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Improved delineation with diffusion weighted imaging for laryngeal and hypopharyngeal tumors validated with pathology. Radiother Oncol 2024; 194:110182. [PMID: 38403024 DOI: 10.1016/j.radonc.2024.110182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 02/16/2024] [Accepted: 02/18/2024] [Indexed: 02/27/2024]
Abstract
OBJECTIVE This study aims to determine the added value of a geometrically accurate diffusion-weighted (DW-) MRI sequence on the accuracy of gross tumor volume (GTV) delineations, using pathological tumor delineations as a ground truth. METHODS Sixteen patients with laryngeal or hypopharyngeal carcinoma were included. After total laryngectomy, the specimen was cut into slices. Photographs of these slices were stacked to create a 3D digital specimen reconstruction, which was registered to the in vivo imaging. The pathological tumor (tumorHE) was delineated on the specimen reconstruction. Six observers delineated all tumors twice: once with only anatomical MR imaging, and once (a few weeks later) when DW sequences were also provided. The majority voting delineation of session one (GTVMRI) and session two (GTVDW-MRI), as well as the clinical target volumes (CTVs), were compared to the tumorHE. RESULTS The mean tumorHE volume was 11.1 cm3, compared to a mean GTVMRI volume of 18.5 cm3 and a mean GTVDW-MRI volume of 15.7 cm3. The median sensitivity (tumor coverage) was comparable between sessions: 0.93 (range: 0.61-0.99) for the GTVMRI and 0.91 (range: 0.53-1.00) for the GTVDW-MRI. The CTV volume also decreased when DWI was available, with a mean CTVMR of 47.1 cm3 and a mean CTVDW-MRI of 41.4 cm3. Complete tumor coverage was achieved in 15 and 14 tumors, respectively. CONCLUSION GTV delineations based on anatomical MR imaging tend to overestimate the tumor volume. The availability of the geometrically accurate DW sequence reduces the GTV overestimation and thereby CTV volumes, while maintaining acceptable tumor coverage.
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Patient-derived head and neck cancer organoids allow treatment stratification and serve as a tool for biomarker validation and identification. MED 2023; 4:290-310.e12. [PMID: 37178682 DOI: 10.1016/j.medj.2023.04.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 03/20/2023] [Accepted: 04/12/2023] [Indexed: 05/15/2023]
Abstract
BACKGROUND Organoids are in vitro three-dimensional structures that can be grown from patient tissue. Head and neck cancer (HNC) is a collective term used for multiple tumor types including squamous cell carcinomas and salivary gland adenocarcinomas. METHODS Organoids were established from HNC patient tumor tissue and characterized using immunohistochemistry and DNA sequencing. Organoids were exposed to chemo- and radiotherapy and a panel of targeted agents. Organoid response was correlated with patient clinical response. CRISPR-Cas9-based gene editing of organoids was applied for biomarker validation. FINDINGS A HNC biobank consisting of 110 models, including 65 tumor models, was generated. Organoids retained DNA alterations found in HNC. Comparison of organoid and patient response to radiotherapy (primary [n = 6] and adjuvant [n = 15]) indicated potential for guiding treatment options in the adjuvant setting. In organoids, the radio-sensitizing potential of cisplatin and carboplatin could be validated. However, cetuximab conveyed radioprotection in most models. HNC-targeted treatments were tested on 31 models, indicating possible novel treatment options with the potential for treatment stratification in the future. Activating PIK3CA mutations did not predict alpelisib response in organoids. Protein arginine methyltransferase 5 (PRMT5) inhibitors were identified as a potential treatment option for cyclin-dependent kinase inhibitor 2A (CDKN2A) null HNC. CONCLUSIONS Organoids hold potential as a diagnostic tool in personalized medicine for HNC. In vitro organoid response to radiotherapy (RT) showed a trend that mimics clinical response, indicating the predictive potential of patient-derived organoids. Moreover, organoids could be used for biomarker discovery and validation. FUNDING This work was funded by Oncode PoC 2018-P0003.
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In Regard to Dennstädt et al. Int J Radiat Oncol Biol Phys 2023; 115:1004-1005. [PMID: 36822770 DOI: 10.1016/j.ijrobp.2022.11.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 11/06/2022] [Indexed: 02/24/2023]
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MRI visibility and displacement of elective lymph nodes during radiotherapy in head and neck cancer patients. FRONTIERS IN RADIOLOGY 2022; 2:1033521. [PMID: 37492674 PMCID: PMC10365081 DOI: 10.3389/fradi.2022.1033521] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 09/27/2022] [Indexed: 07/27/2023]
Abstract
Background and purpose To decrease the impact of radiotherapy to healthy tissues in the head and neck region, we propose to restrict the elective neck irradiation to elective lymph nodes at risk of containing micro metastases instead of the larger lymph node volumes. To assess whether this new concept is achievable in the clinic, we determined the number, volume changes and displacement of elective lymph nodes during the course of radiotherapy. Materials and methods MRI scans of 10 head and neck cancer (HNC) patients were acquired before radiotherapy and in week 2, 3, 4 and 5 during radiotherapy. The weekly delineations of elective lymph nodes inside the lymph node levels (Ib/II/III/IVa/V) were rigidly registered and analyzed regarding number and volume. The displacement of elective lymph nodes was determined by center of mass (COM) distances, vector-based analysis and the isotropic contour expansion of the lymph nodes of the pre-treatment scan or the scan of the previous week in order to geographically cover 95% of the lymph nodes in the scans of the other weeks. Results On average, 31 elective lymph nodes in levels Ib-V on each side of the neck were determined. This number remained constant throughout radiotherapy in most lymph node levels. The volume of the elective lymph nodes reduced significantly in all weeks, up to 50% in week 5, compared to the pre-treatment scan. The largest median COM displacements were seen in level V, for example 5.2 mm in week 5 compared to the pre-treatment scan. The displacement of elective lymph nodes was mainly in cranial direction. Geographical coverage was obtained when the lymph node volumes were expanded with 7 mm in case the pre-treatment scan was used and 6.5 mm in case the scan of the previous week was used. Conclusion Elective lymph nodes of HNC patients remained visible on MRI and decreased in size during radiotherapy. The displacement of elective lymph nodes differ per lymph node level and were mainly directed cranially. Weekly adaptation does not seem to improve coverage of elective lymph nodes. Based on our findings we expect elective lymph node irradiation is achievable in the clinic.
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Correction to: The course of swallowing problems in the first 2 years after diagnosis of head and neck cancer. Support Care Cancer 2022; 30:9539-9540. [PMID: 36085423 PMCID: PMC9633528 DOI: 10.1007/s00520-022-07355-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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The course of swallowing problems in the first 2 years after diagnosis of head and neck cancer. Support Care Cancer 2022; 30:9527-9538. [PMID: 36040669 PMCID: PMC9633522 DOI: 10.1007/s00520-022-07322-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 08/09/2022] [Indexed: 01/05/2023]
Abstract
INTRODUCTION Head and neck cancer (HNC) and its treatment often negatively impact swallowing function. The aim was to investigate the course of patient-reported swallowing problems from diagnosis to 3, 6, 12, and 24 months after treatment, in relation to demographic, clinical, and lifestyle factors. METHODS Data were used of the Netherlands Quality of Life and Biomedical Cohort Study in head and neck cancer research (NET-QUBIC). The primary outcome measures were the subscales of the Swallowing Quality of Life Questionnaire (SWAL-QOL). Linear mixed-effects models (LMM) were conducted to investigate changes over time and associations with patient, clinical, and lifestyle parameters as assessed at baseline. RESULTS Data were available of 603 patients. There was a significant change over time on all subscales. Before treatment, 53% of patients reported swallowing problems. This number increased to 70% at M3 and decreased to 59% at M6, 50% at M12, and 48% at M24. Swallowing problems (i.e., longer eating duration) were more pronounced in the case of female, current smoking, weight loss prior to treatment, and stage III or IV tumor, and were more prevalent at 3 to 6 months after treatment. Especially patients with an oropharynx and oral cavity tumor, and patients receiving (C)RT following surgery or CRT only showed a longer eating duration after treatment, which did not return to baseline levels. CONCLUSION Half of the patients with HNC report swallowing problems before treatment. Eating duration was associated with sex, smoking, weight loss, tumor site and stage, and treatment modality, and was more pronounced 3 to 6 months after treatment.
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Factors associated with swallowing dysfunction in patients with head and neck cancer. Oral Dis 2022. [PMID: 35298058 DOI: 10.1111/odi.14192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 03/03/2022] [Accepted: 03/13/2022] [Indexed: 11/29/2022]
Abstract
BACKGROUND The aim of this prospective cohort study was to investigate swallowing function in relation to personal and clinical factors among patients with head and neck cancer (HNC) from diagnosis up to 2 years after treatment. METHODS The 100 mL water swallow test was measured before treatment, and 3, 6, 12, and 24 months after treatment. Linear mixed-effects model analysis was conducted to investigate changes over time and the association with personal (sex, age) and clinical (tumor site, tumor stage, treatment modality) factors. RESULTS Among 128 included patients, number of swallows increased from baseline to 3 months after treatment and decreased to baseline again at 6 months after treatment. The number of swallows was associated with age and treatment modality. CONCLUSIONS In patients with HNC, swallowing (dys)function changes over time with the worst score 3 months after treatment. A higher age and being treated with surgery are factors associated with swallowing dysfunction over time.
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Magnetic resonance guided elective neck irradiation targeting individual lymph nodes: A new concept. Phys Imaging Radiat Oncol 2022; 20:76-81. [PMID: 35169639 PMCID: PMC8829887 DOI: 10.1016/j.phro.2021.10.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 10/29/2021] [Accepted: 10/29/2021] [Indexed: 11/24/2022] Open
Abstract
Individual elective lymph nodes can be identified using multiple Dixon T2-weighted turbo spin echo with fat suppression. Magnetic Resonance guided individual lymph node irradiation results in lower dose to the organs at risk. Especially the submandibular glands, carotid arteries and thyroid can be spared. The magnetic field on the magnetic resonance imaging - linear accelerator did not lead to increased skin dose depositions.
Background and purpose Conventional elective neck irradiation (ENI) in head and neck cancer consists of radiotherapy (RT) to the regional lymph node (LN) levels contoured on computed tomography. Hybrid Magnetic Resonance (MR) - RT modalities, such as combined magnetic resonance imaging - linear accelerators (MRLs), might enable new ENI strategies in which individual non-suspect lymph nodes (i-LNs) are targeted. In this treatment planning study, new MR-based strategies targeting i-LNs (i-ENI) were compared to conventional treatment. Materials and methods All i-LNs were delineated on MR images of ten retrospectively selected patients with T2-4aN0M0 laryngeal cancer. Three strategies were considered. Strategy A: Conventional ENI delivered with a conventional linear accelerator (35x 1.55 Gy). Strategy B: MRL-based i-ENI (35x 1.55 Gy) to the individual lymph nodes including a background dose to the conventional elective neck volumes (35x 1.03 Gy). Strategy C: Same as Strategy B, but without background dose. In all plans the dose prescription to the primary tumor was 35x 2 Gy. Mean dose (Dmean) reductions in the organs at risk (OAR) were compared using the Wilcoxon signed rank test. Results Compared to conventional ENI (strategy A), significant Dmean reductions of 6.0 Gy and 8.0 Gy were observed in the submandibular glands, of 9.4 Gy and 13 Gy in the carotid arteries and of 9.9 Gy and 19.4 Gy in the thyroid for strategy B and C, respectively. Large inter-patient variations of Dmean reductions were observed in all OARs. Conclusion MRL-based i-ENI is a new promising concept that could reduce the mean dose to OARs in the neck significantly for patients with laryngeal cancer.
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Key Words
- CA, carotid arteries
- Dmean, mean dose
- ENI, elective neck irradiation
- Head and neck neoplasms
- LNs, lymph nodes
- Lymph nodes
- MRL, magnetic resonance imaging linear accelerator
- Magnetic resonance imaging
- OAR, organ at risk
- OC, oral cavity (OC)
- PCM, pharynx constrictor muscle
- PG, parotid gland
- Radiotherapy
- SMG, submandibular gland
- Squamous cell carcinoma of head and neck
- i-ENI, individual non-suspect lymph node elective neck irradiation
- i-LNs, individual lymph nodes
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Factors associated with masticatory function as measured with the Mixing Ability Test in patients with head and neck cancer before and after treatment: a prospective cohort study. Support Care Cancer 2022; 30:4429-4436. [PMID: 35106658 PMCID: PMC8942951 DOI: 10.1007/s00520-022-06867-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 01/24/2022] [Indexed: 11/17/2022]
Abstract
Purpose After treatment for head and neck cancer (HNC), patients often experience major problems in masticatory function. The aim of this prospective cohort study among patients with HNC was to investigate which personal and clinical factors are associated with masticatory function from diagnosis up to 2 years after treatment with curative intent. Methods Masticatory function was measured using the Mixing Ability Test (MAT) before treatment (baseline), and 3, 6, 12, and 24 months after treatment. A linear mixed-effects model with a random intercept and slope was conducted to investigate changes over time and the association with personal (sex, age) and clinical (tumor site, tumor stage, treatment modality) factors as measured at baseline. Result One-hundred-twenty-five patients were included. The prevalence of masticatory dysfunction was estimated at 29% at M0, 38% at M3, 28% at M6, 26% at M12, and 36% at M24. A higher (worse) MAT score was associated with age, tumor stage, tumor site, timing of assessment, and the interaction between assessment moment and tumor site. Conclusion In patients with HNC, masticatory function changed over time and dysfunction was associated with a higher age, a tumor in the oral cavity, a higher tumor stage, and a shorter time since treatment. The prevalence of masticatory dysfunction ranged from 26 to 38%. Supplementary Information The online version contains supplementary material available at 10.1007/s00520-022-06867-0.
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Mastication, swallowing, and salivary flow in patients with head and neck cancer: objective tests versus patient-reported outcomes. Support Care Cancer 2021; 29:7793-7803. [PMID: 34170408 PMCID: PMC8550505 DOI: 10.1007/s00520-021-06368-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 06/14/2021] [Indexed: 11/18/2022]
Abstract
Purpose Before and after treatment for head and neck cancer (HNC), many patients have problems with mastication, swallowing, and salivary flow. The aim of this study was to investigate the association between objective test outcomes of mastication, swallowing, and salivary flow versus patient-reported outcomes (PROs) measuring mastication-, swallowing-, and salivary flow–related quality of life. Methods Data of the prospective cohort “Netherlands Quality of Life and Biomedical Cohort Study” was used as collected before treatment, and 3 and 6 months after treatment. Spearman’s rho was used to test the association between objective test outcomes of the mixing ability test (MAT) for masticatory performance, the water-swallowing test (WST) for swallowing performance, and the salivary flow test versus PROs (subscales of the EORTC QLQ-H&N35, Swallow Quality of Life questionnaire (SWAL-QoL-NL) and Groningen Radiation-Induced Xerostomia (GRIX)). Results Data of 142 patients were used, and in total, 285 measurements were performed. No significant correlations were found between the MAT or WST and subscales of the EORTC QLQ-H&N35. Significant but weak correlations were found between the MAT or WST and 4 subscales of the SWAL-QoL-NL. Weak to moderate correlations were found between the salivary flow test and GRIX at 3 and 6 months after treatment, with the highest correlation between salivary flow and xerostomia during the day (Spearman’s rho = − 0.441, p = 0.001). Conclusion The association between objective test outcomes and PROs is weak, indicating that these outcome measures provide different information about masticatory performance, swallowing, and salivary flow in patients with HNC. Supplementary Information The online version contains supplementary material available at 10.1007/s00520-021-06368-6.
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Reliability of the 100 mL water swallow test in patients with head and neck cancer and healthy subjects. Head Neck 2021; 43:2468-2476. [PMID: 33955058 PMCID: PMC9543915 DOI: 10.1002/hed.26723] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 03/08/2021] [Accepted: 04/14/2021] [Indexed: 12/14/2022] Open
Abstract
Background Dysphagia may occur in up to 44% of patients with head and neck cancer (HNC) treated with radiation therapy and up to 84% of patients treated with surgery. To test the extent of dysphagia, the 100 mL water swallow test (WST) was developed. In this study, reliability of the 100 mL WST was determined in patients with HNC and healthy subjects. Methods Thirty‐three patients and 40 healthy subjects performed the WST twice on the same day. To assess reliability, the intraclass correlation coefficient (ICC2,1), standard error of measurement, smallest detectable change, and limits of agreement were calculated. Results Good to excellent correlations were found for patients with HNC (number of swallows; ICC = 0.923, duration; ICC = 0.893), and excellent correlations for healthy subjects (number of swallows; ICC = 0.950, duration; ICC = 0.916). Conclusion The 100 mL WST has a good to excellent reliability in patients with HNC and healthy subjects.
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Author's response to letter to the editor regarding JHAM Kaanders et al. "Advances in cancer imaging require renewed radiotherapy dose and target volume concepts". Radiother Oncol 2020; 154:e9. [PMID: 32512074 DOI: 10.1016/j.radonc.2020.05.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 05/22/2020] [Indexed: 11/26/2022]
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Reliability of the mixing ability test testing masticatory performance in patients with head and neck cancer and healthy controls. J Oral Rehabil 2020; 47:961-966. [PMID: 32495364 PMCID: PMC7497093 DOI: 10.1111/joor.13029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 05/11/2020] [Accepted: 05/24/2020] [Indexed: 12/19/2022]
Abstract
Background Treatment of patients with head and neck cancer can result in disrupted mastication. To measure masticatory performance in people with compromised mastication, the mixing ability test (MAT) was developed. Objective In this study, the reliability of the MAT was evaluated in patients with head and neck cancer and healthy controls. Methods Thirty‐four patients with head and neck cancer and 42 healthy controls performed the MAT twice on the same day. To assess reliability, the intra‐class correlation coefficient (ICC2,1), standard error of measurement (SEM), smallest detectable change (SDC) and limits of agreement (LoA) were calculated. Results A good (ICC = 0.886) and moderate correlation (ICC = 0.525) were found for patients and healthy controls, respectively. Patients had a worse mixing ability (mean = 19.12, SD = 4.56) in comparison with healthy controls (mean = 16.42, SD = 2.04). The SEM was 0.76 in patients and 1.45 in healthy controls, with a SDC of 2.12 and 4.02, respectively. The LoA was −4.46 to 4.42 in patients and −3.65 to 4.59 in healthy controls. Conclusion The MAT has a good reliability in patients with head and neck cancer and a moderate reliability in healthy controls.
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Brain and Head-and-Neck MRI in Immobilization Mask: A Practical Solution for MR-Only Radiotherapy. Front Oncol 2019; 9:647. [PMID: 31380283 PMCID: PMC6650525 DOI: 10.3389/fonc.2019.00647] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 07/02/2019] [Indexed: 01/08/2023] Open
Abstract
In brain/head-and-neck radiotherapy (RT), thermoplastic immobilization masks guarantee reproducible patient positioning in treatment position between MRI, CT, and irradiation. Since immobilization masks do not fit in the diagnostic MR head/head-and-neck coils, flexible surface coils are used for MRI imaging in clinical practice. These coils are placed around the head/neck, in contact with the immobilization masks. However, the positioning of these flexible coils is technician dependent, thus leading to poor image reproducibility. Additionally, flexible surface coils have an inferior signal-to-noise-ratio (SNR) compared to diagnostic coils. The aim of this work was to create a new immobilization setup which fits into the diagnostic MR coils in order to enhance MR image quality and reproducibility. For this purpose, a practical immobilization setup was constructed. The performances of the standard clinical and the proposed setups were compared with four tests: SNR, image quality, motion restriction, and reproducibility of inter-fraction subject positioning. The new immobilization setup resulted in 3.4 times higher SNR values on average than the standard setup, except directly below the flexible surface coils where similar SNR was observed. Overall, the image quality was superior for brain/head-and-neck images acquired with the proposed RT setup. Comparable motion restriction in feet-head/left-right directions (maximum motion ≈1 mm) and comparable inter-fraction repositioning accuracy (mean inter-fraction movement 1 ± 0.5 mm) were observed for the standard and the new setup.
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Intrafraction motion quantification and planning target volume margin determination of head-and-neck tumors using cine magnetic resonance imaging. Radiother Oncol 2018; 130:82-88. [PMID: 30336955 DOI: 10.1016/j.radonc.2018.09.015] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 09/10/2018] [Accepted: 09/19/2018] [Indexed: 12/21/2022]
Abstract
PURPOSE To quantify intrafractional motion to determine population-based radiotherapy treatment margins for head-and-neck tumors. METHODS Cine MR imaging was performed in 100 patients with head-and-neck cancer on a 3T scanner in a radiotherapy treatment setup. MR images were analyzed using deformable image registration (optical flow algorithm) and changes in tumor contour position were used to calculate the tumor motion. The tumor motion was used together with patient setup errors (450 patients) to calculate population-based PTV margins. RESULTS Tumor motion was quantified in 84 patients (12/43/29 nasopharynx/oropharynx/larynx, 16 excluded). The mean maximum (95th percentile) tumor motion (swallowing excluded) was: 2.3 mm in superior, 2.4 mm in inferior, 1.8 mm in anterior and 1.7 mm in posterior direction. PTV margins were: 2.8 mm isotropic for nasopharyngeal tumors, 3.2 mm isotropic for oropharyngeal tumors and 4.3 mm in inferior-superior and 3.2 mm in anterior-posterior for laryngeal tumors, for our institution. CONCLUSIONS Intrafractional head-and-neck tumor motion was quantified and population-based PTV margins were calculated. Although the average tumor motion was small (95th percentile motion <3.0 mm), tumor motion varied considerably between patients (0.1-12.0 mm). The intrafraction motion expanded the CTV-to-PTV with 1.7 mm for laryngeal tumors, 0.6 mm for oropharyngeal tumors and 0.2 mm for nasopharyngeal tumors.
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Target Volume Delineation Using Diffusion-weighted Imaging for MR-guided Radiotherapy: A Case Series of Laryngeal Cancer Validated by Pathology. Cureus 2018; 10:e2465. [PMID: 29900085 PMCID: PMC5997430 DOI: 10.7759/cureus.2465] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
In radiotherapy treatment planning, tumor delineation based on diffusion-weighted imaging (DWI) by magnetic resonance imaging (MRI) is a promising technique. MR-only-based target definition becomes important with the recent development of MRI integrated radiotherapy treatment modalities. In this case series, DWI-based gross tumor volume (GTV) was validated using pathology and compared with a clinical GTV based on computed tomography (CT) imaging and MRI. This case series includes three patients with a laryngeal tumor. Prior to total laryngectomy (TLE), imaging was performed on CT and MRI, including a DWI scan. After TLE, the surgical specimen was processed and cut into 3-mm thick slices. The tumor was delineated on hematoxylin-eosin (HE) stained sections by a pathologist (tumorHE). This pathological imaging, including the tumorHE delineation, was three-dimensionally reconstructed and registered to the imaging. The GTV was delineated by a radiation oncologist based on CT and MR imaging (GTVclinical) and semi-automatically delineated based on DWI (GTVDWI). The microscopic tumor extent outside the GTVDWI contour was 3.0 mm, 2.7 mm, and 11.3 mm for cases I, II, and III, respectively. The microscopic tumor extent outside the GTVclinical was 7.5 mm, 2.1 mm, and 1.5 mm for cases I, II, and III, respectively. The tumor, on histology, was covered by the GTVs for 80%, 74%, and 31% (GTVDWI) and 73%, 72%, and 89% (GTVclinical) for the three subsequent cases, respectively. The GTVDWI resembled the tumorHE more than the GTVclinical in case I and case II. In case III, GTVDWI missed the caudal part of the tumor that was included in the clinical delineation due to a lack of contrast and the heterogeneous signal intensity of the tumor in DWI. In this case series, we showed the potential of DWI for MR-guided radiotherapy treatment if a clear contrast is visible. DWI-based GTV delineation might be a fast alternative to manual delineation, which could speed up the on-table target definition using an MRI-linac system. A larger case series is needed to verify these results.
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Uniform FDG-PET guided GRAdient Dose prEscription to reduce late Radiation Toxicity (UPGRADE-RT): study protocol for a randomized clinical trial with dose reduction to the elective neck in head and neck squamous cell carcinoma. BMC Cancer 2017; 17:208. [PMID: 28327089 PMCID: PMC5361684 DOI: 10.1186/s12885-017-3195-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 03/14/2017] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND In definitive radiation therapy for head and neck cancer, clinically uninvolved cervical lymph nodes are irradiated with a so-called 'elective dose' in order to achieve control of clinically occult metastases. As a consequence of high-resolution diagnostic imaging, occult tumor volume has significantly decreased in the last decades. Since the elective dose is dependent on occult tumor volume, the currently used elective dose may be higher than necessary. Because bilateral irradiation of the neck contributes to dysphagia, xerostomia and hypothyroidism in a dose dependent way, dose de-escalation to these regions can open a window of opportunity to reduce toxicity and improve quality of life after treatment. METHODS UPGRADE-RT is a multicenter, phase III, single-blinded, randomized controlled trial. Patients to be treated with definitive radiation therapy for a newly diagnosed stage T2-4 N0-2 M0 squamous cell carcinoma of the oropharynx, hypopharynx or larynx are eligible. Exclusion criteria are recurrent disease, oncologic surgery to the head and neck area, concomitant chemotherapy or epidermal growth factor receptor inhibitors. In total, 300 patients will be randomized in a 2:1 ratio to a treatment arm with or without de-escalation of the elective radiation dose and introduction of an intermediate dose-level for selected lymph nodes. Radiation therapy planning FDG-PET/CT-scans will be acquired to guide risk assessment of borderline-sized cervical nodes that can be treated with the intermediate dose level. Treatment will be given with intensity-modulated radiation therapy or volumetric arc therapy with simultaneous-integrated boost using an accelerated fractionation schedule, 33 fractions in 5 weeks. The primary endpoint is 'normalcy of diet' at 1 year after treatment (toxicity). The secondary endpoint is the actuarial rate of recurrence in electively irradiated lymph nodes at 2 years after treatment (safety). DISCUSSION The objective of the UPGRADE-RT trial is to investigate whether de-escalation of elective radiation dose and the introduction of an intermediate dose-level for borderline sized lymph nodes in the treatment of head and neck cancer will result in less radiation sequelae and improved quality of life after treatment without compromising the recurrence rate in the electively treated neck. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT02442375 .
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Modality-specific target definition for laryngeal and hypopharyngeal cancer on FDG-PET, CT and MRI. Radiother Oncol 2017; 123:63-70. [PMID: 28259450 DOI: 10.1016/j.radonc.2017.02.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 12/21/2016] [Accepted: 02/05/2017] [Indexed: 11/19/2022]
Abstract
BACKGROUND AND PURPOSE The goal of this study was to improve target definition by deriving modality-specific margins for clinical target volumes (CTV) for laryngeal and hypopharyngeal cancer on CT, MRI and 18-FDG-PET. MATERIAL AND METHODS Twenty-five patients with T3/T4 laryngeal/hypopharyngeal cancer underwent CT, MRI and 18-FDG-PET scans before laryngectomy. HE-sections were obtained from the surgical specimen and tumor was delineated (tumorHE). The GTVs on CT and MRI were delineated in consensus. PET-based GTVs were automatically segmented. The three-dimensionally reconstructed specimen was registered to the various images. Modality-specific CTV margins were derived and added to the GTVs to achieve adequate tumor coverage. The resulting CTVs were compared with each other, to tumorHE, and to CTVCT10 constructed on CT with the clinical margin of 10mm. RESULTS CTV margins of 4.3mm (CT), 6.1mm (MRI) and 5.2mm (PET) were needed to achieve adequate tumor coverage. The median volumes of the resulting modality-specific CTVs were 44ml (CT), 48ml (MRI) and 39ml (PET), while the CTV10mm was 80ml. CONCLUSION For laryngohypopharyngeal tumors, 45-52% target volume reduction compared with CTV10mm is achievable when modality-specific CTV margins are used. PET-based CTVs were significantly smaller compared to CT- and MRI-based CTVs.
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Interobserver variation among pathologists for delineation of tumor on H&E-sections of laryngeal and hypopharyngeal carcinoma. How good is the gold standard? Acta Oncol 2015; 55:391-5. [PMID: 26073449 DOI: 10.3109/0284186x.2015.1049661] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Comparison of DCE-CT models for quantitative evaluation ofKtransin larynx tumors. Phys Med Biol 2015; 60:3759-73. [DOI: 10.1088/0031-9155/60/9/3759] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
BACKGROUND AND PURPOSE To determine the spatial correspondence between the gross tumor volume (GTV) delineated on computer tomography (CT) and the actual tumor on histopathology. MATERIAL AND METHODS Sixteen patients with T3 or T4 laryngeal or hypopharyngeal cancer underwent a CT scan before total laryngectomy. The GTV was delineated on CT by three independent observers and by consensus between the three observers. After surgery, whole-mount hematoxylin-eosin stained (H&E) sections were obtained. One pathologist delineated the tumor in the H&E sections (tumorH&E). The reconstructed specimen was registered to the CT scan in order to compare the GTV to the tumorH&E in three dimensions. The overlap between the GTV and the tumorH&E was calculated and the distance between the volumes was determined. RESULTS Tumor tissue was delineated in 203 of 516 H&E sections. For 14 patients a detailed analysis could be performed. The GTV volume was on average 1.7 times larger than the volume of the tumorH&E. The mean coverage of the tumorH&E by the consensus GTV was 88%. tumorH&E tissue was found at 1.6 mm to 12.9 mm distance outside the GTV depending on observer and patient. CONCLUSIONS GTVs delineated on CT for laryngeal and hypopharyngeal cancer were 1.7 times larger than the tumor. Complete coverage of the tumor by the GTV was, however, not obtained.
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GTV delineation in supraglottic laryngeal carcinoma: interobserver agreement of CT versus CT-MR delineation. Radiat Oncol 2015; 10:26. [PMID: 25612508 PMCID: PMC4327804 DOI: 10.1186/s13014-014-0321-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Accepted: 12/23/2014] [Indexed: 11/10/2022] Open
Abstract
Background GTV delineation is the first crucial step in radiotherapy and requires high accuracy, especially with the growing use of highly conformal and adaptive radiotherapy techniques. If GTV delineations of observers concord, they are considered to be of high accuracy. The aim of the study is to determine the interobserver agreement for GTV delineations of supraglottic laryngeal carcinoma on CT and on CT combined with MR-images and to determine the effect of adding MR images to CT-based delineation on the delineated volume and the interobserver agreement. Methods Twenty patients with biopsy proven T1-T4 supraglottic laryngeal cancer, treated with curative intent were included. For all patients a contrast enhanced planning CT and a 1.5-T MRI with gadolinium were acquired in the same head-and-shoulder mask for fixation as used during treatment. For MRI, a two element surface coil was used as a receiver coil. Three dedicated observers independently delineated the GTV on CT. After an interval of 2 weeks, a set of co-registered CT and MR-images was provided to delineate the GTV on CT. Common volumes (C) and encompassing volumes (E) were calculated and C/E ratios were determined for each pair of observers. The conformity index general (CIgen) was used to quantify the interobserver agreement. Results: In general, a large variation in interobserver agreement was found for CT (range: 0.29-0.77) as well as for CT-MR delineations (range: 0.17-0.80). The mean CIgen for CT (0.61) was larger compared to CT-MR (0.57) (p = 0.032). Mean GTV volume delineated on CT-MR (6.6 cm3) was larger compared to CT (5.6 cm3) (p = 0.002). Conclusion Delineation on CT with co-registered MR-images resulted in a larger mean GTV volume and in a decrease in interobserver agreement compared to CT only delineation for supraglottic laryngeal carcinoma. Electronic supplementary material The online version of this article (doi:10.1186/s13014-014-0321-4) contains supplementary material, which is available to authorized users.
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Consequences of tumor planning target volume reduction in treatment of T2-T4 laryngeal cancer. Radiat Oncol 2014; 9:195. [PMID: 25190181 PMCID: PMC4261247 DOI: 10.1186/1748-717x-9-195] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 07/11/2014] [Indexed: 12/02/2022] Open
Abstract
Background and purpose Since lymph nodes volumes are generally four times the volume of the primary PTV, the advantage of using tight margins around the primary PTV is not clear. Therefore treatment margins of T2-T4 laryngeal carcinoma for IMRT are generally chosen in such a way that the PTV is comparable to that in conventional radiotherapy. The aim of this study is to quantify the effect of volume reduction of the primary PTV of T2-T4 laryngeal carcinoma with regard to late toxicity despite elective irradiation of lymph node levels II to IV. Methods Two treatment plans based on conservative (GTV-PTV = 15 mm and 20 mm cranial), and on evidence-based tight margins (GTV-PTV = 8 mm) were calculated for 16 patients. Toxicity effects were estimated based on the dose distributions. Results Compared to conservative margins, using tight margins resulted in: 1) significant reduction of the normal tissue complication probability (NTCP) for swallowing muscles and submandibular glands, 2) significant reduction of the mean dose in all organs at risk (OAR), 3) a mean dose smaller than 60 Gy for all OARs except for the laryngeal cartilages. When the lymph node levels II to IV were prescribed with an elective dose, an NTCP reduction of 53% for the swallowing muscles and of 23% for the submandibular glands was found by using tight instead of conservative margins. When positive nodes were present, NTCP reduction amounted to 29% and 15%, respectively. Conclusions There is a potential benefit in realizing evidence-based tight margins for laryngeal cancer patients despite elective irradiation of lymph node levels II to IV.
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Xerostomia: a day and night difference. Radiother Oncol 2012; 104:219-23. [PMID: 22809589 DOI: 10.1016/j.radonc.2012.06.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Revised: 05/18/2012] [Accepted: 06/07/2012] [Indexed: 10/28/2022]
Abstract
PURPOSE To compare patient-reported xerostomia during daytime and during nighttime with objectively measured parotid and submandibular gland function in a cohort of head-and-neck cancer (HNC) patients treated with RT. MATERIALS AND METHODS A cohort of 138 HNC patients underwent objective measurements of parotid (PF) and submandibular (SMF) gland function and completed a xerostomia questionnaire (XQ) before RT, at 6 weeks, 6 months and 1 year after RT. No attempt was made to spare the submandibular gland(s). The XQ contained specific questions concerning the sensation of dry mouth during day- (XD) and nighttime (XN), scored on a 5-point Likert scale. Patients with no or mild (grade 1-3) xerostomia and patients with more severe (grade 4-5) complaints were grouped together. RESULTS Before RT, no association existed between dry mouth complaints and PF or SMF. At 6 weeks, 6 months and 1 year after RT; 37%, 51% and 36% had grade 4-5 XD and 65%, 64% and 56% had grade 4-5 XN, respectively. Patients with grade 4-5 XD and XN had significantly worse SMF at all time points after RT compared to patients with grade 1-3 XD and XN, while PF was significantly worse only at 6 weeks after RT. In multivariate analyses, SMF was consistently the most important factor related to XN after treatment. PF significantly influenced XD at 6 weeks and 1 year after RT. CONCLUSIONS Differentiating between complaints during day- and nighttime in xerostomia research is necessary. Dry mouth at night is a frequent problem after (parotid-sparing) RT for HNC and is explained by submandibular gland dysfunction. Sparing of the contralateral submandibular gland, in addition to parotid gland sparing, may result in improved patient-reported xerostomia.
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MUC5B levels in submandibular gland saliva of patients treated with radiotherapy for head-and-neck cancer: a pilot study. Radiat Oncol 2012; 7:91. [PMID: 22704532 PMCID: PMC3434044 DOI: 10.1186/1748-717x-7-91] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Accepted: 06/05/2012] [Indexed: 11/13/2022] Open
Abstract
Background The salivary mucin MUC5B, present in (sero)mucous secretions including submandibular gland (SMG) saliva, plays an important role in the lubrication of the oral mucosa and is thought to be related to the feeling of dry mouth. We investigated if MUC5B levels in SMG saliva could distinguish between the presence or absence of severe dry mouth complaints 12 months after radiotherapy (RT) for head-and-neck cancer (HNC). Findings Twenty-nine HNC patients with a residual stimulated SMG secretion rate of ≥0.2 ml/10 min at 12 months after RT were analyzed. MUC5B (in U; normalized to 1) and total protein levels (mg/ml) were measured in SMG saliva at baseline and 12 months after RT using ELISA and BCA protein assay, respectively. Overall, median MUC5B levels decreased after RT from 0.12 to 0.03 U (p = 0.47). Patients were dichotomized into none/mild xerostomia (n = 12) and severe xerostomia (n = 17) based on a questionnaire completed at 12 months. SMG and whole saliva flow rates decreased after RT but were comparable in both groups. The median MUC5B level was higher in patients with no or mild xerostomia compared to patients with severe xerostomia (0.14 vs 0.01 U, p = 0.22). Half of the patients with severe xerostomia had no detectable MUC5B at 12 months after RT. No differences in total protein levels were observed. Conclusions Qualitative saliva parameters like MUC5B need further investigation in RT-induced xerostomia. This pilot study showed a trend towards lower MUC5B levels in the SMG saliva of patients with severe xerostomia 12 months after RT for HNC.
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MRI to quantify early radiation-induced changes in the salivary glands. Radiother Oncol 2011; 100:386-9. [PMID: 21924787 DOI: 10.1016/j.radonc.2011.08.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2011] [Revised: 08/24/2011] [Accepted: 08/25/2011] [Indexed: 10/17/2022]
Abstract
PURPOSE We investigated radiation-induced changes in the salivary glands, 6 weeks after RT, using MRI. MATERIALS AND METHODS Eighteen oropharyngeal cancer patients were treated with salivary gland sparing IMRT. All patients received a 3T MRI exam before and 6 weeks after the end of RT, including a T(1)-weighted (T(1)w), a T(2)-weighted (T(2)w), and a dynamic contrast-enhanced (DCE) MRI. For both time points separately, the parotid and submandibular glands were delineated on the MR images. Differences in median signal intensity and signal variation within the glands were tested for significance. Correlations were studied between the MR changes and the planned RT dose. RESULTS The volume of the glands reduced significantly by 25%. The T(1)w signal decreased by 10% and the T(2)w signal increased by 23%. The k(ep) value decreased, while the v(e) increased. A correlation of the changes in T(2)w signal with the mean dose was found in both glands. CONCLUSIONS Overall radiation-induced changes and volume loss were observed in the parotid and submandibular gland using MR. The observed differences indicated an increased water content such as found in oedema. The overall changes could be related to the mean dose, with a slightly greater impact in the high dose area.
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Validation of imaging with pathology in laryngeal cancer: accuracy of the registration methodology. Int J Radiat Oncol Biol Phys 2011; 82:e289-98. [PMID: 21719209 DOI: 10.1016/j.ijrobp.2011.05.004] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Revised: 03/23/2011] [Accepted: 05/10/2011] [Indexed: 11/25/2022]
Abstract
PURPOSE To investigate the feasibility and accuracy of an automated method to validate gross tumor volume (GTV) delineations with pathology in laryngeal and hypopharyngeal cancer. METHODS AND MATERIALS High-resolution computed tomography (CT(HR)), magnetic resonance imaging (MRI), and positron emission tomography (PET) scans were obtained from 10 patients before total laryngectomy. The GTV was delineated separately in each imaging modality. The laryngectomy specimen was sliced transversely in 3-mm-thick slices, and whole-mount hematoxylin-eosin stained (H&E) sections were obtained. A pathologist delineated tumor tissue in the H&E sections (GTV(PATH)). An automatic three-dimensional (3D) reconstruction of the specimen was performed, and the CT(HR), MRI, and PET were semiautomatically and rigidly registered to the 3D specimen. The accuracy of the pathology-imaging registration and the specimen deformation and shrinkage were assessed. The tumor delineation inaccuracies were compared with the registration errors. RESULTS Good agreement was observed between anatomical landmarks in the 3D specimen and in the in vivo images. Limited deformations and shrinkage (3% ± 1%) were found inside the cartilage skeleton. The root mean squared error of the registration between the 3D specimen and the CT, MRI, and PET was on average 1.5, 3.0, and 3.3 mm, respectively, in the cartilage skeleton. The GTV(PATH) volume was 7.2 mL, on average. The GTVs based on CT, MRI, and PET generated a mean volume of 14.9, 18.3, and 9.8 mL and covered the GTV(PATH) by 85%, 88%, and 77%, respectively. The tumor delineation inaccuracies exceeded the registration error in all the imaging modalities. CONCLUSIONS Validation of GTV delineations with pathology is feasible with an average overall accuracy below 3.5 mm inside the laryngeal skeleton. The tumor delineation inaccuracies were larger than the registration error. Therefore, an accurate histological validation of anatomical and functional imaging techniques for GTV delineation is possible in laryngeal cancer patients.
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Parotid gland function after radiotherapy: the combined michigan and utrecht experience. Int J Radiat Oncol Biol Phys 2010; 78:449-53. [PMID: 20056347 DOI: 10.1016/j.ijrobp.2009.07.1708] [Citation(s) in RCA: 130] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Revised: 07/24/2009] [Accepted: 07/24/2009] [Indexed: 01/25/2023]
Abstract
PURPOSE To analyze the combined and updated results from the University of Michigan and University Medical Center Utrecht on normal tissue complication probability (NTCP) of the parotid gland 1 year after radiotherapy (RT) for head-and-neck (HN) cancer. PATIENTS AND METHODS A total of 222 prospectively analyzed patients with various HN malignancies were treated with conventional and intensity-modulated RT. Stimulated individual parotid gland flow rates were measured before RT and 1 year after RT using Lashley cups at both centers. A flow ratio <25% of pretreatment was defined as a complication. The data were fitted to the Lyman-Kutcher-Burman model. RESULTS A total of 384 parotid glands (Michigan: 157; Utrecht: 227 glands) was available for analysis 1 year after RT. Combined NTCP analysis based on mean dose resulted in a TD(50) (uniform dose leading to 50% complication probability) of 39.9 Gy and m (steepness of the curve) of 0.40. The resulting NTCP curve had good qualitative agreement with the combined clinical data. Mean doses of 25-30 Gy were associated with 17-26% NTCP. CONCLUSIONS A definite NTCP curve for parotid gland function 1 year after RT is presented, based on mean dose. No threshold dose was observed, and TD(50) was equal to 40 Gy.
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A comparison of dose-response models for the parotid gland in a large group of head-and-neck cancer patients. Int J Radiat Oncol Biol Phys 2009; 76:1259-65. [PMID: 20005639 DOI: 10.1016/j.ijrobp.2009.07.1685] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2009] [Revised: 06/26/2009] [Accepted: 07/15/2009] [Indexed: 10/20/2022]
Abstract
PURPOSE The dose-response relationship of the parotid gland has been described most frequently using the Lyman-Kutcher-Burman model. However, various other normal tissue complication probability (NTCP) models exist. We evaluated in a large group of patients the value of six NTCP models that describe the parotid gland dose response 1 year after radiotherapy. METHODS AND MATERIALS A total of 347 patients with head-and-neck tumors were included in this prospective parotid gland dose-response study. The patients were treated with either conventional radiotherapy or intensity-modulated radiotherapy. Dose-volume histograms for the parotid glands were derived from three-dimensional dose calculations using computed tomography scans. Stimulated salivary flow rates were measured before and 1 year after radiotherapy. A threshold of 25% of the pretreatment flow rate was used to define a complication. The evaluated models included the Lyman-Kutcher-Burman model, the mean dose model, the relative seriality model, the critical volume model, the parallel functional subunit model, and the dose-threshold model. The goodness of fit (GOF) was determined by the deviance and a Monte Carlo hypothesis test. Ranking of the models was based on Akaike's information criterion (AIC). RESULTS None of the models was rejected based on the evaluation of the GOF. The mean dose model was ranked as the best model based on the AIC. The TD(50) in these models was approximately 39 Gy. CONCLUSIONS The mean dose model was preferred for describing the dose-response relationship of the parotid gland.
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Magnetic resonance imaging protocol optimization for delineation of gross tumor volume in hypopharyngeal and laryngeal tumors. Int J Radiat Oncol Biol Phys 2009; 74:630-6. [PMID: 19427562 DOI: 10.1016/j.ijrobp.2009.01.014] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2008] [Revised: 01/05/2009] [Accepted: 01/06/2009] [Indexed: 10/20/2022]
Abstract
PURPOSE To optimize the use of MRI for delineation of gross tumor volume for radiotherapy treatment planning purposes in hypopharyngeal and laryngeal tumors. METHODS AND MATERIALS Magnetic resonance images (T1 weighted and T2 weighted) of a healthy volunteer were acquired using a 1.5 T and 3.0 T MR scanner. Various receiver coils were investigated that were compatible with the immobilization mask needed for reliable coregistration with computed tomography data. For the optimal receiver coil, the influence of resolution, slice thickness, and strength of magnetic field on the signal-to-noise ratio (SNR) was studied. Feasibility of the definitive protocol was tested on patients with hypopharyngeal (n = 19) and laryngeal (n = 42) carcinoma. RESULTS Large differences in SNR were obtained for the various coils. The SNR values obtained using surface coils that were compatible with the immobilization mask were three times higher than those obtained using a standard head-and-neck coil and five times higher than those obtained using a body coil. High-resolution images (0.4 x 0.4 x 4 mm(3)) showed superior anatomic detail and resulted in a 4-min scan time. Image quality at 3.0 T was not significantly better compared with 1.5 T. In 3 patients the MR study could not be performed; for 5 patients images were severely deteriorated by motion artefacts. High-quality MR images were obtained in 53 patients. CONCLUSIONS High-resolution MR images of the hypopharynx and larynx can be obtained in the majority of patients using surface receiver coils in combination with the radiotherapy mask. These MR images can be successfully used for tumor delineation in radiotherapy.
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[Saliva and intensity modulated radiotherapy]. Ned Tijdschr Tandheelkd 2008; 115:107-110. [PMID: 18326407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A dry mouth (xerostomia) is a serious side effect for head and neck cancer patients treated with radiotherapy. The degree of xerostomia is dependent on the dosage in the parotid glands. New, advanced radiation techniques, such as intensity-modulated radiotherapy, can reduce the dosage in the parotid glands, resulting in a significant improvement in the functioning of these glands by comparison with conventional radiation techniques.
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Dose optimization for the MRI-accelerator: IMRT in the presence of a magnetic field. Phys Med Biol 2007; 52:7045-54. [DOI: 10.1088/0031-9155/52/23/018] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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3D MR sialography as a tool to investigate radiation-induced xerostomia: feasibility study. Int J Radiat Oncol Biol Phys 2007; 68:1310-9. [PMID: 17482767 DOI: 10.1016/j.ijrobp.2007.01.062] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2006] [Revised: 01/08/2007] [Accepted: 01/30/2007] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate whether magnetic-resonance (MR) sialography can be used to investigate radiation-induced xerostomia. Preradiotherapy (pre-RT) and postradiotherapy (post-RT) MR sialographic images of the major salivary ducts (parotid and submandibular) were compared. METHODS AND MATERIALS Magnetic-resonance sialography was performed pre-RT, and 6 weeks and 6 months post-RT on 9 patients with T1-4N0-2M0 naso- or oropharyngeal tumors, on a 1.5-T MR scanner. Patients were positioned in the scanner, using a radiotherapy immobilization mask. Image registration of the MR sialograms pre- and post-RT with each other and with the CT and consequently the dose distribution was performed. A categorical scoring system was used to compare the visibility of ducts pre-RT and post-RT. RESULTS Good-quality MR sialographic images were obtained, and image registration was successful in all cases. The visibility score of the parotid ducts and submandibular ducts was reduced at 6 weeks post-RT, which means that the full trajectory of the salivary ducts, from the intraglandular space to the mouth cavity, was only partially visualized. For some of the parotid ducts, the visibility score improved at 6 months post-RT, but not for the submandibular ducts. The mean dose for the parotid glands was 35 Gy (1 standard deviation [SD] 3 Gy), and for the submandibular glands it was 62 Gy (SD, 8 Gy). CONCLUSION Three-dimensional MR sialography is a promising approach for investigating xerostomia, because radiation-induced changes to the saliva content of the ducts can be visualized.
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Cranial location of level II lymph nodes in laryngeal cancer: Implications for elective nodal target volume delineation. Int J Radiat Oncol Biol Phys 2007; 67:462-8. [PMID: 17236968 DOI: 10.1016/j.ijrobp.2006.10.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2006] [Revised: 10/04/2006] [Accepted: 10/04/2006] [Indexed: 10/23/2022]
Abstract
PURPOSE To analyze the cranial distribution of level II lymph nodes in patients with laryngeal cancer to optimize the elective radiation nodal target volume delineation. METHODS AND MATERIALS The most cranially located metastatic lymph node was delineated in 67 diagnostic CT data sets. The minimum distance from the base of the skull (BOS) to the lymph node was determined. RESULTS A total of 98 lymph nodes were delineated including 62 ipsilateral and 36 contralateral lymph nodes. The mean ipsilateral and contralateral distance from the top of the most cranial metastatic lymph node to the BOS was 36 mm (range, -9-120; standard deviation [SD], 17.9) and 35 mm (range, 14-78; SD 15.0), respectively. Only 5% and 12% of the ipsilateral and 3% and 9% of the contralateral metastatic lymph nodes were located within 15 mm and 20 mm below the BOS, respectively. No significant differences were found between patients with only ipsilateral metastatic lymph nodes and patients with bilateral metastatic lymph nodes. Between tumors that do cross the midline and those that do not, no significant difference was found in the distance of the most cranial lymph node to the BOS and the occurrence ipsilateral or contralateral. CONCLUSIONS Setting the cranial border of the nodal target volume 1.5 cm below the base of the skull covers 95% of the lymph nodes and should be considered in elective nodal irradiation for laryngeal cancer. Bilateral neck irradiation is mandatory, including patients with unilateral laryngeal cancer, when elective irradiation is advised.
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Abstract
In this study, we quantify the impact of linac/MLC design parameters on IMRT treatment plans. The investigated parameters were leaf width in the MLC, leaf transmission, related to the thickness of the leaves, and penumbra related primarily to the source size. Seven head-and-neck patients with stage T1-T3N0-N2cM0 oropharyngeal cancer were studied. For each patient nine plans were made with a different set of linac/MLC parameters. The plans were optimized in Pinnacle(3) v7.6c and PLATO RTS v2.6.4, ITP v1.1.8. A hypothetical ideal linac/MLC was introduced to investigate the influence of one parameter at a time without interaction of other parameters. When any of the three parameters was increased from the ideal set-up values (leaf width 2.5 mm, transmission 0%, penumbra 3 mm), the mean dose to the parotid glands increased, given the same tumour coverage. The largest increase was found for increasing leaf transmission. The investigation showed that by changing more than one parameter of the ideal linac/MLC set-up, the increase in the mean dose was smaller than the sum of dose increments for each parameter separately. As a reference to clinical practice, we also optimized the plans of the seven patients with the clinically used Elekta SLi 15, equipped with a standard MLC with a leaf width of 10 mm. As compared to the ideal linac, this resulted in an increase of the average dose to the parotid glands of 5.8 Gy.
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Intensity-modulated radiotherapy significantly reduces xerostomia compared with conventional radiotherapy. Int J Radiat Oncol Biol Phys 2006; 66:975-80. [PMID: 16965864 DOI: 10.1016/j.ijrobp.2006.06.045] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2006] [Revised: 06/13/2006] [Accepted: 06/20/2006] [Indexed: 12/12/2022]
Abstract
PURPOSE Xerostomia is a severe complication after radiotherapy for oropharyngeal cancer, as the salivary glands are in close proximity with the primary tumor. Intensity-modulated radiotherapy (IMRT) offers theoretical advantages for normal tissue sparing. A Phase II study was conducted to determine the value of IMRT for salivary output preservation compared with conventional radiotherapy (CRT). METHODS AND MATERIALS A total of 56 patients with oropharyngeal cancer were prospectively evaluated. Of these, 30 patients were treated with IMRT and 26 with CRT. Stimulated parotid salivary flow was measured before, 6 weeks, and 6 months after treatment. A complication was defined as a stimulated parotid flow rate <25% of the preradiotherapy flow rate. RESULTS The mean dose to the parotid glands was 48.1 Gy (SD 14 Gy) for CRT and 33.7 Gy (SD 10 Gy) for IMRT (p < 0.005). The mean parotid flow ratio 6 weeks and 6 months after treatment was respectively 41% and 64% for IMRT and respectively 11% and 18% for CRT. As a result, 6 weeks after treatment, the number of parotid flow complications was significantly lower after IMRT (55%) than after CRT (87%) (p = 0.002). The number of complications 6 months after treatment was 56% for IMRT and 81% for CRT (p = 0.04). CONCLUSIONS IMRT significantly reduces the number of parotid flow complications for patients with oropharyngeal cancer.
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Assessment of induction of secondary tumours due to various radiotherapy modalities. RADIATION PROTECTION DOSIMETRY 2006; 118:219-26. [PMID: 16513818 DOI: 10.1093/rpd/ncl020] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
One of the objectives of the European Sixth Framework integrated project MAESTRO is to perform an assessment of risk due to various radiotherapy modalities, regarding secondary tumour induction. Initially, the study will focus on cancer of the prostate and the present work represents the first step towards that goal. One of the intended tools, to be used in the assessment, is the Monte Carlo radiation transport code ORANGE. A validation of the ORANGE code's capability to tally dose on a grid superimposed on an existing MCNP geometry is given. Preliminary results on the dose distribution due to conventional radiotherapy treatment of prostate cancer are discussed. Two mathematical models of the patient are proposed and the clinical relevance of the ADAM phantom is investigated. A problem in comparing average doses provided by commercial treatment planning systems and those calculated with Monte Carlo is noticed. The two proposed models are shown to receive a lower dose and average energy deposition than a 'real' patient.
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Comparing step-and-shoot IMRT with dynamic helical tomotherapy IMRT plans for head-and-neck cancer. Int J Radiat Oncol Biol Phys 2005; 62:1535-9. [PMID: 15925457 DOI: 10.1016/j.ijrobp.2005.04.011] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2005] [Revised: 04/07/2005] [Accepted: 04/07/2005] [Indexed: 11/30/2022]
Abstract
PURPOSE The goal of this planning study was to compare step-and-shoot intensity-modulated radiotherapy (IMRT) plans with helical dynamic IMRT plans for oropharynx patients on the basis of dose distribution. METHODS AND MATERIALS Five patients with oropharynx cancer had been previously treated by step-and-shoot IMRT at the University Medical Centre Utrecht, The Netherlands, applying five fields and approximately 60-90 segments. Inverse planning was carried out using Plato, version 2.6.2. For each patient, an inverse IMRT plan was also made using Tomotherapy Hi-Art System, version 2.0, and using the same targets and optimization goals. Statistical analysis was performed by a paired t test. RESULTS All tomotherapy plans compared favorably with the step-and-shoot plans regarding sparing of the organs at risk and keeping an equivalent target dose homogeneity. Tomotherapy plans in particular realized sharper dose gradients compared with the step-and-shoot plans. The mean dose to all parotid glands (n = 10) decreased on average 6.5 Gy (range, -4 to 14; p = 0.002). The theoretical reduction in normal tissue complication probabilities in favor of the tomotherapy plans depended on the parotid normal tissue complication probability model used (range, -3% to 32%). CONCLUSION Helical tomotherapy IMRT plans realized sharper dose gradients compared with the clinically applied step-and shoot plans. They are expected to be able to reduce the parotid normal tissue complication probability further, keeping a similar target dose homogeneity.
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Interobserver variability of clinical target volume delineation of glandular breast tissue and of boost volume in tangential breast irradiation. Radiother Oncol 2005; 76:293-9. [PMID: 16165237 DOI: 10.1016/j.radonc.2005.03.029] [Citation(s) in RCA: 145] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2004] [Revised: 03/04/2005] [Accepted: 03/21/2005] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND PURPOSE To determine the interobserver variability of clinical target volume delineation of glandular breast tissue and of boost volume in tangential breast irradiation. PATIENTS AND METHODS Eighteen consecutive patients with left sided breast cancer treated by breast conserving surgery agreed to participate in our study. Volumes of the glandular breast tissue (CTV breast) and of the boost (CTV boost) were delineated by five observers. We determined 'conformity indices' (CI) and the ratio between the volume of each CTV and the mean volume of all CTVs (CTV ratio). Subsequently we determined the most medial, lateral, anterior, posterior, cranial and caudal extensions both of CTV breast and CTV boost for all observers separately. RESULTS The mean CI breast was 0.87. For one observer we noted the highest CTV ratio in 17 out of 18 cases. No association was noted between CI breast and menopausal status. The mean CI boost was 0.56. We did not find a relation between the presence or absence of clips and the CI boost. For another observer we noted the lowest CTV boost ratio in 10 out of 17 cases. CONCLUSIONS We recommend that each institute should determine its interobserver variability with respect to CTV breast and CTV boost before implementing the delineation of target volumes by planning CT in daily practice.
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Long-term parotid gland function after radiotherapy. Int J Radiat Oncol Biol Phys 2005; 62:659-64. [PMID: 15936542 DOI: 10.1016/j.ijrobp.2004.12.015] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2004] [Revised: 11/24/2004] [Accepted: 12/01/2004] [Indexed: 01/12/2023]
Abstract
PURPOSE Irradiation of the parotid glands causes salivary dysfunction, resulting in reduced salivary flow. Recovery can be seen with time; however, long-term prospective data are lacking. The objective of this study was to analyze the long-term parotid gland function after irradiation for head-and-neck cancer. METHODS AND MATERIALS A total of 52 patients with head-and-neck cancer and treated with radiotherapy (RT) were prospectively evaluated. Stimulated bilateral parotid salivary flow rates were measured before RT and 6 weeks, 6 months, 12 months, and at least 3.5 years after RT completion. A complication was defined as a stimulated parotid flow rate of <25% of the pre-RT flow rate. The normal tissue complication probability model proposed by Lyman was fit to the data. Multilevel techniques were used to model the patterns of flow rates with time. RESULTS The mean stimulated flow rate of the parotid glands before RT was 0.31 mL/min (standard deviation [SD], 0.21). This was reduced to 0.14 mL/min (SD, 0.15) at 6 weeks after RT and recovered to 0.20 mL/min (SD, 0.22) at 6 months and 0.19 mL/min (SD, 0.21) at 12 months after RT. The mean stimulated flow rate was 0.25 mL/min (SD, 0.28) 5 years after RT. The mean dose to the parotid gland resulting in a 50% complication probability increased from 34 Gy at 6 weeks to 40 Gy at 6 months, 42 Gy at 12 months, and 46 Gy at 5 years after RT. Multilevel modeling indicated that both dose and time were significantly associated with the flow ratio. CONCLUSION Salivary output can still recover many years after RT. At 5 years after RT, we found an increase in the salivary flow rate of approximately 32% compared with at 12 months after RT.
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A comparison of mean parotid gland dose with measures of parotid gland function after radiotherapy for head-and-neck cancer: implications for future trials. Int J Radiat Oncol Biol Phys 2005; 63:1006-9. [PMID: 15964708 DOI: 10.1016/j.ijrobp.2005.04.023] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2005] [Revised: 04/12/2005] [Accepted: 04/12/2005] [Indexed: 11/18/2022]
Abstract
PURPOSE To determine the most adequate parameter to measure the consequences of reducing the parotid gland dose. METHODS AND MATERIALS One hundred eight patients treated with radiotherapy for various malignancies of the head and neck were prospectively evaluated using three methods. Parotid gland function was objectively determined by measuring stimulated parotid flow using Lashley cups and scintigraphy. To assess xerostomia-related quality of life, the head-and-neck cancer module European Organization for Research and Treatment of Cancer QLQ (Quality of Life Questionnaire) H&N35 was used. Measurements took place before radiotherapy and 6 weeks and 12 months after the completion of radiotherapy. Complication was defined for each method using cutoff values. The correlation between these complications and the mean parotid gland dose was investigated to find the best measure for parotid gland function. RESULTS For both flow and scintigraphy data, the best definition for objective parotid gland toxicity seemed to be reduction of stimulated parotid flow to < or =25% of the preradiotherapy flow. Of all the subjective variables, only the single item dry mouth 6 weeks after radiotherapy was found to be significant. The best correlation with the mean parotid gland dose was found for the stimulated flow measurements. The predictive ability was the highest for the time point 1 year after radiotherapy. Subjective findings did not correlate with the mean parotid dose. CONCLUSIONS Stimulated flow measurements using Lashley cups, with a complication defined as flow < or =25% of the preradiotherapy output, correlated best with the mean parotid gland dose. When reduction of the mean dose to the parotid gland is intended, the stimulated flow measurement is the best method for evaluating parotid gland function.
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Adequate margins for random setup uncertainties in head-and-neck IMRT. Int J Radiat Oncol Biol Phys 2005; 61:938-44. [PMID: 15708278 DOI: 10.1016/j.ijrobp.2004.11.016] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2004] [Revised: 11/02/2004] [Accepted: 11/09/2004] [Indexed: 10/25/2022]
Abstract
PURPOSE To investigate the effect of random setup uncertainties on the highly conformal dose distributions produced by intensity-modulated radiotherapy (IMRT) for clinical head-and-neck cancer patients and to determine adequate margins to account for those uncertainties. METHODS AND MATERIALS We have implemented in our clinical treatment planning system the possibility of simulating normally distributed patient setup displacements, translations, and rotations. The planning CT data of 8 patients with Stage T1-T3N0M0 oropharyngeal cancer were used. The clinical target volumes of the primary tumor (CTV(primary)) and of the lymph nodes (CTV(elective)) were expanded by 0.0, 1.5, 3.0, and 5.0 mm in all directions, creating the planning target volumes (PTVs). We performed IMRT dose calculation using our class solution for each PTV margin, resulting in the conventional static plans. Then, the system recalculated the plan for each positioning displacement derived from a normal distribution with sigma = 2 mm and sigma = 4 mm (standard deviation) for translational deviations and sigma = 1 degrees for rotational deviations. The dose distributions of the 30 fractions were summed, resulting in the actual plan. The CTV dose coverage of the actual plans was compared with that of the static plans. RESULTS Random translational deviations of sigma = 2 mm and rotational deviations of sigma = 1 degrees did not affect the CTV(primary) volume receiving 95% of the prescribed dose (V(95)) regardless of the PTV margin used. A V(95) reduction of 3% and 1% for a 0.0-mm and 1.5-mm PTV margin, respectively, was observed for sigma = 4 mm. The V(95) of the CTV(elective) contralateral was approximately 1% and 5% lower than that of the static plan for sigma = 2 mm and sigma = 4 mm, respectively, and for PTV margins <5.0 mm. An additional reduction of 1% was observed when rotational deviations were included. The same effect was observed for the CTV(elective) ipsilateral but with smaller dose differences than those for the contralateral side. The effect of the random uncertainties on the mean dose to the parotid glands was not significant. The maximal dose to the spinal cord increased by a maximum of 3 Gy. CONCLUSIONS The margins to account for random setup uncertainties, in our clinical IMRT solution, should be 1.5 mm and 3.0 mm in the case of sigma = 2 mm and sigma = 4 mm, respectively, for the CTV(primary). Larger margins (5.0 mm), however, should be applied to the CTV(elective), if the goal of treatment is a V(95) value of at least 99%.
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Loco-regional conformal radiotherapy of the breast: delineation of the regional lymph node clinical target volumes in treatment position. Radiother Oncol 2004; 71:287-95. [PMID: 15172144 DOI: 10.1016/j.radonc.2004.02.017] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2003] [Revised: 02/14/2004] [Accepted: 02/26/2004] [Indexed: 11/22/2022]
Abstract
BACKGROUND AND PURPOSE As the location of the regional lymph nodes (LNs) of the breast varies largely between patients and may be dependant on the position of the arm, adequate localization of these nodes is mandatory in order to fully take advantage of optimized conformal radiotherapy. For this purpose, the anatomical boundaries of the regional lymph node (LN) clinical target volumes (CTVs) for delineation on transverse CT-slices, made in treatment position, were established. PATIENTS AND METHODS Anatomical and surgical descriptions of the regional LNs of the breast, as well as a shoulder dissection, were studied. Axial slices of a human cadaver with one arm in abduction and the other in adduction were investigated, to assess the displacement of LNs by abduction of the arm into treatment position. Based on these findings, we defined the anatomical boundaries of the regional LN CTVs visible on transverse CT-slices. RESULTS Standard anatomical and surgical descriptions appeared to be inadequate for determination of the boundaries of the regional LN CTVs in treatment position. With abduction of the arm, a change in position of all regional LNs, except for the medial supraclavicular LNs and internal mammary LNs, was observed in the anatomical cross-sections. This was also taken into account in our delineation protocol proposal. CONCLUSIONS Anatomically based guidelines for delineation of the regional LN CTVs for loco-regional irradiation of the breast on transverse CT-slices, made in treatment position, have been developed in this study. These could be used as a basis for conformal radiotherapy.
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Implanted gold markers for position verification during irradiation of head-and-neck cancers: a feasibility study. Int J Radiat Oncol Biol Phys 2004; 59:1011-7. [PMID: 15234034 DOI: 10.1016/j.ijrobp.2004.01.022] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2003] [Revised: 12/29/2003] [Accepted: 01/05/2004] [Indexed: 11/17/2022]
Abstract
PURPOSE To assess the toxicity and reliability of the use of implanted gold markers for position verification during irradiation of head-and-neck cancer. METHODS AND MATERIALS Ten patients with localized head-and-neck tumors received two gold markers in the parapharyngeal region. The acute and late radiation-related toxicity were scored prospectively using the Common Toxicity Criteria. The patients were immobilized during irradiation using a five-point mask. The marker location was detected in portal images taken with an a-Si flat panel imager. The intermarker distance, as well as the interfraction motion of the markers, was determined for all patients. RESULTS No acute major complications were observed. The acute toxicity grade was not greater than normally detected. The markers were visible in all images. On average, the projected intermarker distance varied 0.8 mm (1 standard deviation). A small time trend was observed in the intermarker distance for 3 patients. For these patients, at least one marker was located in the mucosa or pharyngeal constrictor muscle. Deeper-seated gold markers did not show a time trend in the intermarker distance. The random positioning uncertainty determined using the markers was on average 1.1 and 1.4 mm (1 SD) in the craniocaudal and AP direction, respectively. CONCLUSION The use of implanted gold markers for position verification during radiotherapy for head-and-neck cancer patients seems safe and feasible. To avoid any chance of migration, markers should be placed in deep muscular compartments.
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Abstract
PURPOSE To investigate the influence of the cranial border of electively irradiated Level II lymph nodes on xerostomia in patients with oropharyngeal cancer using three-dimensional conformal and intensity-modulated radiotherapy (3D-CRT and IMRT). METHODS AND MATERIALS The target volumes and organs at risk were delineated on the planning CT scans of 12 patients. Two elective target volumes were delineated. The first had the transverse process of the C1 atlas and the second had the transverse process of the C2 axis as cranial border of the Level II lymph nodes. 3D-CRT and IMRT planning were performed for both elective volumes, resulting in two plans per patient and technique, called the C1 and C2 plans, respectively. Irradiation of the ipsilateral elective volume up to C1 and the contralateral up to C2 was also performed for IMRT. The normal tissue complication probability (NTCP) for xerostomia 1 year after RT was calculated using the parotid mean dose. RESULTS The average mean dose +/- standard deviation (SD) to the contralateral parotid gland was reduced from 33 +/- 5 Gy for the IMRT C1 plans to 26 +/- 4 Gy for the IMRT C2 plans and from 51 +/- 6 Gy to 49 +/- 7 Gy for the 3D-CRT C1 and C2 plans, respectively. The associated NTCP +/- SD for xerostomia was 38% +/- 10% for IMRT C1 plans and 24% +/- 6% for IMRT up to C2 on the contralateral side, regardless of which cranial border was irradiated on the ipsilateral side. For the 3D-CRT C1 and C2 plans, an NTCP value of 74% +/- 12% and 71% +/- 15% was obtained, respectively. The NTCP for xerostomia of the ipsilateral parotid gland was 53% +/- 17% and 45% +/- 20% for the IMRT C1 and C2 plans and 89% +/- 11% and 87% +/- 12% for the 3D-CRT C1 and C2 plans, respectively. CONCLUSION Lowering the cranial border of the Level II lymph nodes from C1 to C2, in the case of bilateral elective neck irradiation, could be considered on the contralateral side when the risk of metastasis on that side is very low. This is especially true when IMRT is used, because the relative reduction of NTCP for xerostomia 1 year after RT could be up to 68% compared with conventional conformal RT up to C1.
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Location of cervical lymph node metastases in oropharyngeal and hypopharyngeal carcinoma: implications for cranial border of elective nodal target volumes. Int J Radiat Oncol Biol Phys 2004; 58:132-8. [PMID: 14697430 DOI: 10.1016/s0360-3016(03)00719-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE To analyze the exact location of the most cranial metastatic cervical lymph node in patients with oropharyngeal or hypopharyngeal carcinoma. This was done to specify the cranial border of the elective nodal target volume for improvement of parotid-sparing irradiation. METHODS AND MATERIALS The most cranial metastatic lymph node, ipsilateral and, when present, contralateral, was delineated on 58 diagnostic CT scans of patients with node-positive oropharyngeal or hypopharyngeal carcinoma. The distances from the delineated lymph node to the base of the skull were measured in all planes. RESULTS The mean ipsilateral and contralateral distance to the base of the skull in the coronal plane was 25.6 mm (range 2.6-73.8; SD 14.7) and 34.7 mm (range 10.4-78.9; SD 14.0), respectively (p = 0.002). Ipsilateral and contralateral metastatic lymph nodes were located within 20 mm below the base of the skull in 24 patients (41%) and 3 patients (5%), respectively. CONCLUSION Contralateral metastatic lymph nodes are more caudally located than are ipsilateral metastatic lymph nodes. In elective irradiation, lowering the cranial border of the contralateral nodal target volume with 20 mm below the base of the skull should be considered.
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Abstract
BACKGROUND AND PURPOSE To develop a segmental intensity-modulated radiotherapy (IMRT) technique for the treatment of oropharyngeal cancer. PATIENTS AND METHODS Eight patients previously treated for oropharyngeal cancer were replanned with segmental IMRT. The dose distribution was optimized using beam geometries consisting of 3, 5, 7 and 9 equiangular beams. The optimization procedure resulted in a theoretical fluence for each beam. In order to vary the number of segments, the optimized fluence was divided into four different equidistant levels. The final dose distribution was calculated using clinically deliverable segments obtained from optimized fluence. RESULTS For our segmental IMRT technique the dose homogeneity within the target volumes improved when the total number of segments increased and reached a saturation level at approximately 150 segments. Seven beams were sufficient to achieve the saturation level for dose homogeneity. The mean dose to the parotid glands depended on the beam geometry and tumor location and did not depend on the number of segments. On average the mean dose to the contralateral parotid gland was 35.7 Gy (27.1-39.9 Gy) for all seven beam plans. CONCLUSIONS Seven beams are sufficient to achieve an acceptable dose homogeneity within the target volumes and significant parotid sparing. These results will be used to introduce IMRT in routine clinical practice.
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Abstract
PURPOSE To quantify the intrafraction motions of the larynx during radiotherapy of laryngeal cancer. Depending on the magnitude, duration, and incidence, these motions may have clinical consequences for the choice of margins around the clinical target volume. METHODS AND MATERIALS The intrafraction motions were analyzed for 10 patients, treated in 33 or 35 fractions. The intrafraction motions of the larynx were visualized using an a-Si flat panel imager. Images were obtained every 200 ms, resulting in a movie of images for each beam. In addition to visual analysis of all movies, the tip of the epiglottis was delineated and used as a landmark, the coordinates of which were followed in time. RESULTS Movies were obtained during 79% of the total number of radiotherapy fractions. The total duration of swallowing was on average 0.45% (range 0.0-1.5) of the total irradiation time. Deviations of motions other than swallowing ranged between 0.3 and 11.5 mm. Some of these motions were more sudden, and others were probably related to breathing, because the frequency of these motions was 8-20/min. CONCLUSION The incidence and total duration of swallowing is low. Therefore, it is not necessary to apply an internal margin to take into account these displacements. Other motions, however, occur more often. In 95% of the irradiation time, the tip of the epiglottis moves within a range of 7.1 mm. A margin should be applied to the clinical target volume to take into account these motions.
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The dose to the parotid glands with IMRT for oropharyngeal tumors: the effect of reduction of positioning margins. Radiother Oncol 2002; 64:197-204. [PMID: 12242130 DOI: 10.1016/s0167-8140(02)00152-4] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PURPOSE The aim of this paper is to quantify the importance of the reduction of positioning margins applied to the clinical target volume (CTV) on the dose distribution of the parotid gland for different intensity-modulated radiotherapy (IMRT) strategies for the treatment of oropharyngeal cancer. METHODS AND MATERIALS CTVs and organs at risk were delineated in the planning computed tomographic (CT) scans of three patients. Margins of 0, 3, 6 and 9mm were applied to the CTVs in order to obtain the planning target volumes (PTVs). Three IMRT strategies were used to optimize the dose distribution. RESULTS The analysis of the three IMRT strategies resulted in: (1) an optimal dose distribution in the PTV; (2) optimal dose distribution in the PTV while sparing the parotid gland and (3) more parotid gland sparing but at expense of the dose homogeneity in the PTV. The mean parotid dose increased linearly with increasing margin by approximately 1.3Gy per mm. As a result, the normal complication probability (NTCP) for xerostomia decreased when smaller margins were applied. Reducing the margin from 6 to 3mm resulted in an NTCP reduction of approximately 20%. CONCLUSION Reducing the CTV-PTV margin by improving the patient position accuracy may lead to a significant reduction of NTCP for the IMRT treatment of the oropharyngeal tumors and lymph nodes level II.
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