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Background/aim: This study aimed to compare the dosimetric consequences of respiratory movement in volumetric‐modulated arc therapy (VMAT) and three‐dimensional conformal radiation therapy (3D‐CRT) during postmastectomy radiation therapy, including internal mammary nodes (IMNs). Materials and methods: Respiratory motion was implemented to a phantom using a dynamic device. The plans were delivered during cranial‐caudal and ventral‐dorsal movement in 5‐mm (R05) and 10‐mm (R10) amplitudes. Results: At the IMN, the dose errors were –2.8% (R05) and –6.2% (R10) for 3D‐CRT and –4.9% (R05) and –8.5% (R10) for VMAT. The dose errors in chest wall were –.5% (R05) and –6.0% (R10) for 3D‐CRT and –1.9% (R05) and –5.3% (R10) for VMAT. The left anterior descending doses showed significantly small absolute values. The gamma pass rates of VMAT were higher than those of 3D‐CRT. Conclusions: The benefit of VMAT technique in dose distribution was maintained, except in occasional instances of large breathing motion. [ABSTRACT FROM AUTHOR]

At the 2017 St. Gallen International Expert Consensus Conference on the Primary Therapy for Early Breast Cancer, the consensus panel recognized "partial breast irradiation as an option for women meeting the low‐risk criteria put forward by the American Society for Radiation Oncology/European Society for Radiotherapy and Oncology (ASTRO/ESTRO) guideline," although acknowledging that there was less evidence for this approach. Partial breast irradiation is defined as irradiation localized to the surgical resection cavity only as opposed to the entire breast. Accelerated partial breast irradiation (APBI) involves intensive treatment in a short time period. The methods vary, and three available APBI options are brachytherapy, external beam and intra‐operative irradiation. The long‐term follow‐up results from two large‐scale, well‐designed phase III randomized clinical trials have been released. However, further discussion of the optimal treatment candidates and delivery method is needed before the clinical application of APBI as a mainstream breast conservation treatment. [ABSTRACT FROM AUTHOR]

Background: There is controversy regarding the relationship between margin status and risk of local recurrence (LR) in patients with Ductal carcinoma in situ(DCIS) treated by mastectomy. Purpose: We sought to assess the LR rates for patients with DCIS breast cancer treated by mastectomy with respect to the resection margin (RM) status. Materials and Methods: Systematic search of MEDLINE, EMBASE, and Cochrane library published was performed. Studies of pure DCIS breast cancer with treatment of mastectomy and studies that reported surgical RM and LR were included. Results:A total of 12 retrospective studies were included, encompassing 2902 patients with a mean follow-up of 86.4 months. Overall LR rates were 5.3% (27/508) for positive or close margins and 1.6% (37/2367) for negative margin, and most of the recurrences (93.7%) are invasive cancers. Patients with positive or close margins showed a 3.72-fold (95% confidence interval [CI] = 2.30–6.01,P < 0.01, I[2] = 11%) higher risk of LR than patients with negative margin. Patients with positive margin showed a 2.91-fold (95% CI = 1.14–7.41,P = 0.03, I[2] = 0%) higher risk of LR than patients with close margin. Postmastectomy radiation therapy (RT) was not associated with a decreased risk of LR (Risk ratio 0.50; 95% CI = 0.06–4.08,P= 0.52, I[2] = 0%) in patients with positive or close margins. Conclusions: The RM status after mastectomy has a great impact on LR. However, the recurrence rate was insufficient to warrant a recommendation for postmastectomy RT in patients with close or positive margins. [ABSTRACT FROM AUTHOR]

Background: There is controversy regarding the relationship between margin status and risk of local recurrence (LR) in patients with Ductal carcinoma in situ(DCIS) treated by mastectomy.Purpose: We sought to assess the LR rates for patients with DCIS breast cancer treated by mastectomy with respect to the resection margin (RM) status.Materials and Methods: Systematic search of MEDLINE, EMBASE, and Cochrane library published was performed. Studies of pure DCIS breast cancer with treatment of mastectomy and studies that reported surgical RM and LR were included.Results: A total of 12 retrospective studies were included, encompassing 2902 patients with a mean follow-up of 86.4 months. Overall LR rates were 5.3% (27/508) for positive or close margins and 1.6% (37/2367) for negative margin, and most of the recurrences (93.7%) are invasive cancers. Patients with positive or close margins showed a 3.72-fold (95% confidence interval [CI] = 2.30-6.01,P < 0.01, I[2] = 11%) higher risk of LR than patients with negative margin. Patients with positive margin showed a 2.91-fold (95% CI = 1.14-7.41,P = 0.03, I[2] = 0%) higher risk of LR than patients with close margin. Postmastectomy radiation therapy (RT) was not associated with a decreased risk of LR (Risk ratio 0.50; 95% CI = 0.06-4.08,P= 0.52, I[2] = 0%) in patients with positive or close margins.Conclusions: The RM status after mastectomy has a great impact on LR. However, the recurrence rate was insufficient to warrant a recommendation for postmastectomy RT in patients with close or positive margins. [ABSTRACT FROM AUTHOR]