Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 2023 May;128(5):612-618.
doi: 10.1007/s11547-023-01624-7. Epub 2023 Apr 13.

Linac-based versus MR-guided SBRT for localized prostate cancer: a comparative evaluation of acute tolerability

Luca Nicosia  1 , Rosario Mazzola  2 , Michele Rigo  2 , Niccolò Giaj-Levra  2 , Edoardo Pastorello  2 , Francesco Ricchetti  2 , Claudio Vitale  2 , Vanessa Figlia  2 , Francesco Cuccia  2 , Ruggero Ruggieri  2 , Filippo Alongi  2   3
Affiliations
Comparative Study

Linac-based versus MR-guided SBRT for localized prostate cancer: a comparative evaluation of acute tolerability

Luca Nicosia et al. Radiol Med. 2023 May.

Abstract

Aim: This study aims to compare acute toxicity of prostate cancer (PCa) stereotactic body radiotherapy (SBRT) delivered by MR-guided radiotherapy (MRgRT) with 1.5-T MR-linac or by volumetric modulated arc (VMAT) with conventional linac.

Methods: Patients with low-to-favorable intermediate risk class PCa were treated with exclusive SBRT (35 Gy in five fractions). Patients treated with MRgRT were enrolled in an Ethical Committee (EC) approved trial (Prot. n° 23,748), while patients treated with conventional linac were enrolled in an EC approved phase II trial (n° SBRT PROG112CESC). The primary end-point was the acute toxicity. Patients were included in the analysis if they had at least 6 months of follow-up for the primary end-point evaluation. Toxicity assessment was performed according to CTCAE v5.0 scale. International Prostatic Symptoms Score (IPSS) was also performed.

Results: A total of 135 patients were included in the analysis. Seventy-two (53.3%) were treated with MR-linac and 63 (46.7%) with conventional linac. The median initial PSA before RT was 6.1 ng/ml (range 0.49-19). Globally, acute G1, G2, and G3 toxicity occurred in 39 (28.8%), 20 (14.5%), and 5 (3.7%) patients. At the univariate analysis, acute G1 toxicity did not differ between MR-linac and conventional linac (26.4% versus 31.8%), as well as G2 toxicity (12.5% versus 17.5%; p = 0.52). Acute G2 gastrointestinal (GI) toxicity occurred in 7% and 12.5% of cases in MR-linac and conventional linac group, respectively (p = 0.06), while acute G2 genitourinary toxicity occurred in 11% and 12.8% in MR-linac and conventional linac, respectively (p = 0.82). The median IPSS before and after SBRT was 3 (1-16) and 5 (1-18). Acute G3 toxicity occurred in two cases in the MR-linac and three cases in the conventional linac group (p = n.s.).

Conclusion: Prostate SBRT with 1.5-T MR-linac is feasible and safe. Compared to conventional linac, MRgRT might to potentially reduce the overall G1 acute toxicity at 6 months, and seems to show a trend toward a lower incidence of grade 2 GI toxicity. A longer follow-up is necessary to assess the late efficacy and toxicity.

Keywords: Adaptive radiotherapy; MR-linac; MRgRT; Prostate cancer; SBRT.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

References

    1. Hamdy FC, Donovan JL, Lane JA, Mason M, Metcalfe C, Holding P, Davis M, Peters TJ, Turner EL, Martin RM, Oxley J, Robinson M, Staffurth J, Walsh E, Bollina P, Catto J, Doble A, Doherty A, Gillatt D, Kockelbergh R, Kynaston H, Paul A, Powell P, Prescott S, Rosario DJ, Rowe E, Neal DE (2016) 10-Year outcomes after monitoring, surgery, or radiotherapy for localized prostate cancer. N Engl J Med 375(15):1415–1424. https://doi.org/10.1056/NEJMoa1606220 - DOI - PubMed
    1. Fowler J, Chappell R, Ritter M (2001) Is α/β for prostate tumors really low? Int J Radiat Oncol Biol Phys 50(4):1021–1031 - DOI - PubMed
    1. Brenner DJ, Hall EJ (1999) Fractionation and protraction for radiotherapy of prostate carcinoma. Int J Radiat Oncol Biol Phys 43(5):1095–1101 - DOI - PubMed
    1. Incrocci L, Wortel RC, Alemayehu WG, Aluwini S, Schimmel E, Krol S, van der Toorn PP, Jager H, Heemsbergen W, Heijmen B, Pos F (2016) Hypofractionated versus conventionally fractionated radiotherapy for patients with localised prostate cancer (HYPRO): final efficacy results from a randomised, multicentre, open-label, phase 3 trial. Lancet Oncol 17(8):1061–1069. https://doi.org/10.1016/S1470-2045(16)30070-5 - DOI - PubMed
    1. Lee WR et al (2016) Randomized phase III non-inferiority study comparing two radiotherapy fractionation schedules in patients with low-risk prostate cancer. J Clin Oncol 34(20):2325 - DOI - PubMed - PMC

LinkOut - more resources