Zeitschrift für Karzinogenese und Mutagenese

Abstrakt

Outcomes, toxicities and dosimetric comparison of different hypofractionated Intensity modulated Radiotherapy techniques for treatment of Localized Prostate Cancer

Sherif Elzawawy, Taha Ismail Mohamed Hawala, Doaa Mahmoud Alzayat, Ramadan Hammam

Background: conventional fractionation IMRT is the standard treatment for localized prostate cancer patients. The objectives of this study were to evaluate safety and efficacy of Hypofractionated radiotherapy with dosimetric comparison between 5, 7 and 9 IMRT fields.

Methods: Low or intermediate risk patients included. Three sets of Inverse planning IMRT were carried out (5, 7 and 9 Fields) for each patient with total dose of 70 Gy/28 fractions.

Results: 20 patients were recruited. Regarding PTV coverage, there were no statistically significant differences regarding D2%, D5%, D50%, D95%, D98%, Dmax, Dmin, Dmean, conformity index, homogeneity index, between 5, 7 or 9 Fields. (p=0.25, 0.38, 0.969, 0.057, 0.294, 0.057, 0.517, 0.969, 0.313 and 0.969, respectively). Statistically significant difference regarding longer treatment time (p=0.039) and more monitor units (p=0.015) between 5 and 9 fields with no significant difference between 7 and 9 fields. The mean doses to V25%, V35% and V50% of the rectum were significantly higher for the 5 fields compared to 7 and 9 fields (p=0.001, 0.001, 0.006). The 2 year biochemical control rate was 95% and the DFS was 100%. Acute gastero intestinal toxicities G1 55%, G2 40% and G3 5% while late toxicities G1 25% and G2 15%. Acute genitourinary toxicities G 1 60%, G2 35% and G3 5% and for late toxicities G1 30% and G2 10%. No late G3 nor G4 toxicities were observed.

Conclusion: Hypofractionated radiotherapy is safe and effective regarding the biochemical control and toxicity profile, more convenient and less costly.