COMPARATIVE STUDY OF IMRT AND 3D-CRT RADIOTHERAPY TECHNIQUES IN BREAST CANCER PATIENTS IN MEDAN

Abstract

Breast cancer remains one of the most prevalent and deadly malignancies globally, impacting millions of women annually and imposing a significant public health burden. In Indonesia, it ranks as the leading cause of cancer-related mortality in women, with a continuously rising incidence trend, including in major cities like Medan. Despite advancements in early detection and multimodal therapy, radiotherapy remains a crucial pillar in breast cancer management, aiming for tumor control while minimizing toxicity to surrounding healthy tissues. Modern radiotherapy techniques, particularly Intensity-Modulated Radiation Therapy (IMRT), have been developed to deliver more precise dose distributions compared to conventional techniques like Three-Dimensional Conformal Radiation Therapy (3D-CRT). However, empirical evidence directly comparing the efficacy, toxicity, and long-term clinical outcomes of these two techniques in the Indonesian breast cancer patient population, specifically in the Medan region, is limited, creating a critical research gap for optimizing clinical practice. This study aimed to comprehensively compare the clinical efficacy, acute and subacute toxicity profiles, and local tumor control rates of IMRT versus 3D-CRT in breast cancer patients in Medan, referencing the physical principles of radiotherapy and tumor control theory. A retrospective cohort design was employed, allowing for the analysis of historical data from patients undergoing radiotherapy at a prominent Cancer Center in Medan. The study sample comprised 150 early to advanced-stage breast cancer patients meeting inclusion criteria, divided proportionally into two groups: 75 patients receiving IMRT and 75 patients receiving 3D-CRT, selected systematically based on medical records. Data were collected using standardized data collection forms detailing patient demographics, tumor characteristics, radiotherapy planning parameters, and medical records related to toxicity (using CTCAE v5.0) and local tumor control status up to 2 years post-therapy. Statistical analysis included Chi-square and independent t-tests for comparing baseline characteristics and outcomes, and Kaplan-Meier analysis for local recurrence-free and toxicity survival curves. Our findings revealed that patients receiving IMRT experienced a statistically significant reduction in acute toxicity rates for organs at risk, particularly skin toxicity (p < 0.01) and mucositis (p < 0.05), with lower mean CTCAE scores compared to the 3D-CRT group. Furthermore, IMRT demonstrated a positive trend in improving local tumor control, with a lower local recurrence rate of 5% in the IMRT group versus 12% in the 3D-CRT group within the 2-year observation period, although this difference did not reach strong statistical significance (p = 0.08). Secondary analysis of dose distribution to critical organs (heart and lungs) confirmed IMRT's superiority in minimizing cumulative dose to healthy tissues, potentially reducing the risk of long-term toxicities. An unexpected significant finding was a positive correlation between more complex IMRT planning and improved patient adherence to therapy schedules. In conclusion, this study posits that IMRT offers a superior acute toxicity profile and potentially improved local tumor control compared to 3D-CRT in breast cancer patients in Medan, thereby contributing to enhanced patient quality of life. These findings have theoretical implications for strengthening the understanding of modern radiotherapy techniques' superiority in minimizing side effects and improving cancer treatment effectiveness, as well as practical implications for clinicians and policymakers to consider broader adoption of IMRT in Indonesian breast cancer management protocols. Future research is recommended to extend observation periods for evaluating long-term outcomes and to conduct health economic analyses.