Ultrahypofractionated radiotherapy for localized prostate cancer with simultaneous boost to the dominant intraprostatic lesion: a plan comparison

• Published in: Tumori 2022-06, Vol.108 (3), p.263-269
• Main Authors: Cambria, Raffaella, Ciardo, Delia, Bazani, Alessia, Pansini, Floriana, Rondi, Elena, Maestri, Davide, Zerini, Dario, Marvaso, Giulia, Romanelli, Pola, Timon, Giorgia, Fodor, Cristiana, Petralia, Giuseppe, Alessi, Sarah, Pricolo, Paola, Vischioni, Barbara, Fossati, Piero, Molinelli, Sivia, Russo, Stefania, Ciocca, Mario, De Cobelli, Ottavio, Renne, Giuseppe, Orecchia, Roberto, Cattani, Federica, Jereczek-Fossa, Barbara A.
• Format: Article
• Language: English
• ISSN: 0300-8916; 2038-2529
• DOI: 10.1177/03008916211011667

Objective: To compare different stereotactic body techniques—intensity-modulated radiotherapy with photons and protons, applied to radiotherapy of prostatic cancer—with simultaneous integrated boost (SIB) on the dominant intraprostatic lesion (DIL). Methods: Ten patients were selected for this planning study. Dosimetric results were compared between volumetric modulated arc therapy, intensity-modulated radiation therapy (IMRT), and intensity-modulated proton therapy both with two (IMPT 2F) and five fields (IMPT 5F) planning while applying the prescription schemes of 7.25 Gy/fraction to the prostate gland and 7.5 Gy/fraction to the DIL in 5 fractions. Results: Comparison of the coverages of the planning target volumes showed that small differences exist. The IMPT-2F-5F techniques allowed higher doses in the targets; conformal indexes resulted similar; homogeneity was better in the photon techniques (2%–5%). Regarding the organs at risk, all the techniques were able to maintain the dose well below the prescribed constraints: in the rectum, the IMPT-2F-5F and IMRT were more efficient in lowering the intermediate doses; in the bladder, the median dose was significantly better in the case of IMPT (2F–5F). In the urethra, the best sparing was achieved only by IMPT-5F. Conclusions: Stereotactic radiotherapy with SIB for localized prostate cancer is feasible with all the investigated techniques. Concerning IMPT, the two-beam technique does not seem to have a greater advantage compared to the standard techniques; the 5-beam technique seems more promising also accounting for the range uncertainty.