Prostate Cancer Stereotactic Body Radiation Therapy with Image-guided Radiation Therapy (IGRT) Technique with Three-Dimensional Transperineal Ultrasound for IGRT Tracking of the Prostate

Abstract

Introduction Ultrahypofractionated radical radiotherapy for prostate cancer, also known as stereotactic body radiation therapy (SBRT), is an unprecedented modality of prostate radiotherapy and is still used very sparsely in Brazil. The use of fiducial implants and spacers may make it even more difficult to implement prostate SBRT on a large scale in Brazil. We describe a completely non-invasive technique for the treatment of localized prostate cancer with stereotactic body radiotherapy.

Materials and Methods This is a case series study with 9 patients and 48 SBRT fractions analyzed. In our treatment protocol, we use the Elekta Versa-HD linear accelerator (Elekta, Stokholm, Sweden), a transperineal ultrasound (TPUS) with tracking and synchronization capabilities (Clarity 4D ultrasound system, Elekta), and the Monaco Planning System (Elekta). Displacements were measured in the three axes (lateral, longitudinal, and vertical). The discrepancy between the initial ultrasound location of the prostate and the location of the cone beam has also been documented.

Results The mean displacements were 2.02 mm, 3.12 mm, and 2.93 mm for the lateral, longitudinal, and vertical directions, respectively. The data show that treatment was interrupted in 14 of the 48 treatment fractions (29.17%), 8 (57%) with displacements greater than 5 mm and 6 (43%) with displacements between 3 and 5 mm.

The initial TPUS image-guided radiation therapy (IGRT) and its mean displacements for localization with the cone-beam computed tomography (CBCT) were 1.3 mm, 1.9 mm, and 1.5 mm, for the lateral, longitudinal, and vertical directions, respectively. Using van Herk formula, a margin of 7.3 mm in the lateral directions, 9.35 mm longitudinally, and 7.74 mm vertically, would be required

Conclusion Here we describe an SBRT technique for prostate cancer that is completely non-invasive and allows for a high level of accuracy. Transperineal 3D ultrasound provides real-time position data to the prostate that can be used to gate the SBRT treatment, allowing for smaller, more personalized planning target volume (PTV) margins even without fiducial markers or spacers, which may be more applicable for low- and middle-income countries.

Keywords

prostatic neoplasms - radiosurgery - radiotherapy - image-guided - ultrasonography

Authors' Contribution

IM: collection and assembly of data, conception and study design, data analysis and interpretation, manuscript writing, provision of study materials or patient, final approval of the manuscript; AM: conception and study design, data analysis and interpretation, manuscript review and editing and final approval of the manuscript.

Publication History

Received: 17 February 2024

Accepted: 28 June 2024

Article published online:
05 February 2025

• References

• 1 Instituto Nacional de Câncer. Estimativa 2023: incidência de câncer no Brasil. INCA; 2022
• 2 Lehrer EJ, Kishan AU, Yu JB. et al. Ultrahypofractionated versus hypofractionated and conventionally fractionated radiation therapy for localized prostate cancer: A systematic review and meta-analysis of phase III randomized trials. Radiother Oncol 2020; 148: 235-242
• 3 Morgan SC, Hoffman K, Loblaw A. et al. ASTRO guideline. Pract Radiat Oncol 2018; 8: 354-360
• 4 Holmes OE, Gratton J, Szanto J. et al. Reducing errors in prostate tracking with an improved fiducial implantation protocol for CyberKnife based stereotactic body radiotherapy (SBRT). J Radiosurg SBRT 2018; 5 (03) 217-227
• 5 Mariados N, Sylvester J, Shah D. et al. Hydrogel Spacer Prospective Multicenter Randomized Controlled Pivotal Trial: Dosimetric and Clinical Effects of Perirectal Spacer Application in Men Undergoing Prostate Image Guided Intensity Modulated Radiation Therapy. Int J Radiat Oncol Biol Phys 2015; 92 (05) 971-977
• 6 ANVISA [homepage na internet] [acessado em 10 de abril de 2021]. Disponível em: https://www.gov.br/anvisa/pt-br/sistemas/consulta-a-registro
• 7 Mendez LC, Moraes FY, Fernandes GDS, Weltman E. Cancer Deaths due to Lack of Universal Access to Radiotherapy in the Brazilian Public Health System. Clin Oncol (R Coll Radiol) 2018; 30 (01) e29-e36
• 8 Widmark A, Gunnlaugsson A, Beckman L. et al. Ultra-hypofractionated versus conventionally fractionated radiotherapy for prostate cancer: 5-year outcomes of the HYPO-RT-PC randomised, non-inferiority, phase 3 trial. Lancet 2020
• 9 Parker CC, James ND, Brawley CD. et al; Systemic Therapy for Advanced or Metastatic Prostate cancer: Evaluation of Drug Efficacy (STAMPEDE) investigators. Radiotherapy to the primary tumour for newly diagnosed, metastatic prostate cancer (STAMPEDE): a randomised controlled phase 3 trial. Lancet 2018; 392 (10162): 2353-2366
• 10 National Comprehensive Cancer Network (NCCN) [internet homepage] [Accessed in March 14, 2021]. Available in https://www.nccn.org/professionals/physician_gls/pdf/prostate.pdf
• 11 Repka MC, Guleria S, Cyr RA. et al. Acute Urinary Morbidity Following Stereotactic Body Radiation Therapy for Prostate Cancer with Prophylactic Alpha-Adrenergic Antagonist and Urethral Dose Reduction. Front Oncol 2016; 6: 122
• 12 van Herk M. Errors and margins in radiotherapy. Semin Radiat Oncol 2004; 14 (01) 52-64
• 13 Rasch C, Steenbakkers R, van Herk M. Target definition in prostate, head, and neck. Semin Radiat Oncol 2005; 15 (03) 136-145
• 14 Smith AL, Stephans KL, Kolar MD. et al. Prostate SBRT IntrafractionMonitoring with Transperineal Ultrasound, IJROBP 2017)
• 15 Yu AS, Najafi M, Hristov DH, Phillips T. Intrafractional tracking accuracy of a transperineal ultrasound image guidance system for prostate radiotherapy. Technol Cancer Res Treat 2017; 16 (06) 1067-1078
• 16 Han B, Najafi M, Cooper DT. et al. Evaluation of transperineal ultrasound imaging as a potential solution for target tracking during hypofractionated radiotherapy for prostate cancer. Radiat Oncol 2018; 13 (01) 151
• 17 Salter BJ, Szegedi M, Tward J. et al. 3D transperineal ultrasound image guidance methods for prostate SBRT radiotherapy treatment. ESTRO; 2015
• 18 Robinson D, Liu D, Steciw S. et al. An evaluation of the Clarity 3D ultrasound system for prostate localization. J Appl Clin Med Phys 2012; 13 (04) 3753