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Dive into the research topics where Joost Knegjens is active.

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Featured researches published by Joost Knegjens.


The Lancet | 2015

Use of thoracic radiotherapy for extensive stage small-cell lung cancer: a phase 3 randomised controlled trial

Ben J. Slotman; Harm van Tinteren; J. Praag; Joost Knegjens; Sherif Y. El Sharouni; M.Q. Hatton; Astrid Keijser; Corinne Faivre-Finn; Suresh Senan

BACKGROUND Most patients with extensive stage small-cell lung cancer (ES-SCLC) who undergo chemotherapy, and prophylactic cranial irradiation, have persistent intrathoracic disease. We assessed thoracic radiotherapy for treatment of this patient group. METHODS We did this phase 3 randomised controlled trial at 42 hospitals: 16 in Netherlands, 22 in the UK, three in Norway, and one in Belgium. We enrolled patients with WHO performance score 0-2 and confirmed ES-SCLC who responded to chemotherapy. They were randomly assigned (1:1) to receive either thoracic radiotherapy (30 Gy in ten fractions) or no thoracic radiotherapy. All underwent prophylactic cranial irradiation. The primary endpoint was overall survival at 1 year in the intention-to-treat population. Secondary endpoints included progression-free survival. This study is registered with the Nederlands Trial Register, number NTR1527. FINDINGS We randomly assigned 498 patients between Feb 18, 2009, and Dec 21, 2012. Three withdrew informed consent, leaving 247 patients in the thoracic radiotherapy group and 248 in the control group. Mean interval between diagnosis and randomisation was 17 weeks. Median follow-up was 24 months. Overall survival at 1 year was not significantly different between groups: 33% (95% CI 27-39) for the thoracic radiotherapy group versus 28% (95% CI 22-34) for the control group (hazard ratio [HR] 0.84, 95% CI 0.69-1.01; p=0.066). However, in a secondary analysis, 2-year overall survival was 13% (95% CI 9-19) versus 3% (95% CI 2-8; p=0.004). Progression was less likely in the thoracic radiotherapy group than in the control group (HR 0.73, 95% CI 0.61-0.87; p=0.001). At 6 months, progression-free survival was 24% (95% CI 19-30) versus 7% (95% CI 4-11; p=0.001). We recorded no severe toxic effects. The most common grade 3 or higher toxic effects were fatigue (11 vs 9) and dyspnoea (three vs four). INTERPRETATION Thoracic radiotherapy in addition to prophylactic cranial irradiation should be considered for all patients with ES-SCLC who respond to chemotherapy. FUNDING Dutch Cancer Society (CKTO), Dutch Lung Cancer Research Group, Cancer Research UK, Manchester Academic Health Science Centre Trials Coordination Unit, and the UK National Cancer Research Network.


Radiation Oncology | 2012

Management of radiation oncology patients with a pacemaker or ICD: A new comprehensive practical guideline in The Netherlands

Coen W. Hurkmans; Joost Knegjens; Bing Oei; A. J. T. Maas; G J Uiterwaal; Arnoud J van der Borden; Marleen M. J. Ploegmakers; Lieselot van Erven

Current clinical guidelines for the management of radiotherapy patients having either a pacemaker or implantable cardioverter defibrillator (both CIEDs: Cardiac Implantable Electronic Devices) do not cover modern radiotherapy techniques and do not take the patient’s perspective into account. Available data on the frequency and cause of CIED failure during radiation therapy are limited and do not converge. The Dutch Society of Radiotherapy and Oncology (NVRO) initiated a multidisciplinary task group consisting of clinical physicists, cardiologists, radiation oncologists, pacemaker and ICD technologists to develop evidence based consensus guidelines for the management of CIED patients. CIED patients receiving radiotherapy should be categorised based on the chance of device failure and the clinical consequences in case of failure. Although there is no clear cut-off point nor a clear linear relationship, in general, chances of device failure increase with increasing doses. Clinical consequences of device failures like loss of pacing, carry the most risks in pacing dependent patients. Cumulative dose and pacing dependency have been combined to categorise patients into low, medium and high risk groups. Patients receiving a dose of less than 2 Gy to their CIED are categorised as low risk, unless pacing dependent since then they are medium risk. Between 2 and 10 Gy, all patients are categorised as medium risk, while above 10 Gy every patient is categorised as high risk. Measures to secure patient safety are described for each category. This guideline for the management of CIED patients receiving radiotherapy takes into account modern radiotherapy techniques, CIED technology, the patients’ perspective and the practical aspects necessary for the safe management of these patients. The guideline is implemented in The Netherlands in 2012 and is expected to find clinical acceptance outside The Netherlands as well.


Head and Neck-journal for The Sciences and Specialties of The Head and Neck | 2010

Tumor volume as prognostic factor in chemoradiation for advanced head and neck cancer

Joost Knegjens; Michael Hauptmann; Frank A. Pameijer; Alfons J. M. Balm; F. Hoebers; Josien de Bois; Johannes H.A.M. Kaanders; Carla M.L. van Herpen; Cornelia G. Verhoef; Oda B. Wijers; Ruud Wiggenraad; Jan Buter; Coen R. N. Rasch

Tumor volume is an important predictor of outcome in radiotherapy alone. Its significance in concomitant chemoradiation (CCRT) is much less clear. We analyzed the prognostic value of primary tumor volume for advanced head and neck squamous cell carcinoma (HNSCC) treated with CCRT.


International Journal of Radiation Oncology Biology Physics | 2012

Microscopic disease extension in three dimensions for non-small-cell lung cancer: development of a prediction model using pathology-validated positron emission tomography and computed tomography features.

Judith van Loon; Christian Siedschlag; J. Stroom; Hans Blauwgeers; Robert-Jan van Suylen; Joost Knegjens; M. Rossi; Angela van Baardwijk; Liesbeth Boersma; Houke M. Klomp; Wouter V. Vogel; Sjaak Burgers; K. Gilhuijs

PURPOSE One major uncertainty in radiotherapy planning of non-small-cell lung cancer concerns the definition of the clinical target volume (CTV), meant to cover potential microscopic disease extension (MDE) around the macroscopically visible tumor. The primary aim of this study was to establish pretreatment risk factors for the presence of MDE. The secondary aim was to establish the impact of these factors on the accuracy of positron emission tomography (PET) and computed tomography (CT) to assess the total tumor-bearing region at pathologic examination (CTV(path)). METHODS AND MATERIALS 34 patients with non-small-cell lung cancer who underwent CT and PET before lobectomy were included. Specimens were examined microscopically for MDE. The gross tumor volume (GTV) on CT and PET (GTV(CT) and GTV(PET), respectively) was compared with the GTV and the CTV at pathologic examination, tissue deformations being taken into account. Using multivariate logistic regression, image-based risk factors for the presence of MDE were identified, and a prediction model was developed based on these factors. RESULTS MDE was found in 17 of 34 patients (50%). The MDE did not exceed 26 mm in 90% of patients. In multivariate analysis, two parameters (mean CT tumor density and GTV(CT)) were significantly associated with MDE. The area under the curve of the two-parameter prediction model was 0.86. Thirteen tumors (38%, 95% CI: 24-55%) were identified as low risk for MDE, being potential candidates for reduced-intensity therapy around the GTV. In the low-risk group, the effective diameter of the GTV(CT/PET) accurately represented the CTV(path). In the high-risk group, GTV(CT/PET) underestimated the CTV(path) with, on average, 19.2 and 26.7 mm, respectively. CONCLUSIONS CT features have potential to predict the presence of MDE. Tumors identified as low risk of MDE show lower rates of disease around the GTV than do high-risk tumors. Both CT and PET accurately visualize the CTV(path) in low-risk tumors but underestimate it in high-risk tumors.


International Journal of Radiation Oncology Biology Physics | 2012

Acute esophagus toxicity in lung cancer patients after intensity modulated radiation therapy and concurrent chemotherapy.

Margriet Kwint; Wilma Uyterlinde; Jasper Nijkamp; Chun Chen; Josien de Bois; Jan-Jakob Sonke; Michel M. van den Heuvel; Joost Knegjens; Marcel van Herk; J. Belderbos

PURPOSE The purpose of this study was to investigate the dose-effect relation between acute esophageal toxicity (AET) and the dose-volume parameters of the esophagus after intensity modulated radiation therapy (IMRT) and concurrent chemotherapy for patients with non-small cell lung cancer (NSCLC). PATIENTS AND METHODS One hundred thirty-nine patients with inoperable NSCLC treated with IMRT and concurrent chemotherapy were prospectively analyzed. The fractionation scheme was 66 Gy in 24 fractions. All patients received concurrently a daily dose of cisplatin (6 mg/m(2)). Maximum AET was scored according to Common Toxicity Criteria 3.0. Dose-volume parameters V5 to V70, D(mean) and D(max) of the esophagus were calculated. A logistic regression analysis was performed to analyze the dose-effect relation between these parameters and grade ≥ 2 and grade ≥ 3 AET. The outcome was compared with the clinically used esophagus V35 prediction model for grade ≥ 2 after radical 3-dimensional conformal radiation therapy (3DCRT) treatment. RESULTS In our patient group, 9% did not experience AET, and 31% experienced grade 1 AET, 38% grade 2 AET, and 22% grade 3 AET. The incidence of grade 2 and grade 3 AET was not different from that in patients treated with CCRT using 3DCRT. The V50 turned out to be the most significant dosimetric predictor for grade ≥ 3 AET (P=.012). The derived V50 model was shown to predict grade ≥ 2 AET significantly better than the clinical V35 model (P<.001). CONCLUSIONS For NSCLC patients treated with IMRT and concurrent chemotherapy, the V50 was identified as most accurate predictor of grade ≥ 3 AET. There was no difference in the incidence of grade ≥ 2 AET between 3DCRT and IMRT in patients treated with concurrent chemoradiation therapy.


Radiotherapy and Oncology | 2010

HPV and high-risk gene expression profiles predict response to chemoradiotherapy in head and neck cancer, independent of clinical factors

Monique C. de Jong; Jimmy Pramana; Joost Knegjens; Alfons J. M. Balm; Michiel W. M. van den Brekel; Michael Hauptmann; Adrian C. Begg; Coen R. N. Rasch

PURPOSE The purpose of this study was to combine gene expression profiles and clinical factors to provide a better prediction model of local control after chemoradiotherapy for advanced head and neck cancer. MATERIAL AND METHODS Gene expression data were available for a series of 92 advanced stage head and neck cancer patients treated with primary chemoradiotherapy. The effect of the Chung high-risk and Slebos HPV expression profiles on local control was analyzed in a model with age at diagnosis, gender, tumor site, tumor volume, T-stage and N-stage and HPV profile status. RESULTS Among 75 patients included in the study, the only factors significantly predicting local control were tumor site (oral cavity vs. Pharynx, hazard ratio 4.2 [95% CI 1.4-12.5]), Chung gene expression status (high vs. Low risk profile, hazard ratio 4.4 [95% CI 1.5-13.3]) and HPV profile (negative vs. Positive profile, hazard ratio 6.2 [95% CI 1.7-22.5]). CONCLUSIONS Chung high-risk expression profile and a negative HPV expression profile were significantly associated with increased risk of local recurrence after chemoradiotherapy in advanced pharynx and oral cavity tumors, independent of clinical factors.


Radiotherapy and Oncology | 2014

Additional weekly Cetuximab to concurrent chemoradiotherapy in locally advanced non-small cell lung carcinoma: efficacy and safety outcomes of a randomized, multi-center phase II study investigating.

Michel M. van den Heuvel; Wilma Uyterlinde; Andrew Vincent; Jeroen de Jong; Joachim Aerts; Frederike Koppe; Joost Knegjens; Henk Codrington; Peter W.E. Kunst; Edith Dieleman; Marcel Verheij; J. Belderbos

BACKGROUND Modest benefits from concurrent chemoradiotherapy in patients with locally advanced NSCLC warrant further clinical investigations to identify more effective treatment regimens. Cetuximab, a monoclonal antibody against the epidermal growth factor receptor has shown activity in NSCLC. We report on the safety and efficacy of the combination of daily dose Cisplatin and concurrent radiotherapy with or without weekly Cetuximab. PATIENTS AND METHODS Patients received high dose accelerated radiotherapy (66 Gy in 24 fractions) and concurrent daily Cisplatin (6 mg/m(2)) without (Arm A) or with (Arm B) weekly Cetuximab (400 mg/m(2) loading dose one week prior to radiotherapy followed by weekly 250 mg/m(2)). The primary endpoint of the trial was objective local control rate (OLCR) determined at 6-8 weeks after treatment. Toxicity was reported as well. RESULTS Between February 2009 and May 2011, 102 patients were randomized. Median follow up was 29 months. The OLCR was 84% in Arm A and 92% in Arm B (p=0.36). The one-year local progression free interval (LPFI) and overall survival (OS) were 69% and 82% for Arm A and 73% and 71% for Arm B, respectively (LPFI p=0.39; OS p=0.99). Toxicity compared equally between both groups. CONCLUSION The addition of Cetuximab to radiotherapy and concurrent Cisplatin did not improve disease control in patients with locally advanced NSCLC but increased treatment related toxicity.


Clinical Lung Cancer | 2013

Prediction of Acute Toxicity Grade ≥ 3 in Patients With Locally Advanced Non–Small-Cell Lung Cancer Receiving Intensity Modulated Radiotherapy and Concurrent Low-Dose Cisplatin

Wilma Uyterlinde; J. Belderbos; Claudia Baas; Erik van Werkhoven; Joost Knegjens; Paul Baas; Arthur Smit; Chris Rikers; Michel M. van den Heuvel

BACKGROUND Intensity modulated radiotherapy (IMRT) is increasingly used with concurrent chemotherapy but toxicity data are not well investigated. We correlated clinical and dosimetric parameters with acute toxicity grade ≥ 3 in patients with locally advanced NSCLC treated with IMRT and concurrent low-dose cisplatin. PATIENTS AND METHODS We analyzed age, PS, comorbidities, gross tumor volume, and the volume of the esophagus irradiated with 50 Gy (V50oes) in relation with acute toxicity. The mean lung dose (MLD) and pulmonary toxicity was described. Treatment consisted of 24 × 2, 75 Gy, and daily cisplatin 6 mg/m². Patients with an MLD ≥ 20 Gy or a PS > 2 were excluded from CCRT. Toxicity was prospectively scored using the Common Toxicity Criteria for adverse events version 3.0. The Charlson Comorbidity Index (CCI) was applied for scoring comorbidities. Multivariable logistic regressions for toxicity and survival estimates (Kaplan-Meier) were used for evaluation. RESULTS From 2008 to 2011, 188 patients received standard CCRT. In 35% of the patients, acute toxicity grade ≥ 3 was reported. Grade 5 toxicity was scored in 1% of the patients. V50oes (odds ratio [OR], 1.33 per 10% increase; P = .01) and PS ≥ 2 (OR, 3.45; P = .07) were significantly correlated with acute toxicity ≥ grade 3. No differences in toxicity were observed between age groups (< 70 and ≥ 70; P = .26), and those with a CCI score < 5 and ≥ 5, and acute severe toxicity (P = .36). Grade ≥ 3 pulmonary toxicity was seen in 7%. The 1- and 2-year overall survival in stage III disease were 78% and 52%, respectively. Patients with a poor PS or a high CCI score had similar survival outcomes. CONCLUSION Concurrent low-dose cisplatin using IMRT is effective in a large cohort of consecutive patients with NSCLC and life threatening toxicity is rare (1%). PS ≥ 2 and V50oes are correlated with acute toxicity grade ≥ 3.


Lung Cancer | 2017

Which patients with ES-SCLC are most likely to benefit from more aggressive radiotherapy: A secondary analysis of the Phase III CREST trial

Ben J. Slotman; Corinne Faivre-Finn; Harm van Tinteren; Astrid Keijser; J. Praag; Joost Knegjens; M.Q. Hatton; Iris van Dam; Annija van der Leest; Bart Reymen; Jos A. Stigt; Kate Haslett; Devashish Tripathi; Egbert F. Smit; Suresh Senan

INTRODUCTION In ES-SCLC patients with residual intrathoracic disease after first-line chemotherapy, the addition of thoracic radiotherapy reduces the risk of intrathoracic recurrence, and improves 2-year survival. To identify patient subgroups for future trials investigating higher dose (extra)thoracic radiotherapy, we investigated the prognostic importance of number and sites of metastases in patients included in the CREST trial. MATERIALS/ METHODS Additional data on sites and numbers of metastases were collected from individual records of 260 patients from the top 9 recruiting centers in the randomized CREST trial (53% of 495 study patients), which compared thoracic radiotherapy (TRT) to no TRT in ES-SCLC patients after any response to chemotherapy. All patients received prophylactic cranial irradiation. RESULTS The clinical characteristics and outcomes of the 260 patients analyzed here did not differ significantly from that of the other 235 patients included in the CREST trial, except that fewer patients had a WHO=0 performance status (24% vs 45%), and a higher proportion had WHO=2 (15% vs 5%; p<0.0001). No distant metastases were recorded in 5%, 39% had metastases confined to one organ, 34% to two, and 22% to three or more organ sites. Metastases were present in the liver (47%), bone (40%), lung (28%), extrathoracic (non-supraclavicular) lymph nodes (19%), supraclavicular nodes (18%), adrenals (17%) and other sites (12%). The OS (p=0.02) and PFS (p=0.04) were significantly better in patients with 2 or fewer metastases, with OS significantly worse if liver (p=0.03) and/or bone metastases (p=0.04) were present. DISCUSSION This analysis of patients recruited from the top 9 accruing centers in the CREST trial suggests that future studies evaluating more intensive thoracic and extra-thoracic radiotherapy in ES-SCLC should focus on patients with fewer than 3 distant metastases.


Lung Cancer | 2017

Outcome of radical local treatment of non-small cell lung cancer patients with synchronous oligometastases

Margriet Kwint; Iris Walraven; Sjaak Burgers; Koen J. Hartemink; Houke M. Klomp; Joost Knegjens; Marcel Verheij; J. Belderbos

OBJECTIVES Patients with stage IV non-small cell lung cancer (NSCLC) are considered incurable and are mainly treated with palliative intent. This patient group has a poor overall survival (OS) and progression free survival (PFS). The purpose of this study was to investigate PFS and OS of NSCLC patients diagnosed with synchronous oligometastatic disease who underwent radical treatment of both intrathoracic disease and metastases. MATERIALS AND METHODS Patients with NSCLC and oligometastatic disease at diagnosis, who were treated with radical intent between 2008 and 2016, were included in this observational study. Treatment consisted of systemic treatment and radical radiotherapy or resection of the intrathoracic disease. Treatment of the metastases consisted of radical or stereotactic radiotherapy, surgical resection or radiofrequency ablation. RESULTS AND CONCLUSIONS Ninety-one patients (52% men, mean age 60 years) in good performance status were included. Thirty-eight patients (42%) died during follow-up (median follow-up 35 months). The cause of dead was lung cancer in all patients, except one. Sixty-three (69%) patients developed recurrent disease. Eleven recurrences (17%) occurred within the irradiated area. For the whole group, the median PFS was 14 months (range 2-89, 95%CI 12-16) and the median OS was 32 months (range 3-89, 95%CI 25-39). The 1- and 2-year OS rates were 85% and 58% and the 1- and 2-year PFS rates were 55% and 27%, respectively. Radical local treatment of a selected group of NSCLC patients with good performance status presenting with synchronous oligometastatic disease resulted in favorable long-term PFS and OS.

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J. Belderbos

Netherlands Cancer Institute

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J.J. Sonke

Netherlands Cancer Institute

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J. Praag

Erasmus University Rotterdam

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Margriet Kwint

Netherlands Cancer Institute

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Suresh Senan

VU University Medical Center

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Wilma Uyterlinde

Netherlands Cancer Institute

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Wouter V. Vogel

Netherlands Cancer Institute

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M. Rossi

Netherlands Cancer Institute

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