A global Unified Dosimetry Index (gUDI) to evaluate simultaneous integrated boost radiotherapy plans in prostate cancer. Issue 2 (August 2018)

• Record Type: Journal Article
• Authors: Mambretti, Maddalena; Romanò, Chiara; Marvaso, Giulia; Comi, Stefania; Cambria, Raffaella; Ciardo, Delia; Emiro, Francesca; Fodor, Cristiana; Zerini, Dario; Riva, Giulia; Petralia, Giuseppe; De Cobelli, Ottavio; Orecchia, R.; Cattani, Federica; Jereczek-Fossa, Barbara Alicja
• Is Part Of: Radiotherapy and oncology. Volume 128:Issue 2(2018)
• Page Start: 315
• Page End: 320
• Publication Date: 2018-08
• Subjects: Simultaneous integrated boost radiotherapy -- Plans quality evaluation -- global Unified Dosimetry Index -- Prostate cancer; Oncology -- Periodicals; Radiotherapy -- Periodicals; Tumors -- Periodicals; Medical Oncology -- Periodicals; Neoplasms -- radiotherapy -- Periodicals; Radiotherapy -- Periodicals; Radiothérapie -- Périodiques; Cancérologie -- Périodiques; Tumeurs -- Périodiques; Electronic journals; 616.9940642
• DOI: 10.1016/j.radonc.2018.06.002
• Languages: English
• ISSNs: 0167-8140

Abstract

Abstract: Purpose: Formulation of a global Unified Dosimetry Index (gUDI) for the evaluation of prostate simultaneous integrated boost Volumetric Modulated Arc Therapy (VMAT by RapidArc) radiotherapy plans. Methods and materials: Dose coverage, conformity, homogeneity and dose gradient index could be included in the Unified Dosimetry Index (UDI). We developed a global UDI to evaluate treatment plans containing volumes irradiated with different dose prescriptions: Intensity Modulated Radiation Therapy with simultaneous integrated boost (IMRT-SIB) with 2 dose levels (36.25 Gy/5 fz for the whole prostate gland and 37.5 Gy/5 fz for Dominant Intraprostatic Lesion (DIL)). To validate gUDI scoring system, 65 prostate cancer patients were evaluated. Mean ( µ ) and standard deviations ( σ ) were calculated for all dosimetry indices and gUDI. Furthermore, gUDI µ and σ were analyzed to compare and classify treatment plans: plans can be ranked as "excellent", "good", "average" or "poor". Results: Prostate Dose Gradient, Prostate Conformity and DIL Conformity indices had highlighted a major deviation from ideal scores. gUDI index classification showed most of the plans scored as "average" and "good". Conclusion: gUDI score can be a useful tool to quantify treatment plans quality also when volumes with different dose-prescription are treated.