Evaluation of 3D-CRT and VMAT Radiotherapy Plans for Left Breast Cancer with Regional Lymph Nodes Irradiation

Introduction: Radiation therapy after breast surgery is an integral part of the treatment of early breast cancer. The goal of radiation therapy is to achieve the best possible coverage of the planning target volume (PTV), while reducing the dose to organs at risk (OARs) which are normal tissues whose sensitivity to irradiation could cause damage that can lead to modification of the treatment plan. In the last decade, radiation oncologist started to use the Intensity Modulated Radiotherapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT) for irradiating the breast, in order to achieve better dose distribution and target dose to the PTV and OAR. The aim of this study is to compare 2 external radiotherapy techniques (VMAT vs 3D) for patients with node-positive left breast cancer. Patients and Methods: We randomly selected 10 cases of postoperative radiotherapy for breast cancer in our hospital. The patients are all female, the average age was 45.4 years old, and the primary lesions are left breast. The ANOVA test was used to compare the mean difference between subgroups, and the p value Results: Dose volume histogram (DVH) was used to analyze each evaluation dose of clinical target volume (CTV) and organs at risk (OARs). Compared to 3DCRT plans, VMAT provided more uniform coverage to the breast and regional lymph nodes. The max point dose for tVMAT was lower on average (106.4% for VMAT versus 109% for 3DCRT). OAR sparing was improved with tVMAT, with a lower average V17Gy for the left lung (27.91% for VMAT versus 30.04% for 3DCRT, p and lower for V28Gy (13.75% for VMAT versus 22.34% for 3DCRT, p = 0.01). We also found a lower V35Gy for the heart on VMAT plan (p = 0.02). On the contrary, dose of contralateral breast was lower in 3DCRT than VMAT (0.59 Gy vs 3.65 Gy, p = 0.00). Conclusion: The both types of plans can meet the clinical dosimetry demands of postoperative radiotherapy for left breast cancer. The VMAT plan has a better conformity, but 3CDRT can provide a lower dose to the contralateral organs (breast and lung) to avoid the risk of secondary cancers.

Inetetamab combined with pyrotinib and chemotherapy in the treatment of breast cancer brain metastasis: A case report

BACKGROUND Breast cancer brain metastasis(BCBM)is an advanced breast disease that is difficult to treat and is associated with a high risk of death.Patient prognosis is usually poor,with reduced quality of life.In this context,we report the case of a patient with HER-2-positive BCBM treated with a macromolecular mAb(ine-tetamab)combined with a small molecule tyrosine kinase inhibitor(TKI).CASE SUMMARY The patient was a 58-year-old woman with a 12-year history of type 2 diabetes.She was compliant with regular insulin treatment and had good blood glucose control.The patient was diagnosed with invasive carcinoma of the right breast(T3N1M0 stage IIIa,HER2-positive type)through aspiration biopsy of the ipsilateral breast due to the discovery of a breast tumor in February 2019.Immunohistochemistry showed ER(-),PR(-),HER-2(3+),and Ki-67(55-60%+).Preoperative neoadjuvant chemotherapy,i.e.,the AC-TH regimen(epirubicin,cyclophosphamide,docetaxel-paclitaxel,and trastuzumab),was administered for 8 cycles.She underwent modified radical mastectomy of the right breast in November 2019 and received tocilizumab targeted therapy for 1 year.Brain metastasis was found 9 mo after surgery.She underwent brain metastasectomy in August 2020.Immunohistochemistry showed ER(-)and PR.(-),HER-2(3+),and Ki-67(10-20%+).In November 2020,the patient experienced headache symptoms.After an examination,tumor recurrence in the original surgical region of the brain was observed,and the patient was treated with inetetamab,pyrotinib,and capecitabine.Whole-brain radiotherapy was recommended.The patient and her family refused radiotherapy for personal reasons.In September 2021,a routine examination revealed that the brain tumor was considerably larger.The original systemic treatment was continued and combined with intensity-modulated radiation therapy for brain metastases,followed by regular hospitalization and routine examinations.The patient’s condition is generally stable,and she has a relatively high quality of life.This case report demonstrates that in patients with BCBM and resistance to trastuzumab,inetetamab combined with pyrotinib and chemotherapy can prolong survival.CONCLUSION Inetetamab combined with small molecule TKI drugs,chemotherapy and radiation may be an effective regimen for maintaining stable disease in patients with BCBM.

Adaptive radiation therapy of breast cancer by repeated imaging during irradiation

Breast cancer is the most frequent cancer among females and also a leading cause of cancer related mortality worldwide.A multimodality treatment approach may be utilized for optimal management of patients with combinations of surgery,radiation therapy(RT)and systemic treatment.RT composes an integral part of breast conserving treatment,and is typically used after breast conserving surgery to improve local control.Recent years have witnessed significant improvements in the discipline of radiation oncology which allow for more focused and precise treatment delivery.Adaptive radiation therapy(ART)is among the most important RT techniques which may be utilized for redesigning of treatment plans to account for dynamic changes in tumor size and anatomy during the course of irradiation.In the context of breast cancer,ART may serve as an excellent tool for patients receiving breast irradiation followed by a sequential boost to the tumor bed.Primary benefits of ART include more precise boost localization and potential for improved normal tissue sparing with adapted boost target volumes particularly in the setting of seroma reduction during the course of irradiation.Herein,we provide a concise review of ART for breast cancer in light of the literature.

Angiosarcoma Following Radiation Therapy for Breast Cancer:Case Presentation and Clinical Management Considerations

A 59-year-old woman presented with erythema and pruritis of the breast 4.5 years after undergoing lumpectomy and radiation for breast cancer. Biopsy confirmed a diagnosis of angiosarcoma. This tumor stained positive for CD34 as well as 70% Ki67 prior to therapy initiation. A multidisciplinary approach yielded a plan for neoadjuvant chemoradiation and surgical resection including delayed completion transverse rectus abdominis flap for tissue coverage. Neoadjuvant therapy successfully decreased rates of cellular proliferation, as reflected by a Ki67 of 5%, at the time of resection. Pathophysiologically, angiosarcomas may be very aggressive and may develop following radiation for breast cancer. Such tumors may become more common as breast cancer therapies, which frequently include radiation therapy, improve with time. Early recognition of angiosarcoma is imperative for successful therapy. These tumors may present with a wide range of symptoms, but may be asymptomatic. Surgical resection is the preferred therapy, but early recognition is critical.

Hypofractionated Radiation Therapy for the Treatment of Breast Cancer: Experience of National Institute of Oncology, Rabat, Morocco

Hypofractionated radiation therapy has proven effective on locoregional control and tolerance in the adjuvant treatment of breast cancer. The aim of this study is to compare the results of hypofractionated radiation therapy versus conventional radiation therapy in terms of local control and tolerance. It was a retrospective study of patients observations collected from January 2007 to December 2008 in Department of Radiation Therapy in Institut National d’Oncologie de Rabat. The treatment results were evaluated by the rate of locoregional recurrence, distant recurrence and research of late toxicities. Radiotherapy was delivered using the same technique in both groups, by gamma photons of cobalt 60 with an energy of 1.25 MeV. They were 2 groups: the first group treated with standard dose rate and the second group treated by hypofractionated radiation therapy. The mean age of the patients was 42.8 ± 6.9 years old in the standard group and 43.22 ± 7.2 years old in the hypofractionation group. We noted a predominance of infiltrating ductal carcinoma. The majority of patients were pT2, pN0 and pN1. The majority of patients had radical surgery and chemotherapy with anthracyclines in both groups. We noted a statistically significant difference in the irradiation of chest wall between the standard (89.2%) and hypofractionated group (70.3%), with p = 0.043. The median duration of radiation therapy was statistically different in both groups: 39 days in the standard and 23 days in the hypofractionated group (p 0.001). The local recurrences were statistically identical to 12 and 24 months (p = 0.999). Concerning toxicities, the frequency of adverse event was similar in both groups. Hypofractionated radiation therapy with a total dose of 42 Gy at 2.8 Gy per fraction in 5 fractions weekly is comparable to standard radiotherapy in terms of local control and tolerance and is therefore a very good alternative to standard treatment.

Reirradiation of recurrent breast cancer with proton beam therapy:A case report and literature review

BACKGROUND Locoregional recurrence of breast cancer is challenging for clinicians,due to the various former treatments patients have undergone.However,treatment of the recurrence with systemic therapy and subsequent reirradiation of chest wall is accompanied by increased toxicities,particularly radiation-induced cardiovascular disease.Reirradiation by proton beam therapy(PBT)enables superior preservation of adjacent organs at risk as well as concurrent dose escalation for delivery to the gross tumor.This technology is expected to improve the overall outcome of recurrent breast cancer.CASE SUMMARY A 47-year-old female presented with an extensive locoregional recurrence at 10 yr after primary treatment of a luminal A breast cancer.Because of tumor progression despite having undergone bilateral ovarectomy and systemic therapy,the patient was treated with PBT BE total dose of 64.40 Gy to each gross tumor and 56.00 Gy to the upper mediastinal and retrosternal lymphatics including the entire sternum in 28 fractions.Follow-up computed tomography showed a partial remission,without evidence of newly emerging metastasis.At 19 mo after the PBT,the patient developed a radiation-induced pericardial disease and pleural effusions with clinical burden of dyspnea,which were successfully treated by drainage and corticosteroid.Cytological analysis of the puncture fluid showed no malignancy,and the subsequent computed tomography scan indicated stable disease as well as significantly decreased pericardial and pleural effusions.The patient remains free of progression to date.CONCLUSION PBT was a safe and effective method of reirradiation for locoregionally recurrent breast cancer in our patient.

Research Progress in Brain Metastasis of Breast Cancer

The incidence rate of breast cancer is very high.Some patients were diagnosed as stage IV patients at the first diagnosis and had distant metastasis.Bone,lung and liver are the common metastatic sites of breast cancer.Although brain is the least common metastatic site of breast cancer,the incidence of brain metastasis in newly diagnosed breast cancer patients is increasing year by year.After brain metastasis,the disease develops rapidly,and because of the existence of blood cerebrospinal fluid barrier,it is difficult for drugs to reach the focus,and the curative effect is poor,leading to poor prognosis of patients with brain metastasis of breast cancer.Previous studies have also explored the clinical characteristics of brain metastases from breast cancer and the factors affecting prognosis.Different ages,races,histological grades,T stages,N stages,molecular subtypes,and pathological types are the main factors affecting the occurrence and prognosis of brain metastases from breast cancer.Studies on the characteristics,mechanisms,and treatment plans of brain metastases from breast cancer have also been reported at home and abroad.This article reviews the clinical characteristics,pathogenesis and treatment progress of brain metastases from breast cancer,aiming to provide some ideas and basis for clinical diagnosis and treatment and drug research of brain metastases from breast cancer.

Effects of Yttrium-90 selective internal radiation therapy on non-conventional liver tumors

The liver is a common site of metastasis, with essentially all metastatic malignancies having been known to spread to the liver. Nearly half of all patients with extrahepatic primary cancer have hepatic metastases. The severe prognostic implications of hepatic metastases have made surgical resection an important first line treatment in management. However, limitations such as the presence of extrahepatic spread or poor functional hepatic reserve exclude the majority of patients as surgical candidates, leaving chemotherapy and locoregional therapies as next best options. Selective internal radiation therapy(SIRT) is a form of catheter-based locoregional cancer treatment modality for unresectable tumors, involving trans-arterial injection of microspheres embedded with a radioisotope Yttrium-90. The therapeutic radiation dose is selectively delivered as the microspheres permanently embed themselves within the tumor vascular bed. Use of SIRT has been conventionally aimed at treating primary hepatic tumors(hepatocellular carcinoma) or colorectal and neuroendocrine metastases. Numerous reviews are available for these tumor types. However, little is known or reviewed on non-colorectal or nonneuroendocrine primaries. Therefore, the aim of this paper is to systematically review the current literature to evaluate the effects of Yttrium-90 radioembolization on non-conventional liver tumors including those secondary to breast cancer, cholangiocarcinoma, ocular and percutaneous melanoma, pancreatic cancer, renal cell carcinoma, and lung cancer.

Helical tomotherapy and volumetric modulated arc therapy:New therapeutic arms in the breast cancer radiotherapy

AIM To analyse clinical and dosimetric results of helical tomotherapy(HT) and volumetric modulated arc therapy(VMAT) in complex adjuvant breast and nodes irradiation.METHODS Seventy-three patients were included(31 HT and 42 VMAT). Dose were 63.8 Gy(HT) and 63.2 Gy(VMAT) in the tumour bed, 52.2 Gy in the breast, 50.4 Gy in supraclavicular nodes(SCN) and internal mammary chain(IMC) with HT and 52.2 Gy and 49.3 Gy in IMC and SCN with VMAT in 29 fractions. Margins to particle tracking velocimetry were greater in the VMAT cohort(7 mm vs 5 mm).RESULTS For the HT cohort, the coverage of clinical target volumes was as follows: Tumour bed: 99.4% ± 2.4%; breast: 98.4% ± 4.3%; SCN: 99.5% ± 1.2%; IMC:96.5% ± 13.9%. For the VMAT cohort, the coverage was as follows: Tumour bed: 99.7% ± 0.5%, breast: 99.3% ± 0.7%; SCN: 99.6% ± 1.4%; IMC: 99.3% ± 3%. For ipsilateral lung, Dmean and V20 were 13.6 ± 1.2 Gy, 21.1% ± 5%(HT) and 13.6 ± 1.4 Gy, 20.1% ± 3.2%(VMAT). Dmean and V30 of the heart were 7.4 ± 1.4 Gy, 1% ± 1%(HT) and 10.3 ± 4.2 Gy, 2.5% ± 3.9%(VMAT). For controlateral breast Dmean was 3.6 ± 0.2 Gy(HT) and 4.6 ± 0.9 Gy(VMAT). Acute skin toxicity grade 3 was 5% in the two cohorts.CONCLUSION HT and VMAT in complex adjuvant breast irradiation allow a good coverage of target volumes with an acceptable acute tolerance. A longer follow-up is needed to assess the impact of low doses to healthy tissues.

Accelerated partial breast irradiation:Current evidence and future developments

Whole breast irradiation after breast-conserving surgery for early breast cancer has become one of the standard treatment modes for breast cancer and yields the same effect as radical surgery.Accelerated partial breast irradiation(APBI)as a substitute for whole breast irradiation for patients with early breast cancer is a hot spot in clinical research.APBI is characterised by simple high-dose local irradiation of the tumour bed in a short time,thus improving convenience for patients and saving costs.The implementation methods of APBI mainly include brachytherapy,external beam radiation therapy,and intraoperative radiotherapy.This review provides an overview of the clinical effects and adverse reactions of the main technologies of APBI and discusses the prospects for the future development of APBI.

Dosimetric evaluation of CR, 3DCRT and two types of IMRT for breast cancer after conservative surgery

Objective: The purpose of this study was to compare the dose distribution and dose volume histogram (DVH) of the planning target volume (PTV) and organs at risk (OARs) among conventional radiation therapy (CR), three-dimensional conformal radiation therapy (3DCRT), two-step intensity-modulated radiation therapy (TS-IMRT) and direct machine parameter optimization intensity-modulated radiation therapy (DMPO-IMRT) after breast-conserving surgery. Methods: For each of 20 randomly chosen patients, 4 plans were designed using 4 irradiation techniques. The prescribed dose was 50 Gy/2 Gy/25 f, 95% of the planning target volume received this dose. The cumulated DVHs and 3D dose distributions of CR, 3DCRT, TS-IMRT and DMPO-IMRT plans were compared. Results: For the homogeneity indices, no statistically significant difference was observed among CR, 3DCRT, TS-IMRT and DMPO-IMRT while the difference of the conformality indices were statistically significant. With regard to the organs at risk, IMRT and 3DCRT showed a significantly fewer exposure dose to the ipsilateral lung than CR in the high-dose area while in the low-dose area, IMRT demonstrated a significant increase of exposure dose to ipsilateral lung, heart and contralateral breast compared with 3DCRT and CR. In addition, the monitor units (MUs) for DMPO-IMRT were approximately 26% more than those of TS-IMRT and the segments of the former were approximately 24% less than those of the latter. Conclusion: Compared with CR, 3DCRT and IMRT improved the homogeneity and conformity of PTV, reduced the irradiated volume of OARs in high dose area but IMRT increased the irradiated volume of OARs in low dose area. DMPO-IMRT plan has fewer delivery time but more MUs than TS-IMRT.

聚氨酯发泡胶联合个体化头枕固定在乳腺癌术后放疗摆位精度研究

目的探究聚氨酯发泡胶联合个体化头枕固定在乳腺癌术后放疗的固定精度研究,提高乳腺癌放疗摆位精度与重复性。方法选取乳腺癌术后放疗患者52例,使用聚氨酯发泡胶(对照组)与发泡胶联合个体化头枕(研究组)固定,采用调强放疗技术照射乳腺/胸壁靶区与锁骨上野,使用锥形束CT(CBCT)影像引导配准获得乳腺/胸壁靶区与锁骨上野的摆位误差,对327套CBCT影像摆位误差数据进行分析两组乳腺/胸壁和锁骨上野靶区位置的一致性。结果两组乳腺/胸壁靶区平移误差在腹背和头脚方向差异无统计学意义(P>0.05),左右方向研究组优于对照组[(1.87±1.45)mm vs.(2.32±1.66)mm,P=0.012],旋转误差在左右和头脚方向差异无统计学意义(P>0.05),在腹背方向研究组优于对照组[(0.78±0.66)°vs.(0.97±0.79)°,P=0.029];两组锁骨上下区域平移误差在头脚与腹背方向差异无统计学意义(P>0.05),在左右方向研究组优于对照组[(2.07±1.65)mm vs.(2.53±1.96)mm,P=0.047],旋转误差在左右和头脚方向研究组均小于对照组[(0.79±0.67)°vs.(1.07±0.88)°,P=0.009和(0.52±0.41)°vs.(0.79±0.67)°,P=0.001],腹背方向差异无统计学意义(P>0.05)。研究组和对照组乳腺/胸壁靶区左右、头脚和腹背方向PTV外扩值分别为2.62、3.46、3.30 mm与3.74、3.64、3.26 mm;锁骨上野PTV外扩值分别为3.36、3.49、4.14 mm与4.38、2.98、4.35 mm。结论聚氨酯发泡胶联合个体化头枕固定可提高乳腺癌术后放疗乳腺/胸壁靶区与锁骨上野的固定精度,乳腺/胸壁靶区与锁骨上野体位一致性更高。

摆位误差对乳腺癌术后放疗患者心脏剂量影响

目的研究模拟摆位误差对左侧乳腺癌患者术后放疗心脏受照剂量的影响。方法选取17例左侧乳腺癌根治术后进行调强放疗的患者为研究对象。在计划系统中,模拟靶区中心相对于计划射野中心的偏移,包括向颅(S)、尾(I)、左(L)、右(R)、前(A)和后(P)各移动5 mm,并评估心脏受照剂量,分析不同方向的摆位误差对心脏剂量的影响。结果原始计划心脏平均剂量(Dmean)为5.72 Gy。射野中心向6个不同方向移动5 mm后,L、A、S方向心脏受照剂量减少,R、P、I方向心脏受照剂量增加,P方向心脏Dmean增加(1.46±0.24)Gy,R方向心脏Dmean增加(1.14±0.17)Gy,I方向心脏Dmean增加(0.43±0.25)Gy。结论左侧乳腺癌改良根治术后放疗,向R、P、I方向的摆位误差可增加心脏受照剂量,向L、A、S方向的摆位误差可减少心脏受照剂量。

乳腺癌术后调强放疗患者体质情况与摆位误差的关系研究

目的探讨乳腺癌术后调强放疗患者体质量指数(BMI)、胸围、乳腺体积与摆位误差的关系。方法选取2019年1月至2022年10月在南通市第三人民医院接受调强放疗的乳腺癌患者63例,比较不同BMI、胸围、乳腺体积等患者摆位误差差异。结果63例乳腺癌患者中,左右方向(X轴)摆位误差为(2.61±0.72)mm,头脚方向(Y轴)摆位误差为(2.84±0.80)mm,前后方向(Z轴)摆位误差为(2.89±0.78)mm。随着BMI增加,X轴、Y轴和Z轴摆位误差逐渐增加(P<0.05),其中BMI≥24.0 kg/m^(2)患者X轴、Y轴和Z轴摆位误差分别为(3.13±0.53)mm、(3.60±0.63)mm和(3.88±0.66)mm,明显高于BMI<18.5 kg/m^(2)和18.5~23.9 kg/m^(2)患者(P<0.05)。胸围≥89 cm患者X轴和Y轴摆位误差分别为(2.84±0.52)mm和(3.07±0.56)mm,明显高于胸围<89 cm患者。随着乳腺体积增加,X轴摆位误差逐渐增加(P<0.05),其中乳腺体积>800 cm^(3)患者X轴摆位误差为(3.16±0.68)mm,明显高于乳腺体积<500 cm^(3)和500~800 cm^(3)患者(P<0.05)。不同年龄患者X轴、Y轴和Z轴摆位误差比较差异无统计学意义(P>0.05)。结论乳腺癌术后调强放疗摆位误差受患者BMI、胸围及乳腺体积的影响,与患者年龄无明显关系。

摆位误差对左乳癌术后放射治疗剂量分布的影响

目的 使用千伏级锥形束计算机断层扫描(kV-CBCT)技术测量左乳癌术后放射治疗摆位误差,探讨摆位误差对剂量分布的影响。方法 选取2021年9月至2022年12月在宣城市人民医院接受放射治疗的左乳癌术后患者30例为研究对象,提取每位患者前3次放射治疗前的kV-CBCT图像,分别与计划CT图像配准,由配准系统计算获得患者左右(X)、头脚(Y)、胸背(Z)方向摆位误差。以第1次配准结果作为校正前的误差,以第2、3次配准结果作为校正后的误差,在治疗计划系统中按校正前、后误差大小平移计划中心点,计算校正前的计划(S-Plan)和校正后的计划(C-Plan)的剂量,并与治疗计划(T-Plan)进行比较,分析3者在计划靶区(PTV)、浅表区域、危及器官方面的剂量差异,以及计划的伽马通过率差异。结果 校正前摆位误差分别为(1.85±3.76) mm、(-1.80±3.25) mm、(-2.10±3.99) mm,校正后摆位误差平均值分别为(0.04±1.59) mm、(0.10±1.55) mm、(-0.01±1.47) mm。3组计划的PTV D_(98)、D_(95)、D_(mean)、均匀性指数(HI)、适形性指数(CI)和浅表区域D_(mean)间差异均具有统计学意义(P<0.05),两两比较显示,S-Plan和T-Plan、C-Plan间差异均具有统计学意义(P<0.05),3组计划患侧肺的V_(5)、V_(20)、V_(30)、D_(mean)、心脏的D_(mean)、V_(5)和脊髓D_(max)间差异均具有统计学意义(P<0.05),两两比较显示,S-Plan和T-Plan、C-Plan间差异均具有统计学意义(P<0.05),3组计划的伽马通过率间差异具有统计学意义(P<0.05),两两比较显示,S-Plan和T-Plan、C-Plan间差异均具有统计学意义(P<0.05)。结论 使用kV-CBCT测量并校正左乳癌术后放射治疗患者摆位,能有效减少摆位误差及其对剂量分布的影响,具有良好的可靠性和可重复性。

调强放疗与容积弧形调强放疗技术对乳腺癌患者分次内位移误差的影响研究

目的比较保乳术后乳腺癌患者在应用调强放疗(Intensity Modulated Radiation Therapy,IMRT)与容积弧形调强放疗(Volumetric Modulated Arc Therapy,VMAT)技术中的分次内位移误差大小,并研究体位固定时增加腹部热塑膜能否减少分次内位移误差。方法选取2022年10月至2023年3月乳腺癌保乳术后接受放射治疗的60例女性患者为研究对象,按照治疗技术不同将其随机分为IMRT组(n=30)和VMAT组(n=30);在2组中各随机选取15例患者在体位固定时增加腹部热塑膜,按照固定附件是否采用腹部热塑膜分为常规组和腹膜组;以计划靶区为主要配准区域,应用锥形束CT灰度配准算法分别比较IMRT组与VMAT组、常规组与腹膜组的分次内位移误差大小。结果经独立样本t检验,VMAT组的治疗时长显著小于IMRT组[(4.17±0.86)min vs.(9.69±1.13)min],差异有统计学意义(P<0.05);经Wilcoxon秩和检验,VMAT组的患者在左右(x)、头脚(y)、前后(z)方向分次内位移误差均小于IMRT组,差异有统计学意义(P<0.05)。经独立样本t检验,常规组的治疗时长与腹膜组差异无统计学意义(P>0.05);经Wilcoxon秩和检验,腹膜组患者在x、y方向分次内位移误差小于常规组,差异有统计学意义(P<0.05),在z方向的差异则无统计学意义(P>0.05)。结论保乳术后乳腺癌患者使用VMAT相比于IMRT,患者的分次内位移误差更小,在体位固定环节增加腹部热塑膜可减少患者x和y方向的分次内位移误差。

乳腺癌保乳术后采用APBI-IMRT的效果

目的:探讨乳腺癌保乳术后采用加速部分乳腺调强放疗(accelerated partial breast irradiation with intensitymodulated radiation therapy,APBI-IMRT)的效果。方法:选择2018年6月—2022年9月南京大学医学院附属苏州医院收治的82例行乳腺癌保乳术患者作为研究对象,以随机数表法将患者分为对照组与研究组,各41例。对照组应用常规放疗,研究组应用APBI-IMRT,比较两组肿瘤标志物、危险器官剂量、心功能指标。结果:治疗前,两组肿瘤标志物、心功能指标比较,差异无统计学意义(P>0.05);治疗后,两组癌胚抗原(carcinoembryonic antigen,CEA)、β_(2)-微球蛋白(β_(2)-Microglobulin,β_(2)-MG)、细胞角蛋白19片段(cytokeratin 19 fragment,CYFRA21-1)、甲胎蛋白(alpha fetoprotein,AFP)水平、左房收缩末期内径(left atrial end-systolic diameter,LADs)、左室舒张末期内径(left ventricular end diastolic dimension,LVDD)、射血分数(ejection fraction,EF)、左心室短轴缩短率(fraction shortening,FS)较治疗前降低,且研究组肿瘤标志物低于对照组,但心功能指标高于对照组,差异有统计学意义(P<0.05)。研究组危险器官剂量低于对照组,差异有统计学意义(P<0.05)。结论:APBI-IMRT在乳腺癌保乳术后应用可增强治疗效果,降低对心肺功能的损伤。

POSIREST-2手臂支撑装置联合真空垫在乳腺癌调强放疗中的应用

目的探讨乳腺癌保乳术后使用POSIREST-2手臂支撑装置联合真空垫固定进行调强放疗的应用效果。方法选取罗定市人民医院肿瘤科2021年6月至2022年12月收治的50例乳腺癌保乳术后患者,采用随机数表法将其分为真空垫组(使用真空垫,n=25)和联合支撑组(使用POSIREST-2手臂支撑装置联合真空垫,n=25)。在患者分次治疗前,通过直线加速器验证系统拍摄患者正侧位片,测量骨性标志物与数字重建放射影像在左右(X)、头脚(Y)、腹背(Z)三个维度的误差值,分析两种固定方式的摆位精度、稳定性及操作重复性,并利用数据计算两组患者临床靶区(CTV)至计划靶区(PTV)的外扩值。结果两组在X方向的摆位误差比较,差异无统计学意义(P>0.05),在Y和Z方向的摆位误差比较,差异有统计学意义(P<0.05)。两组CTV至PTV的外扩值在三个维度X、Y、Z方向分别为0.56、0.57、0.39 cm与0.37、0.25、0.20 cm。结论尽管真空垫固定方式在一定程度上可以满足临床的需求,但联合支撑固定方法在术后保乳患者的摆位精度和重复性方面表现更为优越。因此,POSIREST-2手臂支撑装置联合真空垫的固定方式在乳腺癌保乳术后放射治疗的临床应用上具有推广和实用价值。

不同靶区边缘参数对乳腺癌根治术后容积弧形调强放射治疗计划质量的影响

目的探讨不同靶区边缘参数对乳腺癌根治术后容积弧形调强放射治疗(VMAT)计划质量的影响。方法回顾性分析2021年1月至2022年12月于医院行VMAT的14例乳腺癌根治术后患者的临床资料。所有患者均采用Monaco计划系统设计Tight组、Narrow组、Normal组3组不同靶区边缘参数的VMAT计划,并比较3组靶区剂量学指标[PTV的平均剂量(D_(mean))、最大剂量(D_(max)),2%PTV体积受照射剂量(D_(2%))、98%PTV体积受照射剂量(D_(98%))、50%PTV体积受照射剂量(D_(50%)),适形度指数(CI)、均匀性指数(HI)、剂量梯度指标(GI)]、危及器官(OARs)剂量学指标[患侧肺体积百分比(V_(5)、V_(20)、V_(30))和平均剂量(D_(mean)),健侧肺体积百分比(V_(5))和平均剂量(D_(mean)),心脏体积百分比(V_(5))和平均剂量(D_(mean)),脊髓最大剂量(D_(max))及健侧乳腺平均剂量(D_(mean))]及计划参数[计划控制点数(CP)、机器跳数(MU)和出束时间(T)]。结果Tight组的D_(mean)、D_(max)、D_(2%)、D_(50%)、HI、GI均低于Narrow组和Normal组,且Narrow组的D_(mean)、D_(2%)、D_(50%)、HI、GI均低于Normal组,差异有统计学意义(P<0.05);Narrow组和Normal组的D_(max)比较,差异无统计学意义(P>0.05);Tight组的D_(98%)和CI均高于Narrow组和Normal组,且Narrow组的D_(98%)高于Normal组,差异有统计学意义(P<0.05);Narrow组和Normal组的CI比较,差异无统计学意义(P>0.05)。Tight组的心脏V_(5)、D_(mean)和脊髓D_(max)均低于Narrow组和Normal组,且Narrow组低于Normal组,差异有统计学意义(P<0.05);Tight组和Narrow组的健侧乳腺D_(mean)均低于Narrow组,差异有统计学意义(P<0.05);3组其他OARs剂量学指标比较,差异均无统计学意义(P>0.05)。Tight组的CP、MU和T均高于Narrow组和Normal组,且Narrow组高于Normal组,差异有统计学意义(P<0.05);Tight组的MU高于Narrow组和Normal组,差异均有统计学意义(P<0.05);Narrow组和Normal组的MU比较,差异无统计学意义(P>0.05)。结论设计乳腺癌根治术后VMAT计划时,合理设置靶区边缘参数可改善剂量学特性,有助于提高放射治疗的精准性和治疗效果。

容积旋转调强与固定野调强放疗技术用于乳腺癌术后放疗中的剂量学比较

目的比较容积旋转调强(VMAT)与固定野调强放疗(IMRT)技术用于乳腺癌术后放疗中的剂量学差异。方法选取收治的乳腺癌患者254例为研究对象,均在相同的剂量学限制条件下设计VMAT及IMRT放疗程序,依据剂量体积直方图评估其计划靶区(PTV)剂量、适形度指数(CI)、均匀性指数(HI)、危及器官受量。结果两种放疗技术下,PTV Dmean、PTV V95%、PTV V110%对比差异无统计学意义(P>0.05),VMAT计划的每分次治疗时间、靶区HI均小于IMRT,而VMAT的靶区CI、机器跳数多于IMRT(P<0.05);VMAT的健侧乳腺Dmax与Dmean、患侧肺V20、V30均低于IMRT,VMAT的冠脉左前降支Dmean、心脏V30、Dmean及脊髓Dmax、Dmean也低于IMRT,VMAT的健侧肺V5、V10大于IMRT(P<0.05)。结论在乳腺癌术后放疗中,选择VMAT放疗技术较IMRT放疗技术可获得更好的靶区均匀性、适形性及较低的危及器官受量,同时缩短治疗时间,可作为首选治疗方案。