Maarten Lambrecht - Academia.edu (original) (raw)

Papers by Maarten Lambrecht

Radiotherapy and Oncology, 2013

Radiotherapy and Oncology, 2014

Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology, 2014

Quality assurance (QA) for radiation treatment has become a priority since poorly delivered radio... more Quality assurance (QA) for radiation treatment has become a priority since poorly delivered radiotherapy can negatively influence patient outcome. Within a national project we evaluated the feasibility of a central review platform and its role in improving uniformity of clinical target volume (CTV) delineation in daily practice. All Belgian radiotherapy departments were invited to participate and were asked to upload CTVs for rectal cancer treatment onto a secured server. These were centrally reviewed and feedback was given per e-mail. For each five consecutive patients per centre, the overlap parameter dice coefficient (DC) and the volumetric parameters volumetric ratio (RV) and commonly contoured volume (VCC) were calculated. Twenty departments submitted 1224 eligible cases of which 909 were modified (74.3%). There was a significant increase in RV and VCC between the first ten patients per centre and the others. This was not seen for DC. Statistical analysis did not show a further...

Strahlentherapie und Onkologie, 2014

Several planning studies have already proven the substantial dosimetric advantages of RapidArc (R... more Several planning studies have already proven the substantial dosimetric advantages of RapidArc (RA) over standard intensity-modulated radiotherapy. We retrospectively compared RapidArc and standard sliding window IMRT (swIMRT) in locally advanced head and neck cancer, looking both at dosimetrics as well as toxicity and outcome. CT datasets of 78 patients treated with swIMRT and 79 patients treated with RA were included. To compare the resulting dose distributions, the dose-volume parameters were evaluated for the planning target volumes (PTVs), clinical target volumes (CTVs), and organs at risk (OARs), and the number of MU were calculated. Acute toxicity was assessed by the Common Toxicity Criteria version 3.0. PTV coverage with the 95% isodose was slightly better for RA. Dose distribution has proven to be significantly more homogenous with RA and led to a reduction of 62% in MU with better OAR sparing. As for toxicity, more grade 3 mucositis and dysphagia was observed for swIMRT, though we observed more grade 3 dermatitis for RA. In our retrospective analysis, RA had better target coverage and better sparing of the OAR. Overall, the grade of acute toxicity was lower for RA than for swIMRT for the same types of tumor locations, except for the grade of dermatitis.

Radiotherapy and Oncology, 2011

F1000Prime Reports, 2014

Squamous cell carcinoma of the head and neck (SCCHN) is the sixth most common cancer worldwide. T... more Squamous cell carcinoma of the head and neck (SCCHN) is the sixth most common cancer worldwide. The main risk factors for cancers of the oral cavity, larynx, oropharynx, and hypopharynx are alcohol and tobacco use. In addition, the human papillomavirus (HPV) is an established cause of oropharyngeal cancer. An experienced multidisciplinary team is necessary for adequate management and optimal outcome. The treatment of locally advanced disease generally requires various combinations of radiotherapy, surgery, and systemic therapy, but despite this aggressive multimodal treatment, 40% to 60% of the patients will relapse. In this report, we will discuss recent advances in the management of SCCHN, including new developments in molecular biology, imaging, and treatment.

Radiotherapy and Oncology, 2011

Radiotherapy and Oncology, 2012

Radiotherapy and Oncology, 2010

FDG-PET Head and neck carcinomas Radiotherapy planning Hypoxia Proliferation Radioresistance a b ... more FDG-PET Head and neck carcinomas Radiotherapy planning Hypoxia Proliferation Radioresistance a b s t r a c t

Strahlentherapie und Onkologie, 2013

Intensity-modulated radiotherapy (IMRT) has rapidly become standard of care in the management of ... more Intensity-modulated radiotherapy (IMRT) has rapidly become standard of care in the management of locally advanced head and neck squamous cell carcinoma (HNSCC). In this study, our aim was to retrospectively investigate the effect of the introducing IMRT on outcome and treatment-related toxicity compared to parotid-sparing 3D conformal radiotherapy (3DCRT). A total of 245 patients with stage III and IV HNSCC treated with primary radiotherapy between January 2003 and December 2010 were included in this analysis: 135 patients were treated with 3DCRT, 110 patients with IMRT. Groups were compared for acute and late toxicity, locoregional control (LRC), and overall survival (OS). Oncologic outcomes were estimated using Kaplan-Meier analysis and compared using a log-rank test. Acute toxicity was analyzed according to the Common Terminology Criteria for Adverse Events v3.0 and late toxicity was scored using the RTOG/EORTC late toxicity scoring system. Median follow-up was 35 months in the IMRT group and 68 months in the 3DCRT group. No significant differences were found in 3-year LRC and OS rates between the IMRT group and 3DCRT group. Significantly less acute mucositis ≥ grade 3 was observed in the IMRT group (32% vs. 44%, p = 0.03). There was significantly less late xerostomia ≥ grade 2 in the IMRT group than in the 3DCRT group (23% vs. 68%, p < 0.001). After 24 months, there was less dysphagia ≥ grade 2 in the IMRT group although differences failed to reach statistical significance. The introduction of IMRT in the radiotherapeutic management of locally advanced head and neck cancer significantly improved late toxicity without compromising tumor control compared to a parotid-sparing 3D conformal radiotherapy technique.

Radiotherapy and Oncology, 2014

In head and neck squamous cell carcinoma (HNSCC) the ability to anticipate an individual patient&... more In head and neck squamous cell carcinoma (HNSCC) the ability to anticipate an individual patient's outcome is very valuable. With this study we wanted to assess the prognostic value of pretreatment apparent diffusion coefficient (ADC) in a large patient population and integrate it into a multivariable prognostic model. From 2004 to 2010 175 patients with pathology proven HNSCC were included in this study. All patients underwent a pretreatment MRI with diffusion weighted imaging (DWI) using six b-values. For each tumor, three ADC values were calculated using different b-value combinations: ADC(low) (b 0-50-100 s/mm(2)), ADChigh (b 500-750-1000 s/mm(2)) and ADC(avg) (all b-values). The clinical and radiological variables included: tumor and nodal volume, tumor location and age. Disease recurrence was analyzed using competing risk regression. A prognostic model for disease recurrence was developed, and internal validation was performed using bootstrapping and by dividing patients in three equal sized groups based on prognosis. One hundred and sixty-one patients were eligible for analysis. Median follow-up was 50 months (range 4-86). A total of 67 patients experienced disease recurrence during follow-up (42%). ADC(high) was a prognostic factor for disease recurrence (adjusted hazard ratio: 1.14 per 10(-4) mm(2)/s, 95% CI 1.04-1.25). Harrell's c-index of the multivariable prognostic model was 0.62 (95% CI 0.56-0.70) after internal validation. The validated 3-year disease recurrence rates for the groups with worst, intermediate, and best prognosis were 56%, 33% and 31% respectively. Pretreatment ADC value derived from high b-values is an independent prognostic factor in HNSCC and increases the performance of a multivariable prognostic model in addition to known clinical and radiological variables. Integration of other biomarkers and external validation is necessary to ensure its clinical applicability.

Radiotherapy and Oncology, 2011

Radiotherapy and Oncology, 2011

Radiotherapy and Oncology, 2009

Objective: To evaluate the incidence and localization of regional recurrences after definitive (c... more Objective: To evaluate the incidence and localization of regional recurrences after definitive (chemo-) radiotherapy for head and neck squamous cell carcinoma (HNSCC). Methods: From May 1987 to March 2008, 368 patients with advanced HNSCC were irradiated to 66-80.5 Gray in 6-7 weeks, with (37%) or without (63%) concomitant chemotherapy (Cisplatinum 100 mg/m 2 ) every 3 weeks. No planned neck dissections were performed. Data on clinical outcome were retrospectively reviewed, location of the original nodal disease and the regional recurrence was indicated on imaging and correlated with radiation dose. Results: Mean follow-up was 34 months (range: 50 days-216 months). Three-year overall survival and disease-specific survival were 55% and 62%, respectively. Loco-regional, local and regional controls were 58%, 65%, and 80%, respectively. Forty-one patients (11.1%) relapsed in the neck, but only 11 patients (2.99%) developed a true isolated regional recurrence, 6 of whom could be successfully salvaged by surgery. Only 2 patients (0.54%) developed an isolated recurrence in the electively treated nodal levels. Conclusion: Isolated nodal recurrences are uncommon and recurrences in the electively treated neck are extremely uncommon.

Radiotherapy and Oncology, 2013

A randomized trial was initiated to investigate whether a reduction of the dose to the elective n... more A randomized trial was initiated to investigate whether a reduction of the dose to the elective nodal sites and the swallowing apparatus delivered by IMRT would result in a reduction of acute and late side effects without compromising tumor control. The aim of this paper is to report on dosimetrical analysis and acute toxicity. Two-hundred patients were randomized. In the standard arm, elective nodal volumes (PTVelect) were irradiated up to an equivalent dose of 50Gy. In the experimental arm an equivalent dose of 40Gy was prescribed to the PTVelect. The dose to the swallowing apparatus was kept as low as possible without compromising therapeutic PTV (PTVther) coverage. No significant difference was seen between both arms concerning PTVther coverage. The median D95 of the PTVelect was significantly lower in the experimental arm (39.5 vs 49.8Gy; p<0.001). Concerning the organs at risk, the dose to swallowing structures and spinal cord was significantly reduced. There was no significant difference in acute toxicity. Three months after radiotherapy there was significantly less grade ⩾3 dysphagia in the experimental arm (2% vs 11%; p=0.03). With a median follow-up of 6months no significant differences were observed in locoregional control, disease free survival or overall survival. Using IMRT we were able to significantly reduce the dose to the PTVelect and several organs at risk without compromising PTVther coverage. This resulted in a significant reduction of severe dysphagia 3months after radiotherapy. Further follow-up is necessary to investigate whether these observations translate into a benefit on late treatment related dysphagia without affecting treatment outcome.

Radiotherapy and Oncology, 2014

In head and neck cancer, diffusion weighted MRI (DWI) can predict response early during treatment... more In head and neck cancer, diffusion weighted MRI (DWI) can predict response early during treatment. Treatment-induced changes and DWI-specific artifacts hinder an accurate registration between apparent diffusion coefficient (ADC) maps. The aim of the study was to develop a registration tool which calculates and visualizes regional changes in ADC. Twenty patients with stage IV HNC treated with primary radiotherapy received an MRI including DWI before and early during treatment. Markers were manually placed at anatomical landmarks on the different modalities at both time points. A registration method, consisting of a fully automatic rigid and nonrigid registration and two semi-automatic thin-plate spline (TPS) warps was developed and applied to the image sets. After each registration step the mean registration errors were calculated and ΔADC was compared between good and poor responders. Adding the TPS warps significantly reduced the registration error (in mm, 6.3 ± 6.2 vs 3.2 ± 3.3 mm, p<0.001). After the marker based registration the median ΔADC in poor responders was significantly lower than in good responders (7% vs. 21%; p<0.001). This registration method allowed for a significant reduction of the mean registration error. Furthermore the voxel-wise calculation of the ΔADC early during radiotherapy allowed for a visualization of the regional differences of ΔADC within the tumor.

Radiotherapy and Oncology, 2012

Oral Oncology, 2014

s u m m a r y Background: We investigated the incidence and survival of non-cutaneous head and ne... more s u m m a r y Background: We investigated the incidence and survival of non-cutaneous head and neck cancer (HNC) after solid organ transplantation and identified prognostic factors impacting the outcome after treatment. Methods: A retrospective analysis of patients who underwent solid organ transplantation in our institution between 1987 and 2012. Results: Of 5255 organ transplant patients, 48 recipients (0.9%) developed HNC in the posttransplant follow-up period. Liver transplant recipients showed the highest risk. Median follow-up of cancer patients was 46.7 months (range 2.9-256.2 months). Three-year overall survival and disease free survival (DFS) were 70% and 53%. Locoregional control was 67% and 48% at 3 and 5 years, respectively. Smoking and initial AJCC stage were two significant prognostic factors influencing DFS. Conclusions: Non-cutaneous HNC is rare in transplant recipients, but slightly more common after liver transplantation. Outcome after treatment is poor with locoregional recurrence being the main problem. Screening of high risk groups might be relevant.

Neuroradiology, 2010

In the head and neck, squamous cell carcinoma is one of the most common tumour types. Currently, ... more In the head and neck, squamous cell carcinoma is one of the most common tumour types. Currently, the primary imaging modalities for initial locoregional staging are computed tomography and-to a lesser extentmagnetic resonance imaging, whilst [ 18 F]fluorodeoxyglucose (FDG) positron emission tomography has additional value in the detection of subcentimetric metastatic lymph nodes and of tumour recurrence after chemoradiotherapy (CRT). However, dependency on the morphological and size-related criteria of anatomical imaging and the limited spatial resolution and FDG avidity of inflammation in metabolic imaging may reduce diagnostic accuracy in the head and neck. Diffusion-weighted magnetic resonance imaging (DWI) is a noninvasive imaging technique that measures the differences in water mobility in different tissue microstructures. Water mobility is likely influenced by cell size, density, and cellular membrane integrity and is quantified by means of the apparent diffusion coefficient. As such, the technique is able to differentiate tumoural tissue from normal tissue, inflammatory tissue and necrosis. In this article, we examine the use of DWI in head and neck cancer, focussing on technique optimization and image interpretation. Afterwards, the value of DWI will be outlined for clinical questions regarding nodal staging, lesion characterization, differentiation of post-CRT tumour recurrence from necrosis and inflammation, and predictive imaging towards treatment outcome. The possible consequences of adding DWI towards therapeutic management are outlined.

Radiotherapy and Oncology, 2013

Radiotherapy and Oncology, 2014

Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology, 2014

Quality assurance (QA) for radiation treatment has become a priority since poorly delivered radio... more Quality assurance (QA) for radiation treatment has become a priority since poorly delivered radiotherapy can negatively influence patient outcome. Within a national project we evaluated the feasibility of a central review platform and its role in improving uniformity of clinical target volume (CTV) delineation in daily practice. All Belgian radiotherapy departments were invited to participate and were asked to upload CTVs for rectal cancer treatment onto a secured server. These were centrally reviewed and feedback was given per e-mail. For each five consecutive patients per centre, the overlap parameter dice coefficient (DC) and the volumetric parameters volumetric ratio (RV) and commonly contoured volume (VCC) were calculated. Twenty departments submitted 1224 eligible cases of which 909 were modified (74.3%). There was a significant increase in RV and VCC between the first ten patients per centre and the others. This was not seen for DC. Statistical analysis did not show a further...

Strahlentherapie und Onkologie, 2014

Several planning studies have already proven the substantial dosimetric advantages of RapidArc (R... more Several planning studies have already proven the substantial dosimetric advantages of RapidArc (RA) over standard intensity-modulated radiotherapy. We retrospectively compared RapidArc and standard sliding window IMRT (swIMRT) in locally advanced head and neck cancer, looking both at dosimetrics as well as toxicity and outcome. CT datasets of 78 patients treated with swIMRT and 79 patients treated with RA were included. To compare the resulting dose distributions, the dose-volume parameters were evaluated for the planning target volumes (PTVs), clinical target volumes (CTVs), and organs at risk (OARs), and the number of MU were calculated. Acute toxicity was assessed by the Common Toxicity Criteria version 3.0. PTV coverage with the 95% isodose was slightly better for RA. Dose distribution has proven to be significantly more homogenous with RA and led to a reduction of 62% in MU with better OAR sparing. As for toxicity, more grade 3 mucositis and dysphagia was observed for swIMRT, though we observed more grade 3 dermatitis for RA. In our retrospective analysis, RA had better target coverage and better sparing of the OAR. Overall, the grade of acute toxicity was lower for RA than for swIMRT for the same types of tumor locations, except for the grade of dermatitis.

Radiotherapy and Oncology, 2011

F1000Prime Reports, 2014

Squamous cell carcinoma of the head and neck (SCCHN) is the sixth most common cancer worldwide. T... more Squamous cell carcinoma of the head and neck (SCCHN) is the sixth most common cancer worldwide. The main risk factors for cancers of the oral cavity, larynx, oropharynx, and hypopharynx are alcohol and tobacco use. In addition, the human papillomavirus (HPV) is an established cause of oropharyngeal cancer. An experienced multidisciplinary team is necessary for adequate management and optimal outcome. The treatment of locally advanced disease generally requires various combinations of radiotherapy, surgery, and systemic therapy, but despite this aggressive multimodal treatment, 40% to 60% of the patients will relapse. In this report, we will discuss recent advances in the management of SCCHN, including new developments in molecular biology, imaging, and treatment.

Radiotherapy and Oncology, 2011

Radiotherapy and Oncology, 2012

Radiotherapy and Oncology, 2010

FDG-PET Head and neck carcinomas Radiotherapy planning Hypoxia Proliferation Radioresistance a b ... more FDG-PET Head and neck carcinomas Radiotherapy planning Hypoxia Proliferation Radioresistance a b s t r a c t

Strahlentherapie und Onkologie, 2013

Intensity-modulated radiotherapy (IMRT) has rapidly become standard of care in the management of ... more Intensity-modulated radiotherapy (IMRT) has rapidly become standard of care in the management of locally advanced head and neck squamous cell carcinoma (HNSCC). In this study, our aim was to retrospectively investigate the effect of the introducing IMRT on outcome and treatment-related toxicity compared to parotid-sparing 3D conformal radiotherapy (3DCRT). A total of 245 patients with stage III and IV HNSCC treated with primary radiotherapy between January 2003 and December 2010 were included in this analysis: 135 patients were treated with 3DCRT, 110 patients with IMRT. Groups were compared for acute and late toxicity, locoregional control (LRC), and overall survival (OS). Oncologic outcomes were estimated using Kaplan-Meier analysis and compared using a log-rank test. Acute toxicity was analyzed according to the Common Terminology Criteria for Adverse Events v3.0 and late toxicity was scored using the RTOG/EORTC late toxicity scoring system. Median follow-up was 35 months in the IMRT group and 68 months in the 3DCRT group. No significant differences were found in 3-year LRC and OS rates between the IMRT group and 3DCRT group. Significantly less acute mucositis ≥ grade 3 was observed in the IMRT group (32% vs. 44%, p = 0.03). There was significantly less late xerostomia ≥ grade 2 in the IMRT group than in the 3DCRT group (23% vs. 68%, p < 0.001). After 24 months, there was less dysphagia ≥ grade 2 in the IMRT group although differences failed to reach statistical significance. The introduction of IMRT in the radiotherapeutic management of locally advanced head and neck cancer significantly improved late toxicity without compromising tumor control compared to a parotid-sparing 3D conformal radiotherapy technique.

Radiotherapy and Oncology, 2014

In head and neck squamous cell carcinoma (HNSCC) the ability to anticipate an individual patient&... more In head and neck squamous cell carcinoma (HNSCC) the ability to anticipate an individual patient's outcome is very valuable. With this study we wanted to assess the prognostic value of pretreatment apparent diffusion coefficient (ADC) in a large patient population and integrate it into a multivariable prognostic model. From 2004 to 2010 175 patients with pathology proven HNSCC were included in this study. All patients underwent a pretreatment MRI with diffusion weighted imaging (DWI) using six b-values. For each tumor, three ADC values were calculated using different b-value combinations: ADC(low) (b 0-50-100 s/mm(2)), ADChigh (b 500-750-1000 s/mm(2)) and ADC(avg) (all b-values). The clinical and radiological variables included: tumor and nodal volume, tumor location and age. Disease recurrence was analyzed using competing risk regression. A prognostic model for disease recurrence was developed, and internal validation was performed using bootstrapping and by dividing patients in three equal sized groups based on prognosis. One hundred and sixty-one patients were eligible for analysis. Median follow-up was 50 months (range 4-86). A total of 67 patients experienced disease recurrence during follow-up (42%). ADC(high) was a prognostic factor for disease recurrence (adjusted hazard ratio: 1.14 per 10(-4) mm(2)/s, 95% CI 1.04-1.25). Harrell's c-index of the multivariable prognostic model was 0.62 (95% CI 0.56-0.70) after internal validation. The validated 3-year disease recurrence rates for the groups with worst, intermediate, and best prognosis were 56%, 33% and 31% respectively. Pretreatment ADC value derived from high b-values is an independent prognostic factor in HNSCC and increases the performance of a multivariable prognostic model in addition to known clinical and radiological variables. Integration of other biomarkers and external validation is necessary to ensure its clinical applicability.

Radiotherapy and Oncology, 2011

Radiotherapy and Oncology, 2011

Radiotherapy and Oncology, 2009

Objective: To evaluate the incidence and localization of regional recurrences after definitive (c... more Objective: To evaluate the incidence and localization of regional recurrences after definitive (chemo-) radiotherapy for head and neck squamous cell carcinoma (HNSCC). Methods: From May 1987 to March 2008, 368 patients with advanced HNSCC were irradiated to 66-80.5 Gray in 6-7 weeks, with (37%) or without (63%) concomitant chemotherapy (Cisplatinum 100 mg/m 2 ) every 3 weeks. No planned neck dissections were performed. Data on clinical outcome were retrospectively reviewed, location of the original nodal disease and the regional recurrence was indicated on imaging and correlated with radiation dose. Results: Mean follow-up was 34 months (range: 50 days-216 months). Three-year overall survival and disease-specific survival were 55% and 62%, respectively. Loco-regional, local and regional controls were 58%, 65%, and 80%, respectively. Forty-one patients (11.1%) relapsed in the neck, but only 11 patients (2.99%) developed a true isolated regional recurrence, 6 of whom could be successfully salvaged by surgery. Only 2 patients (0.54%) developed an isolated recurrence in the electively treated nodal levels. Conclusion: Isolated nodal recurrences are uncommon and recurrences in the electively treated neck are extremely uncommon.

Radiotherapy and Oncology, 2013

A randomized trial was initiated to investigate whether a reduction of the dose to the elective n... more A randomized trial was initiated to investigate whether a reduction of the dose to the elective nodal sites and the swallowing apparatus delivered by IMRT would result in a reduction of acute and late side effects without compromising tumor control. The aim of this paper is to report on dosimetrical analysis and acute toxicity. Two-hundred patients were randomized. In the standard arm, elective nodal volumes (PTVelect) were irradiated up to an equivalent dose of 50Gy. In the experimental arm an equivalent dose of 40Gy was prescribed to the PTVelect. The dose to the swallowing apparatus was kept as low as possible without compromising therapeutic PTV (PTVther) coverage. No significant difference was seen between both arms concerning PTVther coverage. The median D95 of the PTVelect was significantly lower in the experimental arm (39.5 vs 49.8Gy; p<0.001). Concerning the organs at risk, the dose to swallowing structures and spinal cord was significantly reduced. There was no significant difference in acute toxicity. Three months after radiotherapy there was significantly less grade ⩾3 dysphagia in the experimental arm (2% vs 11%; p=0.03). With a median follow-up of 6months no significant differences were observed in locoregional control, disease free survival or overall survival. Using IMRT we were able to significantly reduce the dose to the PTVelect and several organs at risk without compromising PTVther coverage. This resulted in a significant reduction of severe dysphagia 3months after radiotherapy. Further follow-up is necessary to investigate whether these observations translate into a benefit on late treatment related dysphagia without affecting treatment outcome.

Radiotherapy and Oncology, 2014

In head and neck cancer, diffusion weighted MRI (DWI) can predict response early during treatment... more In head and neck cancer, diffusion weighted MRI (DWI) can predict response early during treatment. Treatment-induced changes and DWI-specific artifacts hinder an accurate registration between apparent diffusion coefficient (ADC) maps. The aim of the study was to develop a registration tool which calculates and visualizes regional changes in ADC. Twenty patients with stage IV HNC treated with primary radiotherapy received an MRI including DWI before and early during treatment. Markers were manually placed at anatomical landmarks on the different modalities at both time points. A registration method, consisting of a fully automatic rigid and nonrigid registration and two semi-automatic thin-plate spline (TPS) warps was developed and applied to the image sets. After each registration step the mean registration errors were calculated and ΔADC was compared between good and poor responders. Adding the TPS warps significantly reduced the registration error (in mm, 6.3 ± 6.2 vs 3.2 ± 3.3 mm, p<0.001). After the marker based registration the median ΔADC in poor responders was significantly lower than in good responders (7% vs. 21%; p<0.001). This registration method allowed for a significant reduction of the mean registration error. Furthermore the voxel-wise calculation of the ΔADC early during radiotherapy allowed for a visualization of the regional differences of ΔADC within the tumor.

Radiotherapy and Oncology, 2012

Oral Oncology, 2014

s u m m a r y Background: We investigated the incidence and survival of non-cutaneous head and ne... more s u m m a r y Background: We investigated the incidence and survival of non-cutaneous head and neck cancer (HNC) after solid organ transplantation and identified prognostic factors impacting the outcome after treatment. Methods: A retrospective analysis of patients who underwent solid organ transplantation in our institution between 1987 and 2012. Results: Of 5255 organ transplant patients, 48 recipients (0.9%) developed HNC in the posttransplant follow-up period. Liver transplant recipients showed the highest risk. Median follow-up of cancer patients was 46.7 months (range 2.9-256.2 months). Three-year overall survival and disease free survival (DFS) were 70% and 53%. Locoregional control was 67% and 48% at 3 and 5 years, respectively. Smoking and initial AJCC stage were two significant prognostic factors influencing DFS. Conclusions: Non-cutaneous HNC is rare in transplant recipients, but slightly more common after liver transplantation. Outcome after treatment is poor with locoregional recurrence being the main problem. Screening of high risk groups might be relevant.

Neuroradiology, 2010

In the head and neck, squamous cell carcinoma is one of the most common tumour types. Currently, ... more In the head and neck, squamous cell carcinoma is one of the most common tumour types. Currently, the primary imaging modalities for initial locoregional staging are computed tomography and-to a lesser extentmagnetic resonance imaging, whilst [ 18 F]fluorodeoxyglucose (FDG) positron emission tomography has additional value in the detection of subcentimetric metastatic lymph nodes and of tumour recurrence after chemoradiotherapy (CRT). However, dependency on the morphological and size-related criteria of anatomical imaging and the limited spatial resolution and FDG avidity of inflammation in metabolic imaging may reduce diagnostic accuracy in the head and neck. Diffusion-weighted magnetic resonance imaging (DWI) is a noninvasive imaging technique that measures the differences in water mobility in different tissue microstructures. Water mobility is likely influenced by cell size, density, and cellular membrane integrity and is quantified by means of the apparent diffusion coefficient. As such, the technique is able to differentiate tumoural tissue from normal tissue, inflammatory tissue and necrosis. In this article, we examine the use of DWI in head and neck cancer, focussing on technique optimization and image interpretation. Afterwards, the value of DWI will be outlined for clinical questions regarding nodal staging, lesion characterization, differentiation of post-CRT tumour recurrence from necrosis and inflammation, and predictive imaging towards treatment outcome. The possible consequences of adding DWI towards therapeutic management are outlined.