Effect of Postoperative Radiotherapy after Primary Tumor Resection in De Novo Stage IV Breast Cancer: A Multicenter Retrospective Study (KROG 19-02) / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#This study aimed to investigate the impact of postoperative radiotherapy (PORT) in de novo metastatic breast cancer (dnMBC) patients undergoing planned primary tumor resection (PTR) and to identify the subgroup of patients who would most benefit from PORT. @*Materials and Methods@#This study enrolled 426 patients with dnMBC administered PTR alone or with PORT. The primary and secondary outcomes were overall and progression-free survival (OS and PFS), respectively. @*Results@#The median follow-up time was 53.7 months (range, 3.1 to 194.4). The 5-year OS and PFS rates were 73.2% and 32.0%, respectively. For OS, clinical T3/4 category, triple-negative breast cancer (TNBC), postoperative chemotherapy alone were significantly poor prognostic factors, and administration of PORT failed to show its significance. Regarding PFS, PORT was a favorable prognostic factor (hazard ratio, 0.64; 95% confidence interval, 0.50 to 0.82; p < 0.001), in addition to T1/2 category, ≤ 5 metastases, and non-TNBC. According to the multivariate analyses of OS in the PORT group, we divided the patients into three groups (group 1, T1/2 and non-TNBC [n=193]; group 2, T3/4 and non-TNBC [n=171]; and group 3, TNBC [n=49]), and evaluated the effect of PORT. Although PORT had no significance for OS in all subgroups, it was a significant factor for good prognosis regarding PFS in groups 1 and 2, not in group 3. @*Conclusion@#PORT was associated with a significantly better PFS in patients with dnMBC who underwent PTR. Patients with clinical T1/2 category and non-TNBC benefited most from PORT, while those with TNBC showed little benefit.

Non-coplanar whole brain radiotherapy is an effective modality for parotid sparing / 영남의대학술지

BACKGROUND: The purpose of this study was to evaluate the efficacy and feasibility of non-coplanar whole brain radiotherapy (NC-WBRT) for parotid sparing.METHODS: Fifteen cases, previously treated with WBRT were selected. NC-WBRT plans were generated. The beam arrangement for the non-coplanar plans consisted of superior anterior, right, and left beams. After generation of the non-coplanar plans a field-in-field technique was applied to the bilateral parallel opposed beams in order to reduce maximum dose and increase dose homogeneity. The NC-WBRT plans were subsequently compared with the previously generated bilateral WBRT (B-WBRT) plans. A field-in-field technique was also used with the B-WBRT plans according to our departmental protocol. As per our institutional practice a total dose of 30 Gy in 10 fractions of WBRT was administered 5 days a week.RESULTS: The mean dose to the parotid gland for the two different plans were 16.2 Gy with B-WBRT and 13.7 Gy with NC-WBRT (p < 0.05). In the NC-WBRT plan, the V5Gy, V10Gy, V15Gy, V20Gy, and V25Gy of the parotid were significantly lower (p < 0.05) than those of the B-WBRT plan. The Dmax of the lens was also lower by 10% with NC-WBRT.CONCLUSION: The use of NC-WBRT plans could be a simple and effective method to reduce irradiated volumes and improve the dose-volume parameters of the parotid gland.

Non-coplanar whole brain radiotherapy is an effective modality for parotid sparing / 영남의대학술지

BACKGROUND@#The purpose of this study was to evaluate the efficacy and feasibility of non-coplanar whole brain radiotherapy (NC-WBRT) for parotid sparing.@*METHODS@#Fifteen cases, previously treated with WBRT were selected. NC-WBRT plans were generated. The beam arrangement for the non-coplanar plans consisted of superior anterior, right, and left beams. After generation of the non-coplanar plans a field-in-field technique was applied to the bilateral parallel opposed beams in order to reduce maximum dose and increase dose homogeneity. The NC-WBRT plans were subsequently compared with the previously generated bilateral WBRT (B-WBRT) plans. A field-in-field technique was also used with the B-WBRT plans according to our departmental protocol. As per our institutional practice a total dose of 30 Gy in 10 fractions of WBRT was administered 5 days a week.@*RESULTS@#The mean dose to the parotid gland for the two different plans were 16.2 Gy with B-WBRT and 13.7 Gy with NC-WBRT (p < 0.05). In the NC-WBRT plan, the V5Gy, V10Gy, V15Gy, V20Gy, and V25Gy of the parotid were significantly lower (p < 0.05) than those of the B-WBRT plan. The Dmax of the lens was also lower by 10% with NC-WBRT.@*CONCLUSION@#The use of NC-WBRT plans could be a simple and effective method to reduce irradiated volumes and improve the dose-volume parameters of the parotid gland.

Whole brain radiotherapy using four-field box technique with tilting baseplate for parotid gland sparing

PURPOSE: The aim of this study is to evaluate the efficacy and feasibility of four-field box whole brain radiotherapy (FB-WBRT) with tilting baseplate by comparing bilateral WBRT (B-WBRT). METHODS AND MATERIALS: Between March 2016 and September 2018, 20 patients with brain metastases underwent WBRT using the four-field box technique. WBRT is performed with a dose of 30 Gy in 10 fractions daily. Two computed tomography simulations per person were performed. One was in the traditional supine position for B-WBRT and the other by applying the tilting acrylic supine baseplate to elevate the head by 40° for FB-WBRT. The B-WBRT used the field-in-field technique, which is the most commonly used method in our institution. The FB-WBRT comprised anterior, posterior, and bilateral beams. A wedge was applied in anterior and posterior fields to compensate for skull convexity. RESULTS: The average of Dmean of both parotid glands was 10.2 Gy (range, 3.8 to 17.8 Gy) in B-WBRT and 5.4 Gy (range, 2.0 to 11.7 Gy) in FB-WBRT (p < 0.05). Compared to B-WBRT, FB-WBRT reduced the mean dose of the right and left parotid glands from 10.1 Gy to 4.9 Gy and from 10.4 Gy to 5.8 Gy, respectively (p < 0.05). Further, V₅, V₁₀, V₁₅, V₂₀ for the parotid gland decreased significantly in FB-WBRT (p < 0.05). The Dmax and Dmean of lens decreased according to the dose-volume histogram. CONCLUSION: Compared to B-WBRT, FB-WBRT with a tilting baseplate is a simple and effective method that takes feature of noncoplanar beam to protect the parotid gland.

Effects of total body irradiation-based conditioning on allogeneic stem cell transplantation for pediatric acute leukemia: a single-institution study

PURPOSE: To evaluate the effects of total body irradiation (TBI), as a conditioning regimen prior to allogeneic stem cell transplantation (allo-SCT), in pediatric acute leukemia patients. MATERIALS AND METHODS: From January 2001 to December 2011, 28 patients, aged less than 18 years, were treated with TBI-based conditioning for allo-SCT in our institution. Of the 28 patients, 21 patients were diagnosed with acute lymphoblastic leukemia (ALL, 75%) and 7 were diagnosed with acute myeloid leukemia (AML, 25%). TBI was completed 4 days or 1 day before stem cell infusion. Patients underwent radiation therapy with bilateral parallel opposing fields and 6-MV X-rays. The Kaplan-Meier method was used to calculate survival outcomes. RESULTS: The 2-year event-free survival and overall survival rates were 66% and 56%, respectively (71.4% and 60.0% in AML patients vs. 64.3% and 52.4% in ALL patients, respectively). Treatment related mortality rate were 25%. Acute and chronic graft-versus-host disease was a major complication; other complications included endocrine dysfunction and pulmonary complications. Common complications from TBI were nausea (89%) and cataracts (7.1%). CONCLUSION: The efficacy and toxicity data in this study of TBI-based conditioning to pediatric acute leukemia patients were comparable with previous studies. However, clinicians need to focus on the acute and chronic complications related to allo-SCT.

Postoperative radiation therapy following the incomplete resection of a non-small cell lung cancer

PURPOSE: To review the results of postoperative radiation therapy (PORT) for residual non-small cell lung cancer (NSCLC) following surgical resection and evaluate multiple clinicopathologic prognostic factors. MATERIALS AND METHODS: A total of 58 patients, who completed scheduled PORT for positive resection margin, among 658 patients treated with PORT from January 2001 to November 2011 were retrospectively analyzed. Radiation therapy was started at 4 to 6 weeks after surgery. Chemotherapy was also administered to 35 patients, either sequentially or concurrently with PORT. RESULTS: The median age of patients was 63 years (range, 40 to 82 years). The postoperative pathological stage I NSCLC was diagnosed in 10 (17.2%), stage II in 18 (31.0%), and stage III in 30 patients (51.7%). Squamous cell carcinoma was identified in 43, adenocarcinoma in 10, large cell in 1, others in 4 patients. Microscopic residual disease (R1) was diagnosed in 55 patients (94.8%), and the remaining three patients were diagnosed with gross residual disease (R2). The median dose of PORT was 59.4 Gy (range, 50.0 to 64.8 Gy). Chemotherapy was administered to 35 patients (60%), and the median follow-up time was 22.0 months (range, 6.0 to 84.0 months). The 3-year locoregional relapse-free survival and distant metastasis-free survival rates were 82.1% and 52.9%, respectively. The median overall survival was 23.8 months (range, 6.0 to 84.1 months), and the 3-year overall survival rate was 58.2%. Chemotherapy did not influence the failure pattern or survival outcome. CONCLUSION: PORT is an effective modality for improving local tumor control in incompletely resected NSCLC patients. Major failure pattern was distant metastasis despite chemotherapy.