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Dive into the research topics where Ben J. Slotman is active.

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Featured researches published by Ben J. Slotman.


Lancet Oncology | 2015

Stereotactic ablative radiotherapy versus lobectomy for operable stage I non-small-cell lung cancer: a pooled analysis of two randomised trials

Joe Y. Chang; Suresh Senan; Marinus A. Paul; Reza J. Mehran; Alexander V. Louie; P Balter; Harry J.M. Groen; Stephen E. McRae; Joachim Widder; Lei Feng; Ben E.E.M. van den Borne; Mark F. Munsell; Coen W. Hurkmans; Donald A. Berry; Erik van Werkhoven; John J. Kresl; Anne-Marie C. Dingemans; Omar Dawood; Cornelis J.A. Haasbeek; Larry S. Carpenter; Katrien De Jaeger; Ritsuko Komaki; Ben J. Slotman; Egbert F. Smit; Jack A. Roth

BACKGROUND The standard of care for operable, stage I, non-small-cell lung cancer (NSCLC) is lobectomy with mediastinal lymph node dissection or sampling. Stereotactic ablative radiotherapy (SABR) for inoperable stage I NSCLC has shown promising results, but two independent, randomised, phase 3 trials of SABR in patients with operable stage I NSCLC (STARS and ROSEL) closed early due to slow accrual. We aimed to assess overall survival for SABR versus surgery by pooling data from these trials. METHODS Eligible patients in the STARS and ROSEL studies were those with clinical T1-2a (<4 cm), N0M0, operable NSCLC. Patients were randomly assigned in a 1:1 ratio to SABR or lobectomy with mediastinal lymph node dissection or sampling. We did a pooled analysis in the intention-to-treat population using overall survival as the primary endpoint. Both trials are registered with ClinicalTrials.gov (STARS: NCT00840749; ROSEL: NCT00687986). FINDINGS 58 patients were enrolled and randomly assigned (31 to SABR and 27 to surgery). Median follow-up was 40·2 months (IQR 23·0-47·3) for the SABR group and 35·4 months (18·9-40·7) for the surgery group. Six patients in the surgery group died compared with one patient in the SABR group. Estimated overall survival at 3 years was 95% (95% CI 85-100) in the SABR group compared with 79% (64-97) in the surgery group (hazard ratio [HR] 0·14 [95% CI 0·017-1·190], log-rank p=0·037). Recurrence-free survival at 3 years was 86% (95% CI 74-100) in the SABR group and 80% (65-97) in the surgery group (HR 0·69 [95% CI 0·21-2·29], log-rank p=0·54). In the surgery group, one patient had regional nodal recurrence and two had distant metastases; in the SABR group, one patient had local recurrence, four had regional nodal recurrence, and one had distant metastases. Three (10%) patients in the SABR group had grade 3 treatment-related adverse events (three [10%] chest wall pain, two [6%] dyspnoea or cough, and one [3%] fatigue and rib fracture). No patients given SABR had grade 4 events or treatment-related death. In the surgery group, one (4%) patient died of surgical complications and 12 (44%) patients had grade 3-4 treatment-related adverse events. Grade 3 events occurring in more than one patient in the surgery group were dyspnoea (four [15%] patients), chest pain (four [15%] patients), and lung infections (two [7%]). INTERPRETATION SABR could be an option for treating operable stage I NSCLC. Because of the small patient sample size and short follow-up, additional randomised studies comparing SABR with surgery in operable patients are warranted. FUNDING Accuray Inc, Netherlands Organisation for Health Research and Development, NCI Cancer Center Support, NCI Clinical and Translational Science Award.


The Lancet | 2002

Effect of radiotherapy and other treatment-related factors on mid-term to long-term cognitive sequelae in low-grade gliomas : a comparative study

Martin Klein; Jan J. Heimans; Neil K. Aaronson; H.M. van der Ploeg; J Grit; Marco Müller; T.J. Postma; Jacob J Mooij; Rudolf H. Boerman; Guus Beute; Gj Ossenkoppele; van Gustaaf Imhoff; Aw Dekker; J. Jolles; Ben J. Slotman; H Struikmans; Mjb Taphoorn

BACKGROUND Because survival benefits of treatment with radiotherapy are questionable and such treatment can cause substantial damage to the brain over time, the optimum management strategy for low-grade gliomas remains controversial. We aimed to identify the specific effects of radiotherapy on objective and self-reported cognitive function, and on cognitive deterioration over time, in patients with low-grade gliomas treated with early radiotherapy. METHODS 195 patients with low-grade glioma (of whom 104 had received radiotherapy 1-22 years previously) were compared with 100 low-grade haematological patients and 195 healthy controls. Our analyses aimed to differentiate between the effects of the tumour (eg, disease duration, lateralisation) and treatment effects (neurosurgery, radiotherapy, antiepileptic drugs) on cognitive function and on relative risk of cognitive disability. FINDINGS Low-grade glioma patients had lower ability in all cognitive domains than did low-grade haematological patients, and did even less well by comparison with healthy controls. Use of radiotherapy was associated with poorer cognitive function; however, cognitive disability in the memory domain was found only in radiotherapy patients who received fraction doses exceeding 2 Gy. Antiepileptic drug use was strongly associated with disability in attentional and executive function. INTERPRETATION Our findings suggest that the tumour itself has the most deleterious effect on cognitive function and that radiotherapy mainly results in additional long-term cognitive disability when high fraction doses are used. Additionally, the effects of other medical factors, especially antiepileptic drug use, on cognitive function in glioma patients deserve attention.


Lancet Neurology | 2009

Cognitive and radiological effects of radiotherapy in patients with low-grade glioma : long-term follow-up

Linda Douw; Martin Klein; Selene Saa Fagel; Josje van den Heuvel; Martin J. B. Taphoorn; Neil K. Aaronson; Tjeerd J. Postma; W. Peter Vandertop; Jacob J Mooij; Rudolf H. Boerman; G.N. Beute; J.D. Sluimer; Ben J. Slotman; Jaap C. Reijneveld; Jan J. Heimans

BACKGROUND Our previous study on cognitive functioning among 195 patients with low-grade glioma (LGG) a mean of 6 years after diagnosis suggested that the tumour itself, rather than the radiotherapy used to treat it, has the most deleterious effect on cognitive functioning; only high fraction dose radiotherapy (>2 Gy) resulted in significant added cognitive deterioration. The present study assesses the radiological and cognitive abnormalities in survivors of LGG at a mean of 12 years after first diagnosis. METHODS Patients who have had stable disease since the first assessment were invited for follow-up cognitive assessment (letter-digit substitution test, concept shifting test, Stroop colour-word test, visual verbal learning test, memory comparison test, and categoric word fluency). Compound scores in six cognitive domains (attention, executive functioning, verbal memory, working memory, psychomotor functioning, and information processing speed) were calculated to detect differences between patients who had radiotherapy and patients who did not have radiotherapy. White-matter hyperintensities and global cortical atrophy were rated on MRI scans. FINDINGS 65 patients completed neuropsychological follow-up at a mean of 12 years (range 6-28 years). 32 (49%) patients had received radiotherapy (three had fraction doses >2 Gy). The patients who had radiotherapy had more deficits that affected attentional functioning at the second follow-up, regardless of fraction dose, than those who did not have radiotherapy (-1.6 [SD 2.4] vs -0.1 [1.3], p=0.003; mean difference 1.4, 95% CI 0.5-2.4). The patients who had radiotherapy also did worse in measures of executive functioning (-2.0 [3.7] vs -0.5 [1.2], p=0.03; mean difference 1.5, 0.2-2.9) and information processing speed (-2.0 [3.7] vs -0.6 [1.5], p=0.05; mean difference 0.8, 0.009-1.6]) between the two assessments. Furthermore, attentional functioning deteriorated significantly between the first and second assessments in patients who had radiotherapy (p=0.25). In total, 17 (53%) patients who had radiotherapy developed cognitive disabilities deficits in at least five of 18 neuropsychological test parameters compared with four (27%) patients who were radiotherapy naive. White-matter hyperintensities and global cortical atrophy were associated with worse cognitive functioning in several domains. INTERPRETATION Long-term survivors of LGG who did not have radiotherapy had stable radiological and cognitive status. By contrast, patients with low-grade glioma who received radiotherapy showed a progressive decline in attentional functioning, even those who received fraction doses that are regarded as safe (</=2 Gy). These cognitive deficits are associated with radiological abnormalities. Our results suggest that the risk of long-term cognitive and radiological compromise that is associated with radiotherapy should be considered when treatment is planned. FUNDING Kaptein Fonds; Schering Plough.


Journal of Clinical Oncology | 2008

Impact of Late Treatment-Related Toxicity on Quality of Life Among Patients With Head and Neck Cancer Treated With Radiotherapy

Johannes A. Langendijk; P. Doornaert; Irma M. Verdonck-de Leeuw; Charles R. Leemans; Neil K. Aaronson; Ben J. Slotman

PURPOSE To investigate the impact of treatment-related toxicity on health-related quality of life (HRQoL) among patients with head and neck squamous cell carcinoma treated with radiotherapy either alone or in combination with chemotherapy or surgery. PATIENTS AND METHODS The study sample was composed of 425 disease-free patients. Toxicity was scored according to the European Organisation for Research and Treatment of Cancer (EORTC)/Radiation Therapy Oncology Group (RTOG) late radiation-induced morbidity scoring system. HRQoL was assessed using the EORTC Quality of Life Questionnaire C30. These assessments took place at 6, 12, 18, and 24 months after completion of radiotherapy. The analysis was performed using a multivariate analysis of variance. RESULTS Of the six RTOG scales investigated, two significantly affected self-reported HRQoL, salivary gland (RTOG(xerostomia)) and esophagus/pharynx (RTOG(swallowing)). Although RTOG(xerostomia) was reported most frequently, HRQoL was most affected by RTOG(swallowing), particularly in the first 18 months after completion of radiotherapy. CONCLUSION Late radiation-induced toxicity, particularly RTOG(swallowing) and RTOG(xerostomia), has a significant impact on the more general dimensions of HRQoL. These findings suggest that the development of new radiation-induced delivery techniques should not only focus on reduction of the dose to the salivary glands, but also on anatomic structures that are involved in swallowing.


International Journal of Radiation Oncology Biology Physics | 2009

Volumetric Intensity-Modulated Arc Therapy Vs. Conventional IMRT in Head-and-Neck Cancer: A Comparative Planning and Dosimetric Study

Wilko F.A.R. Verbakel; Johan P. Cuijpers; Daan Hoffmans; Michael Bieker; Ben J. Slotman; Suresh Senan

PURPOSE Volumetric intensity-modulated arc therapy (RA) allows for rapid delivery of highly conformal dose distributions. In this study, planning and dosimetry of RA were compared with conventional intensity-modulated radiation therapy (IMRT) plans of head-and-neck cancer patients. MATERIALS AND METHODS Computed tomography scans of 12 patients who had completed IMRT for advanced tumors of the naso-, oro- and hypopharynx were replanned using RA using either one or two arcs. Calculated doses to planning target volume (PTV) and organs at risk (OAR) were compared between IMRT and RA plans. Dose distributions for single arc (n = 8) and double arc (n = 4) plans were verified using film dosimetry in three to five coronal planes using a quality assurance phantom. RESULTS RA plans allowed for a mean reduction in number of monitor units (MU) by nearly 60%, relative to seven field sliding window IMRT plans. RA plans achieved similar sparing of all OAR as IMRT. Double arc RA provided the best dose homogeneity to PTV with a lower standard deviation of PTV dose (1.4 Gy), vs. single arc plans (2.0 Gy) and IMRT (1.7 Gy). Film measurements showed good correspondence with calculated doses; the mean gamma value was 0.30 (double arc) and area of the film with a gamma exceeding 1 was 0.82%. CONCLUSIONS RA is a fast, safe, and accurate technique that uses lower MUs than conventional IMRT. Double arc plans provided at least similar sparing of OAR and better PTV dose homogeneity than single arc or IMRT.


Journal of Clinical Oncology | 2010

Impact of Introducing Stereotactic Lung Radiotherapy for Elderly Patients With Stage I Non–Small-Cell Lung Cancer: A Population-Based Time-Trend Analysis

David A. Palma; Otto Visser; Frank J. Lagerwaard; J. Belderbos; Ben J. Slotman; Suresh Senan

PURPOSE Stereotactic body radiotherapy (SBRT) for stage I non-small-cell lung cancer (NSCLC) is associated with high local control rates. The impact of introducing SBRT in patients 75 years of age or older was studied using a population-based cancer registry. METHODS The Amsterdam Cancer Registry was assessed in three eras: 1999 to 2001 (period A, pre-SBRT); 2002 to 2004 (period B, some availability of SBRT), and 2005 to 2007 (period C, full access to SBRT). χ(2), Kaplan-Meier, and Cox regression were used to compare treatment patterns and overall survival (OS) in three treatment groups: surgery, radiotherapy (RT), or neither. RESULTS A total of 875 elderly patients were diagnosed with stage I NSCLC in the study period. Median follow-up was 54 months. Primary treatment was surgery in 299 patients (34%), RT in 299 patients (34%), and neither in 277 patients (32%). RT use increased between periods A and C (26% v 42%, P < .01), corresponding to a decrease in untreated patients. The percentage of RT patients undergoing SBRT in periods B and C was 23% and 55%, respectively. Median survival for all patients increased from 16 months in period A to 21 months in period C (log-rank P < .01; hazard ratio [HR] = 0.65; 95% CI, 0.54 to 0.80). The improvement in OS was confined to RT patients (HR = 0.70; 95% CI, 0.49 to 0.99), whereas no significant survival improvements were seen in the other groups. CONCLUSION SBRT introduction was associated with a 16% absolute increase in RT use, a decline in the proportion of untreated elderly patients, and an improvement in OS.


Lancet Oncology | 2012

Patterns of disease recurrence after stereotactic ablative radiotherapy for early stage non-small-cell lung cancer: a retrospective analysis.

Sashendra Senthi; Frank J. Lagerwaard; Cornelis J.A. Haasbeek; Ben J. Slotman; Suresh Senan

BACKGROUND Stereotactic ablative radiotherapy (SABR) is increasingly used in the treatment of medically inoperable early stage non-small-cell lung cancer (NSCLC). Because patterns of late disease recurrence after SABR are not well characterised, we aimed to assess these outcomes in a cohort of patients with NSCLC. METHODS Patients with (18)F-fluorodeoxyglucose ((18)F-FDG)-PET confirmed stage 1-2 NSCLC who were treated with SABR at the VU University Medical Center (Amsterdam, Netherlands) were identified from an institutional database. SABR doses were 54-60 Gy, delivered in three to eight once-daily fractions, depending on tumour size and location. Clinical follow-up and CT scans were done at 3, 6, and 12 months, then yearly thereafter. (18)F-FDG-PET restaging was only done when clinically indicated. Initial sites of recurrence were classified as local, regional, and distant, and were differentiated from second primary tumours in the lung at multidisciplinary tumour board review. FINDINGS Between April 4, 2003, and Dec 5, 2011, 676 patients were treated with SABR and were eligible for assessment of recurrence. The median follow-up was 32·9 months (IQR 14·9-50·9 months). 124 (18%) of 676 patients had disease recurrence. Actuarial 2-year rates of local, regional, and distant recurrence were 4·9% (95% CI 2·7-7·1), 7·8% (5·3-10·3), and 14·7% (11·4-18·0), respectively. Corresponding 5-year rates were 10·5% (95% CI 6·4-14·6), 12·7% (8·4-17·0), and 19·9% (14·9-24·6), respectively. Of the 124 recurrences, 82 (66%) were distant recurrences and 57 (46%) were isolated distant recurrences. Isolated locoregional recurrences occurred in the remaining 42 patients with disease recurrence (34%), 35 (83%) of whom did not develop subsequent distant recurrence. The median times to local, regional, and distant recurrence were 14·9 months (95% CI 11·4-18·4), 13·1 months (7·9-18·3), and 9·6 months (6·8-12·4), respectively. New pulmonary lesions characterised as second primary tumours in the lung developed in 42 (6%) of 676 patients at a median of 18·0 months (95% CI 12·5-23·5) after SABR. INTERPRETATION Late recurrences after SABR are infrequent and two distinct patterns account for most cases. The predominant pattern is out-of-field, isolated distant recurrence presenting early, despite initial PET staging. A third of patients develop isolated locoregional recurrence; for these patients standardised follow-up is important to ensure that appropriate salvage treatments are considered. FUNDING None.


International Journal of Radiation Oncology Biology Physics | 2009

Intensity-Modulated Radiotherapy Reduces Radiation-Induced Morbidity and Improves Health-Related Quality of Life: Results of A Nonrandomized Prospective Study Using A Standardized Follow-Up Program

Marije R. Vergeer; P. Doornaert; D. Rietveld; C. René Leemans; Ben J. Slotman; Johannes A. Langendijk

PURPOSE The purpose of this study was to compare intensity-modulated radiation therapy (IMRT) and three-dimensional conventional radiotherapy (3D-CRT) with regard to patient-rated xerostomia, Radiation Therapy Oncology Group (RTOG) acute and late xerostomia and health-related quality of life (HRQoL) among patients with head and neck squamous cell carcinoma (HNSCC). METHODS AND MATERIALS Included were 241 patients with HNSCC treated with bilateral irradiation +/- chemotherapy. Since 2000, all patients treated with HNSCC were included in a program, which prospectively assessed acute and late morbidity according to the RTOG and HRQoL on a routine basis at regular intervals. Before October 2004, all patients were treated with 3D-CRT (N = 150). After clinical implementation in October 2004, 91 patients received IMRT. In this study, the differences regarding RTOG toxicity, xerostomia, and other items of HRQoL were analyzed. RESULTS The use of IMRT resulted in a significant reduction of the mean dose of the parotid glands (27 Gy vs. 43 Gy (p < 0.001). During radiation, Grade 2 RTOG xerostomia was significantly less with IMRT than with 3D-CRT. At 6 months, the prevalence of patient-rated moderate to severe xerostomia and Grade 2 or higher RTOG xerostomia was significantly lower after IMRT versus 3D-CRT. Treatment with IMRT also had a positive effect on several general and head and neck cancer-specific HRQoL dimensions. CONCLUSIONS IMRT results in a significant reduction of patient- and observer-rated xerostomia, as well as other head and neck symptoms, compared with standard 3D-CRT. These differences translate into a significant improvement of the more general dimensions of HRQoL.


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.


Radiotherapy and Oncology | 2009

Rapid delivery of stereotactic radiotherapy for peripheral lung tumors using volumetric intensity-modulated arcs

Wilko F.A.R. Verbakel; Suresh Senan; Johan P. Cuijpers; Ben J. Slotman; Frank J. Lagerwaard

The delivery of high dose conventional stereotactic body radiotherapy (SBRT) for patients with stage I lung tumors generally takes 30-45min per fraction. The novel volumetric intensity-modulated arc therapy (RA) for planning and delivery enabled much faster treatment for three patients with different fractionation schemes. This reduces the risk of intrafraction motion and is more patient friendly. In addition, in comparison to the conventional plans using 10 static non-coplanar fields, RA plans achieved superior dose conformity around the PTV and reduced chest wall doses.

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Suresh Senan

VU University Amsterdam

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Max Dahele

VU University Medical Center

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Frank J. Lagerwaard

VU University Medical Center

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Johan P. Cuijpers

VU University Medical Center

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P. Doornaert

VU University Medical Center

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C. René Leemans

VU University Medical Center

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