This file was created with JabRef 2.2.
Encoding: Cp1252

@INPROCEEDINGS{wendler2007snmbeta,
  author = {Thomas Wendler and Joerg Traub and Sibylle Ziegler and Nassir Navab},
  title = {Validation of navigated beta-probe imaging with PET/CT-generated
	activity surfaces. New approach in radio-guided resection for FDG-positive
	tumors},
  booktitle = {Proceedings of SNM 2007},
  year = {2007},
  address = {Washington D.C., USA},
  month = {Jun.},
  organization = {Society of Nuclear Medicine},
  abstract = {Objectives: In a previous work, we introduced a surface imaging system
	based on beta-probes and spatial localization systems. There we proved
	in phantoms that such a system gave instinctive feedback to the surgeons
	in the control of resection borders of FDG-positive tumors. Here,
	we develop an approach and generate data to validate the thus acquired
	images by comparing them with beta-emission surfaces created from
	a preoperative PET/CT. 
	
	Methods: We implemented a system that acquires the position and the
	reading of a beta-probe using an optical spatial localization system.
	Such a system was used to obtain - in 4 experiments of 2-3min (sampling
	time 0.1s) - the shape and surface distribution of radioactivity
	on an ad-hoc designed phantom. The phantom was injected in 2 different
	spots with an aqueous solution of FDG (each 0.5MBq) and then scanned
	with a PET/CT. With a specially developed model of positron-dispersion
	together with the PET data we calculated the expected beta-flow at
	each probe position. In a second step, we extracted the surface of
	the phantom from the CT and used the model and the PET data to generate
	the beta-activity at each point of the extracted surface. Finally,
	the acquired readings and the calculated ones were  compared. 
	
	Results: Both PET and PET/CT generated activities and the acquired
	probe readings qualitatively agreed well, showing the spots at the
	expected positions in all experiments. Furthermore, the normalized
	cross-correlation between beta-probe and PET surfaces was found to
	be 0.51±0.11. Longer scans (more points) yielded better results due
	to the increase in counts. 
	
	Conclusions: The qualitative and quantitative match of the activity
	surfaces validates the navigated beta-probe imaging system. Moreover,
	the PET/CT-generated surfaces present a promising visualization for
	surgical planning. This novel approach is thus introduced as an intuitive
	intraoperative visualization toward a less invasive and more accurate
	radio-guided cancer resection. 
	
	Research Support: The beta-probe was kindly provided by Dr. Farhad
	Daghighian from IntraMedical Imaging LLC (Los Angeles, California).}
}


