Review of Radiosurgery of Pineal Parenchymal Tumors. Long Survival Following 125-Iodine Brachytherapy of Pineoblastomas in 2 Cases

Abstract OBJECTIVE: The aim of the present work is to report the volumetric changes of tumor in two pineoblastoma patients treated with stereotactic interstitial irradiation and to present a review on radiosurgery of pineal parenchymal tumors. METHODS: Two of our patients with pineoblastoma were treated with CT and image-fusion guided 125-iodine brachytherapy. The tumor volumes were determined with outlined contours on planning and control CT/MRI images and were compared. RESULTS: Until January 2006, there were 61- and 58-month follow-up periods in the two cases. 56 and 53 months after irradiation the MRI images showed significant tumor shrinkage. In case 1 tumor volume was 0.76 cm 3 on the last control MRI image, compared to the 2.87 cm 3 at the time of interstitial irradiation, which means 73% shrinkage. In case 2, tumor volume measured with the last control MRI examination was 0.29 cm 3 , which represents 77% shrinkage of the original tumor volume. In both Cases 1 and 2, PET examinations using 11 C-methionine showed no active tumor mass 56 and 53 months following brachytherapy. CONCLUSION: Two successful treatments of pineoblastoma are reported. The interstitial irradiation of the tumors decreased their volumes significantly. The CT and image fusion-guided 125-iodine stereotactic brachytherapy can be planned well dosimetrically and is surgically precise.