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Objective:To evaluate the effect of image-guided with cone-beam computed tomography (CBCT) based on volumetric modulated arc therapy (VMAT)-flattening filter free (FFF) on the setup errors of stereotactic body radiotherapy (SBRT) in patients with spinal metastatic tumors.Methods:The clinical data of 15 patients with spinal metastatic tumors who underwent SBRT in Jilin Cancer Hospital from August 2020 to January 2022 were retrospectively analyzed. The radiotherapy dose of bone metastasis was 32 Gy per 4 times and CBCT scanning was performed before and after radiotherapy. Every patient received radiotherapy 4 times; all 15 patients underwent SBRT 60 times in total and 120 CBCT volume images were finally obtained and analyzed. The systematic error (Σ) and random error (σ) were calculated at different correction threshold levels. The translational setup error and rotational setup error at the left-right (X axis), head-foot (Y axis) and front-back (Z axis) directions before and after radiotherapy were compared, which were expressed as Σ ± σ.Results:The pre-SBRT and post-SBRT translational setup errors were (0.14±0.27) cm and (0.07±0.19) cm, respectively ( P<0.001) in the X direction, (-0.05±0.33) cm and (0.00±0.19) cm, respectively ( P = 0.001) in the Y direction, (-0.13±0.19) cm and (-0.02±0.14) cm, respectively ( P = 0.012) in the Z direction. The pre-SBRT and post-SBRT rotational setup errors were (-0.31±0.76)° and (-0.09±0.34)°, respectively ( P < 0.001) in the X direction, (-0.13±0.88)° and (-0.07±0.36) °, respectively ( P < 0.001) in the Y direction, (0.10±0.51)° and (0.16±0.38)°, respectively ( P < 0.001) in the Z direction. Conclusions:CBCT correction could reduce Σ and σof the translational setup and rotational setup, increase the accuracy of SBRT based on VMAT-FFF for patients with spinal metastatic tumors.
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Objective:To analyze locoregional recurrence (LRR) pattern of patients with pT 1-2N 1 breast cancer after modified radical mastectomy, with and without adjuvant radiotherapy (RT). Methods:A total of 5442 eligible patients with breast cancer from 12 Chinese centers were included. The LRR sites and the effect of RT at different sites on recurrence in patients with and without RT were analyzed. The Kaplan-Meier method was used to calculate the cumulative LRR rate, and the difference was compared by the log-rank test.Results:With a median follow-up time of 63.8 months for the entire cohort, 395 patients developed LRR. The chest wall and supraclavicular fossa were the most common LRR sites, regardless of RT or molecular subtypes. The 5-year chest wall recurrence rates for patients with and without chest wall irradiation were 2.5% and 3.8%( P=0.003); the 5-year supraclavicular lymph nodal recurrence rates for patients with and without supraclavicular fossa irradiation were 1.3% and 4.1%( P<0.001); the 5-year axillary recurrence-free rates for patients with and without axillary irradiation were 0.8% and 1.5%( HR=0.31, 95% CI: 0.04-2.23, P=0.219); and the 5-year internal mammary nodal recurrence-free rates for patients with and without internal mammary nodal irradiation were 0.8% and 1.5%( HR=0.45, 95% CI: 0.11-1.90, P=0.268). Conclusions:The chest wall and supraclavicular fossa are the most common LRR sites of patients with pT 1-2N 1 breast cancer after modified radical mastectomy, which is not affected by adjuvant RT or molecular subtypes. The chest wall and supraclavicular fossa irradiation significantly reduce the risk of recurrence in the corresponding area. However, axillary and internal mammary nodal irradiation has no impact on the risk of recurrence in the corresponding area.
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Objective:To compare the dosimetric differences between accelerated partial breast irradiation intensity modulated radiation therapy (APBI-IMRT) and whole breast irradiation with simultaneous integrated boost intensity modulated radiotherapy (WBI-SIB-IMRT) for early-stage breast cancer after breast-conserving surgery.Methods:A total of 35 patients with early-stage breast cancer in Jilin Province Cancer Hospital between July 2009 and December 2014 after breast-conserving surgery were enrolled. The targeted regions of APBI-IMRT and WBI-SIB-IMRT were created for each patient. The dosimetric difference comparison of the targeted region and normal tissues was evaluated by using dose volume histogram (DVH).Results:There was no significant difference in the dosimetric comparison of gross tumor volume (GTVtb) and planning gross tumor volume (PGTVtb) after correction of cumulative radiation effect (CRE) between WBI-SIB-IMRT group and APBI-IMRT group (both P > 0.05). The dose of clinical target volume (CTV) and planning target volume(PTV) in APBI-IMRT group was higher than that in WBI-SIB-IMRT group [CTV: (4 720±71) cGy vs. (3 889±79) cGy, t = 3.184, P = 0.027; PTV: (4 675±164) cGy vs. (3 807±199) cGy, t = 2.751, P = 0.032] after CRE correction. Compared with WBI-SIB-IMRT group, the dose of ipsilateral lung tissue and left heart tissue in APBI-IMRT group was decreased after CRE correction [(558.5±8.9) cGy vs. (1 304.9±34.4) cGy, t = -7.328, P = 0.001; (35.5±5.3) cGy vs. (843.0±41.5) cGy, t = -8.137, P = 0.001]. V 5/3.6 Gy, V 10/7.3 Gy, V 15/10.9 Gy, V 20/14.6 Gy, V 25/18.2 Gy and V 30/21.9 Gy of the ipsilateral lung and V 30/21.9Gy, V 40/29.2Gy of left heart in all breast cancer patients after two chemotherapy treatments had significant differences (all P = 0.001). Conclusion:Compared with WBI-SIB, APBI-IMRT can improve the dose distribution in target area and reduce the volume of high dose irradiation in organs at risk.
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Objective To evaluate the effect of surgery-radiotherapy interval (SRI) on clinical prognosis of locally advanced stage c Ⅱ-Ⅲ breast cancer patients treated with neoadjuvant chemtherapy and modified radical mastectomy.Methods Clinical data of 1 087 breast cancer patients treated with neoadjuvant chemotherapy and modified radical mastectomy from 11 hospitals in China were retrospectively analyzed.The optimal threshold value of SRI upon clinical prognosis was determined by maxstat method.The effect of SRI on clinical prognosis was evaluated by using multivariate Cox regression analysis and propensity score matching (PSM).Results The median follow-up time was 72.9 months.The 5-year disease-free survival (DFS) and overall survival (OS) rates were 68.1％ and 81.8％.All patients were divided into SRI ≤18 weeks (n=917) and SRI＞ 18 weeks groups (n=170).Multivariate Cox regression analysis demonstrated that hormone receptor status (P＜0.001),pathological T stage (P＜0.001),pathological N stage (P＜0.001) and SRI (P=0.023) were independent influencing factors of DFS.Hormone receptor status (P=0.013),pathological T stage (P=0.006),pathological N stage (P＜0.001),endocrine therapy (P=0.013) and SRI (P=0.001) were significantly associated with OS.After balancing the clinical and pathological factors with PSM,patients with SRI＜ 18 weeks had superior DFS and OS to those with SRI＞ 18 weeks.Conclusions SRI affects the clinical prognosis of locally advanced breast cancer patients treated with neoadjuvant chemotherapy and modified radical mastectomy.Radiotherapy should be performed within 18 weeks after mastectomy.
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Objective To evaluate the efficacy of accelerated partial breast irradiation ( APBI ) and whole breast irradiation ( WBI ) with simultaneous integrated boost ( SIB ) from the perspective of economics, and provide a reference for postoperative adjuvant therapy mode selection for early-stage breast cancer after breast-conserving surgery. Methods A total of 355 early-stage breast cancer patients who underwent APBI or WBI-SIB after breast-conserving surgery were evaluated on efficacy and cost-effectiveness, of which 177 patients received APBI, and 178 patients received WBI-SIB. Survival analysis was done according to treatment received. NCI-CTC 3.0 was used to score the toxicities. Breast aesthetic outcome were evaluated with Harris standards. Results Median follow-up was 42 months ( 5.8 -92.7 months) . The 3-year locoregional recurrence free survival( LRFS) rates in APBI group and WBI-SIB group were 98.2％ and 97.6％, distant metastasis free survival( DMFS) were 94.3％ and 93.7％, disease-free survival ( DFS) were 93.1％ and 91.6％, and overall survival 95.5％ and 94.3％, respectively, without statistically significant differences(P>0.05). Compared with WBI-SIB group, the acute reaction rates in APBI group decreased from 5. 6％ to 3.4％(χ2 =6.044, P <0. 05), and late reactions from 5.6％ to 2.3％ (χ2 =6.149, P<0. 05), while the cosmetic outcome improved from 88.8％ to 93.8％(χ2 =5.22, P<0. 05). Moreover, the processing average time was shortened by 26.5 d (χ2 =40.76, P<0. 05). Conclusions After breast-conserving surgery, the efficacy of APBI showed no difference from WBI-SIB with respect to 3-year local control, disease-free survival, and overall survival, but displayed a significantly better toxicity profile and cost-effectiveness ratio for early breast cancer patients. It can be used as a good radiotherapy model after breast-conserving surgery in early-stage breast cancer.