[Show abstract][Hide abstract] ABSTRACT: Purpose:
To compare set-up and 2-dimensional (2D) electronic portal imaging device (EPID) dosimetry data of breast cancer patients treated during voluntary moderately deep inspiration breath hold (vmDIBH) and free breathing (FB).
Methods and materials:
Set-up data were analyzed for 29 and 51 consecutively treated patients, irradiated during FB and vmDIBH, respectively. Of the 51 vmDIBH patients, the first 25 had undergone an extra trained computed tomography (CT) scan and used an additional "breathing stick" (vmDIBH_trained). The last 26 patients did not use the breathing stick and did not undergo a trained CT (vmDIBH_untrained). The delivered 2D transit dose was measured with EPID in 15 FB and 28 vmDIBH patients and compared with a 2D predicted dose by calculating global gamma values γ using 5% and 5 mm as dose difference and distance-to-agreement criteria, respectively. Measurements with a percentage of pixels with an absolute gamma value > 1 (|γ| > 1) greater than 10% were classified as deviating.
Only small, sub-millimeter differences were seen in the set-up data between the different patient groups. The mean of means, systematic error, and random error ranged from - 0.6 mm to 3.3 mm. The percentage of pixels with |γ| > 1 for all patients was 9.8% (2-25.8). No statistically significant differences were observed between the patient groups. In total, 38% of the gamma images were classified as deviating: 43.6% in vmDIBH_untrained patients compared with 38.0% in vmDIBH_trained patients and 33.3% in FB patients (P > .05).
Both set-up and 2D EPID dosimetry data indicate that reproducibility of radiation therapy for patients treated during FB and vmDIBH is similar. Small but not significant differences in 2D EPID dosimetry were observed. Further investigation with 3-dimensional EPID dosimetry is recommended to investigate the clinical relevance of deviant gamma images.
[Show abstract][Hide abstract] ABSTRACT: Objective:
The aim of this review is to investigate the effect of timing of the reconstruction and radiotherapy, with respect to complication rate and cosmetic outcome, with a special focus on the timing of the placement of the definite implant.
PubMed was searched for publications between January 2000 and December 2012. Of 37 eligible studies, timing of reconstruction, type, and incidence of complications were recorded. First, we calculated the weighted mean including confidence intervals for complications and cosmetic outcome overall, and for the following subgroups: (1) Autologous reconstruction after radiotherapy; (2) Definite implant reconstruction after radiotherapy; (3) Autologous reconstruction before radiotherapy; (4) Definite implant reconstruction before radiotherapy. A second analysis was performed using only studies that directly compared group 1 versus 3 and 2 versus 4.
A large variation in complication rates (8.7-70.0%) and in acceptable cosmetic outcome (41.4-93.3%) was reported. The first analysis showed more complications and a higher revision rate if an implant reconstruction was performed after radiotherapy; for autologous reconstruction fibrosis occurred more often if reconstruction was applied first. The second analysis showed no significant differences in total complication rate. Only implant failure occurred more often if applied after radiotherapy (odds ratio (OR) 3.03 [1.59-5.77]). No differences were found in both patient and physician satisfaction.
A definite implant reconstruction placed before radiotherapy limits the rate of complications. For autologous reconstruction, less fibrosis is seen if reconstruction is performed after radiotherapy, but timing had no significant impact on total complication rate.
European journal of cancer (Oxford, England: 1990) 08/2014; 50(16). DOI:10.1016/j.ejca.2014.07.023 · 5.42 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Decision Support Systems, based on statistical prediction models, have the potential to change the way medicine is being practiced, but their application is currently hampered by the astonishing lack of impact studies. Showing the theoretical benefit of using these models could stimulate conductance of such studies. In addition, it would pave the way for developing more advanced models, based on genomics, proteomics and imaging information, to further improve the performance of the models.
Radiotherapy and Oncology 05/2014; 112(1). DOI:10.1016/j.radonc.2014.04.012 · 4.36 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In this open-label phase I study, the maximum-tolerated dose of cetuximab with concurrent chemoradiotherapy (C-CRT) in stage III non-small-cell lung cancer together with individualized, isotoxic accelerated radiotherapy (RT) was investigated.
Patients with stage III non-small-cell lung cancer, World Health Organization performance status 0-1, forced expiratory volume in 1 second more than 50%, carbon monoxide diffusing capacity more than 50%, weight loss less than 10%, and no severe comorbidity were enrolled. Patients without progression after one to two cycles of gemcitabine-carboplatin were included and treated with cetuximab 400 mg/kg d7 and 250 mg/kg weekly together with RT and cisplatin (50 mg/m d1, 8; 40 mg/m d22)-vinorelbine for 5 weeks. Vinorelbine was escalated in three steps; (1) 10 mg/m d1, 8 and 8 mg/m d22, 29; (2) 20 mg/m d1, 8 and 8 mg/m d22, 29; (3) 20 mg/m d1, 8; 15 mg/m d22, 29. An individualized prescribed RT dose based on normal tissue dose constraints was applied (e.g., mean lung dose 19 Gy). The primary endpoint was the maximum-tolerated dose 3 months after the end of C-CRT; secondary endpoints were toxicity and metabolic response as assessed by positron emission tomography.
Between September 2007 and October 2010, 25 patients (12 men, 13 women, mean age 59 years) were included. The mean RT dose was 62 ± 6.6 Gy. The vinorelbine dose could be escalated to dose level 3. Twelve of 25 patients experienced greater than or equal to grade 3 toxicity (esophagitis 3, rash 1, diarrhea 1, cough 1, dyspnea 1, vomiting 1, and pulmonary embolism 1). No dose-limiting toxicities were observed. One patient with a complete pathological response in dose level 3 developed a fatal hemoptysis 4 months after RT. Metabolic remissions were observed in 19 of 22 patients.
C-CRT with cetuximab and cisplatin-vinorelbine is safe to deliver at full dose. The recommended phase II dose is therefore cetuximab 400 mg/m d7 and 250 mg/m weekly, cisplatin 50 mg/m d1, 8; 40 mg/m d22 and vinorelbine 20 mg/m d1, 8; 15 mg/m d22, 29 for 5 weeks together with RT.
Journal of thoracic oncology: official publication of the International Association for the Study of Lung Cancer 05/2014; 9(5):710-6. DOI:10.1097/JTO.0000000000000151 · 5.28 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Non-small cell lung cancer (NSCLC) stage T4N0-1 or single nodal station IIIA-N2 are two stage III sub-groups for which the outcome of non-surgical therapy is not well known. We investigated the results of individualised isotoxic accelerated radiotherapy (INDAR) and chemotherapy in this setting.
Analysis of NSCLC patients included in 2 prospective trials (NCT00573040 and NCT00572325) stage T4N0-1 or IIIA-N2 with 1 pathologic nodal station, treated with chemo-radiotherapy (CRT) using INDAR with concurrent or sequential platinum-based chemotherapy. Overall survival (OS) was updated and calculated from date of diagnosis (Kaplan-Meier). Toxicity was scored following CTCAEv3.0. To allow comparison with other articles the subgroups were also analysed separately for toxicity, progression free and overall survival.
83 patients (42 T4N0-1 and 41 IIIA-N2) were identified: the median radiotherapy dose was 65Gy. Thirty-seven percent of patients received sequential CRT and 63% received concurrent CRT. At a median follow-up of 48months the median OS for T4N0-1 patients was 34months with 55% 2-year survival and 25% 5-year survival. For stage IIIA-N2 at a median follow-up of 50months the median OS was 26months with 2- and 5-year survival rates of 53% and 24%, respectively.
Chemo-radiation using INDAR yields promising survival results in patients with single-station stage IIIA-N2 or T4N0-1 NSCLC.
Radiotherapy and Oncology 01/2014; 110(3). DOI:10.1016/j.radonc.2013.12.005 · 4.36 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background
Decision Support Systems, based on statistical prediction models, have the potential to change the way medicine is being practiced, but their application is currently hampered by the astonishing lack of impact studies. Showing the theoretical benefit of using these models could stimulate conductance of such studies. In addition, it would pave the way for developing more advanced models, based on genomics, proteomics and imaging information, to further improve the performance of the models.
In this prospective single-center study, previously developed and validated statistical models were used to predict the two-year survival (2yrS), dyspnea (DPN), and dysphagia (DPH) outcomes for lung cancer patients treated with chemo radiation. These predictions were compared to probabilities provided by doctors and guideline-based recommendations currently used. We hypothesized that model predictions would significantly outperform predictions from doctors.
Materials and methods
Experienced radiation oncologists (ROs) predicted all outcomes at two timepoints: (1) after the first consultation of the patient, and (2) after the radiation treatment plan was made. Differences in the performances of doctors and models were assessed using Area Under the Curve (AUC) analysis.
A total number of 155 patients were included. At timepoint #1 the differences in AUCs between the ROs and the models were 0.15, 0.17, and 0.20 (for 2yrS, DPN, and DPH, respectively), with p-values of 0.02, 0.07, and 0.03. Comparable differences at timepoint #2 were not statistically significant due to the limited number of patients. Comparison to guideline-based recommendations also favored the models.
The models substantially outperformed ROs’ predictions and guideline-based recommendations currently used in clinical practice. Identification of risk groups on the basis of the models facilitates individualized treatment, and should be further investigated in clinical impact studies.
[Show abstract][Hide abstract] ABSTRACT: Accurate volumetric assessment in non-small cell lung cancer (NSCLC) is critical for adequately informing treatments. In this study we assessed the clinical relevance of a semiautomatic computed tomography (CT)-based segmentation method using the competitive region-growing based algorithm, implemented in the free and public available 3D-Slicer software platform. We compared the 3D-Slicer segmented volumes by three independent observers, who segmented the primary tumour of 20 NSCLC patients twice, to manual slice-by-slice delineations of five physicians. Furthermore, we compared all tumour contours to the macroscopic diameter of the tumour in pathology, considered as the "gold standard". The 3D-Slicer segmented volumes demonstrated high agreement (overlap fractions > 0.90), lower volume variability (p = 0.0003) and smaller uncertainty areas (p = 0.0002), compared to manual slice-by-slice delineations. Furthermore, 3D-Slicer segmentations showed a strong correlation to pathology (r = 0.89, 95%CI, 0.81-0.94). Our results show that semiautomatic 3D-Slicer segmentations can be used for accurate contouring and are more stable than manual delineations. Therefore, 3D-Slicer can be employed as a starting point for treatment decisions or for high-throughput data mining research, such as Radiomics, where manual delineating often represent a time-consuming bottleneck.
[Show abstract][Hide abstract] ABSTRACT: [(18)F]HX4 is a promising hypoxia PET-tracer. Uptake, spatio-temporal stability and optimal acquisition parameters for [(18)F]HX4 PET imaging were evaluated in non-small cell lung cancer (NSCLC) patients.
[(18)F]HX4 PET/CT images of 15 NSCLC patients were acquired 2h and 4h after injection (p.i.). Maximum standardized-uptake-value (SUVmax), tumor-to-blood-ratio (TBRmax), hypoxic fraction (HF) and contrast-to-noise-ratio (CNR) were determined for all lesions. To evaluate spatio-temporal stability, DICE-similarity and Pearson correlation coefficients were calculated. Optimal acquisition-duration was assessed by comparing 30, 20, 10 and 5min acquisitions.
Considerable uptake (TBR >1.4) was observed in 18/25 target lesions. TBRmax increased significantly from 2h (1.6±0.3) to 4h p.i. (2.0±0.6). Uptake patterns at 2h and 4h p.i. showed a strong correlation (R=0.77±0.10) with a DICE similarity coefficient of 0.69±0.08 for the 30% highest uptake volume. Reducing acquisition-time resulted in significant changes in SUVmax and CNR. TBRmax and HF were only affected for scan-times of 5min.
The majority of NSCLC lesions showed considerable [(18)F]HX4 uptake. The heterogeneous uptake pattern was stable between 2h and 4h p.i. [(18)F]HX4 PET imaging at 4h p.i. is superior to 2h p.i. to reach highest contrast. Acquisition time may be reduced to 10min without significant effects on TBRmax and HF.
Radiotherapy and Oncology 09/2013; 109(1). DOI:10.1016/j.radonc.2013.08.031 · 4.36 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To test the hypothesis that cardiac comorbidity before the start of radiotherapy (RT) is associated with an increased risk of radiation-induced lung toxicity (RILT) in lung cancer patients.
A retrospective analysis was performed of a prospective cohort of 259 patients with locoregional lung cancer treated with definitive radio(chemo)therapy between 2007 and 2011 (ClinicalTrials.gov Identifiers: NCT00572325 and NCT00573040). We defined RILT as dyspnea CTCv.3.0 grade ⩾2 within 6months after RT, and cardiac comorbidity as a recorded treatment of a cardiac pathology at a cardiology department. Univariate and multivariate analyses, as well as external validation, were performed. The model-performance measure was the area under the receiver operating characteristic curve (AUC).
Prior to RT, 75/259 (28.9%) patients had cardiac comorbidity, 44% of whom (33/75) developed RILT. The odds ratio of developing RILT for patients with cardiac comorbidity was 2.58 (p<0.01). The cross-validated AUC of a model with cardiac comorbidity, tumor location, forced expiratory volume in 1s, sequential chemotherapy and pretreatment dyspnea score was 0.72 (p<0.001) on the training set, and 0.67 (p<0.001) on the validation set.
Cardiac comorbidity is an important risk factor for developing RILT after definite radio(chemo)therapy of lung cancer patients.
Radiotherapy and Oncology 09/2013; 109(1). DOI:10.1016/j.radonc.2013.08.035 · 4.36 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Purpose:
This study explored international radiation oncology trainee decision making in the management of radiotherapy-induced nausea and vomiting (RINV).
Radiation oncology trainees who were members of the national radiation oncology associations of the USA, Canada, Netherlands, Australia, New Zealand, France, Spain and Singapore completed a Web-based survey. Respondents estimated the risks of nausea and vomiting associated with six standardised radiotherapy-only clinical case vignettes modelled after international anti-emetic guidelines and then committed to prophylactic, rescue or no therapy as an initial management approach for each case.
One hundred and seventy-six trainees from 11 countries responded. Only 28 % were aware of any anti-emetic guideline. In general, risk estimates and management approaches for the high-risk and minimal risk cases varied less and were more in line with guideline standards than were estimates and approaches for the moderate- and low-risk cases. Prophylactic therapy was the most common approach for the high-risk and a moderate-risk case (83 and 71 % of respondents respectively), while rescue therapy was the most common approach for a second moderate-risk case (69 %), two low-risk cases (69 and 76 %) and a minimal risk case (68 %). A serotonin receptor antagonist was the most commonly recommended prophylactic agent. On multivariate analysis, a higher estimated risk of nausea predicted for recommending prophylactic therapy, and a lower estimated risk of nausea predicted for recommending rescue therapy.
Radiation oncology trainee risk estimates and recommended management approaches for RINV clinical case vignettes varied and matched guideline standards more often for high-risk and minimal risk cases than for moderate- and low-risk cases. Risk estimates of nausea specifically were strong predictors of management decisions.
Supportive Care in Cancer 02/2013; 21(7). DOI:10.1007/s00520-013-1759-x · 2.36 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Purpose:
In non-small cell lung cancer, gross tumor volume (GTV) influences survival more than other risk factors. This could also apply to small cell lung cancer.
Methods and materials:
Analysis of our prospective database with stage I to III SCLC patients referred for concurrent chemo radiation therapy. Standard treatment was 45 Gy in 1.5-Gy fractions twice daily concurrently with carboplatin-etoposide, followed by prophylactic cranial irradiation (PCI) in case of non-progression. Only fluorodeoxyglucose (FDG)-positron emission tomography (PET)-positive or pathologically proven nodal sites were included in the target volume. Total GTV consisted of post chemotherapy tumor volume and pre chemotherapy nodal volume. Survival was calculated from diagnosis (Kaplan-Meier ).
A total of 119 patients were included between May 2004 and June 2009. Median total GTV was 93 ± 152 cc (7.5-895 cc). Isolated elective nodal failure occurred in 2 patients (1.7%). Median follow-up was 38 months, median overall survival 20 months (95% confidence interval = 17.8-22.1 months), and 2-year survival 38.4%. In multivariate analysis, only total GTV (P=.026) and performance status (P=.016) significantly influenced survival.
In this series of stage I to III small cell lung cancer patients treated with FDG-PET-based selective nodal irradiation total GTV is an independent risk factor for survival.
International journal of radiation oncology, biology, physics 11/2012; 85(5). DOI:10.1016/j.ijrobp.2012.10.003 · 4.26 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background and purpose:
For stereotactic body radiotherapy (SBRT), typically a scheme of 60 Gy in 3-8 fractions is applied, producing local tumour control rates around 90%. The dose specification is in one point only and ignores possible underdosages at the edge of the planning target volume (PTV). We investigated the doses at the edge of the PTV and correlated this with local tumour control with the aim to shed light on the radiation dose needed to eradicate stage I NSCLC.
Materials and methods:
Published data on the freedom from local progression (FFLP) data from SBRT and accelerated high-dose conventional radiotherapy series for stage I NSCLC with a follow up of at least 30 months were included. The EQD(2,T) was calculated from the dose at the periphery of the PTV.
Fifteen studies for SBRT (1076 patients) showed a median FFLP of 88.0±10.4% with a median EQD(2,T) of 76.9±17.4 Gy. The median FFLP was 87.6±6.0% for the accelerated schedules with an EQD(2,T) of 86.9±39.1 Gy, respectively. No significant relation was found between FFLP and the EQD(2,T) (p=0.23).
Several fractionated and accelerated schedules with equal biological doses achieve the same tumour control rates as SBRT. Lower, but more uniform doses to the whole PTV may be sufficient to achieve similar control rates, with the possibility to deliver SBRT in adapted schedules, beneficial to centrally located tumours in the vicinity of critical structures like the oesophagus and great vessels.
Radiotherapy and Oncology 10/2012; 105(2). DOI:10.1016/j.radonc.2012.09.008 · 4.36 Impact Factor