Incidence of local breast cancer recurrence with delayed radiation therapy.

BACKGROUND: The purpose of this research was to examine the probability of ipsilateral breast cancer recurrence in individuals whose RT was delayed after the first chemotherapy and surgery. PURPOSE: To analyze the effect of delaying RT for breast cancer patients (by more than 6 weeks after treatment). METHODOLOGY: A retrospective analysis comprised 136 female breast cancer patients treated at the Baghdad Centre for Radiation Oncology and Nuclear Medicine from 2021 to May 2022. External beam radiation was started more than 6 weeks after chemotherapy was finished for all patients who also had surgery. Clinical examination and ultrasound were part of the follow-up process. RESULTS: Patients' ages varied from 28 to 71, and the majority (83%) had a mastectomy. The majority of cases (95.5%) were diagnosed as invasive ductal carcinoma on histopathology, with 49.6% being at stage 2 and 42.6% being at stage 3. Seventy-six percent of patients tested positive for hormones. Although 10 patients (7.35%) acquired distant metastases within 5 years, only 2 (1.47%) had local recurrence because of the delay in RT. Specifically, 91.1% had complete local control with no evidence of disease spread. CONCLUSION: Delaying RT by more than 6 weeks in patients with breast cancer did not substantially affect local control, according to the results of a new research, the first of its type in Iraq.

Assessing setup errors and shifting margins for planning target volume in head, neck, and breast cancer.

Accurately calculating setup errors is crucial in ensuring quality assurance for patients undergoing radiation therapy treatment. This cross-sectional study aimed to determine the systematic, random, and planning target volume (PTV) margin errors for patients with head and neck cancer (n=48) and breast cancer (n=50). The treatment setup was performed using electronic portal imaging (EPIDs) and irradiated using Elekta linac. The errors were calculated using the van Herk formula. The systematic error for the head and neck was 0.89, 0.43, and 1.49 mm on the x, y, and z-axis, respectively, and 0.39, 0.74, 0.38 for the breast cases. The random error was 0.82, 0.68, 0.94 mm for the head and neck and 0.66, 0.72, 0.79 mm for the breast. The PTV margin shifting error for the head and neck were 2.79, 1.55, and 4.38 mm, while it was 1.43, 2.35, and 1.50 mm for the breast. The setup errors varied according to the tumor location. The study highlights the potential benefits of using EPIDs for reducing uncertainties in setup verification procedures.