a way that balances reliability and comprehensiveness.

Adult↗
PubMed1999

Breast boost--why, how, when...?

BACKGROUND: Breast conservation management including tumorectomy or quadrantectomy and external beam radiotherapy with a dose of 45 to 50 Gy in the treatment of small breast carcinomas is generally accepted. The use of a radiation boost--in particular for specific subgroups--has not been clarified. With regard to the boost technique there is some controversy between groups emphasizing the value of electron boost treatment and groups pointing out the value of interstitial boost treatment. This controversy has become even more complicated as there is an increasing number of institutions reporting the use of HDR interstitial brachytherapy for boost treatment. The most critical issue with regard to interstitial HDR brachytherapy is the assumed serious long-term morbidity after a high single radiation dose as used in HDR-treatments. METHODS AND RESULTS: This article gives a perspective and recommendations on some aspects of this issue (indication, timing, target volume, dose and dose rate). CONCLUSION: More information about the indication for a boost is to be expected from the EORTC trial 22881/10882. Careful selection of treatment procedures for specific subgroups of patients and refinement in surgical procedures and radiotherapy techniques may be useful in improving the clinical and cosmetic results in breast conservation therapy. Prospective trials comparing on the one hand different boost techniques and on the other hand particular morphologic criteria in treatments with boost and without boost are needed to give more detailed recommendations for boost indications and for boost techniques.

Brachytherapy↗
PubMed1999

Radiation-associated choroidal neovasculopathy, exudative detachment and neovascular glaucoma. A case report.

Radiotherapy remains a controversial type of therapy for subfoveal neovascularization. Recently a peculiar pattern of neovascular growth of the irradiated choroidal neovascular membrane has been described. This evolution may be associated with extensive exudative reaction. In one of our patients with this complication, the disease progressed to a total exudative retinal detachment and neovascular glaucoma.

Aged↗
PubMed1999

Confrontation of mammography systems in flanders with the European Guidelines for Quality Assurance in mammography screening. Analysis of initial results.

From May 1997 to April 98, 30 radiological centers made an agreement with the Leuvens Universitair Centrum voor Kankerpreventie (LUCK) for the work out of physical and technical quality control in mammography screening. A protocol was used based on the European Guidelines for Quality Assurance. The reports of all 30 acceptance tests were retrospectively reviewed. The following parts showed to be most critical: alignment of radiation field and film in the bucky, tube voltage precision, automatic exposure controller, average optical density of a standard exposure, dark room and its safe lights. The mean film gradient was in the majority of the centers higher than what is prescribed in the European document. This is acceptable and even desirable whenever daily quality control shows that the development system is sufficiently stable. Although it is difficult to compare the scores for the specific tests with results in other countries, there is evidence that the tendencies are very similar.

Absorptiometry, Photon↗
PubMed1998

Clinical and manometric effects of combined external beam irradiation and brachytherapy for anal cancer.

This study evaluates anorectal function after combined tele- and brachytherapy for anal cancer using manometric measurements and a standardized questionnaire. Eight patients received 44 +/- 3 Gy external beam radiation followed by 20 +/- 4 Gy interstitial brachytherapy with iridium-192. Patients were examined 43 months (range 25-83) after therapy. Maximum anal basal pressure, squeeze pressure, and squeeze increment were significantly lower in patients (50, 163, 115 mmHg, respectively) than in control subjects (75, 285, 180 mmHg, respectively). Decreased anal elasticity was not observed. Anal prestretch "normalized" the contractility of the internal and external sphincter. Thus damage to the anal epithelium and hemorrhoidal cushions seems to be the most important mechanism explaining reduced anal closing pressure values. The rectoanal inhibitory reflex was observed in all but one patient. Rectal compliance was significantly reduced. Whereas all patients could retain a water filled rectal balloon until the maximum tolerable sensation level was reached, the rectal saline infusion test was strongly abnormal. Four patients were perfectly continent. Four patients were incontinent for gas and presented urgency in case of liquid stools with limited soiling occurring once weekly or less; three of them also had urgency for solids. Defecation frequency was increased but regular in most patients. Reduced anal closure together with reduced rectal compliance are at the basis of stool frequency, urgency and partial incontinence with occasional soiling. However, enough reserve sphincter function was maintained to preserve a clinically acceptable degree of anal continence in our patients.

Adenocarcinoma↗
PubMed1998

Results of treatment of choroidal malignant melanoma with high-dose-rate strontium-90 brachytherapy. A retrospective study of 46 patients treated between 1983 and 1995.

PURPOSE: We review the results of treatment of small to medium-sized choroidal malignant melanomas after high-dose-rate brachytherapy with a strontium-90 applicator. METHODS: The applicator is positioned against the sclera using an afterloading technique. Brachytherapy is completed in a single session lasting 2-4 h with the patient under local anaesthesia. From September 1983 until March 1995, 46 eyes were treated in this way. Most tumours were 7-11 mm in diameter (range from 4.5-15 mm) with a mean height of approximately 3 mm (range from 1.5-7 mm). Follow-up ranged from 6 months to 12 years (mean 49 months). RESULTS: Thirty of the 46 eyes had at the final evaluation a nonevolutive scar (20 of these after a single application, the others with some additional treatment). In 13 eyes the tumours were in involution but their complete destruction was not yet certain, and 3 eyes were enucleated for local recurrence. Three patients developed systemic metastases. No radiogenic complications were noticed. CONCLUSION: Strontium-90 brachytherapy is a valuable and safe treatment technique for small to medium-sized choroidal malignant melanomas. In addition the use of a strontium-90 applicator is inexpensive thanks to this element's long half-life and the short application time.

Adult↗
PubMed1998

Retrospective study on the evolution of visual acuity after external beam radiotherapy (20 Gy, 2 Gy fractions) for subfoveal choroidal neovascular membranes in ARMD.

This is a retrospective study of 104 patients with a total follow-up between 12 and 48 months (mean follow-up of 24 months), in which the effect of External Beam Radiotherapy with a total dose of 20 Gy (2 Gy fractions) on the visual acuity of eyes affected by subfoveal choroidal neovascularization is evaluated. The evolution of the visual acuity of the irradiated eyes is compared with the evolution of the visual acuity of their fellow eyes which were also affected by choroidal neovascularization but were not treated or treated by laser photocoagulation. This study suggests that the effect of radiotherapy, with a total dose of 20 Gy, on the visual acuity of eyes affected by subfoveal choroidal neovascularization, seems to be not better than the natural course of choroidal neovascularization or the evolution after laser therapy.

Adult↗
PubMed1997

External beam radiotherapy (20 Gy, 2 Gy fractions) fails to control the growth of choroidal neovascularization in age-related macular degeneration: a review of 111 cases.

BACKGROUND: Control of the natural course of choroidal neovascularization (CNV) in age-related macular degeneration (ARMD) is difficult, and laser photocoagulation is recommended in only a subset of patients. Alternative modalities of treatment are under investigation. METHODS: We have used external beam radiotherapy (20 gray radiation units [Gy], 2 Gy fractions) to treat CNV in ARMD. A total of 111 patients have been followed for 12-30 months after radiotherapy. This study evaluates the effect of radiotherapy on the size of CNV, which was digitally measured on serial fluorescein angiograms. RESULTS: Analysis of results in the classic (or mixed classic and occult) CNV group was conclusive for fast growth of CNV and continuous increase of size during follow up. In the occult CNV group, a slowly progressive growth of CNV was demonstrated. In patients with vascularized pigment epithelium detachments, "hot spots" persisted; in a few patients, flattening of the macula was observed. Nearly all treated patients experienced further loss of vision. CNV growth in the radiotherapy treated eye was usually similar to growth in the untreated fellow eye, and in some, even worse. CONCLUSION: External beam radiotherapy (20 Gy, 2 Gy fractions) failed to control growth of CNV and was ineffective in stabilizing vision.

Aged↗
PubMed1995

[Dental care in patients undergoing radiotherapy of the head and neck].

Radiotherapy involving the oral cavity and salivary glands induces a wide range of alterations in oral tissues and salivary gland functions which may result in oral side effects. Some of these are inevitable and transient such as radiation mucositis, some however may be permanent such as xerostomia. Others however are preventable, and are caused by poor radiation techniques, application of excessive radiation doses or lack of necessary preventive measures. Frequent complications in these patients are development of caries, dental hypersensitivity, rapidly progressive periodontal disease and loss of taste. Occasionally, trismus and osteoradionecrosis may develop. Careful treatment planning before start of radiotherapy with adequate dosimetry and careful shielding of the healthy tissues as well as close monitoring of the oral cavity with strict application of preventive measures (dental care protocol) can significantly reduce the incidence of these complications. The private practitioner should keep in mind the life-long precautions that are necessary when treating these patients.

Dental Caries↗
PubMed1994

High dose level radiation therapy for local tumour control in esthesioneuroblastoma.

Esthesioneuroblastoma is an uncommon tumour of neural crest origin arising in the nasal cavity. This paper is a retrospective review of 7 patients with esthesioneuroblastoma treated at a single institution from May 1974 to July 1990. 5 patients were treated with radiation therapy alone and 2 patients were irradiated after surgical resection. No local or regional occurrence was observed in any patient at 6 months, or at 1, 3, 6, 11.5 and 12 years following treatment. One patient died of intercurrent disease 6 years after radiation therapy. 2 patients died of disease, 1 of distant metastasis at 6 months and the other patient of meningeal carcinomatosis and distant metastases 1 year after treatment. One patient is alive with distant metastases 1 year after treatment. None of the patients experienced significant complications of irradiation. High-dose irradiation (60 Gy or more) alone or in combination with resection is an effective local treatment modality for esthesioneuroblastoma.

Adolescent↗
PubMed1990

Local control of operable breast cancer after radiotherapy alone.

221 patients with operable breast carcinoma stage Tis, T1, T2, T3, N0N1 were treated with radiotherapy alone without tumorectomy. The mean follow-up time was 15.5 years (range 5-22). The annual risk for local recurrence was 3% during the first 5 years and 1% during the following 10 years, resulting in an actuarial local control rate of 75.4% after 15 years. The risk for local recurrence was assessed in multivariate analysis and was significantly related to the size of the tumour measured on mammography (P = 0.0002), the radiation dose administered (P = 0.0018), the length of the split-course intervals being longer than 75 days (P = 0.001) and age (P = 0.019). Dose was related to response over a wide range as a function of tumour volume. All 18 patients with minimal tumour load (T0 and Paget's disease) treated with doses above 55 Gy in 6 weeks achieved local control. 5-year local control rates ranged from 40 to 100% for T1 carcinomas treated with 45-110 Gy, and from 0 to 95.3% for T2 carcinomas at the same dose. For T3 carcinomas local control varied between 50 and 83% at 60-110 Gy. The risk for local failure increased by 8% per cm tumour diameter. With exclusive radiotherapy, the doses needed to provide local control rates similar to those obtained after tumorectomy and irradiation are 10 Gy higher for T1 (95% 5 year control) and 35 Gy higher for T2 (90% 5 year control).

Adult↗
PubMed1990

The source-skin distance measuring bridge: a method to avoid radiation teleangiectasia in the skin after interstitial therapy for breast cancer.

Inappropriate positioning of interstitial Iridium 192 implants, used as booster dose in the breast conserving treatment of mammary cancer, may cause disturbing teleangiectasia of the breast skin, when high radiation doses are delivered on the dermal blood vessels. Based on the localization of the vascular plexuses in human breast skin, and on the dose distribution around different types of interstitial implants, a method is described to avoid overlap between the high dose area of the implant and the blood vessels in the skin. The latter are demonstrated to run within the first 5 mm under the epiderm. For source lengths varying from 5 to 8 cm, simple mathematical relations exist between the maximal security margin (MSM) and intersource distance (E) for single plane implants (MSM = 0.4 (E + 1)), double plane square implants (MSM = 0.4 E) and double plane triangular implants (MSM = 0.4 (E - 1)). We developed a device to measure precisely the distance between the radioactive wires and the overlying skin, along the whole source trajectory. Using this method, the occurrence of teleangiectasia in the breast skin after interstitial implants with Ir 192 may be significantly reduced.

Brachytherapy↗