Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Accurate quantification of131I distribution by gamma camera imaging


The development of targeted therapy requires that the concentration of the therapeutic agent can be estimated in target and normal tissues. Single photon emission tomography (SPET), with and without scatter correction, and planar imaging using131I have been compared to develop a method for investigation of targeted therapy. Compton scatter was investigated using line spread functions in air and water, these data were used to set a second peak, adjacent to the photopeak, for scatter correction. The system was calibrated with an eliptical phantom containing sources in background activity of various intensities. Scatter corrected reconstructions gave accurate estimates of activity in the sources regardless of background activity. For planar scanning and SPET without scatter correction there was an overestimate of activity in the source of 290% and 40% respectively. The validity of this method was confirmed in patients by comparing activity in the cardiac ventricles measured by SPET with scatter correction with that in a simultaneous blood sample. A coefficient of correlation of 0.955 was achieved with 25 data points. SPET with scatter correction was compared with planar imaging in measuring activity in the liver and spleen of patients receiving 75 mCi131I-antibody to CEA intravenously. Planar imaging gave significantly higher values than SPET for the spleen (t=5.4,P<0.001 by the pairedt-test) but no significant difference for the liver. SPET with scatter correction forms a basis for an improved technique of quantifying the targeting efficiency.

This is a preview of subscription content, log in to check access.


  1. Begent RHJ, Keep PA, Searle F, Green AJ, Mitchell HDC, Jones BE, Dent J, Pendower JEH, Parkins RA, Reynolds KW, Cooke TG, Allenmersh T, Bagshawe KD (1986) Radioimmunolocalisation and selection for surgery in recurrent colorectal cancer. Br J Surg 73:64–67

  2. Carrasquillo JA, Krohn KA, Beaumier P, McGuffin RW, Brown JP, Hellstrom KE, Hellstrom I, Larson SM (1984) Diagnosis of and therapy for solid tumours with radiolabeled antibodies and immune fragments. Cancer Treat Rep 68:317–328

  3. Chang LT (1978) A method for attenuation correction in radionuclide computed tomography. IEEE Trans Nucl Sci NS-25:638–643

  4. Goldenberg DM, Deland FH, Kim EE, Bennett S, Primus FJ, Nagell JR van, Estes N, DeSimone P, Rayburn P (1978) Use of radiolabelled antibodies to carcinoembryonic antigen for the detection and localisation of diverse cancers by external photo-scanning. New Engl J Med 1:131–139

  5. Hammond ND, Moldofsky PJ, Beardsley MR, Mulhern CB (1984) External imaging techniques for quantitation of distribution of 131I F(ab')2 fragments of monoclonal antibody in humans. Med Phys 11:778–783

  6. Jaszczak RS, Greer KL, Floyd CE, Harris CC, Coleman RE (1984) Improved SPECT quantification using compensation for scattered photons. J Nucl Med 25:893–900

  7. Ledermann JA, Begent RHJ, Bagshawe KD, Riggs SJ, Searle F, Glaser MG, Green AJ, Dale RG (1988) Repeated antitumour antibody therapy in man with suppression of the host response by cyclosporin A. Br J Cancer 58:654–657

  8. Leichner PK, Klein JL, Garrison JB, Jenkins RE, Nickloff EL, Ettinger DS, Order SE (1981) Dosimetry of 131I-labeled antiferritin in hepatoma: a model for radioimmunoglobulin dosimetry. Int J Radiol Oncol Biol Phys 7:323–333

  9. Mach JP, Carrel S, Form M, Ritschard J, Donarth A, Alberto P (1980) N Engl J Med 303:5–10

  10. Sorenson JA, Phelps ME (1980) Physics in Nuclear Medicine. Grune and Stratton, Orlando, Florida

  11. Thomas SR, Maxan HR, Kereiaakes JC (1976) In vivo quantitation of lesion radioactivity using external counting methods. Med Phys 3:253–255

Download references

Author information

Correspondence to Alan J. Green.

Additional information

This work is supported by the Cancer Research Campaign

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Green, A.J., Dewhurst, S.E., Begent, R.H.J. et al. Accurate quantification of131I distribution by gamma camera imaging. Eur J Nucl Med 16, 361–365 (1990). https://doi.org/10.1007/BF00842793

Download citation

Key words

  • Emission tomography
  • SPET
  • Scatter correction
  • Radiolabelled antibody
  • Targeted therapy