PURPOSE: To establish whether intraprostatic calcifications can serve as natural fiducials for image-guided radiotherapy (IGRT), replacing the implantation of intraprostatic fiducial markers.
PATIENTS AND METHODS: Patients with prostate cancer, having intraprostatic calcifications visible on CT scan were selected and underwent intensity-modulated radiotherapy/3D conformal radiotherapy with IGRT in the department of radiotherapy of Henri-Mondor Hospital. All cone-beam computed tomographies (CBCT) were repositioned on intraprostatic calcifications. For each acquired image, displacements of intraprostatic calcifications were calculated with reference to position on planning CT in three directions: lateral, longitudinal and vertical.
RESULTS: Between 2011 and 2013, nine patients had 183 CBCT. For each image, three displacements and space coordinates were calculated using a single reference (intraprostatic calcification). Mean lateral, longitudinal and vertical movements were 0.26±5.7mm, -1±4.6mm and 0.42±3.5mm, respectively.
CONCLUSION: Studies exploring prostatic movements with fiducial markers as reference and ours with natural fiducials yield similar results. Our data confirm previous studies that have suggested that intraprostatic calcifications can be used as natural fiducials with potential reduction of iatrogenic risks and costs associated with the implantation of fiducial markers.
Sbai A, Thariat J, Tachfouti N, Pan Q, Lagrange JL. Are you the author?
Centre régional d'oncologie Hassan-II, BP 2013, oued Nachef, Oujda, Maroc; Département de radiothérapie, centre Antoine-Lacassagne, 33, avenue Valombrose, 06189 Nice cedex 2, France; Université Nice-Sophia-Antipolis, 33, avenue Valombrose, 06189 Nice cedex 2, France; Laboratoire d'épidémiologie, recherche clinique et de santé communautaire, CHU Hassan-II, Fès, Maroc; Service de radiothérapie, hôpital Henri-Mondor, 51, avenue du Maréchal-de-Lattre-de-Tassigny, 94010 Créteil cedex, France; Université Paris Est Créteil, avenue du Général-de-Gaulle, 94010 Créteil cedex, France.
Reference: Cancer Radiother. 2014 Dec;18(8):740-4.
Article in French.