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Moe YM, Groendahl AR, Tomic O, Dale E, Malinen E, Futsaether CM. Deep learning-based auto-delineation of gross tumour volumes and involved nodes in PET/CT images of head and neck cancer patients. Eur J Nucl Med Mol Imaging 2021; 48:2782-2792. [PMID: 33559711 PMCID: PMC8263429 DOI: 10.1007/s00259-020-05125-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 11/15/2020] [Indexed: 11/29/2022]
Abstract
PURPOSE Identification and delineation of the gross tumour and malignant nodal volume (GTV) in medical images are vital in radiotherapy. We assessed the applicability of convolutional neural networks (CNNs) for fully automatic delineation of the GTV from FDG-PET/CT images of patients with head and neck cancer (HNC). CNN models were compared to manual GTV delineations made by experienced specialists. New structure-based performance metrics were introduced to enable in-depth assessment of auto-delineation of multiple malignant structures in individual patients. METHODS U-Net CNN models were trained and evaluated on images and manual GTV delineations from 197 HNC patients. The dataset was split into training, validation and test cohorts (n= 142, n = 15 and n = 40, respectively). The Dice score, surface distance metrics and the new structure-based metrics were used for model evaluation. Additionally, auto-delineations were manually assessed by an oncologist for 15 randomly selected patients in the test cohort. RESULTS The mean Dice scores of the auto-delineations were 55%, 69% and 71% for the CT-based, PET-based and PET/CT-based CNN models, respectively. The PET signal was essential for delineating all structures. Models based on PET/CT images identified 86% of the true GTV structures, whereas models built solely on CT images identified only 55% of the true structures. The oncologist reported very high-quality auto-delineations for 14 out of the 15 randomly selected patients. CONCLUSIONS CNNs provided high-quality auto-delineations for HNC using multimodality PET/CT. The introduced structure-wise evaluation metrics provided valuable information on CNN model strengths and weaknesses for multi-structure auto-delineation.
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Affiliation(s)
- Yngve Mardal Moe
- Faculty of Science and Technology, Norwegian University of Life Sciences, Ås, Norway
| | | | - Oliver Tomic
- Faculty of Science and Technology, Norwegian University of Life Sciences, Ås, Norway
| | - Einar Dale
- Department of Oncology, Oslo University Hospital, Oslo, Norway
| | - Eirik Malinen
- Department of Medical Physics, Oslo University Hospital, Oslo, Norway.,Department of Physics, University of Oslo, Oslo, Norway
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PET/MRI-guided GTV delineation during radiotherapy planning in patients with squamous cell carcinoma of the tongue. Strahlenther Onkol 2019; 195:780-791. [PMID: 31214735 PMCID: PMC6704108 DOI: 10.1007/s00066-019-01480-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 05/30/2019] [Indexed: 01/17/2023]
Abstract
Purpose The aim of the study was to evaluate the usefulness and accuracy of 18-fluorine-labeled fluorodeoxyglucose (PET) and magnetic resonance imaging (MRI) hybrid in gross tumor volume (GTV) delineation during radiotherapy planning in patients with carcinoma of the tongue. Methods Ten patients with squamous cell carcinoma (SCC) of the tongue underwent computed tomography (CT) and PET/MRI examination. The GTV for primary tumor and lymph nodes (nGTV) were defined on CT (GTV-CT) and compared to GTVs obtained from PET (GTV-PET) and MRI (GTV-MRI) images. Two methods of GTV determination were used: visual interpretation of CT, PET (GTV-PETvis) and MRI images and quantitative automatic method (Syngovia, Siemens) based on a chosen threshold value (20%, 30%, 40%, 50%) of standardized uptake values (SUVmax) from PET examination (GTV-PET20%, GTV-PET30%, etc.). Statistical analysis of differences in GTV values obtained from CT, PET and MRI studies was performed. GTV-CT was used as a reference. Results In all, 80% of GTV-MRI and 40% of GTV-PETvis were larger than GTV-CT. Respectively, 20% of GTV-MRI and 60% of GTV-PETvis were smaller than GTV-CT. Taking into account all threshold measurements, 70% of volumes were smaller than GTV-CT. GTV-PET30% were the most closely related volumes to GTV-CT from all threshold methods in 50% of patients. GTV-PETvis generated the most similar volumes in relation to GTV-CT from all PET measurements. Statistical analysis confirmed those results. Compared to nGTV-CT, 70% of nGTV-MRI and 20% of nGTV-PETvis were larger. The remaining nGTV-MRI and nGTV-PETvis measurements were smaller than nGTV-CT. Measurements of all thresholds nGTVs were smaller than nGTV-CTV in 52.5% of cases. nGTV-PET20% were the most closely related volumes to nGTV-CT in 40% of the cases. Statistical analysis showed that nGTV-PET20% (p = 0.0468), nGTV-PETvis (p = 0.0166), and nGTV-PET50% (p = 0.0166) diverge significantly from nGTV-CT results. nGTV-MRI (p = 0.1141), nGTV-PET30% (p = 0.2845), and nGTV-PET40% (p = 0.5076) were significantly related with nGTV-CT. Conclusion Combination of PET/MRI provides more information during target tumor mass delineation in radiotherapy planning of patients with SCC of the tongue than other standard imaging methods. The most frequently matching threshold value was 30% of SUVmax for primary tumor delineation and 30–40% of SUVmax for nGTV determination. Electronic supplementary material The online version of this article (10.1007/s00066-019-01480-3) contains supplementary material, which is available to authorized users.
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Gudi S, Ghosh-Laskar S, Agarwal JP, Chaudhari S, Rangarajan V, Nojin Paul S, Upreti R, Murthy V, Budrukkar A, Gupta T. Interobserver Variability in the Delineation of Gross Tumour Volume and Specified Organs-at-risk During IMRT for Head and Neck Cancers and the Impact of FDG-PET/CT on Such Variability at the Primary Site. J Med Imaging Radiat Sci 2017; 48:184-192. [DOI: 10.1016/j.jmir.2016.11.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Revised: 10/29/2016] [Accepted: 11/07/2016] [Indexed: 11/25/2022]
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Piva C, Genovesi D, Filippi AR, Balducci M, Barra S, Buglione M, Busetto M, Ciammella P, Franzone P, De Sanctis V, Simontacchi G, Fusella M, Ricardi U. Interobserver variability in clinical target volume delineation for primary mediastinal B-cell lymphoma. Pract Radiat Oncol 2016; 5:383-9. [PMID: 26547826 DOI: 10.1016/j.prro.2015.04.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 04/07/2015] [Accepted: 04/10/2015] [Indexed: 11/24/2022]
Abstract
PURPOSE The purpose of this study was to evaluate interobserver variability among radiation oncologists with experience in the field of lymphoma radiation therapy in the delineation of clinical target volume (CTV) in a challenging case of primary mediastinal B-cell lymphoma. METHODS AND MATERIALS Ten experienced radiation oncologists were invited to a 1-day contouring session. The case of a 56-year-old man with primary mediastinal B-cell lymphoma with complete metabolic response after chemotherapy was chosen as the sample for the study. A brief presentation of his clinical history was given, together with guidelines for contouring. The 10 CTVs obtained were then compared in terms of variation in total volume and in craniocaudal, laterolateral, and anteroposterior diameters. The CTV with the best Dice similarity coefficient (DSC) between the union of all 10 CTVs and the individual CTV was considered the reference CTV, and the DSC and the Hausdorff distance (HD) for each volume compared with the reference CTV were then calculated. RESULTS A significant variability was found in total volume (mean, 498.3 cm(3); range, 181.8-1003 cm(3)) and craniocaudal (median, 144.7 mm; range, 80.6-159 mm), laterolateral (median, 133.5 mm; range, 83.7-149.5 mm), and anteroposterior diameters (median, 136.2 mm; range, 84-150.5 mm). Analysis of the DSC and the HD showed a mean DSC of 0.53 (range, 0.31-0.74) and a mean HD of 6.4 cm (range, 1.8-14.8 cm). CONCLUSIONS Results of this study strongly indicate the need to develop and share appropriate contouring guidelines among experts and suggest the promotion of specific educational activities to improve radiation therapy quality in both clinical trials and routine clinical practice.
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Affiliation(s)
- Cristina Piva
- Department of Oncology, University of Torino, Turin, Italy
| | - Domenico Genovesi
- Department of Radiation Oncology, University of Chieti, SS Annunziata Hospital, Chieti, Italy
| | | | - Mario Balducci
- Radiotherapy Department, Radiation Oncology, Catholic University, Rome, Italy
| | - Salvina Barra
- Radiation Oncology, Istituto Nazionale per la Ricerca sul Cancro, Genoa, Italy
| | | | - Mario Busetto
- Radiotherapy Unit, Ospedale dell'Angelo, Mestre, Italy
| | - Patrizia Ciammella
- Department of Oncology and Advanced Technology, Radiation Therapy Unit, Arcispedale S. Maria Nuova Hospital-Istituto di Ricovero e Cura a Carattere Scientifico, Reggio Emilia, Italy
| | - Paola Franzone
- Radiation Oncology, Azienda Ospedaliera SS Antonio, Biagio e Cesare Arrigo, Alessandria, Italy
| | - Vitaliana De Sanctis
- Radiation Oncology, Azienda Ospedaliera S. Andrea, La Sapienza University, Rome, Italy
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Yang J, Beadle BM, Garden AS, Schwartz DL, Aristophanous M. A multimodality segmentation framework for automatic target delineation in head and neck radiotherapy. Med Phys 2016; 42:5310-20. [PMID: 26328980 DOI: 10.1118/1.4928485] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To develop an automatic segmentation algorithm integrating imaging information from computed tomography (CT), positron emission tomography (PET), and magnetic resonance imaging (MRI) to delineate target volume in head and neck cancer radiotherapy. METHODS Eleven patients with unresectable disease at the tonsil or base of tongue who underwent MRI, CT, and PET/CT within two months before the start of radiotherapy or chemoradiotherapy were recruited for the study. For each patient, PET/CT and T1-weighted contrast MRI scans were first registered to the planning CT using deformable and rigid registration, respectively, to resample the PET and magnetic resonance (MR) images to the planning CT space. A binary mask was manually defined to identify the tumor area. The resampled PET and MR images, the planning CT image, and the binary mask were fed into the automatic segmentation algorithm for target delineation. The algorithm was based on a multichannel Gaussian mixture model and solved using an expectation-maximization algorithm with Markov random fields. To evaluate the algorithm, we compared the multichannel autosegmentation with an autosegmentation method using only PET images. The physician-defined gross tumor volume (GTV) was used as the "ground truth" for quantitative evaluation. RESULTS The median multichannel segmented GTV of the primary tumor was 15.7 cm(3) (range, 6.6-44.3 cm(3)), while the PET segmented GTV was 10.2 cm(3) (range, 2.8-45.1 cm(3)). The median physician-defined GTV was 22.1 cm(3) (range, 4.2-38.4 cm(3)). The median difference between the multichannel segmented and physician-defined GTVs was -10.7%, not showing a statistically significant difference (p-value = 0.43). However, the median difference between the PET segmented and physician-defined GTVs was -19.2%, showing a statistically significant difference (p-value =0.0037). The median Dice similarity coefficient between the multichannel segmented and physician-defined GTVs was 0.75 (range, 0.55-0.84), and the median sensitivity and positive predictive value between them were 0.76 and 0.81, respectively. CONCLUSIONS The authors developed an automated multimodality segmentation algorithm for tumor volume delineation and validated this algorithm for head and neck cancer radiotherapy. The multichannel segmented GTV agreed well with the physician-defined GTV. The authors expect that their algorithm will improve the accuracy and consistency in target definition for radiotherapy.
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Affiliation(s)
- Jinzhong Yang
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Beth M Beadle
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Adam S Garden
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - David L Schwartz
- Department of Radiation Oncology, The University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Michalis Aristophanous
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030
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Evaluation of Time-Phase Effect on 18F-FDG PET/CT Delineation Methods for Treatment Planning of Nasopharyngeal Carcinoma. Clin Nucl Med 2016; 41:354-61. [DOI: 10.1097/rlu.0000000000001161] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Tchelebi L, Ashamalla H. Overcoming the hurdles of using PET/CT for target volume delineation in curative intent radiotherapy of non-small cell lung cancer. ANNALS OF TRANSLATIONAL MEDICINE 2015; 3:191. [PMID: 26417575 DOI: 10.3978/j.issn.2305-5839.2015.07.02] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Leila Tchelebi
- Department of Radiation Oncology, New York Methodist Hospital, Brooklyn, NY 11215, USA
| | - Hani Ashamalla
- Department of Radiation Oncology, New York Methodist Hospital, Brooklyn, NY 11215, USA
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Jiang J, Wu H, Huang M, Wu Y, Wang Q, Zhao J, Yang W, Chen W, Feng Q. Variability of Gross Tumor Volume in Nasopharyngeal Carcinoma Using 11C-Choline and 18F-FDG PET/CT. PLoS One 2015; 10:e0131801. [PMID: 26161910 PMCID: PMC4498791 DOI: 10.1371/journal.pone.0131801] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 06/05/2015] [Indexed: 11/19/2022] Open
Abstract
This study was conducted to evaluate the variability of gross tumor volume (GTV) using 11C-Choline and 18F-FDG PET/CT images for nasopharyngeal carcinomas boundary definition. Assessment consisted of inter-observer and inter-modality variation analysis. Four radiation oncologists were invited to manually contour GTV by using PET/CT fusion obtained from a cohort of 12 patients with nasopharyngeal carcinoma (NPC) and who underwent both 11C-Choline and 18F-FDG scans. Student’s paired-sample t-test was performed for analyzing inter-observer and inter-modality variability. Semi-automatic segmentation methods, including thresholding and region growing, were also validated against the manual contouring of the two types of PET images. We observed no significant variation in the results obtained by different oncologists in terms of the same type of PET/CT volumes. Choline fusion volumes were significantly larger than the FDG volumes (p < 0.0001, mean ± SD = 18.21 ± 8.19). While significantly consistent results were obtained between the oncologists and the standard references in Choline volumes compared with those in FDG volumes (p = 0.0025). Simple semi-automatic delineation methods indicated that 11C-Choline PET images could provide better results than FDG volumes (p = 0.076, CI = [–0.29, 0.025]). 11C-Choline PET/CT may be more advantageous in GTV delineation for the radiotherapy of NPC than 18F-FDG. Phantom simulations and clinical trials should be conducted to prove the possible improvement of the treatment outcome.
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Affiliation(s)
- Jun Jiang
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
| | - Hubing Wu
- Department of PET Center, Nanfang Hospital, Guangzhou, China
| | - Meiyan Huang
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
| | - Yao Wu
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
| | - Quanshi Wang
- Department of PET Center, Nanfang Hospital, Guangzhou, China
| | - Jianqi Zhao
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
| | - Wei Yang
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
| | - Wufan Chen
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
| | - Qianjin Feng
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
- * E-mail:
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Ashamalla H, Mattes M, Guirguis A, Zaidi A, Mokhtar B, Tejwani A. The Anatomical Biological Value on Pretreatment (18)F-fluorodeoxyglucose Positron Emission Tomography Computed Tomography Predicts Response and Survival in Locally Advanced Head and Neck Cancer. World J Nucl Med 2014; 13:102-7. [PMID: 25191124 PMCID: PMC4150151 DOI: 10.4103/1450-1147.139139] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) has become increasingly relevant in the staging of head and neck cancers, but its prognostic value is controversial. The objective of this study was to evaluate different PET/CT parameters for their ability to predict response to therapy and survival in patients treated for head and neck cancer. A total of 28 consecutive patients with a variety of newly diagnosed head and neck cancers underwent PET/CT scanning at our institution before initiating definitive radiation therapy. All underwent a posttreatment PET/CT to gauge tumor response. Pretreatment PET/CT parameters calculated include the standardized uptake value (SUV) and the anatomical biological value (ABV), which is the product of SUV and greatest tumor diameter. Maximum and mean values were studied for both SUV and ABV, and correlated with response rate and survival. The mean pretreatment tumor ABVmax decreased from 35.5 to 7.9 (P = 0.0001). Of the parameters tested, only pretreatment ABVmax was significantly different among those patients with a complete response (CR) and incomplete response (22.8 vs. 65, respectively, P = 0.021). This difference was maximized at a cut-off ABVmax of 30 and those patients with ABVmax < 30 were significantly more likely to have a CR compared to those with ABVmax of ≥ 30 (93.8% vs. 50%, respectively, P = 0.023). The 5-year overall survival was 80% compared to 36%, respectively, (P = 0.028). Multivariate analysis confirmed that ABVmax was an independent prognostic factor. Our data supports the use of PET/CT, and specifically ABVmax, as a prognostic factor in head and neck cancer. Patients who have an ABVmax ≥ 30 were more likely to have a poor outcome with chemoradiation alone, and a more aggressive trimodality approach may be indicated in these patients.
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Affiliation(s)
- Hani Ashamalla
- Department of Radiation Oncology, NY Methodist Hospital, Weill Medical College of Cornell University, Brooklyn, NY 11215, USA ; Department of Radiation Oncology, Leading Edge Radiation Oncology Services, Brooklyn, NY 11209, USA
| | - Malcolm Mattes
- Department of Radiation Oncology, NY Methodist Hospital, Weill Medical College of Cornell University, Brooklyn, NY 11215, USA
| | - Adel Guirguis
- Department of Radiation Oncology, NY Methodist Hospital, Weill Medical College of Cornell University, Brooklyn, NY 11215, USA
| | - Arifa Zaidi
- Department of Radiation Oncology, NY Methodist Hospital, Weill Medical College of Cornell University, Brooklyn, NY 11215, USA
| | - Bahaa Mokhtar
- Department of Radiation Oncology, NY Methodist Hospital, Weill Medical College of Cornell University, Brooklyn, NY 11215, USA ; Department of Radiation Oncology, Leading Edge Radiation Oncology Services, Brooklyn, NY 11209, USA
| | - Ajay Tejwani
- Department of Radiation Oncology, NY Methodist Hospital, Weill Medical College of Cornell University, Brooklyn, NY 11215, USA
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Rusten E, Rødal J, Bruland ØS, Malinen E. Biologic targets identified from dynamic 18FDG-PET and implications for image-guided therapy. Acta Oncol 2013; 52:1378-83. [PMID: 23981046 DOI: 10.3109/0284186x.2013.813071] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE The outcome of biologic image-guided radiotherapy depends on the definition of the biologic target. The purpose of the current work was to extract hyperperfused and hypermetabolic regions from dynamic positron emission tomography (D-PET) images, to dose escalate either region and to discuss implications of such image guided strategies. METHODS Eleven patients with soft tissue sarcomas were investigated with D-PET. The images were analyzed using a two-compartment model producing parametric maps of perfusion and metabolic rate. The two image series were segmented and exported to a treatment planning system, and biological target volumes BTVper and BTVmet (perfusion and metabolism, respectively) were generated. Dice's similarity coefficient was used to compare the two biologic targets. Intensity-modulated radiation therapy (IMRT) plans were generated for a dose painting by contours regime, where planning target volume (PTV) was planned to 60 Gy and BTV to 70 Gy. Thus, two separate plans were created for each patient with dose escalation of either BTVper or BTVmet. RESULTS BTVper was somewhat smaller than BTVmet (209 ± 170 cm(3) against 243 ± 143 cm(3), respectively; population-based mean and s.d.). Dice's coefficient depended on the applied margin, and was 0.72 ± 0.10 for a margin of 10 mm. Boosting BTVper resulted in mean dose of 69 ± 1.0 Gy to this region, while BTVmet received 67 ± 3.2 Gy. Boosting BTVmet gave smaller dose differences between the respective non-boost DVHs (such as D98). CONCLUSIONS Dose escalation of one of the BTVs results in a partial dose escalation of the other BTV as well. If tumor aggressiveness is equally pronounced in hyperperfused and hypermetabolic regions, this should be taken into account in the treatment planning.
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Affiliation(s)
- Espen Rusten
- Department of Physics, University of Oslo , Oslo , Norway
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Hoeben BAW, Bussink J, Troost EGC, Oyen WJG, Kaanders JHAM. Molecular PET imaging for biology-guided adaptive radiotherapy of head and neck cancer. Acta Oncol 2013; 52:1257-71. [PMID: 24003853 DOI: 10.3109/0284186x.2013.812799] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Integration of molecular imaging PET techniques into therapy selection strategies and radiation treatment planning for head and neck squamous cell carcinoma (HNSCC) can serve several purposes. First, pre-treatment assessments can steer decisions about radiotherapy modifications or combinations with other modalities. Second, biology-based objective functions can be introduced to the radiation treatment planning process by co-registration of molecular imaging with planning computed tomography (CT) scans. Thus, customized heterogeneous dose distributions can be generated with escalated doses to tumor areas where radiotherapy resistance mechanisms are most prevalent. Third, monitoring of temporal and spatial variations in these radiotherapy resistance mechanisms early during the course of treatment can discriminate responders from non-responders. With such information available shortly after the start of treatment, modifications can be implemented or the radiation treatment plan can be adapted tailing the biological response pattern. Currently, these strategies are in various phases of clinical testing, mostly in single-center studies. Further validation in multicenter set-up is needed. Ultimately, this should result in availability for routine clinical practice requiring stable production and accessibility of tracers, reproducibility and standardization of imaging and analysis methods, as well as general availability of knowledge and expertise. Small studies employing adaptive radiotherapy based on functional dynamics and early response mechanisms demonstrate promising results. In this context, we focus this review on the widely used PET tracer (18)F-FDG and PET tracers depicting hypoxia and proliferation; two well-known radiation resistance mechanisms.
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Affiliation(s)
- Bianca A W Hoeben
- Department of Radiation Oncology, Radboud University Nijmegen Medical Centre , Nijmegen , The Netherlands
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Skretting A, Evensen JF, Løndalen AM, Bogsrud TV, Glomset OK, Eilertsen K. A gel tumour phantom for assessment of the accuracy of manual and automatic delineation of gross tumour volume from FDG-PET/CT. Acta Oncol 2013; 52:636-44. [PMID: 23075421 DOI: 10.3109/0284186x.2012.718095] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
INTRODUCTION Our primary aim was to make a phantom for PET that could mimic a highly irregular tumour and provide true tumour contours. The secondary aim was to use the phantom to assess the accuracy of different methods for delineation of tumour volume from the PET images. MATERIAL AND METHODS An empty mould was produced on the basis of a contrast enhanced computed tomography (CT) study of a patient with a squamous cell carcinoma in the head and neck region. The mould was filled with a homogeneous fast-settling gel that contained both (18)F for positron emission tomography (PET) and an iodine contrast agent. This phantom (mould and gel) was scanned on a PET/CT scanner. A series of reference tumour contours were obtained from the CT images in the PET/CT. Tumour delineation based on the PET images was achieved manually, by isoSUV thresholding, and by a recently developed three-dimensional (3D) Difference of Gaussians algorithm (DoG). Average distances between the PET-derived and reference contours were assessed by a 3D distance transform. RESULTS The manual, thresholding and DoG delineation methods resulted in volumes that were 146%, 86% and 100% of the reference volume, respectively, and average distance deviations from the reference surface were 1.57 mm, 1.48 mm and 1.0, mm, respectively. DISCUSSION Manual drawing as well as isoSUV determination of tumour contours in geometrically irregular tumours may be unreliable. The DoG method may contribute to more correct delineation of the tumour. Although the present phantom had a homogeneous distribution of activity, it may also provide useful knowledge in the case of inhomogeneous activity distributions. CONCLUSION The geometric irregular tumour phantom with its inherent reference contours was an important tool for testing of different delineation methods and for teaching delineation.
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Affiliation(s)
- Arne Skretting
- The Intervention Centre, Oslo University Hospital,
Oslo, Norway
- Faculty Division of Clinical Medicine, University of Oslo,
Oslo, Norway
| | - Jan F. Evensen
- Department of Cancer treatment, Oslo University Hospital,
Oslo, Norway
| | - Ayca M. Løndalen
- Department of radiology and nuclear medicine, Oslo University Hospital,
Oslo, Norway
| | - Trond V. Bogsrud
- Department of radiology and nuclear medicine, Oslo University Hospital,
Oslo, Norway
| | - Otto K. Glomset
- The Intervention Centre, Oslo University Hospital,
Oslo, Norway
- Faculty Division of Clinical Medicine, University of Oslo,
Oslo, Norway
| | - Karsten Eilertsen
- Department of Medical Physics, Oslo University Hospital,
Oslo, Norway
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Garg MK, Glanzman J, Kalnicki S. The Evolving Role of Positron Emission Tomography-Computed Tomography in Organ-Preserving Treatment of Head and Neck Cancer. Semin Nucl Med 2012; 42:320-7. [DOI: 10.1053/j.semnuclmed.2012.04.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Karam SD, Snider JW, Wang H, Wooster M, Lominska C, Deeken J, Newkirk K, Davidson B, Harter KW. Survival outcomes of patients treated with hypofractionated stereotactic body radiation therapy for parotid gland tumors: a retrospective analysis. Front Oncol 2012; 2:55. [PMID: 22666661 PMCID: PMC3364484 DOI: 10.3389/fonc.2012.00055] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Accepted: 05/10/2012] [Indexed: 11/13/2022] Open
Abstract
Background: to review a single-institution experience with the management of parotid malignancies treated by fractionated stereotactic body radiosurgery (SBRT). Findings: Between 2003 and 2011, 13 patients diagnosed with parotid malignancies were treated with adjuvant or definitive SBRT to a median dose of 33 Gy (range 25–40 Gy). There were 11 male and two female patients with a median age of 80. Ten patients declined conventional radiation treatment and three patients had received prior unrelated radiation therapy to neighboring structures with unavailable radiation records. Six patients were treated with definitive intent while seven patients were treated adjuvantly for adverse surgical or pathologic features. Five patients had clinical or pathologic evidence of lymph node disease. Conclusion: at a median follow-up of 14 months only one patient failed locally, and four failed distantly. The actuarial 2-year overall survival, progression-free survival, and local-regional control rates were 46, 84, and 47%, respectively. Statistical analysis revealed surgery as a positive predictor of overall survival while presence of gross disease was a negatively correlated factor (p < 0.05).
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Affiliation(s)
- Sana D Karam
- Department of Radiation Medicine, Georgetown University Hospital Washington, DC, USA
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Prestwich RJD, Sykes J, Carey B, Sen M, Dyker KE, Scarsbrook AF. Improving target definition for head and neck radiotherapy: a place for magnetic resonance imaging and 18-fluoride fluorodeoxyglucose positron emission tomography? Clin Oncol (R Coll Radiol) 2012; 24:577-89. [PMID: 22592142 DOI: 10.1016/j.clon.2012.04.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Revised: 02/06/2012] [Accepted: 04/18/2012] [Indexed: 12/25/2022]
Abstract
Defining the target for head and neck radiotherapy is a critical issue with the introduction of steep dose gradients associated with intensity-modulated radiotherapy. Tumour delineation inaccuracies are a major source of error in radiotherapy planning. The integration of 18-fluoride fluorodeoxyglucose positron emission tomography ((18)FDG-PET) and magnetic resonance imaging directly into the radiotherapy planning process has the potential to greatly improve target identification/selection and delineation. This raises a range of new issues surrounding image co-registration, delineation methodology and the use of functional data and treatment adaptation. This overview will discuss the practical aspects of integrating (18)FDG-PET and magnetic resonance imaging into head and neck radiotherapy planning.
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Affiliation(s)
- R J D Prestwich
- Department of Nuclear Medicine, St. James's Institute of Oncology, Leeds, UK.
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Delouya G, Igidbashian L, Houle A, Bélair M, Boucher L, Cohade C, Beaulieu S, Filion EJ, Coulombe G, Hinse M, Martel C, Després P, Nguyen-Tan PF. ¹⁸F-FDG-PET imaging in radiotherapy tumor volume delineation in treatment of head and neck cancer. Radiother Oncol 2011; 101:362-8. [PMID: 21885143 DOI: 10.1016/j.radonc.2011.07.025] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2011] [Revised: 06/29/2011] [Accepted: 07/13/2011] [Indexed: 11/27/2022]
Abstract
PURPOSE To determine the impact of (18)F-fluorodeoxyglucose positron emission tomography (PET) in radiotherapy target delineation and patient management for head and neck squamous cell carcinoma (HNSCC) compared to computed tomography (CT) alone. MATERIALS AND METHODS Twenty-nine patients with HNSCC were included. CT and PET/CT obtained for treatment planning purposes were reviewed respectively by a neuroradiologist and a nuclear medicine specialist who were blinded to the findings from each other. The attending radiation oncologist together with the neuroradiologist initially defined all gross tumor volume of the primary (GTVp) and the suspicious lymph nodes (GTVn) on CT. Subsequently, the same radiation oncologist and the nuclear medicine specialist defined the GTVp and GTVn on (18)F-FDG-PET/CT. Upon disagreement between CT and (18)F-FDG-PET on the status of a particular lymph node, an ultrasound-guided fine needle aspiration was performed. Volumes based on CT and (18)F-FDG-PET were compared with a paired Student's t-test. RESULTS For the primary disease, four patients had previous diagnostic tonsillectomy and therefore, FDG uptake occurred in 25 patients. For these patients, GTVp contoured on (18)F-FDG-PET (GTVp-PET) were smaller than the GTVp contoured on CT (GTVp-CT) in 80% of the cases, leading to a statistically significant volume difference (p=0.001). Of the 60 lymph nodes suspicious on PET, 55 were also detected on CT. No volume change was observed (p=0.08). Ten biopsies were performed for lymph nodes that were discordant between modalities and all were of benign histology. Distant metastases were found in two patients and one had a newly diagnosed lung adenocarcinoma. CONCLUSIONS GTVp-CT was significantly larger when compared to GTVp-PET. No such change was observed for the lymph nodes. (18)F-FDG-PET modified treatment management in three patients, including two for which no curative radiotherapy was attempted. Larger multicenter studies are needed to ascertain whether combined (18)F-FDG-PET/CT in target delineation can influence the main clinical outcomes.
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Affiliation(s)
- Guila Delouya
- Department of Radiation Oncology, Centre Hospitalier de l'Université de Montréal, Montréal, Canada.
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Prionas ND, Gillen MA, Boone JM. Longitudinal volume analysis from computed tomography: Reproducibility using adrenal glands as surrogate tumors. J Med Phys 2011; 35:174-80. [PMID: 20927226 PMCID: PMC2936188 DOI: 10.4103/0971-6203.62130] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2009] [Revised: 11/29/2009] [Accepted: 12/19/2009] [Indexed: 01/18/2023] Open
Abstract
This study aims to determine the precision (reproducibility) of volume assessment in routine clinical computed tomography (CT) using adrenal glands as surrogate tumors. Seven patients at our institution were identified retrospectively as having received numerous abdominal CT scans (average 13.1, range 5 to 20). The adrenal glands were used as surrogate tumors, assuming no actual volume change. Left and right adrenal gland volumes were assessed by hand segmentation for each patient scan. Over 1240 regions of interest were outlined in total. The reproducibility, expressed as the coefficient of variation (COV), was used to characterize measurement precision. The average volumes were 5.9 and 4.5 cm3 for the left and right adrenal gland, respectively, with COVs of 17.8% and 18.9%, respectively. Using one patient’s data (20 scans) as an example surrogate for a spherical tumor, it was calculated that a 13% change in volume (4.2% change in diameter) could be determined with statistical significance at P=0.05. For this case, cursor positioning error in linear measurement of object size, by even 1 pixel on the CT image, corresponded to a significant change in volume (P=0.05). The precision of volume determination was dependent on total volume. Precision improved with increasing object size (r2 =0.367). Given the small dimensions of the adrenal glands, the ~18% COV is likely to be a high estimate compared to larger tumors. Modern CT scanners working with thinner sections (i.e. <1 mm) are likely to produce better measurement precision. The use of volume measurement to quantify changing tumor size is supported as a more precise metric than linear measurement.
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Affiliation(s)
- Nicolas D Prionas
- Department of Radiology, University of California Davis Medical Center, Ellison Ambulatory Care Center, 4860 Y Street Suite 3100, Sacramento, CA, USA
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Metwally H, Courbon F, David I, Filleron T, Blouet A, Rives M, Izar F, Zerdoud S, Plat G, Vial J, Robert A, Laprie A. Coregistration of Prechemotherapy PET-CT for Planning Pediatric Hodgkin's Disease Radiotherapy Significantly Diminishes Interobserver Variability of Clinical Target Volume Definition. Int J Radiat Oncol Biol Phys 2011; 80:793-9. [DOI: 10.1016/j.ijrobp.2010.02.024] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Revised: 02/10/2010] [Accepted: 02/17/2010] [Indexed: 11/26/2022]
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Adaptive 18Fluoro-2-deoxyglucose Positron Emission Tomography/Computed Tomography-based Target Volume Delineation in Radiotherapy Planning of Head and Neck Cancer. Clin Oncol (R Coll Radiol) 2011; 23:364-71. [DOI: 10.1016/j.clon.2010.11.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2010] [Revised: 10/18/2010] [Accepted: 10/19/2010] [Indexed: 12/18/2022]
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20
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Tsai CJ, Das P. Impact of PET/CT-Based Radiation Therapy Planning in Gastrointestinal Malignancies. PET Clin 2011; 6:185-93. [DOI: 10.1016/j.cpet.2011.02.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Fox T, Lawson J, Schreibmann E. Technical Aspects of PET/CT-Based Radiotherapy Planning. PET Clin 2011; 6:117-29. [DOI: 10.1016/j.cpet.2011.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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22
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Moule RN, Kayani I, Moinuddin SA, Meer K, Lemon C, Goodchild K, Saunders MI. The potential advantages of 18FDG PET/CT-based target volume delineation in radiotherapy planning of head and neck cancer. Radiother Oncol 2010; 97:189-93. [DOI: 10.1016/j.radonc.2010.04.025] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 04/07/2010] [Accepted: 04/29/2010] [Indexed: 11/16/2022]
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Zheng Y, Syh J, Yao M, Wessels BW. An automatic method for PET target segmentation using a lookup table based on volume and concentration ratio. Technol Cancer Res Treat 2010; 9:243-52. [PMID: 20441234 DOI: 10.1177/153303461000900303] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Accurate evaluation of functionally significant target volumes in combination with anatomic imaging is of primary importance for effective radiation therapy treatment planning. In this study, a method for rapid and accurate PET image segmentation and volumetrics based on phantom measurements and independent of scanner calibration was developed. A series of spheres ranging in volume from 0.5 mL to 95 mL were imaged in an anthropomorphic phantom of human thorax using two commercial PET and CT/PET scanners. The target to background radioactivity concentration ratio ranged from 3:1 to 12:1 in 11 separate phantom scanning experiments. The results confirmed that optimal segmentation thresholding depends on target volume and radioactivity concentration ratio. This information can be derived from a generalized pre-determined "lookup table" of volume and contrast dependent threshold values instead of using fitted curves derived from machine specific information. A three-step method based on the PET image intensity information alone was used to delineate volumes of interest. First, a mean intensity segmentation method was used to generate an initial estimate of target volume, and the radioactivity concentration ratio was computed by a family of recovery coefficient curves to compensate for the partial volume effect. Next, the appropriate threshold value was obtained from a phantom-generated threshold lookup table. Lastly, a threshold level set method was performed on the threshold value to further refine the target contour by reducing the limitation of global thresholding. The segmentation results were consistent for spheres greater than 2.5 mL which yielded volume average uncertainty of 11.2% in phantom studies. The results of segmented volumes were comparable to those determined by contrast-oriented method and iterative threshold method (ITM). In addition, the new volume segmentation method was applied clinically to ten patients undergoing PET/CT volume analysis for radiation therapy treatment planning of solitary lung metastases. For these patients, the average PET segmented volumes were within 8.0% of the CT volumes and were highly dependent on the extension of functionally inactive tumor volume. In summary, the current method does not require fitted threshold curves or a priori knowledge of the CT/MRI target volume. This threshold method can be universally applied to radiation therapy treatment planning with comparable accuracy, and may be useful in the rapid identification and assessment of plans containing multiple targets.
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Affiliation(s)
- Yiran Zheng
- Department of Radiation Oncology, Case Western Reserve University, School of Medicine B181, 11000 Euclid Avenue, Cleveland, OH 44106, USA.
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Iğdem S, Alço G, Ercan T, Unalan B, Kara B, Geceer G, Akman C, Zengin FO, Atilla S, Okkan S. The application of positron emission tomography/computed tomography in radiation treatment planning: effect on gross target volume definition and treatment management. Clin Oncol (R Coll Radiol) 2010; 22:173-8. [PMID: 20116979 DOI: 10.1016/j.clon.2010.01.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Revised: 12/21/2009] [Accepted: 12/23/2009] [Indexed: 10/19/2022]
Abstract
AIMS To analyse the effect of the use of molecular imaging on gross target volume (GTV) definition and treatment management. MATERIALS AND METHODS Fifty patients with various solid tumours who underwent positron emission tomography (PET)/computed tomography (CT) simulation for radiotherapy planning from 2006 to 2008 were enrolled in this study. First, F-18 fluorodeoxyglucose (FDG)-PET and CT scans of the treatment site in the treatment position and then a whole body scan were carried out with a dedicated PET/CT scanner and fused thereafter. FDG-avid primary tumour and lymph nodes were included into the GTV. A multidisciplinary team defined the target volume, and contouring was carried out by a radiation oncologist using visual methods. To compare the PET/CT-based volumes with CT-based volumes, contours were drawn on CT-only data with the help of site-specific radiologists who were blind to the PET/CT results after a median time of 7 months. RESULTS In general, our PET/CT volumes were larger than our CT-based volumes. This difference was significant in patients with head and neck cancers. Major changes (> or =25%) in GTV delineation were observed in 44% of patients. In 16% of cases, PET/CT detected incidental second primaries and metastatic disease, changing the treatment strategy from curative to palliative. CONCLUSIONS Integrating functional imaging with FDG-PET/CT into the radiotherapy planning process resulted in major changes in a significant proportion of our patients. An interdisciplinary approach between imaging and radiation oncology departments is essential in defining the target volumes.
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Affiliation(s)
- S Iğdem
- Department of Radiation Oncology, Istanbul Bilim University, School of Medicine, Cemil Aslan Güder sok 8 Gayrettepe, 34340 Istanbul, Turkey.
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Geets X, Lee JA, Castadot P, Bol A, Grégoire V. [Potential place of FDG-PET for the GTV delineation in head and neck and lung cancers]. Cancer Radiother 2009; 13:594-9. [PMID: 19766523 DOI: 10.1016/j.canrad.2009.06.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2009] [Accepted: 06/26/2009] [Indexed: 10/20/2022]
Abstract
The recent progresses performed in imaging, computational and technological fields bring new opportunities to achieve high precision radiation dose delivery. However, IMRT requires a particular attention at the target delineation step to avoid inadequate dosage to TVs/OARs. In this context, the biological information provided by PET might advantageously complete CT-Scan to refine the target delineation in HNSCC and lung cancer. Integrating PET into the treatment planning however requires the use and validation of accurate and reproducible segmentation methods, which adequately integrate the PET image properties such as the blur effect and the high level of noise. In this context, we developed specific tools, i.e. edge-preserving filters for denoising and deconvolution algorithms for deblurring that allowed the detection of gradient intensity peaks. Our gradient-based method has been validated on phantom and patient materials, and proved to be more accurate than threshold-based approaches. With this tool in hand, we demonstrated that the use of FDG-PET resulted in smaller TVs than the CT-based TVs, on both pre- and per-treatment images, and significantly improved the dose distributions to the TVs/OARs. This opens avenues for dose escalation strategies that might potentially improve the tumor local control.
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Affiliation(s)
- X Geets
- Département de Radiothérapie Oncologique, Centre d'Imagerie Moléculaire et Radiothérapie Expérimentale, Université Catholique de Louvain, Cliniques Universitaires Saint-Luc, 1200 Bruxelles, Belgique.
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Zaidi H, Vees H, Wissmeyer M. Molecular PET/CT imaging-guided radiation therapy treatment planning. Acad Radiol 2009; 16:1108-33. [PMID: 19427800 DOI: 10.1016/j.acra.2009.02.014] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2008] [Revised: 02/11/2009] [Accepted: 02/19/2009] [Indexed: 01/01/2023]
Abstract
The role of positron emission tomography (PET) during the past decade has evolved rapidly from that of a pure research tool to a methodology of enormous clinical potential. (18)F-fluorodeoxyglucose (FDG)-PET is currently the most widely used probe in the diagnosis, staging, assessment of tumor response to treatment, and radiation therapy planning because metabolic changes generally precede the more conventionally measured parameter of change in tumor size. Data accumulated rapidly during the last decade, thus validating the efficacy of FDG imaging and many other tracers in a wide variety of malignant tumors with sensitivities and specificities often in the high 90 percentile range. As a result, PET/computed tomography (CT) had a significant impact on the management of patients because it obviated the need for further evaluation, guided further diagnostic procedures, and assisted in planning therapy for a considerable number of patients. On the other hand, the progress in radiation therapy technology has been enormous during the last two decades, now offering the possibility to plan highly conformal radiation dose distributions through the use of sophisticated beam targeting techniques such as intensity-modulated radiation therapy (IMRT) using tomotherapy, volumetric modulated arc therapy, and many other promising technologies for sculpted three-dimensional (3D) dose distribution. The foundation of molecular imaging-guided radiation therapy lies in the use of advanced imaging technology for improved definition of tumor target volumes, thus relating the absorbed dose information to image-based patient representations. This review documents technological advancements in the field concentrating on the conceptual role of molecular PET/CT imaging in radiation therapy treatment planning and related image processing issues with special emphasis on segmentation of medical images for the purpose of defining target volumes. There is still much more work to be done and many of the techniques reviewed are themselves not yet widely implemented in clinical settings.
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Simon E, Fox TH, Lee D, Waller AF, Pantalone P, Jani AB. PET Lesion Segmentation Using Automated Iso-intensity Contouring in Head and Neck Cancer. Technol Cancer Res Treat 2009; 8:249-55. [DOI: 10.1177/153303460900800401] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
To improve the objectivity of the integration of positron emission tomography (PET), we used the conformality index (CI) to measure the goodness of fit of a given PET iso-SUV (standardized uptake value) level with the GTV defined on PET (GTVPET) and CT (GTVCT). Twenty-two datasets involving 20 head and neck cancer patients were identified. GTVPET and GTVCT were delineated manually. An iso-intensity method was developed to automatically segment GTVPET-ISO using (a) SUV and (b) maximum intensity thresholding (%Max), over a range of intensities. For each intensity, GTVPET-ISO was compared to GTVPET using the conformality index CIPET (and, similarly, to GTVCT using CICT). Comparing GTVPET to GTVPET-ISO vs comparing GTVCT to GTVPET-ISO, the average peak CI was 0.68 ± 0.09 vs 0.49 ± 0.12 (p<0.001), the optimum iso-SUV was 2.7 ± 0.7 vs 2.9 ± 1.0 (p=0. 253), and the %Max SUV was 21.8% ± 7.6% vs 23.8% ± 8.6% (p=0. 310), respectively. The radiation oncologist's volumes corresponded to a lower iso-SUV (3.02 ± 0.58 vs 4.36 ± 0.77, p < 0.001) and lower %Max SUV (24.1 ± 9.1% vs 34.3 ± 11.2%, p<0.001) than those drawn by the nuclear medicine physician. Though manual editing may still be necessary, PET iso-contouring is one method to improve the objectivity of GTV definition in head and neck cancer patients. Iso-SUV's can also be used to study the differences between PET's role as a nuclear medicine diagnostic test versus a radiation oncology treatment planning tool.
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Affiliation(s)
- Edmund Simon
- Departments of Radiation Oncology and Nuclear Medicine, Emory University, Department of Radiation Oncology 1365 Clifton Road, NE, Suite A1300 Atlanta, GA 30322
| | - Timothy H. Fox
- Departments of Radiation Oncology and Nuclear Medicine, Emory University, Department of Radiation Oncology 1365 Clifton Road, NE, Suite A1300 Atlanta, GA 30322
| | - Daniel Lee
- Departments of Radiation Oncology and Nuclear Medicine, Emory University, Department of Radiation Oncology 1365 Clifton Road, NE, Suite A1300 Atlanta, GA 30322
| | - Anthony F. Waller
- Departments of Radiation Oncology and Nuclear Medicine, Emory University, Department of Radiation Oncology 1365 Clifton Road, NE, Suite A1300 Atlanta, GA 30322
| | - Paul Pantalone
- Departments of Radiation Oncology and Nuclear Medicine, Emory University, Department of Radiation Oncology 1365 Clifton Road, NE, Suite A1300 Atlanta, GA 30322
| | - Ashesh B. Jani
- Departments of Radiation Oncology and Nuclear Medicine, Emory University, Department of Radiation Oncology 1365 Clifton Road, NE, Suite A1300 Atlanta, GA 30322
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Kapse N, Goh V. Functional imaging of colorectal cancer: positron emission tomography, magnetic resonance imaging, and computed tomography. Clin Colorectal Cancer 2009; 8:77-87. [PMID: 19423500 DOI: 10.3816/ccc.2009.n.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
In the past 10 years, overall survival and disease-free survival of patients with colorectal cancer (CRC) has improved substantially because of a combination of factors: (1) more accurate staging as a result of advances in imaging technology; (2) refinements in surgical technique; (3) 'curative' metastasectomy for patients with limited metastatic disease; (4) improvements in radiation therapy planning and greater precision of radiation therapy delivery; and (5) increasing chemotherapeutic options, including antiangiogenic and vascular targeting drugs. In this era of 'personalized medicine,' the increasingly individualized treatment of patients with CRC has highlighted the need for functional imaging techniques in addition to conventional anatomic-based imaging. This review discusses the contribution of positron emission tomography to the clinical management of CRC. In addition, evolving techniques such as dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), DCE computed tomography (perfusion CT), diffusion-weighted MRI, and blood oxygenation level-dependent MRI that might have a future role will be covered.
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Affiliation(s)
- Nikhil Kapse
- The Paul Strickland Scanner Centre, The Cancer Centre, Mount Vernon Hospital, Northwood, UK
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Gardner M, Halimi P, Valinta D, Plantet MM, Alberini JL, Wartski M, Banal A, Hans S, Floiras JL, Housset M, Labib A. Use of single MRI and 18F-FDG PET-CT scans in both diagnosis and radiotherapy treatment planning in patients with head and neck cancer: Advantage on target volume and critical organ delineation. Head Neck 2009; 31:461-7. [DOI: 10.1002/hed.21005] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Hwang AB, Bacharach SL, Yom SS, Weinberg VK, Quivey JM, Franc BL, Xia P. Can Positron Emission Tomography (PET) or PET/Computed Tomography (CT) Acquired in a Nontreatment Position Be Accurately Registered to a Head-and-Neck Radiotherapy Planning CT? Int J Radiat Oncol Biol Phys 2009; 73:578-84. [PMID: 19084350 DOI: 10.1016/j.ijrobp.2008.09.041] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2008] [Revised: 09/17/2008] [Accepted: 09/19/2008] [Indexed: 11/30/2022]
Affiliation(s)
- Andrew B Hwang
- Department of Radiation Oncology, University of California, San Francisco, San Francisco, CA, USA
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Abstract
PET/CT is an effective tool for the diagnosis, staging and restaging of cancer patients. It combines the complementary information of functional PET images and anatomical CT images in one imaging session. Conventional stand-alone PET has been replaced by PET/CT for improved patient comfort, patient throughput, and most importantly the proven clinical outcome of PET/CT over that of PET and that of separate PET and CT. There are over two thousand PET/CT scanners installed worldwide since 2001. Oncology is the main application for PET/CT. Fluorine-18 deoxyglucose is the choice of radiopharmaceutical in PET for imaging the glucose uptake in tissues, correlated with an increased rate of glycolysis in many tumor cells. New molecular targeted agents are being developed to improve the accuracy of targeting different disease states and assessing therapeutic response. Over 50% of cancer patients receive radiation therapy (RT) in the course of their disease treatment. Clinical data have demonstrated that the information provided by PET/CT often changes patient management of the patient and/or modifies the RT plan from conventional CT simulation. The application of PET/CT in RT is growing and will become increasingly important. Continuing improvement of PET/CT instrumentation will also make it easier for radiation oncologists to integrate PET/CT in RT. The purpose of this article is to provide a review of the current PET/CT technology, to project the future development of PET and CT for PET/CT, and to discuss some issues in adopting PET/CT in RT and potential improvements in PET/CT simulation of the thorax in radiation therapy.
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Affiliation(s)
- Tinsu Pan
- Department of Imaging Physics, M. D. Anderson Cancer Center, The University of Texas, Houston, Texas 77030, USA.
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Lawrence YR, Werner-Wasik M, Dicker AP. Biologically conformal treatment: biomarkers and functional imaging in radiation oncology. Future Oncol 2008; 4:689-704. [PMID: 18922126 DOI: 10.2217/14796694.4.5.689] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
'Conformal radiation therapy' is the standard of care in radiation oncology, referring to the process of shaping the radiation beam to precisely match a tumor's physical dimensions. We describe 'biologically conformal radiotherapy', in which the radiation oncologist matches the prescribed treatment to a tumor's biological characteristics and the host's predicted tolerance of radiation. This paradigm emphasizes that not all tumors are equally sensitive to radiation; conversely, some patients are especially susceptible to radiation's side effects. Patients bearing radioresistant tumors or those prone to toxicity may be best treated with the incorporation of targeted radiation modulators or, in extreme cases, by a different modality. The biological characteristics of tumors can be assessed by a wide range of techniques: functional imaging (positron emission tomography and advanced magnetic resonance imaging), single gene/protein molecular techniques and 'omic' technologies. This paper reviews the latest advances in the use of biomarkers and functional imaging in guiding patients to receive the most appropriate treatment.
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Affiliation(s)
- Yaacov Richard Lawrence
- Department of Radiation Oncology, Division of Experimental Radiation Oncology, Kimmel Cancer Center, Jefferson Medical College of Thomas Jefferson University, Philadelphia, PA 19107, USA.
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Evaluation of different methods of 18F-FDG-PET target volume delineation in the radiotherapy of head and neck cancer. Am J Clin Oncol 2008; 31:439-45. [PMID: 18838879 DOI: 10.1097/coc.0b013e318168ef82] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
OBJECTIVE To quantify differences between the alternative methods of F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET)-based delineation of the gross tumor volume in patients with head and neck cancer. MATERIALS AND METHODS Twelve patients with locally-advanced head and neck carcinomas were studied. The reference gross tumor volume (GTVref) was established by a radiation oncologist, along with a neuroradiologist, using the computed tomography-simulation and diagnostic magnetic resonance imaging data. With the GTVref obscured, a second radiation oncologist and a nuclear medicine physician determined the following contours: (1) high FDG uptake based on visual inspection (GTVvis), (2) the contour derived from the 50% maximum standardized uptake value (SUV) threshold (GTV50), (3) the contour derived from a 2.5 SUV absolute threshold (GTV2.5), and (4) the contours derived from an iterative segmentation algorithm (GTViter). These volumes were compared with the GTVref using a signed-ranks test with the exact reference distribution. RESULTS The average GTVref was 75.5 mL (median 72.8 mL, range 22.2-138.4 mL). The average GTVvis was 57.6 (median 55.4 mL, range 12-115.8 mL). Overall, a 21% reduction in volume size was observed with GTVvis versus GTVref. When the signed-ranks test with the exact reference distribution was applied, the difference was not statistically significant (P = 0.32). The average GTV2.5 was 60 mL (median 64.5, range 8.8-90.3 mL). The differences between GTV2.5 and GTVref were not statistically significant (P = 0.35). The use of GTV50 and GTViter produced significantly smaller volumes with respect to GTVref (P < 0.005). CONCLUSIONS PET-based tumor volumes are strongly affected by the choice of threshold level. Quantitatively, GTVs derived from visual inspection of the region of high FDG uptake do not significantly differ from GTVref in this cohort of patients. The inclusion of alternative FDG-PET segmentation data, other than visual inspection, may reduce target volumes significantly.
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Abstract
The recent wave of enthusiasm for image guidance in radiation therapy is largely due to the advent of on-line imaging devices. The current narrow definition of image-guided radiotherapy (IGRT), in fact, essentially connotes the use of near real-time imaging during treatment delivery to reduce uncertainties in target position and should therefore be termed IGRT-D. However, a broader (and more appropriate) context of image-guidance should include: (1) detection and diagnosis, (2) delineation of target and organs at risk, (3) determining biological attributes, (4) dose distribution design, (5) dose delivery assurance and (6) deciphering treatment response through imaging i.e. the 6 D's of IGRT. Strategies to advance these areas will be discussed.
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Aichi cancer center initial experience of intensity modulated radiation therapy for nasopharyngeal cancer using helical tomotherapy. Int J Radiat Oncol Biol Phys 2008; 73:1129-34. [PMID: 18922651 DOI: 10.1016/j.ijrobp.2008.06.1936] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2008] [Revised: 06/05/2008] [Accepted: 06/09/2008] [Indexed: 11/20/2022]
Abstract
PURPOSE To assess the feasibility of helical tomotherapy (HT) for patients with nasopharyngeal carcinoma. METHODS AND MATERIALS From June 2006 to June 2007, 20 patients with nasopharyngeal carcinoma were treated with HT with (n = 18) or without (n = 2) systemic chemotherapy. The primary tumor and involved lymph node (PTV1) were prescribed 70 Gy and the prophylactic region 54 Gy at D95, respectively. The majority of patients received 2 Gy per fraction for PTV1 in 35 fractions. Parotid function was evaluated using quantitative scintigraphy at pretreatment, and posttreatment at 3 months and 1 year later. RESULTS The median patient age was 53 years, ranging from 15 to 83. Our cohort included 5, 8, 4, 2, and 1 patients with disease Stages IIB, III, IVA, IVB, and IVC, respectively. Histopathological record revealed two for World Health Organization Type I and 18 for Type 2 or 3. The median duration time for treatment preparation was 9.5 days, and all plans were thought to be acceptable regarding dose constraints of both the planning target volume and organ at risk. All patients completed their treatment procedure of intensity-modulated radiation therapy (IMRT). All patients achieved clinical remission after IMRT. The majority of patients had Grade 3 or higher toxicity of skin, mucosa, and neutropenia. At the median follow-up of 10.9 months, two patients recurred, and one patient died from cardiac disease. Parotid gland function at 1 year after completion of IMRT was significantly improved compared with that at 3 months. CONCLUSION HT was clinically effective in terms of IMRT planning and utility for patients with nasopharyngeal cancer.
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Burri RJ, Rangaswamy B, Kostakoglu L, Hoch B, Genden EM, Som PM, Kao J. Correlation of Positron Emission Tomography Standard Uptake Value and Pathologic Specimen Size in Cancer of the Head and Neck. Int J Radiat Oncol Biol Phys 2008; 71:682-8. [DOI: 10.1016/j.ijrobp.2007.10.055] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2007] [Revised: 10/23/2007] [Accepted: 10/24/2007] [Indexed: 10/22/2022]
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Visser EP, Philippens MEP, Kienhorst L, Kaanders JHAM, Corstens FHM, de Geus-Oei LF, Oyen WJG. Comparison of tumor volumes derived from glucose metabolic rate maps and SUV maps in dynamic 18F-FDG PET. J Nucl Med 2008; 49:892-8. [PMID: 18483085 DOI: 10.2967/jnumed.107.049585] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED Tumor delineation using noninvasive medical imaging modalities is important to determine the target volume in radiation treatment planning and to evaluate treatment response. It is expected that combined use of CT and functional information from 18F-FDG PET will improve tumor delineation. However, until now, tumor delineation using PET has been based on static images of 18F-FDG standardized uptake values (SUVs). 18F-FDG uptake depends not only on tumor physiology but also on blood supply, distribution volume, and competitive uptake processes in other tissues. Moreover, 18F-FDG uptake in tumor tissue and in surrounding healthy tissue depends on the time after injection. Therefore, it is expected that the glucose metabolic rate (MRglu) derived from dynamic PET scans gives a better representation of the tumor activity than does SUV. The aim of this study was to determine tumor volumes in MRglu maps and to compare them with the values from SUV maps. METHODS Twenty-nine lesions in 16 dynamic 18F-FDG PET scans in 13 patients with non-small cell lung carcinoma were analyzed. MRglu values were calculated on a voxel-by-voxel basis using the standard 2-compartment 18F-FDG model with trapping in the linear approximation (Patlak analysis). The blood input function was obtained by arterial sampling. Tumor volumes were determined in SUV maps of the last time frame and in MRglu maps using 3-dimensional isocontours at 50% of the maximum SUV and the maximum MRglu, respectively. RESULTS Tumor volumes based on SUV contouring ranged from 1.31 to 52.16 cm3, with a median of 8.57 cm3. Volumes based on MRglu ranged from 0.95 to 37.29 cm3, with a median of 3.14 cm3. For all lesions, the MRglu volumes were significantly smaller than the SUV volumes. The percentage differences (defined as 100% x (V MRglu - V SUV)/V SUV, where V is volume) ranged from -12.8% to -84.8%, with a median of -32.8%. CONCLUSION Tumor volumes from MRglu maps were significantly smaller than SUV-based volumes. These findings can be of importance for PET-based radiotherapy planning and therapy response monitoring.
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Affiliation(s)
- Eric P Visser
- Department of Nuclear Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
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Ahn PH, Garg MK. Positron emission tomography/computed tomography for target delineation in head and neck cancers. Semin Nucl Med 2008; 38:141-8. [PMID: 18243850 DOI: 10.1053/j.semnuclmed.2007.11.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Radiation and concurrent chemoradiation are essential in the treatment of head and neck cancers because they allow a potentially curative organ preservation approach in a manner that greatly affects quality of life. Greater doses of radiation to areas of gross disease have invariably led to greater loco-regional control. Radiation delivery has undergone great strides, especially in the era of intensity-modulated radiotherapy and related technologies. With the ability to sculpt out areas of higher and lower doses of radiation to millimeter accuracy, the role of imaging to better direct the radiation beam to its target via improved localization has become an issue of great promise. The use of (18)F-fluorodeoxyglucose-positron emission tomography (PET) with computed tomography (CT) as a means of noninvasively staging many head and neck cancers has become increasingly popular. With its role as a functional assay of tumor metabolic activity, it is often used in conjunction with physical examination and other imaging modalities to determine levels of nodal metastases as well as the site of head and neck involvement. Several groups have used images derived from PET/CT to outline areas of gross disease to receive definitive doses of radiotherapy. Generally, no statistically significant difference exists in the volumes delineated on CT alone versus PET/CT. However, in the studied populations there is often important and significant wide individual variability. The tumors on PET/CT are either larger or smaller than tumors outlined on CT scan only, in the majority of patients. Although areas of controversy include threshold definition and image resolution, the utility of a functional assay in defining target volume helps determine areas to receive higher doses of radiation in cancers of the head and neck. Exciting new functional modalities are emerging to image other parameters including tumor hypoxia, which presents a new target with the same challenges in target delineation as PET/CT.
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Affiliation(s)
- Peter H Ahn
- Department of Radiation Oncology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY 10467, USA.
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Bassi MC, Turri L, Sacchetti G, Loi G, Cannillo B, La Mattina P, Brambilla M, Inglese E, Krengli M. FDG-PET/CT imaging for staging and target volume delineation in preoperative conformal radiotherapy of rectal cancer. Int J Radiat Oncol Biol Phys 2007; 70:1423-6. [PMID: 17931795 DOI: 10.1016/j.ijrobp.2007.08.043] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2007] [Revised: 08/14/2007] [Accepted: 08/16/2007] [Indexed: 11/16/2022]
Abstract
PURPOSE To investigate the potential impact of using (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) on staging and target volume delineation for patients affected by rectal cancer and candidates for preoperative conformal radiotherapy. METHODS AND MATERIALS Twenty-five patients diagnosed with rectal cancer T3-4 N0-1 M0-1 and candidates for preoperative radiotherapy underwent PET/CT simulation after injection of 5.18 MBq/kg of FDG. Clinical stage was reassessed on the basis of FDG-PET/CT findings. The gross tumor volume (GTV) and the clinical target volume (CTV) were delineated first on CT and then on PET/CT images. The PET/CT-GTV and PET/CT-CTV were analyzed and compared with CT-GTV and CT-CTV, respectively. RESULTS In 4 of 25 cases (24%), PET/CT affected tumor staging or the treatment purpose. In 3 of 25 cases (12%) staged N0 M0, PET/CT showed FDG uptake in regional lymph nodes and in a case also in the liver. In a patient with a single liver metastasis PET/CT detected multiple lesions, changing the treatment intent from curative to palliative. The PET/CT-GTV and PET/CT-CTV were significantly greater than the CT-GTV (p = 0.00013) and CT-CTV (p = 0.00002), respectively. The mean difference between PET/CT-GTV and CT-GTV was 25.4% and between PET/CT-CTV and CT-CTV was 4.1%. CONCLUSIONS Imaging with PET/CT for preoperative radiotherapy of rectal cancer may lead to a change in staging and target volume delineation. Stage variation was observed in 12% of cases and a change of treatment intent in 4%. The GTV and CTV changed significantly, with a mean increase in size of 25% and 4%, respectively.
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Affiliation(s)
- Maria Chiara Bassi
- Department of Radiotherapy, University of Piemonte Orientale, Novara, Italy
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de Andrade RS, Heron DE. Radiation Treatment Planning for Head and Neck Malignancies. PET Clin 2007; 2:511-9. [DOI: 10.1016/j.cpet.2008.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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