124I PET-based 3D-RD dosimetry for a pediatric thyroid cancer patient: Real-time treatment planning and methodologic comparison

Robert F. Hobbs, Richard L. Wahl, Martin A. Lodge, Mehrbod S. Javadi, Steve Y. Cho, David T. Chien, Marge E. Ewertz, Caroline E. Esaias, Paul W. Ladenson, George Sgouros

Research output: Contribution to journalArticle


Patient-specific 3-dimensional radiobiologic dosimetry (3D-RD) was used for 131I treatment planning for an 11-y-old girl with differentiated papillary thyroid cancer, heavy lung involvement, and cerebral metastases. 124I PET was used for pharmacokinetics. Calculation of the recommended administered activity, based on lung toxicity constraints, was performed in real time (i.e., during the data-acquisition interval). The results were available to the physician in time to influence treatment; these estimates were compared with conventional dosimetry methodologies. In subsequent, retrospective analyses, the 3D-RD calculations were expanded to include additional tumor dose estimates, and the conventionalmethodologieswere reexamined to reveal the causes of the differences observed. A higher recommended administered activity than by an S-value-based method with a favorable clinical outcome was obtained. This approach permitted more aggressive treatment while adhering to patientspecific lung toxicity constraints. A retrospective analysis of the conventional methodologies with appropriate corrections yielded absorbed dose estimates consistent with 3D-RD.

Original languageEnglish (US)
Pages (from-to)1844-1847
Number of pages4
JournalJournal of Nuclear Medicine
Issue number11
StatePublished - Nov 1 2009



  • 3D-RD
  • Dosimetry
  • Oncology
  • PET
  • Radiobiology/dosimetry
  • Radionuclide therapy
  • Thyroid
  • Treatment planning

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

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