@article {DI FRANCO1849, author = {ROSSELLA DI FRANCO and VALENTINA BORZILLO and DOMINGO ALBERTI and GIANLUCA AMETRANO and ANGELA PETITO and ANDREA COPPOLARO and ILARIA TARANTINO and SABRINA ROSSETTI and SANDRO PIGNATA and GELSOMINA IOVANE and SISTO PERDON{\`A} and GIUSEPPE QUARTO and GIOVANNI GRIMALDI and ALESSANDRO IZZO and LUIGI CASTALDO and RAFFAELE MUSCARIELLO and MARCELLO SERRA and GAETANO FACCHINI and PAOLO MUTO}, title = {Acute Toxicity in Hypofractionated/Stereotactic Prostate Radiotherapy of Elderly Patients: Use of the Image-guided Radio Therapy (IGRT) Clarity System}, volume = {35}, number = {3}, pages = {1849--1856}, year = {2021}, doi = {10.21873/invivo.12447}, publisher = {International Institute of Anticancer Research}, abstract = {Background: The use of intra-fractional monitoring and correction of prostate position with the Image Guided Radio Therapy (IGRT) system can increase the spatial accuracy of dose delivery. Clarity is a system used for intrafraction prostate-motion management, it provides a real-time visualization of prostate with a transperineal ultrasound. The aim of this study was to evaluate the use of Clarity-IGRT on proper intrafraction alignment and monitoring, its impact on Planning Tumor Volume margin and on urinary and rectal toxicity in elderly patients not eligible for surgery. Patients and Methods: Twenty-five elderly prostate cancer patients, median age=75 years (range=75-90 years) were treated with Volumetric Radiotherapy and Clarity-IGRT using 3 different schemes: A) 64.5/72 Gray (Gy) in 30 fractions on prostate and seminal vesicles (6 patients); B) 35 Gy in 5 fractions on prostate and seminal vesicles (12 patients); C): 35 Gy in 5 fractions on prostate (7 patients). Ultrasound identification of the overlapped structures to the detected ones during simulation has been used in each session. A specific software calculates direction and entity of necessary shift to obtain the perfect match. The average misalignment in the three-dimensional space has been determined and shown in a box-plot. Results: All patients completed treatment with mild-moderate toxicity. During treatment, genitourinary toxicity was 32\% Grade 1; 4\% Grade 2, rectal was 4\% Grade 1. At follow-up of 3 months, genitourinary toxicity was 20\% Grade 1; 4\% Grade 2, rectal toxicity was 4\% Grade 2. At follow-up of 6 months, genitourinary toxicity was 4\% Grade 1; 4\% Grade 2. Rectal toxicity was 4\% Grade 2. Conclusion: Radiotherapy with the Clarity System allows a reduction of PTV margins, the amount of fractions can be reduced increasing the total dose, not exacerbating urinary and rectal toxicity with greater patient{\textquoteright}s compliance.}, issn = {0258-851X}, URL = {https://iv.iiarjournals.org/content/35/3/1849}, eprint = {https://iv.iiarjournals.org/content/35/3/1849.full.pdf}, journal = {In Vivo} }