Nicolas Jansen - Academia.edu (original) (raw)
Papers by Nicolas Jansen
Clinical and Translational Radiation Oncology, Dec 31, 2023
Advances in radiation oncology, Mar 1, 2023
Une introduction concernant la radiothérapie des néoplasies urologiques : tumeurs rénales, de l&#... more Une introduction concernant la radiothérapie des néoplasies urologiques : tumeurs rénales, de l'ureter, de la vessie, de l'urèthre, de la verge, de la prostate, et des testicules
The author gives an overview of the proposals for a new reimbursement system for radiotherapy in ... more The author gives an overview of the proposals for a new reimbursement system for radiotherapy in Belgium, to be possibly introduced in 2013
After an introduction concerning medical aspects of the stereotactic robotic radiotherapy system ... more After an introduction concerning medical aspects of the stereotactic robotic radiotherapy system 'Cyberknife', different possibilities are presented to compare this technical approach to other radiotherapy systems. Specifically dosimetric comparisons are discussed, and pitfalls in doing so
Concrètement, la vidéo de la séance de radiothérapie a été́ visionnée par les patients du groupe ... more Concrètement, la vidéo de la séance de radiothérapie a été́ visionnée par les patients du groupe expérimental au moyen d'un casque Oculus Go®. Il s’agit d’un outil permettant de visionner à 360° un environnement digital recréé ou une vidéo filmée. C’est un système de Réalité Virtuelle totalement autonome : l’écran, l’électronique et le processeur sont logés dans le casque, ce qui permet au patient et au personnel de manipuler plus facilement l’outil en comparaison aux systèmes habituels de RV (casque, capteurs, manette).
PubMed, Sep 1, 2006
Radiotherapy is an important part of breast cancer treatment. After breast conserving surgery, a ... more Radiotherapy is an important part of breast cancer treatment. After breast conserving surgery, a dose of 50 Grays (Gy) is administered to the entire breast. Boost by external radiotherapy or brachytherapy improves local control especially for women under fifty. For lobular in situ lesions, no additional treatment is required, while intraductal lesions are treated with post-operative radiotherapy in case of Van Nuys score of 7, 8 or 9. After mastectomy, irradiation is proposed in case of skin involvement, invasion of pectoral muscle, positivity of at least 3 axillary lymph nodes, SBR III grade, T3 stage or multifocality where the sum of tumour diameters are >5 cm. Irradiation of the axilla has become exceptional. In node positive patients, the supraclavicular region receives 50 Gy with low energy photons, whereas the internal mammary chain is treated at the same dose but half is administered by low energy photons et half by electrons. Exclusive or preoperative irradiation is rare, because of new chemotherapy schedules, new drugs and hormonotherapy developments. Neoadjuvant chemotherapy enhances possibilities of conservative surgery it is followed by radiotherapy depending on the same indiciations listed above. Re-irradiation is possible but one must be aware of the higher risk of late toxicity. Nowadays, major side-effects are rare but close follow-up during and after treatment is required from the radiation oncologist to detect, evaluate, prevent and even treat possible complications.
Physica Medica, 2018
Background and Purpose: The use of Monte Carlo (MC) dose calculation algorithm for lung patients ... more Background and Purpose: The use of Monte Carlo (MC) dose calculation algorithm for lung patients treated with stereotactic body radiotherapy (SBRT) can be challenging. Prescription in low density media and time-consuming optimization conducted CyberKnife centers to propose an equivalent path length (EPL)-to-MC re-prescription method based on GTV median dose. Unknown at the time of planning, GTV D50% practical application remains difficult. The current study aims at creating a re-prescription predictive model in order to limit conflicting dose value during EPL optimization. Material and Methods: 129 patients planned with EPL algorithm were recalculated with MC. Relative GTV_D50% discrepancies were assessed and influencing parameters identified using wrapper feature selection. Based on best descriptive parameters, predictive nomogram was built from multivariate linear regression. EPL-to-MC OARs near max-dose discrepancies were reported. Results: The differences in GTV_D50% (median 10%, SD: 9%) between MC and EPL were significantly (p < .001) impacted by the lesion's surface-to-volume ratio and the average relative electronic density of the GTV and the GTV's 15 mm shell. Built upon those parameters, a nomogram (R2 = 0.79, SE = 4%) predicting the GTV_D50% discrepancies was created. Furthermore EPL-to-MC OAR dose tolerance limit showed a strong linear correlation with coefficient range [0.84-0.99]. Conclusion: Good prediction on the required re-prescription can be achieved prior planning using our nomogram. Based on strong linear correlation between EPL and MC for OARs near max-dose, further restriction on dose constraints during the EPL optimization can be warranted. This a priori knowledge eases the re-prescription process in limiting conflicting dose value.
Cureus, Jun 16, 2016
Berkovic et al. This is an open access article distributed under the terms of the Creative Common... more Berkovic et al. This is an open access article distributed under the terms of the Creative Commons Attribution License CC-BY 3.0., which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Distributed under Creative Commons CC-BY 3.0
BMC Cancer, May 8, 2020
Background: Our aim is to report treatment efficacy and toxicity of patients treated by robotic (... more Background: Our aim is to report treatment efficacy and toxicity of patients treated by robotic (Cyberknife®) stereotactic body radiotherapy (SBRT) for oligorecurrent lung metastases (ORLM). Additionally we wanted to evaluate influence of tumor, patient and treatment related parameters on local control (LC), lung and distant progression free-(lung PFS/Di-PFS) and overall survival (OS). Methods: Consecutive patients with up to 5 ORLM (confirmed by FDG PET/CT) were included in this study. Intended dose was 60Gy in 3 fractions (prescribed to the 80% isodose volume). Patients were followed at regular intervals and tumor control and toxicity was prospectively scored. Tumor, patient and treatment data were analysed using competing risk-and Cox regression. Results: Between May 2010 and March 2016, 104 patients with 132 lesions were irradiated from primary lung carcinoma (47%), gastro-intestinal (34%) and mixed primary histologies (19%). The mean tumor volume was 7.9 cc. After a median follow up of 22 months, the 1, 2 and 3 year LC rate (per lesion) was 89.3, 80.0 and 77.8% respectively. The corresponding (per patient) 1, 2 and 3 years lung PFS were 66.3, 50.0, 42.6%, Di-PFS were 80.5, 64.4, 60.6% and OS rates were 92.2, 80.9 and 72.0% respectively. On univariable analysis, gastro-intestinal (GI) as primary tumor site showed a significant superior local control versus the other primary tumor sites. For OS, significant variables were primary histology and primary tumor site with a superior OS for patients with metastases of primary GI origin. LC was significantly affected by the tumor volume, physical and biologically effective dose coverage. Significant variables in multivariable analysis were BED prescription dose for LC and GI as primary site for OS. The vast majority of patients developed no toxicity or grade 1 acute and late toxicity. Acute and late grade 3 radiation pneumonitis (RP) was observed in 1 and 2 patients respectively. One patient with a centrally located lesion developed grade 4 RP and died due to possible RT-induced pulmonary hemorrhage. Conclusions: SBRT is a highly effective local therapy for oligorecurrent lung metastases and could achieve long term survival in patients with favourable prognostic features.
Radiotherapy and Oncology
Advances in Radiation Oncology
Radiotherapy and Oncology, 2020
Concrètement, la vidéo de la séance de radiothérapie a été́ visionnée par les patients du groupe ... more Concrètement, la vidéo de la séance de radiothérapie a été́ visionnée par les patients du groupe expérimental au moyen d'un casque Oculus Go®. Il s’agit d’un outil permettant de visionner à 360° un environnement digital recréé ou une vidéo filmée. C’est un système de Réalité Virtuelle totalement autonome : l’écran, l’électronique et le processeur sont logés dans le casque, ce qui permet au patient et au personnel de manipuler plus facilement l’outil en comparaison aux systèmes habituels de RV (casque, capteurs, manette).
Une introduction concernant la radiothérapie des néoplasies urologiques : tumeurs rénales, de l&#... more Une introduction concernant la radiothérapie des néoplasies urologiques : tumeurs rénales, de l'ureter, de la vessie, de l'urèthre, de la verge, de la prostate, et des testicules
Radiotherapy and Oncology, 2017
Radiotherapy and Oncology, 2017
22%, p=0.048) and had a smaller further decrease after SBRT (-34% ± 34%, p=0.18). With limited nu... more 22%, p=0.048) and had a smaller further decrease after SBRT (-34% ± 34%, p=0.18). With limited number of patients, there were no differences in changes in any perfusion parameters between patients with and without local failure. Conclusion To our knowledge, this is the first study in humans that evaluates quantitative CT and US perfusion measures of CRC liver metastases treated with bevacizumab and SBRT. Changes in different measures of perfusion can be detected with these imaging biomarkers. Further study in a larger cohort are needed to better understand temporal changes in perfusion and determine if these changes can be used to predict response to treatment. PO-0687 Spleen dosimetry are associated with lymphopenia during radiotherapy for hepatocellular carcinoma
Radiotherapy and Oncology, 2017
Radiotherapy and Oncology, 2015
Clinical and Translational Radiation Oncology, Dec 31, 2023
Advances in radiation oncology, Mar 1, 2023
Une introduction concernant la radiothérapie des néoplasies urologiques : tumeurs rénales, de l&#... more Une introduction concernant la radiothérapie des néoplasies urologiques : tumeurs rénales, de l'ureter, de la vessie, de l'urèthre, de la verge, de la prostate, et des testicules
The author gives an overview of the proposals for a new reimbursement system for radiotherapy in ... more The author gives an overview of the proposals for a new reimbursement system for radiotherapy in Belgium, to be possibly introduced in 2013
After an introduction concerning medical aspects of the stereotactic robotic radiotherapy system ... more After an introduction concerning medical aspects of the stereotactic robotic radiotherapy system 'Cyberknife', different possibilities are presented to compare this technical approach to other radiotherapy systems. Specifically dosimetric comparisons are discussed, and pitfalls in doing so
Concrètement, la vidéo de la séance de radiothérapie a été́ visionnée par les patients du groupe ... more Concrètement, la vidéo de la séance de radiothérapie a été́ visionnée par les patients du groupe expérimental au moyen d'un casque Oculus Go®. Il s’agit d’un outil permettant de visionner à 360° un environnement digital recréé ou une vidéo filmée. C’est un système de Réalité Virtuelle totalement autonome : l’écran, l’électronique et le processeur sont logés dans le casque, ce qui permet au patient et au personnel de manipuler plus facilement l’outil en comparaison aux systèmes habituels de RV (casque, capteurs, manette).
PubMed, Sep 1, 2006
Radiotherapy is an important part of breast cancer treatment. After breast conserving surgery, a ... more Radiotherapy is an important part of breast cancer treatment. After breast conserving surgery, a dose of 50 Grays (Gy) is administered to the entire breast. Boost by external radiotherapy or brachytherapy improves local control especially for women under fifty. For lobular in situ lesions, no additional treatment is required, while intraductal lesions are treated with post-operative radiotherapy in case of Van Nuys score of 7, 8 or 9. After mastectomy, irradiation is proposed in case of skin involvement, invasion of pectoral muscle, positivity of at least 3 axillary lymph nodes, SBR III grade, T3 stage or multifocality where the sum of tumour diameters are >5 cm. Irradiation of the axilla has become exceptional. In node positive patients, the supraclavicular region receives 50 Gy with low energy photons, whereas the internal mammary chain is treated at the same dose but half is administered by low energy photons et half by electrons. Exclusive or preoperative irradiation is rare, because of new chemotherapy schedules, new drugs and hormonotherapy developments. Neoadjuvant chemotherapy enhances possibilities of conservative surgery it is followed by radiotherapy depending on the same indiciations listed above. Re-irradiation is possible but one must be aware of the higher risk of late toxicity. Nowadays, major side-effects are rare but close follow-up during and after treatment is required from the radiation oncologist to detect, evaluate, prevent and even treat possible complications.
Physica Medica, 2018
Background and Purpose: The use of Monte Carlo (MC) dose calculation algorithm for lung patients ... more Background and Purpose: The use of Monte Carlo (MC) dose calculation algorithm for lung patients treated with stereotactic body radiotherapy (SBRT) can be challenging. Prescription in low density media and time-consuming optimization conducted CyberKnife centers to propose an equivalent path length (EPL)-to-MC re-prescription method based on GTV median dose. Unknown at the time of planning, GTV D50% practical application remains difficult. The current study aims at creating a re-prescription predictive model in order to limit conflicting dose value during EPL optimization. Material and Methods: 129 patients planned with EPL algorithm were recalculated with MC. Relative GTV_D50% discrepancies were assessed and influencing parameters identified using wrapper feature selection. Based on best descriptive parameters, predictive nomogram was built from multivariate linear regression. EPL-to-MC OARs near max-dose discrepancies were reported. Results: The differences in GTV_D50% (median 10%, SD: 9%) between MC and EPL were significantly (p < .001) impacted by the lesion's surface-to-volume ratio and the average relative electronic density of the GTV and the GTV's 15 mm shell. Built upon those parameters, a nomogram (R2 = 0.79, SE = 4%) predicting the GTV_D50% discrepancies was created. Furthermore EPL-to-MC OAR dose tolerance limit showed a strong linear correlation with coefficient range [0.84-0.99]. Conclusion: Good prediction on the required re-prescription can be achieved prior planning using our nomogram. Based on strong linear correlation between EPL and MC for OARs near max-dose, further restriction on dose constraints during the EPL optimization can be warranted. This a priori knowledge eases the re-prescription process in limiting conflicting dose value.
Cureus, Jun 16, 2016
Berkovic et al. This is an open access article distributed under the terms of the Creative Common... more Berkovic et al. This is an open access article distributed under the terms of the Creative Commons Attribution License CC-BY 3.0., which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Distributed under Creative Commons CC-BY 3.0
BMC Cancer, May 8, 2020
Background: Our aim is to report treatment efficacy and toxicity of patients treated by robotic (... more Background: Our aim is to report treatment efficacy and toxicity of patients treated by robotic (Cyberknife®) stereotactic body radiotherapy (SBRT) for oligorecurrent lung metastases (ORLM). Additionally we wanted to evaluate influence of tumor, patient and treatment related parameters on local control (LC), lung and distant progression free-(lung PFS/Di-PFS) and overall survival (OS). Methods: Consecutive patients with up to 5 ORLM (confirmed by FDG PET/CT) were included in this study. Intended dose was 60Gy in 3 fractions (prescribed to the 80% isodose volume). Patients were followed at regular intervals and tumor control and toxicity was prospectively scored. Tumor, patient and treatment data were analysed using competing risk-and Cox regression. Results: Between May 2010 and March 2016, 104 patients with 132 lesions were irradiated from primary lung carcinoma (47%), gastro-intestinal (34%) and mixed primary histologies (19%). The mean tumor volume was 7.9 cc. After a median follow up of 22 months, the 1, 2 and 3 year LC rate (per lesion) was 89.3, 80.0 and 77.8% respectively. The corresponding (per patient) 1, 2 and 3 years lung PFS were 66.3, 50.0, 42.6%, Di-PFS were 80.5, 64.4, 60.6% and OS rates were 92.2, 80.9 and 72.0% respectively. On univariable analysis, gastro-intestinal (GI) as primary tumor site showed a significant superior local control versus the other primary tumor sites. For OS, significant variables were primary histology and primary tumor site with a superior OS for patients with metastases of primary GI origin. LC was significantly affected by the tumor volume, physical and biologically effective dose coverage. Significant variables in multivariable analysis were BED prescription dose for LC and GI as primary site for OS. The vast majority of patients developed no toxicity or grade 1 acute and late toxicity. Acute and late grade 3 radiation pneumonitis (RP) was observed in 1 and 2 patients respectively. One patient with a centrally located lesion developed grade 4 RP and died due to possible RT-induced pulmonary hemorrhage. Conclusions: SBRT is a highly effective local therapy for oligorecurrent lung metastases and could achieve long term survival in patients with favourable prognostic features.
Radiotherapy and Oncology
Advances in Radiation Oncology
Radiotherapy and Oncology, 2020
Concrètement, la vidéo de la séance de radiothérapie a été́ visionnée par les patients du groupe ... more Concrètement, la vidéo de la séance de radiothérapie a été́ visionnée par les patients du groupe expérimental au moyen d'un casque Oculus Go®. Il s’agit d’un outil permettant de visionner à 360° un environnement digital recréé ou une vidéo filmée. C’est un système de Réalité Virtuelle totalement autonome : l’écran, l’électronique et le processeur sont logés dans le casque, ce qui permet au patient et au personnel de manipuler plus facilement l’outil en comparaison aux systèmes habituels de RV (casque, capteurs, manette).
Une introduction concernant la radiothérapie des néoplasies urologiques : tumeurs rénales, de l&#... more Une introduction concernant la radiothérapie des néoplasies urologiques : tumeurs rénales, de l'ureter, de la vessie, de l'urèthre, de la verge, de la prostate, et des testicules
Radiotherapy and Oncology, 2017
Radiotherapy and Oncology, 2017
22%, p=0.048) and had a smaller further decrease after SBRT (-34% ± 34%, p=0.18). With limited nu... more 22%, p=0.048) and had a smaller further decrease after SBRT (-34% ± 34%, p=0.18). With limited number of patients, there were no differences in changes in any perfusion parameters between patients with and without local failure. Conclusion To our knowledge, this is the first study in humans that evaluates quantitative CT and US perfusion measures of CRC liver metastases treated with bevacizumab and SBRT. Changes in different measures of perfusion can be detected with these imaging biomarkers. Further study in a larger cohort are needed to better understand temporal changes in perfusion and determine if these changes can be used to predict response to treatment. PO-0687 Spleen dosimetry are associated with lymphopenia during radiotherapy for hepatocellular carcinoma
Radiotherapy and Oncology, 2017
Radiotherapy and Oncology, 2015