Procedure for unmasking localization information from ProstaScint scans for prostate radiation therapy treatment planning

• Published in: International journal of radiation oncology, biology, physics Vol. 60; no. 2; pp. 654 - 662
• Main Authors: DeWyngaert, J. Keith, Noz, Marilyn E., Ellerin, Bruce, Kramer, Elissa L., Maguire, Gerald Q., Zeleznik, Michael P.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.10.2004; Elsevier
• Subjects: 3-dimensional registration; Aged; Aged, 80 and over; ALGORITHMS; Antibodies, Monoclonal; Biological and medical sciences; BLADDER; BLOOD VESSELS; BONE MARROW; brain; cancer; conformal radiotherapy; dose-escalation; fusion; Humans; image registration; in-111 capromab pendetide; INDIUM 111; Indium Radioisotopes; magnetic-resonance; Male; Medical sciences; Middle Aged; NEOPLASMS; NMR IMAGING; PLANNING; ProstaScint; PROSTATE; Prostate cancer treatment planning; Prostatic Neoplasms - diagnostic imaging; Prostatic Neoplasms - radiotherapy; Radioimmunodetection - methods; Radioimmunoguided therapy; RADIOLOGY AND NUCLEAR MEDICINE; RADIOTHERAPY; Radiotherapy Planning, Computer-Assisted - methods; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY; SRA - ICT; SRA - Informations- och kommunikationsteknik; Technetium; TECHNETIUM 99; Technology. Biomaterials. Equipments. Material. Instrumentation; Tomography, Emission-Computed, Single-Photon - methods; UPTAKE; Urinary Bladder - diagnostic imaging; volume data sets; Volume fusion; Volume subtraction; Radioimmunoguided therapy; Volume subtraction; ProstaScint; Prostate cancer treatment planning; Volume fusion; Biomedical engineering
• ISSN: 0360-3016; 1879-355X; 1879-355X
• DOI: 10.1016/j.ijrobp.2004.05.034

To demonstrate a method to extract the meaningful biologic information from 111In-radiolabeled capromab pendetide (ProstaScint) SPECT scans for use in radiation therapy treatment planning by removing that component of the 111In SPECT images associated with normal structures. We examined 20 of more than 80 patients who underwent simultaneous 99mTc/ 111In SPECT scans, which were subsequently registered to the corresponding CT/MRI scans.A thresholding algorithm was used to identify 99mTc uptake associated with blood vessels and CT electron density associated with bone marrow. Corresponding voxels were removed from the 111In image set. No single threshold value was found to be associated with the 99mTc uptake that corresponded to the blood vessels. Intensity values were normalized to a global maximum and, as such, were dependent upon the quantity of 99mTc pooled in the bladder. The reduced ProstaScint volume sets were segmented by use of a thresholding feature of the planning system and superimposed on the CT/MRI scans. ProstaScint images are now closer to becoming a biologically and therapeutically useful and accurate image set. After known sources of normal intensity are stripped away, the remaining areas that demonstrate uptake may be segmented and superimposed on the treatment-planning CT/MRI volume.