Comparison of 3D-conformal and intensity-modulated radiation therapy for left-sided breast cancer

• Published in: SA journal of oncology Vol. 7; no. 1; pp. e1 - e8
• Main Authors: Friedrich-Nel, Hesta, Long, Deirdré, Phahlamohlaka, Nape M.
• Format: Journal Article
• Language: English
• Published: Cape Town AOSIS 01.01.2023; African Online Scientific Information Systems (Pty) Ltd t/a AOSIS; AOSIS (Pty) Ltd
• Subjects: Breast cancer; Cancer therapies; Care and treatment; Comparative analysis; CT imaging; Dosimetry; Esophagus; Fractionation; intensity-modulated radiation therapy; Mastectomy; Medical imaging; Oncology; organs at risk; Patients; Planning; Radiation; Radiation therapy; Radiotherapy; Statistical analysis; three-dimensional conformal radiation therapy; Tomography; Monaco; South Africa; Sweden; United Kingdom > UK; United States > US; Missouri
• ISSN: 2518-8704; 2518-8704
• DOI: 10.4102/sajo.v7i0.262

Background We compared 3D-conformal radiation therapy (3D-CRT) and intensity-modulated radiation therapy (IMRT) planning for left-sided post-mastectomy patients.Aim To compare the dose coverage of the planning target volume (PTV) and dose delivered to organs at risk (OAR) of 3D-CRT and IMRT plans.Setting Department of Oncology, central South Africa.Methods Twenty-six archived CT scans of patients with left-sided breast cancer were included. The 3D-CRT and IMRT plans were designed for each patient and compared using the Monaco© planning system (version 5.11.02). Statistical analysis was performed for PTV coverage (V95%, V98%, V105%) and radiation doses to the heart, ipsilateral lung, combined lungs, contralateral breast, and oesophagus.Results The V98% and V105% target volume dose coverage for the 3D-CRT plans were 67.07% and 0.21%, respectively, compared to 92.32% and 1.10% of the IMRT plans. However, the IMRT plans’ mean volume of PTV, receiving 95% of the prescribed dose (PD), was 7.68% compared to the 3D-CRT’s 32.93%. The IMRT plans resulted in a V22 Gy<10% for the heart, with a value of 4.15%. The V18.87 Gy<45% values for the ipsilateral and combined lungs were 28.09% and 13.70%, respectively. The 3D-CRT plans showed a lower dose to the oesophagus (5.07 Gy) and contralateral breast (V5 Gy<15% = 3.51%).Conclusion It was shown that 3D-CRT and IMRT treatment planning can effectively achieve clinical goals for post-mastectomy left-sided breast cancer radiotherapy.Contribution The findings underscore the continuing relevance of 3D-CRT planning in oncology for optimal PTV dose coverage and low OAR dose.