Objective To prospectively investigate the optimal setting for sentinel lymph node biopsy (SLNB) in patients with breast cancer by comparing the effects of different preparation methods and injection sites of 99Tcm-SC in sentinel lymph node (SLN) mapping and detection.Methods Two batches of 99Tcm-SC were prepared by boiling for 3 min (radiotracer 1) and 5 min (radiotracer 2),respectively.Radioactive chemical purity (RCP) and size of colloid particles were measured at 10 min,1 h,2 h and 4 h after the preparation.One hundred and forty-seven patients with breast cancer were involved and randomly divided into 3 groups.Group A consisted of 40 patients with periareolar injection of radiotracer 1,group B of 40 patients with periareolar injection of radiotracer 2,and group C of 67 patients with peritumoral injection of radiotracer 2.Lymphatic mapping was performed for all patients using SPECT/CT preoperatively and blue dye was subdermally injected over the tumor.The detection rate of the axillary and internal mammary SLN was recorded.One-way analysis of variance,independent two-sample t and x2 tests were used to analyze the data.Results There was no significant difference of RCP between the two radiotracers at 10 min,1 h,2 h and 4 h after preparation (t =-0.267,-0.794,0.826 and-0.977,all P＞0.05).Compared with radiotracer 1,the percentage of particles smaller than 100 nm in radiotracer 2 reduced significantly ((73.72±2.36) ％ vs (65.25±3.56)％,t=6.436,P＜0.05) and the mean effective particle size was significantly larger ((45.27±6.42) nm vs (75.59t7.04) nm,t=7.315,P＜0.05).In groups A,B and C,the detection rate of the internal mammary SLN was 70.0％ (28/40),47.5％ (19/40) and 17.9％ (12/67),respectively,with significant difference (x2=29.525,P＜0.05).In groups A,B and C,the detection rate of the axillary SLN was 100％ (40/40),95.0％ (38/40) and 97.0％ (65/67),respectively,without significant difference (x2 =2.686,P＞ 0.05).Conclusion For SLNB of patients with breast cancer,the axillary and internal mammary SLN could be better detected by SPECT/CT lymphatic mapping using radiotracer prepared with a shorter boiling time,via periareolar injection,and combined with subdermal injection of blue dye.

Objective To evaluate the clinical value of 99Tcm-Tilmanocept(TMC) SPECT/CT for the detection of SLN by comparing with 99Tcm-sulfur colloid(SC) SPECT/CT. Methods From March 2016 to September 2016, a total of 160 patients (age range: 30-70 years), selected from Breast Surgery Department of Shandong Cancer Hospital, underwent SPECT/CT and planar imaging with either 99Tcm-TMC (TMC group, n=76) or 99Tcm-SC (SC group, n=84). The results of SLN SPECT/CT and planar imaging were compared. The positive rate of SLN in SPECT/CT was compared with operative results. One-way analysis of variance, χ2 test, and two-sample t test were used for data analysis. Results The radiochemical purity of 99Tcm-TMC (≥92%) had no significant difference in 4 h(F=0.720, P>0.05). In TMC group, the average number of SLN detected by SPECT/CT imaging was higher than that by planar imaging (1.34±0.64 vs 0.96±034; t=4556, P<005). In SC group, the average number of SLN detected by SPECT/CT imaging was also higher than that by planar imaging (2.57±0.99 vs 1.56±0.87; t=7.010, P<0.05). The positive rates of SLN in TMC and SC groups were 94.7%(72/76)and 96.4%(81/84), showing no significant difference (χ2=0273, P>0.05). The average number of SLN detected by 99Tcm-TMC imaging was significantly lower than that detected by 99Tcm-SC (t=9.115, P<0.05). The intraoperative detection rates of SLN were 100% (76/76 and 84/84) in both groups. The average number of SLN detected during operation in TMC group was significantly lower than that in SC group (1.89±0.86 vs 3.05±1.29; t=6.642, P<0.01). In TMC group, the average number of SLN detected during operation was significantly higher than that detected by SPECT/CT(1.89±086 vs 1.34±0.64; t=4.492, P<0.05). In SC group, the average number of SLN detected during operation was significantly higher than that detected by SPECT/CT(3.05±1.29 vs 2.57±0.99; t=2.740, P<005). Conclusions SPECT/CT is superior to planar imaging for the detection and localization of SLN. 99Tcm-TMC is suitable for SLN imaging and intraoperative detection.

Objective To explore the target definition for internal mammary lymph nodes ( IMLNs) irradiation based on the distribution of internal mammary sentinel lymph nodes ( IM-SLNs ) developing on SPECT/CT fusion imaging. Methods A total of 709 breast cancer patients who underwent preoperative SPECT/CT fusion imaging examination in IM-SLN from 2014 to 2018 were selected. All of the selected patients were first diagnosed and did not receive neoadjuvant treatment before SPECT/CT examination. Finally, totally 97 patients with 136 positive imaging IM-SLNs were included in this study. The clinical target volumes ( CTVs) were delineated according to the consensus guidelines from RTOG and DBCG and defined as CTVRTOG and CTVDBCG , respectively. The positional relationship of CTVRTOG , CTVDBCG and IM-SLNs were determined. Results The number of IM-SLNs from the first to fifth intercostal spaces were 55, 40, 33, 6 and 1, respectively. And the number of IM-SLNs in the first three intercostal spaces accounted for 94. 85％ of the total. The average distance from the edge of CTVRTOG to the centre points and the edges of IM-SLNs were 4. 10 mm ( 95％CI 3. 54-4. 65 mm) and 6. 40 mm ( 95％CI 5. 81-6. 98 mm), respectively (t=-30. 486,P<0. 05). For the CTVDBCG, the average distance was 1. 60 mm ( 95％CI 1. 16-2. 05 mm) and 3. 34 mm ( 95％CI 2. 78-3. 89 mm) , respectively ( t=-16. 364,P<0. 05) . The average distances from the edge of CTV to the centre points and the edge of IM-SLNs for CTVRTOG were all significantly greater than those for CTVDBCG(t=16. 640, 19. 815, P<0. 05). The rate of covering IM-SLN center points for CTVRTOG and CTVDBCG were 18. 4％ and 60. 3％, respectively. In order to cover 90％or 100％ of the IM-SLN center points, the edge of CTVRTOG should be expanded by 8 or 15 mm, respectively, and the edge of CTVDBCG should be expanded by 5 or 13 mm, respectively. If the diameter of IM-SLN was assumed as 5 mm, the edge of CTVRTOG needed an expansion of 11 or 17 mm to contain 90％or 100％ of IM-SLNs, respectively, while the edge of CTVDBCG needed 7 or 16 mm to cover 90％ or 100％of IM-SLNs, respectively. Conclusions It is reasonable to include the first three intercostal spaces IMLNs for prophylactic irradiation based on the distribution of IM-SLNs. However, CTVs based on the two guidelines are both insufficient to cover 90％ of IM-SLNs.

Objective To investigate the clinical value of 99Tcm-methoxyisobutylisonitrile (MIBI) double-phase imaging in differential diagnosis of bone lesions in tumor patients,which was indefinite in 99Tcm-methylene diphosphonate (MDP) bone imaging,and evaluate the correlation between 99Tcm-MIBI imaging and chemotherapy efficacy.Methods Fifty-two tumor patients (23 males,29 females,mean age 58 years) with bone isolated lesions(≤3) found by 99Tcm-MDP bone scintigraphy was enrolled from June 2014 to November 2015.Since the results of 99Tcm-MDP imaging were indefinite,99Tcm-MIBI double-phase (10 min and 30 min after injection of 99Tcm-MIBI) SPECT/CT imaging was then performed within 1 week.The final diagnosis was made according to results of more than two imaging modalities (CT,MRI,PET/CT) and/or follow-up (≥6 months).The diagnostic efficacy of 99Tcm-MIBI SPECT/CT imaging was calculated.The clinical dataof chemotherapy were also collected.Patients with bone metastasis were grouped as the treatment response.Retention index (RI) of metastatic lesions was calculated and compared between different groups using two-sample t test.The relationship between RI and chemotherapy efficacy was investigated by Spearman correlation analysis.Results A total of 12 benign lesions and 84 malignant lesions were eventually diagnosed.The sensitivity,specificity,positive predictive value (PPV),negative predictive value (NPV) and Youden index of 99Tcm-MIBI imaging were 96.43％(81/84),83.33％(10/12),97.59％(81/83),76.92％(10/13),and 0.80,respectively.The RI was statistically different between complete remission (CR)+partial remission (PR) group and stable disease (SD) + progressive disease (PD) group:-0.142± 0.036 vs-0.384± 0.067 (t =2.367,P＜0.05).The RI of 99Tcm-MIBI in bone metastases was positively correlated with the chemotherapy efficacy (rs =0.78,P＜0.01).Conclusions 99Tcm-MIBI imaging is helpful in differential diagnosis of bone lesions with indefinite diagnosis by 99Tcm-MDP bone imaging in tumor patients.99Tcm-MIBI RI of bone metastasis may predict the therapeutic response of chemotherapy efficacy.