Delineation of Biological Tumor Volume from Positron Emission Tomography Images in Nasopharyngeal Carcinoma


Objective: To develop an auto-segmentation method for delineating the biological tumor volume of nasopharyngeal carcinoma from positron emission tomography images. Methods: A phantom consisting of a water tank with fixed background fluorodeoxyglucose [18F-FDG] activity and spheres with diameters ranging from 2.1 to 5 cm with varying activities of FDG were used to simulate tumors of different sizes and FDG uptake. The phantom was scanned with a PET/CT scan at different sphere to background intensity ratios. An optimum fixed percentage threshold (FT) approach and a signal-to-background ratio (SBR) approach were developed to estimate the true size of the spheres from the PET images. Both approaches were further evaluated in patient images for validation. Twenty-two patients with NPC from stage T1 to T4 were included. The PET based biological tumor volumes (BTV) were delineated with both FT (BTVFT) and SBR (BTVSBR) approaches and compared with the gross tumor volume localized from MRI (GTVMR). The mean volumes of BTVFT and BTVSBR were compared and the degree of overlap between GTVMR and both BTVs was evaluated. Paired t-tests were used for statistical analysis. Results: The optimal FT value was 36.5% of maximal intensity, and SBR approach was represented by an inverse linear regression model. The estimated volume of spheres segmented by both approaches shows no significant difference from the true volume of spheres (p > 0.05), but the average absolute errors were smaller from SBR approach than FT approach (p = 0.008). GTVMR was larger than both BTVFT (p = 0.003) and BTVSBR (p < 0.009). The overlapping volume of BTVSBR with GTVMR is significantly larger than with BTVFT (0.52 and 0.42 respectively, p < 0.0005). Conclusions: SBR approach is more feasible than FT approach to localize the BTV of NPC from FDG-PET image, and BTV might help to modify the extent of GTVMR for radiotherapy planning purpose.

Share and Cite:

Wong, K. , Kwong, D. , Khong, P. , Lee, V. , Ng, S. and Law, M. (2014) Delineation of Biological Tumor Volume from Positron Emission Tomography Images in Nasopharyngeal Carcinoma. Journal of Biomedical Science and Engineering, 7, 857-865. doi: 10.4236/jbise.2014.711085.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Zaidi, H. and El Naqa, I. (2010) PET-Guided Delineation of Radiation Therapy Treatment Volumes: A Survey of Image Segmentation Techniques. European Journal of Nuclear Medicine Molecular Imaging, 37, 2165-2187.
[2] Daisne, J.F., Duprez, T., Weynand, B., Lonneux, M., Hamoir, M., Reychler, H., et al. (2004) Tumor Volume in Pharyngolaryngeal Squamous Cell Carcinoma: Comparison at CT, MR Imaging, and FDG PET and Validation with Surgical Specimen1. Radiology, 233, 93-100.
[3] Wang, D., Schultz, C. J., Jursinic, P. A., Bialkowski, M., Zhu, X. R., Brown, W. D., et al. (2006) Initial Experience of FDG-PET/CT Guided IMRT of Head-And-Neck Carcinoma. International Journal of Radiation Oncology*Biology* Physics, 65, 143-151.
[4] Burri, R.J., Rangaswamy, B., Kostakoglu, L., Hoch, B., Genden, E.M., Som, P.M., et al. (2008) Correlation of Positron Emission Tomography Standard Uptake Value and Pathologic Specimen Size in Cancer of the Head and Neck. International Journal of Radiation Oncology*Biology*Physics, 71, 682-688.
[5] Schinagl, D.A.X., Vogel, W.V., Hoffmann, A.L., van Dalen, J.A., Oyen, W.J. and Kaanders, J.H. (2007) Comparison of Five Segmentation Tools for 18F-Fluoro-Deoxy-Glucose-Positron Emission Tomography-Based Target Volume Definition in Head and Neck Cancer. International Journal of Radiation Oncology*Biology*Physics, 69, 1282-1289.
[6] Greco, C., Nehmeh, S.A., Schoder, H., Gonen, M., Raphael, B., Stambuk, H.E., et al. (2008) Evaluation of Different Methods of 18F-FDG-PET Target Volume Delineation in the Radiotherapy of Head and Neck Cancer. American Journal of Clinical Oncology, 31, 439-445.
[7] MacManus, M., Nestle, U., Rosenzweig, K.E., Carrio, I., Messa, C., Belohlavek, O., et al. (2009) Use of PET and PET/CT for Radiation Therapy Planning: IAEA Expert Report 2006-2007. Radiotherapy and Oncology, 91, 85-94.
[8] Ford, E.C., Herman, J., Yorke, E. and Wahl, R.L. (2009) 18F-FDG PET/CT for Image-Guided and Intensity-Modulated Radiotherapy. The Journal of Nuclear Medicine, 50, 1655-1665.
[9] Soret, M., Bacharach, S.L. and Buvat, I. (2007) Partial-Volume Effect in PET Tumor Imaging. The Journal of Nuclear Medicine, 48, 932-945.
[10] Daisne, J.F., Sibomana, M., Bol, A., Cosnard, G., Lonneus, M. and Gregoire, V. (2003) Evaluation of a Multimodality Image (CT, MRI and PET) Coregistration Procedure on Phantom and Head and Neck Cancer Patients: Accuracy, Reproducibility and Consistency. Radiotherapy and Oncology, 69, 237-245.
[11] MacManus, M.P. and Hicks, R.J. (2008) Where Do We Draw the Line? Contouring Tumors on Positron Emission Tomography/Computed Tomography. International Journal of Radiation Oncology*Biology*Physics, 71, 2-4.
[12] Ng, S.H., Chan, S.C., Yen, T.C., Chang, J.T.C., Liao, C.T., Ko, S.F., Liu, F.Y., Chin, S.C., Fan, K.H. and Hsu, C.L. (2009) Staging of Untreated Nasopharyngeal Carcinoma with PET/CT: Comparison with Conventional Imaging Work-Up. European Journal of Nuclear Medicine and Molecular Imaging, 36, 12-22.
[13] Geets, X., Lee, J.A., Bol, A., Lonneux, M. and Gregoire, V. (2007) A Gradient-Based Method for Segmenting FDG-PET Images: Methodology and Validation. European Journal of Nuclear Medicine and Molecular Imaging, 34, 1427-1438.
[14] Guido, A., Fuccio, L., Rombi, B., Castellucci, P., Cecconi, A., Bunkheila, F., et al. (2009) Combined 18F-FDG-PET/CT Imaging in Radiotherapy Target Delineation for Head-and-Neck Cancer. International Journal of Radiation Oncology*Biology*Physics, 73, 759-763.
[15] Hung, G.U., Wu, I.S., Lee, H.S., You, W.C., Chen, H.C. and Chen, M.K. (2011) Primary Tumour Volume Measured by FDG PET and CT in Nasopharyngeal Carcinoma. Clinical Nuclear Medicine, 36, 447-451.
[16] Schoder, H., Yeung, H.W.D., Gonen, M., Kraus, D. and Larson, S.M. (2004) Head and Neck Cancer: Clinical Usefulness and Accuracy of PET/CT Image Fusion1. Radiology, 231, 65-72.
[17] Luke, B. and Graham, M.M. (2007) Positron Emission Tomography-Computerized Tomography in the Management of Head and Neck Cancer. Imaging Decisions MRI, 11, 11-23.
[18] Hwang, A.B., Bacharach, S.L., Yom, S.S., Weinberg, V.K., Quivey, J.M., Franc, B.L. and Xia, P. (2009) 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? International Journal of Radiation Oncology*Biology* Physics, 73, 578-584.
[19] Vees, H., Casanova, N., Zilli, H., Ratib, O., Popowski, Y., Wang, H., Zaidi, H. and Miralbell, R. (2012) Impact of 18F-FDG PET/CT on Target Volume Delineation in Recurrent or Residual Gynaecologic Carcinoma. Radiation Oncology, 7, 176.
[20] Niyazi, M., Landrock, S., Elsner, A., Manapov, F., Hacker, M., Belka, C. and Ganswindt, U. (2013) Automated Biological Target Volume Delineation for Radiotherapy Treatment Planning Using FDG-PET/CT. Radiation Oncology, 8, 180.
[21] Nishioka, T., Shiga, T., Shirato, H., Tsukamoto, E., Tsuchiya, K., Kato, T., et al. (2002) Image Fusion between 18FDG-PET and MRI/CT for Radiotherapy Planning of Oropharyngeal and Nasopharyngeal Carcinomas. International Journal of Radiation Oncology*Biology*Physics, 53, 1051-1057.

Copyright © 2023 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.