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Objective To invesigate the influence of breathing motion on intensity-modulated radiotherapy (IMRT) of chest wall after radical mastectomy,and explore clinical value of accurately determined target volume.Methods A total of 17 radical mastectomy patients underwent 3DCT simulation scans sequentially followed by 4DCT simulation scans during free breathing.The targets and normal organs was determined based on CT images respectively.Three sets of radiotherapy plan were designed for each patient:plan 3D,plan 4D and plan 3D-A.The Plan 3D and plan 4D was designed based on 3D and 4D targets respectively.Plan 3D was copied to 4D target with the same isocenter coordinates.The dose distribution was calculated separately to evaluate the dose-volume histograms parameters for PTV,ipsilateral lung and heart,respectively.Two planning parameters was compared with paired t-test or Wilcoxon sign-rank test.Results The average volume of PTV4D was (10.35 ± 4.80) ％ larger than PTV3D (P =0.000).Compared with plan 3D,the V100,V95,V90,D95,D90,Dmin of plan 3D-A were reduced,that were (0.78 -18.0)％ (P=0.000),(0.01-3.90)％ (P=0.000),(0-2.12)％ (P=0.000),(13-222) cGy (P=0.000),(1-118) cGy (P=0.000),(6-1 910) cGy (P=0.000).However,the V20,V10,V5,Dmean of the ipsilateral lung and V30 of heart were same between 3D plan and 4D plan (P =0.288,0.407,0.435,0.758,0.575).Conclusions The respiratory motion may reduce the target dose and its coverage in chest wall treatments,so 4DCT plan could accurately define target volume without increasing the exposure dose of normal tissues.
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ObjectiveTo evaluate the current practice of breast-conserving radiotherapy (BCR) in mainland China.MethodsA questionnaire on the details of treatment pattern of BCR for early breast cancer was mailed twice to all radiotherapy centers in mainland China in 2009.The responding data were collected and analyzed.ResultsOf the 952 surveyed centers,396 responded (41.6％) and 328 performed BCR.The median interval between surgery and radiotherapy was 9 weeks.Of the 328 centers with BCR,whole breast was the most common irradiation target (319 centers,97.3％ ),followed by supraclavicular region (273 centers,83.2％ ),axilla (138 centers,43.3％ ),and internal mammary chain (85 centers,26.8％ ).In 97.5％ of centers (310/319),whole breast was irradiated in all candidates.Supraclavicular region and axilla irradiation was performed for lymph-node positive patients in 41.8％ (114/273) and 26.8％(37/138) centers,and for ≥4 positive lymph-nodes in 31.5％ (86/273) and 29.0％ (/138)centers,respectively. Internal mammary chain was irradiated for tumors located in the center or inner quadrant in 72.9％ ( 56/85 ) centers.Conformal radiotherapy for the whole breast was used in 51.8％centers.The median total dose was 50 Gy,all using conventional fractionations.ConclusionsA consensus has been reached that radiotherapy is needed for patients receiving breast-conserving surgery and that irradiation to whole breast is necessary.However,establishment and widespread use of guidelines for BCR should be strengthened.
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ObjectiveTo assess the current practice of postmastectomy radiotherapy (PMRT) in mainland China and to evaluate the improvement in the past six years.MethodsA questionnaire on the indications and techniques for PMRT for breast cancer was delivered to all radiotherapy centers of mainland China in 2010 survey,and the results were analyzed and compared with those in 2004 survey.The Fisher's exact test was used.ResultsCompared to 29.4％ (210/275) in 2004,396 of the 952 (41.6％) surveyed centers had performed PMRT.The median interval between surgery and PMRT was increased from 6 weeks to 12 weeks during the past 6 years.Adjuvant chemotherapy followed by PMRT was the most common combination in 73.5％ of the responding centers in 2010 other than Sandwich (71.7％) sequence of chemotherapy and PMRT in 2004.PMRT was only performed for T3 or Stage Ⅲ tumors and/or ≥ 4 positive lymph nodes (LN + ) in 7.1％ centers in 2004 and in 29.5％ centers in 2010 surveys,respectively.The use of PMRT for T1-2 N0 breast cancer,T1-2 N0 with tumors located in the center or inner quadrant,and stage T1-T2 and one to three LN + was decreased from 11.9％,63.8％,and 87.6％ in 2004 to 1.5％,19.7％,and 62.1％ in 2010,respectively (all P =0.000).The chest wall and the supraclavicular region were the most common radiation targets,which were used in 97.0％ and 97.0％ in 2010,similar to 97.1％and 96.2％ in 2004.Irradiation to the inner mammary area and axillary fossa decreased from 85.2％ and 74.8％ in 2004 to 39.1％ and 50.5％ in 2010.The boost to the chest wall was more based on the scar,increasingfrom9.0％ in004to75.0％ in 2010.Conclusions There are a high level of compliance of the practices with current guideline and continuing improvement of PMRT for breast cancer in mainland China.But it needs further improvement.
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PURPOSE: The determine the chest CT findings in breast cancer patients who have undergone postoperative irradiation. MATERIALS AND METHODS: The chest CT findings in 36 female patients who underwent breast surgery and radiotherapy between May 1996 and March 2000 were retrospectively analysed. Prior to radiotherapy, baseline chest CT depicted normal parenchyma in all cases. In 11 patients, the ipsilateral breast and chest wall were irradiated using opposed tangential fields, while 25 were treated by the four fields method (opposed tangential fields plus anterior and posterior supraclavicular/high axillary fields), with a total dose of 5040-5400 cGy for 5-9 weeks. RESULTS: CT after radiotherapy demonstrated reticular opacity (n=24), perpendicular linear opacity (n=15), traction bronchiectasis (n=7), consolidation (n=6), ground glass attenuation (n=3), pathologic rib fractures (n=3), pleural effusion (n=2), and pleural thickening (n=1), while in five patients no abnormality was observed. In addition, in the anterolateral lung area of 23 (64%) of 36 patients who underwent tangential beam irradiation, CT demonstrated peripheral opacities. When supraclavicular and axillary portals were used, radiation-induced lung changes mostly occurred at the apex of the lung (n=24). Chest radiographs were abnormal in 26 patients and normal in ten; in five of these ten, CT demonstrated reticular opacity. CONCLUSION: Depending on the irradiation CT findings of radiation-induced lung injury in breast cancer include areas of increased opacity with or without fibrosis, in apical and/or anterior subpleural regions. CT may help differentiate radiation-induced parenchymal change from superimposed or combined lung disease.