Lukas J. A. Stalpers

Prof. Dr. Lukas J. A. Stalpers

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Research Focus & Metrics

Academic Career Length

25Years (2002-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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16 May 2018 in Radiation Oncology
Verified
Journal Article
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CLC. M. van Leeuwen
C. M. van Leeuwen
AOArlene L. Oei
Arlene L. Oei
Johannes Hans CrezeeJohannes Hans Crezee
Johannes Hans Crezee
ABA. Bel
A. Bel
NFNicolaas Franken
Nicolaas Franken
H.P. KokH.P. Kok
H.P. Kok
Prediction of radiobiological response is a major challenge in radiotherapy. Of several radiobiological models, the linear-quadratic (LQ) model has been best validated by experimental and clinical data. Clinically, the LQ model is mainly used to estimate equivalent radiotherapy schedules (e.g. calculate the equivalent dose in 2 Gy fractions, EQD2), but increasingly also to predict tumour control probability (TCP) and normal tissue complication probability (NTCP) using logistic models. The selection of accurate LQ parameters α, β and α/β is pivotal for a reliable estimate of radiation response. The aim of this review is to provide an overview of published values for the LQ parameters of human tumours as a guideline for radiation oncologists and radiation researchers to select appropriate radiobiological parameter values for LQ modelling in clinical radiotherapy. We performed a systematic literature search and found sixty-four clinical studies reporting α, β and α/β for tumours. Tumour site, histology, stage, number of patients, type of LQ model, radiation type, TCP model, clinical endpoint and radiobiological parameter estimates were extracted. Next, we stratified by tumour site and by tumour histology. Study heterogeneity was expressed by the I2 statistic, i.e. the percentage of variance in reported values not explained by chance. A large heterogeneity in LQ parameters was found within and between studies (I2 > 75%). For the same tumour site, differences in histology partially explain differences in the LQ parameters: epithelial tumours have higher α/β values than adenocarcinomas. For tumour sites with different histologies, such as in oesophageal cancer, the α/β estimates correlate well with histology. However, many other factors contribute to the study heterogeneity of LQ parameters, e.g. tumour stage, type of LQ model, TCP model and clinical endpoint (i.e. survival, tumour control and biochemical control). The value of LQ parameters for tumours as published in clinical radiotherapy studies depends on many clinical and methodological factors. Therefore, for clinical use of the LQ model, LQ parameters for tumour should be selected carefully, based on tumour site, histology and the applied LQ model. To account for uncertainties in LQ parameter estimates, exploring a range of values is recommended.

9 March 2012 in Neuro-Oncology
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Journal Article
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HAHanna van Alkemade
Hanna van Alkemade
MLMichelle de Leau
Michelle de Leau
EDEdith M.T. Dieleman
Edith M.T. Dieleman
JKJan W.P.F. Kardaun
Jan W.P.F. Kardaun
RORob van Os
Rob van Os
LSLukas J. A. Stalpers
Lukas J. A. Stalpers
Purpose: To assess long-term functional outcome and survival among patients with meningioma World Health Organization (WHO) grade I. Methods: Retrospective analysis of 205 patients after resection of WHO grade I intracranial meningioma from 1985 through 2003. Expected age- and sex-specific survival was calculated by applying Dutch life-table statistics to each patient for the individual duration of follow-up. Long-term functional outcome was assessed using a mailed questionnaire to the general practitioner. Results: The mean duration of follow-up was 11.5 years. Survival at 5, 10, 15, and 20 years was 92%, 81%, 63%, and 53%, respectively, which is significantly lower than the expected survival (94%, 86%, 78%, and 66%, respectively). Survival was worse with higher age (P < .001). Survival among patients younger than 45 years and older than 65 years was comparable to the expected survival but significantly worse among patients aged 45–65 years. Analysis of the cause of death suggests an excess mortality associated with both brain tumor death and stroke (P = .07). Recurrence rates at 5, 10, and 15 years were 18%, 26%, and 32%, respectively. Higher Simpson grade (P < .001) and lower age (P = .02) were associated with a higher recurrence rate. In 29 patients (14%) receiving radiotherapy, the 5-year recurrence rate was 18% and the 5-year survival was only 58%. Long-term functioning (≥5 years after last treatment) could be assessed in 89 long-term survivors: 29 patients (33%) showed no deficits, and 60 (67%) showed at least 1 neurological symptom, of whom 24 (27%) were unable to perform normal daily activities. Conclusion: Long-term survival in WHO grade I meningioma is challenged in patients more than45 years of age. Excess mortality seems to be associated with both tumor recurrence and stroke. The majority of patients have long-term neurological problems.

16 December 2009 in BMC Cancer
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JVJoost Jc Verhoeff
Joost Jc Verhoeff
OTOlaf van Tellingen
Olaf van Tellingen
ACAn Claes
An Claes
LSLukas J. A. Stalpers
Lukas J. A. Stalpers
MLMyra E van Linde
Myra E van Linde
WFWouter R van Furth
Wouter R van Furth
Background: The relevance of angiogenesis inhibition in the treatment of glioblastoma multiforme (GBM) should be considered in the unique context of malignant brain tumours. Although patients benefit greatly from reduced cerebral oedema and intracranial pressure, this important clinical improvement on its own may not be considered as an anti-tumour effect. Discussion: GBM can be roughly separated into an angiogenic component, and an invasive or migratory component. Although this latter component seems inert to anti-angiogenic therapy, it is of major importance for disease progression and survival. We reviewed all relevant literature. Published data support that clinical symptoms are tempered by anti-angiogenic treatment, but that tumour invasion continues. Unfortunately, current imaging modalities are affected by anti-angiogenic treatment too, making it even harder to define tumour margins. To illustrate this we present MRI, biopsy and autopsy specimens from bevacizumab-treated patients. Moreover, while treatment of other tumour types may be improved by combining chemotherapy with anti-angiogenic drugs, inhibiting angiogenesis in GBM may antagonise the efficacy of chemotherapeutic drugs by normalising the blood-brain barrier function. Summary: Although angiogenesis inhibition is of considerable value for symptom reduction in GBM patients, lack of proof of a true anti-tumour effect raises concerns about the place of this type of therapy in the treatment of GBM.

1 July 2011 in Neurosurgery
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MWMartin L Waagemans
Martin L Waagemans
DNDavid van Nieuwenhuizen
David van Nieuwenhuizen
MDMonica Dijkstra
Monica Dijkstra
MWMiriam Wumkes
Miriam Wumkes
CDClemens M F Dirven
Clemens M F Dirven
LSLukas J. A. Stalpers
Lukas J. A. Stalpers
BACKGROUND:. WHO Grade I meningiomas are common, usually benign, primary brain tumors. Little is known about the health-related quality of life (HRQOL)

10 June 2020 in Nature Communications
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RNRavi S. Narayan
Ravi S. Narayan
PMPiet Molenaar
Piet Molenaar
JTJian Teng
Jian Teng
FCFleur M. G. Cornelissen
Fleur M. G. Cornelissen
IRIrene Roelofs
Irene Roelofs
BWBart A. Westerman
Bart A. Westerman
Personalized cancer treatments using combinations of drugs with a synergistic effect is attractive but proves to be highly challenging. Here we present an approach to uncover the efficacy of drug combinations based on the analysis of mono-drug effects. For this we used dose-response data from pharmacogenomic encyclopedias and represent these as a drug atlas. The drug atlas represents the relations between drug effects and allows to identify independent processes for which the tumor might be particularly vulnerable when attacked by two drugs. Our approach enables the prediction of combination-therapy which can be linked to tumor-driving mutations. By using this strategy, we can uncover potential effective drug combinations on a pan-cancer scale. Predicted synergies are provided and have been validated in glioblastoma, breast cancer, melanoma and leukemia mouse-models, resulting in therapeutic synergy in 75% of the tested models. This indicates that we can accurately predict effective drug combinations with translational value.

27 April 2017 in Radiation Oncology
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Journal Article
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CLCaspar M. van Leeuwen
Caspar M. van Leeuwen
AOArlene L. Oei
Arlene L. Oei
KCKenneth W. T. K. Chin
Kenneth W. T. K. Chin
Johannes Hans CrezeeJohannes Hans Crezee
Johannes Hans Crezee
ABArjan Bel
Arjan Bel
H.P. KokH.P. Kok
H.P. Kok
Combined radiotherapy and hyperthermia is a well-established alternative to chemoradiotherapy for advanced stage cervical cancer patients with a contraindication for chemotherapy. Pre-clinical evidence suggests that the radiosensitizing effect of hyperthermia decreases substantially for time intervals between radiotherapy and hyperthermia as short as 1–2 h, but clinical evidence is limited. The purpose of this study is to determine the effect of the time interval between external beam radiotherapy (EBRT) and same-day hyperthermia on in-field recurrence rate, overall survival and late toxicity in women with advanced stage cervical cancer. Patients with advanced stage cervical cancer who underwent a full-course of curative daily EBRT and (4–5) weekly hyperthermia sessions between 1999 and 2014 were included for retrospective analysis. The mean time interval between EBRT fractions and same-day hyperthermia was calculated for each patient; the median thereof was used to divide the cohort in a ‘short’ and ‘long’ time-interval group. Kaplan-Meier analysis and stepwise Cox regression were used to compare the in-field recurrence and overall survival. Finally, high-grade (≥3) late toxicity was compared across time-interval groups. DNA repair suppression is an important hyperthermia mechanism, DNA damage repair kinetics were therefore studied in patient biopsies to support clinical findings. Included were 58 patients. The 3-year in field recurrence rate was 18% and 53% in the short (≤79.2 min) and long (>79.2 min) time-interval group, respectively (p = 0.021); the 5-year overall survival was 52% and 17% respectively (p = 0.015). Differences between time-interval groups remained significant for both in-field recurrence (HR = 7.7, p = 0.007) and overall survival (HR = 2.3, p = 0.012) in multivariable Cox regression. No difference in toxicity was observed (p = 1.00), with only 6 and 5 events in the short and long group, respectively. The majority of DNA damage was repaired within 2 h, potentially explaining a reduced effectiveness of hyperthermia for long time intervals. A short time interval between EBRT and hyperthermia is associated with a lower risk of in-field recurrence and a better overall survival. There was no evidence for difference in late toxicity.