The importance of tumor volume in the prognosis of patients with glioblastoma: comparison of computerized volumetry and geometric models.
OBJECTIVE
The importance of tumor volume as a prognostic factor in high-grade gliomas is highly controversial and there are numerous methods estimating this parameter. In this study, a computer-based application was used in order to assess tumor volume from hard copies and a survival analysis was conducted in order to evaluate the prognostic significance of preoperative volumetric data in patients harboring glioblastomas.


METHODS
50 patients suffering from glioblastoma were analyzed retrospectively. Tumor volume was determined by the various geometric models as well as by an own specialized software (Volumio). Age, performance status, type of excision, and tumor location were also included in the multivariate analysis.


RESULTS
The spheroid and rectangular models overestimated tumor volume, while the ellipsoid model offered the best approximation. Volume failed to attain any statistical significance in prognosis, while age and performance status confirmed their importance in progression-free and overall survival of patients.


CONCLUSIONS
Geometric models provide a rough approximation of tumor volume and should not be used, as accurate determination of size is of paramount importance in order to draw safe conclusions in oncology. Although the significance of volumetry was not disclosed, further studies are definitely required.
Iliadis
Georgios
G
Department of Radiation Oncology, "Papageorgiou" General Hospital, Thessaloniki, Greece. iliadisg@the.forthnet.gr
Selviaridis
Panagiotis
P
Kalogera-Fountzila
Anna
A
Fragkoulidi
Anna
A
Baltas
Dimos
D
Tselis
Nikolaos
N
Chatzisotiriou
Athanasios
A
Misailidou
Despina
D
Zamboglou
Nikolaos
N
Fountzilas
George
G
D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001932:Brain Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D002166:Camptothecin / Q000031:analogs & derivatives / Q000627:therapeutic use; D017024:Chemotherapy, Adjuvant; D003606:Dacarbazine / Q000008:administration & dosage / Q000031:analogs & derivatives; D018572:Disease-Free Survival; D005260:Female; D005909:Glioblastoma / Q000188:drug therapy / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional; D000077146:Irinotecan; D053208:Kaplan-Meier Estimate; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D016634:Radiosurgery; D012044:Regression Analysis; D013223:Statistics as Topic; D000077204:Temozolomide; D047368:Tumor Burden
D000077146:Irinotecan; D003606:Dacarbazine; D002166:Camptothecin; D000077204:Temozolomide