1.Pediatric penile incarceration by metal screw nut:a case report and literature review
Zhanyu XU ; Xiang ZHAO ; Ning LI
Journal of Modern Urology 2025;30(4):327-332
Objective: To explore methods about how to treat penile foreign body incarceration,so as to provide reference for clinical treatment of such cases. Methods: The diagnosis and treatment of a patient with penile metal foreign body incarceration from the Department of Pediatric Surgery of Tongji Hospital was analyzed,relevant Chinese and English literature were retrieved,and treatment methods and outcomes were summarized. Results: A 11-year-old boy came to our hospital with a screw nut incarcerated around the penis for over 10 days,the distal penis dark red swelling,local epidermis exfoliation oozing.A wire saw was used to cut and remove the incarcerated object.The patient recovered well,with no secondary damage to the penis,and no dysfunctions like dysuria.The search of the Chinese and English databases obtained a total of 79 penile incarceration-related papers involving 184 cases.Treatment methods included direct removal after bloodletting for detumescence,removal after cutting with various instruments,and penis skin degloving. Conclusion: Since penile incarceration is a rare emergency,early treatment can avoid complications with good prognosis.Methods dealing with penile foreign body incarceration have both pros and cons.Therefore,selection of the appropriate methods needs comprehensive evaluation,or follows the order of simple-to-complex operations.
2.Photoplethysmography signal smoothing technology based on locally orthogonal weighted polynomial fitting
Jinlu LI ; Zhanyu LAI ; Keyang DONG ; Yufan DUAN ; Zidong DAI ; Yurong LIU ; Xiaoping JIANG
Chinese Journal of Medical Physics 2025;42(7):945-951
To address the issue of reduced signal quality of photoplethysmography caused by local fluctuation,an approach called locally orthogonal weighted polynomial fitting(LOWPF)is proposed for signal smoothing.After determining the positions of the fluctuation sequences using the forward-backward difference XOR method,weighted polynomial fitting is applied to these sequences,and the fitted values are used to replace the fluctuation sequences to achieve signal smoothing.By constructing orthogonal basis functions,the condition number of the coefficient matrix is reduced,and the stability of the equation system solution for higher-order fitting is improved.Simulation results demonstrate that the smoothed signal's XOR smoothness of the proposed method surpasses that of the moving average algorithm and the empirical mode decomposition reconstruction algorithm.The smoothing results on 241 sets of measured PPG signals show that LOWPF achieves an efficiency of smoothness of 89.10%,significantly higher than the 78.05%of empirical mode decomposition and the 59.13%of the 5-point moving average algorithm.LOWPF has promising application prospects for smoothing signals with significant local fluctuations.
3.Influence of the complexity metrics of the multi-leaf collimator on the γ-pass rate of volumetric modulated arc therapy plans for nasopharyngeal carcinoma
Junwen TAN ; Yusong LONG ; Xiantao HE ; Gang LI ; Yongfu FENG ; Weixue LIANG ; Zhanyu WANG
Chinese Journal of Radiological Medicine and Protection 2025;45(4):309-316
Objective:To investigate the influence of the complexity metrics of the multi-leaf collimator (MLC) on the γ-pass rate of volumetric modulated arc therapy (VMAT) plans for nasopharyngeal carcinoma (NPC).Methods:A total of 60 VMAT plans for NPC were selected to measure the γ-pass rate. The MLC data across all control points (CPs) in each VMAT plan were analyzed to calculate the mean field area (MFA), average leaf gap (ALG), small aperture score (SAS), and their corresponding weighted metrics including MFAW, ALGW, and SASW, considering dose weight (W). Pearson′s bivariate correlation analysis was conducted to examine the correlations between MLC complexity metrics and the γ-pass rate. Moreover, the receiver operating characteristic (ROC) analysis was employed to assess the predictive efficacy of MLC complexity metrics on dose verification result.Results:Under the 3%/3 mm, 3%/2 mm, and 2%/2 mm criteria, the MFA in the 60 VMAT plans exhibited a positive correlation with the γ-pass rate ( r=0.82, 0.79, 0.72, P<0.05), and the MFAW was also positively correlated with the γ-pass rate ( r=0.83, 0.81, 0.75, P<0.05). The ALG manifested a positive correlation with the γ-pass rate ( r=0.82, 0.79, 0.74, P<0.05), as did the ALGW ( r=0.83, 0.81, 0.77, P<0.05). The SAS(0-1 cm), SAS(1-2 cm), SAS(2-3 cm), and SAS(3-4 cm) displayed negative correlations with the γ-pass rate ( r= -0.86, -0.82, -0.71, -0.84, -0.82, -0.72, -0.79, -0.79, -0.73, -0.30, -0.35, -0.42, P<0.05), whereas the SAS(4-5 cm), SAS(5-6 cm), and SAS(6-40 cm) showed positive correlations with the γ-pass rate ( r=0.49, 0.45, 0.33, 0.73, 0.71, 0.59, 0.79, 0.79, 0.76, P<0.05). The outcomes of SASW reveal slightly stronger correlations than those of SAS. In terms of correlations among complexity metrics, a positive correlation was observed between MFA and ALG ( r=0.98, P<0.05). ALG was negatively correlated with SAS(0-1 cm), SAS(1-2 cm), SAS(2-3 cm), and SAS(3-4 cm) ( r= -0.95, -0.94, -0.89, -0.39, P<0.05), and positively correlated with SAS(4-5 cm), SAS(5-6 cm), and SAS(6-40 cm) ( r=0.51, 0.77, 0.92, P<0.05). The weighted result mirrored these correlations. The ROC-derived analytical result indicate that MFA, MFAW, ALG, ALGW, SAS(0-1 cm), SAS(1-2 cm), SAS(2-3 cm), SAS(6-40 cm), SASW(0-1 cm), SASW(1-2 cm), SASW(2-3 cm), and SASW(6-40 cm) demonstrated exceptional predictive efficacy for dose verification result [Area under the curve (AUC) > 0.9, P<0.05]. Conclusions:The γ-pass rate of VMAT plans for NPC is strongly correlated with MLC complexity metrics, which demonstrate excellent predictive efficacy for dose verification result. The increased uncertainty in dose calculations and measurements caused by narrow fields generated by the MLC is a significant factor contributing to the reduced γ-pass rate of VMAT plans. This finding is associated with discrepancies in the precision of treatment planning system (TPS) modeling and the accuracy of dose verification tools, providing a reference for similar challenges.
4.A comparative study of radiotherapy using three distinct radiotherapy techniques following immediate breast reconstruction for breast cancer
Xiantao HE ; Zhuohua XU ; Yusong LONG ; Junwen TAN ; Gang LI ; Yongfu FENG ; Hui YANG ; Ying LU ; Zhanyu WANG
Chinese Journal of Radiological Medicine and Protection 2025;45(4):317-324
Objective:To investigate the differences in dosimetric parameters for target volumes and organs at risk (OARs), radiation doses to reconstructed tissues, and beam-on time in radiotherapy among helical tomotherapy (HT), volumetric modulated arc therapy (VMAT), and fixed-field intensity-modulated radiotherapy (F_IMRT) following immediate breast reconstruction for breast cancer, thereby providing a reference for the selection of clinical radiotherapy techniques.Methods:This study retrospectively investigated 15 breast cancer patients who underwent radiotherapy following modified radical mastectomy and immediate breast reconstruction at the Liuzhou Worker′s Hospital from August 2018 to July 2023. During target volume delineation, precautions were taken to avoid the reconstructed tissues, which were delineated separately. Customized HT, VMAT, and F_IMRT treatment plans were designed for each patient. The plans were categorized into the HT, VMAT, and F_IMRT groups based on different radiotherapy techniques employed. They were comparatively analyzed through one-way analysis of variance (ANOVA), with multiple comparisons further conducted in the case of significant differences.Results:Statistical analyses reveal significant differences in various parameters of target volumes among the three groups of plans ( F = 38.73, 14.95, 37.01, 48.05, 35.55, 22.56, 34.30, P < 0.05). Pairwise comparisons indicate that the maximum dose ( D2%), minimum dose ( D98%), mean dose ( Dmean), and the proportion of high-dose volumes within the target volume ( V107%and V110%) in both the HT and VMAT groups were significantly better than those in the F_IMRT group. The HT group demonstrated the optimal conformity index (CI), while the VMAT group displayed the superior homogeneity index (HI) compared to the other two groups. In terms of OAR, the V20 of the ipsilateral lung was the lowest in the HT group ( F = 14.31, P < 0.05) and the highest in the F_IMRT group ( F = 14.31, P < 0.05). However, the V5 and Dmean for both the ipsilateral and contralateral lungs in the HT group significantly surpassed those of the other groups ( F = 39.16, 31.91, P < 0.05). The mean dose Dmean ( F = 5.57, P < 0.05) of the contralateral breast was significantly reduced in the VMAT group compared to the other two groups. No statistically significant differences were observed for other OARs, including the heart, spinal cord PRV, thyroid, and humeral head ( P > 0.05). The radiation doses to reconstructed tissues ( Dmax, V53.5, Dmean) ascended in the order of HT, VMAT, and F_IMRT groups ( F = 17.69, 17.53, 15.11, P < 0.05). The HT and F_IMRT groups showed similar beam-on times ( P > 0.05), both exceeding that of the VMAT group by several folds ( F = 28.72, P < 0.05). Conclusions:The comparative analysis indicates that the three radiotherapy techniques exhibit distinct advantages and limitations, with F_IMRT demonstrating the least comprehensive advantage. HT can enhance the conformity of target volumes while reducing the overall radiation doses to reconstructed tissues and the crucial indicator V20 in the ipsilateral lung. VMAT demonstrates the highest treatment efficiency, yielding improved dose uniformity in the target volume and reduced radiation doses to the contralateral breast. It is advisable to prioritize HT or VMAT based on actual clinical conditions.
5.Photoplethysmography signal smoothing technology based on locally orthogonal weighted polynomial fitting
Jinlu LI ; Zhanyu LAI ; Keyang DONG ; Yufan DUAN ; Zidong DAI ; Yurong LIU ; Xiaoping JIANG
Chinese Journal of Medical Physics 2025;42(7):945-951
To address the issue of reduced signal quality of photoplethysmography caused by local fluctuation,an approach called locally orthogonal weighted polynomial fitting(LOWPF)is proposed for signal smoothing.After determining the positions of the fluctuation sequences using the forward-backward difference XOR method,weighted polynomial fitting is applied to these sequences,and the fitted values are used to replace the fluctuation sequences to achieve signal smoothing.By constructing orthogonal basis functions,the condition number of the coefficient matrix is reduced,and the stability of the equation system solution for higher-order fitting is improved.Simulation results demonstrate that the smoothed signal's XOR smoothness of the proposed method surpasses that of the moving average algorithm and the empirical mode decomposition reconstruction algorithm.The smoothing results on 241 sets of measured PPG signals show that LOWPF achieves an efficiency of smoothness of 89.10%,significantly higher than the 78.05%of empirical mode decomposition and the 59.13%of the 5-point moving average algorithm.LOWPF has promising application prospects for smoothing signals with significant local fluctuations.
6.Influence of the complexity metrics of the multi-leaf collimator on the γ-pass rate of volumetric modulated arc therapy plans for nasopharyngeal carcinoma
Junwen TAN ; Yusong LONG ; Xiantao HE ; Gang LI ; Yongfu FENG ; Weixue LIANG ; Zhanyu WANG
Chinese Journal of Radiological Medicine and Protection 2025;45(4):309-316
Objective:To investigate the influence of the complexity metrics of the multi-leaf collimator (MLC) on the γ-pass rate of volumetric modulated arc therapy (VMAT) plans for nasopharyngeal carcinoma (NPC).Methods:A total of 60 VMAT plans for NPC were selected to measure the γ-pass rate. The MLC data across all control points (CPs) in each VMAT plan were analyzed to calculate the mean field area (MFA), average leaf gap (ALG), small aperture score (SAS), and their corresponding weighted metrics including MFAW, ALGW, and SASW, considering dose weight (W). Pearson′s bivariate correlation analysis was conducted to examine the correlations between MLC complexity metrics and the γ-pass rate. Moreover, the receiver operating characteristic (ROC) analysis was employed to assess the predictive efficacy of MLC complexity metrics on dose verification result.Results:Under the 3%/3 mm, 3%/2 mm, and 2%/2 mm criteria, the MFA in the 60 VMAT plans exhibited a positive correlation with the γ-pass rate ( r=0.82, 0.79, 0.72, P<0.05), and the MFAW was also positively correlated with the γ-pass rate ( r=0.83, 0.81, 0.75, P<0.05). The ALG manifested a positive correlation with the γ-pass rate ( r=0.82, 0.79, 0.74, P<0.05), as did the ALGW ( r=0.83, 0.81, 0.77, P<0.05). The SAS(0-1 cm), SAS(1-2 cm), SAS(2-3 cm), and SAS(3-4 cm) displayed negative correlations with the γ-pass rate ( r= -0.86, -0.82, -0.71, -0.84, -0.82, -0.72, -0.79, -0.79, -0.73, -0.30, -0.35, -0.42, P<0.05), whereas the SAS(4-5 cm), SAS(5-6 cm), and SAS(6-40 cm) showed positive correlations with the γ-pass rate ( r=0.49, 0.45, 0.33, 0.73, 0.71, 0.59, 0.79, 0.79, 0.76, P<0.05). The outcomes of SASW reveal slightly stronger correlations than those of SAS. In terms of correlations among complexity metrics, a positive correlation was observed between MFA and ALG ( r=0.98, P<0.05). ALG was negatively correlated with SAS(0-1 cm), SAS(1-2 cm), SAS(2-3 cm), and SAS(3-4 cm) ( r= -0.95, -0.94, -0.89, -0.39, P<0.05), and positively correlated with SAS(4-5 cm), SAS(5-6 cm), and SAS(6-40 cm) ( r=0.51, 0.77, 0.92, P<0.05). The weighted result mirrored these correlations. The ROC-derived analytical result indicate that MFA, MFAW, ALG, ALGW, SAS(0-1 cm), SAS(1-2 cm), SAS(2-3 cm), SAS(6-40 cm), SASW(0-1 cm), SASW(1-2 cm), SASW(2-3 cm), and SASW(6-40 cm) demonstrated exceptional predictive efficacy for dose verification result [Area under the curve (AUC) > 0.9, P<0.05]. Conclusions:The γ-pass rate of VMAT plans for NPC is strongly correlated with MLC complexity metrics, which demonstrate excellent predictive efficacy for dose verification result. The increased uncertainty in dose calculations and measurements caused by narrow fields generated by the MLC is a significant factor contributing to the reduced γ-pass rate of VMAT plans. This finding is associated with discrepancies in the precision of treatment planning system (TPS) modeling and the accuracy of dose verification tools, providing a reference for similar challenges.
7.A comparative study of radiotherapy using three distinct radiotherapy techniques following immediate breast reconstruction for breast cancer
Xiantao HE ; Zhuohua XU ; Yusong LONG ; Junwen TAN ; Gang LI ; Yongfu FENG ; Hui YANG ; Ying LU ; Zhanyu WANG
Chinese Journal of Radiological Medicine and Protection 2025;45(4):317-324
Objective:To investigate the differences in dosimetric parameters for target volumes and organs at risk (OARs), radiation doses to reconstructed tissues, and beam-on time in radiotherapy among helical tomotherapy (HT), volumetric modulated arc therapy (VMAT), and fixed-field intensity-modulated radiotherapy (F_IMRT) following immediate breast reconstruction for breast cancer, thereby providing a reference for the selection of clinical radiotherapy techniques.Methods:This study retrospectively investigated 15 breast cancer patients who underwent radiotherapy following modified radical mastectomy and immediate breast reconstruction at the Liuzhou Worker′s Hospital from August 2018 to July 2023. During target volume delineation, precautions were taken to avoid the reconstructed tissues, which were delineated separately. Customized HT, VMAT, and F_IMRT treatment plans were designed for each patient. The plans were categorized into the HT, VMAT, and F_IMRT groups based on different radiotherapy techniques employed. They were comparatively analyzed through one-way analysis of variance (ANOVA), with multiple comparisons further conducted in the case of significant differences.Results:Statistical analyses reveal significant differences in various parameters of target volumes among the three groups of plans ( F = 38.73, 14.95, 37.01, 48.05, 35.55, 22.56, 34.30, P < 0.05). Pairwise comparisons indicate that the maximum dose ( D2%), minimum dose ( D98%), mean dose ( Dmean), and the proportion of high-dose volumes within the target volume ( V107%and V110%) in both the HT and VMAT groups were significantly better than those in the F_IMRT group. The HT group demonstrated the optimal conformity index (CI), while the VMAT group displayed the superior homogeneity index (HI) compared to the other two groups. In terms of OAR, the V20 of the ipsilateral lung was the lowest in the HT group ( F = 14.31, P < 0.05) and the highest in the F_IMRT group ( F = 14.31, P < 0.05). However, the V5 and Dmean for both the ipsilateral and contralateral lungs in the HT group significantly surpassed those of the other groups ( F = 39.16, 31.91, P < 0.05). The mean dose Dmean ( F = 5.57, P < 0.05) of the contralateral breast was significantly reduced in the VMAT group compared to the other two groups. No statistically significant differences were observed for other OARs, including the heart, spinal cord PRV, thyroid, and humeral head ( P > 0.05). The radiation doses to reconstructed tissues ( Dmax, V53.5, Dmean) ascended in the order of HT, VMAT, and F_IMRT groups ( F = 17.69, 17.53, 15.11, P < 0.05). The HT and F_IMRT groups showed similar beam-on times ( P > 0.05), both exceeding that of the VMAT group by several folds ( F = 28.72, P < 0.05). Conclusions:The comparative analysis indicates that the three radiotherapy techniques exhibit distinct advantages and limitations, with F_IMRT demonstrating the least comprehensive advantage. HT can enhance the conformity of target volumes while reducing the overall radiation doses to reconstructed tissues and the crucial indicator V20 in the ipsilateral lung. VMAT demonstrates the highest treatment efficiency, yielding improved dose uniformity in the target volume and reduced radiation doses to the contralateral breast. It is advisable to prioritize HT or VMAT based on actual clinical conditions.
8.Reconstruction points of intrauterine applicator in intracavitary brachytherapy for cervical cancer
Yongfu FENG ; Shaojun CHEN ; Yusong LONG ; Junwen TAN ; Xiantao HE ; Gang LI ; Chengjun FENG ; Zhanyu WANG
Chinese Journal of Radiation Oncology 2024;33(9):825-832
Objective:To evaluate the effect of different reconstruction points of intrauterine applicator on the source dwell positions and plan dosimetry in intracavitary brachytherapy for cervical cancer.Methods:Clinical data of 43 patients with cervical cancer who had completed radical radiotherapy in Liuzhou Workers' Hospital from May 2020 to October 2022 were retrospectively analyzed. Among 43 patients, aged 32-79 years, 40 cases were diagnosed with squamous carcinoma and 3 cases of adenocarcinoma. All patients received external irradiation for 50.4 Gy / 28 fractions and CT-guided intracavitary brachytherapy (45° intrauterine applicator) was 36 Gy / 6 fractions. Brachytherapy was performed by using Fletcher applicator, the curvature of intrauterine applicator were 15°, 30°and45°. Two sets of brachytherapy plans were simulated for each patient. One set of plans extracted the simulated CT positioning images and the original plan of the patient's brachytherapy. The reconstruction point of the curved part of the 45° intrauterine applicator was adjusted to slice-by-slice reconstruction. The plan was optimized to meet clinical requirements according to the prescription, which was called the slice-by-slice group. In the other set of plans, slice-by-slice group was used as a template. The reconstruction points of the curved section of the 45° intrauterine applicator were adjusted to 1, 3, 5, and 7, without modifying the applicator weights and other parameters, which was called the average group 1, 3, 5 and 7. The deviation analysis of 15°, 30° and 45° intrauterine applicator with different number of reconstruction points was carried out, the reconstruction deviation of 45°, 30° and 15° intrauterine applicator at different reconstruction points was compared. Paired-sample t-test or Wilcoxon signed rank test were used to compare the differences in high-risk clinical target volume (HR-CTV) D 50%, D 90%, D 100%, V 100%, V 150%, V 200% and conformity index (CI) as well as D 2 cm3, D 1 cm3 and D 0.1 cm3 in bladder, rectum, and small intestine between two groups of 45° intrauterine applicator. Results:The reconstruction deviation in the average group was mainly from the vertical direction of the 45° intrauterine applicator. The mean reconstruction deviations of 45° (1, 3, 5, 7 reconstruction points), 30° (1, 3, 5 reconstruction points) and 15° (1, 2 reconstruction points) were 1.30 mm, 0.32 mm, 0.14 mm and 0.08 mm; 0.57 mm, 0.14 mm and 0.06 mm; 0.14 mm and 0.06 mm, respectively. There was no significant difference in the parameters of high-risk clinical target volume (HR-CTV) in the slice-by-slice group compared with the average group 5 and 7 (all P>0.005), and no significant difference was found between the average group 5 and 7 (all P>0.005). There were no statistically significant differences in bladder and rectum doses between the slice-by-slice group and the average groups or within the average groups (all P>0.005). The parameters of small intestine in the slice-by-slice group were higher than those of the average group 1, the difference was statistically significant ( P=0.002,<0.001,<0.001). The dose of small intestine in the slice-by-slice group was not statistically significant compared with those in the average group 5 and 7 (both P>0.005). The dose of small intestine in the average group 5 was not statistically significant compared with that in the average group 7 ( P>0.005). The small intestine dose deviations of D 0.1 cm3, D 1 cm3 and D 2 cm3 in the average groups at 1 reconstruction point were 2.41%±1.70%, 1.95%±1.27% and 1.71%±1.10%, respectively. Conclusion:The number of reconstruction points is recommended to be no less than 1, 3 and 5 of the curved part of the 15°, 30°and 45° Fletcher intrauterine applicator, respectively, during intracavitary brachytherapy for cervical cancer.
9.Advances in imaging examinations for axillary lymph node status assessment in breast cancer patients
Tumor 2024;44(3):296-305
The reduction in surgical axillary lymph node dissection has emerged as a notable trend in the surgical management of breast cancer.In the recent years,with the release of the ten-year data from prospective randomized controlled clinical trials,such as Z0011,NSABP B-32,and AMAROS,in which surgical intervention was primarily utilized,an increasing number of breast cancer patients have been spared from axillary lymph node dissection.Nevertheless,the inclusion criteria employed in these studies rooted in the clinical assessment of axillary lymph node-negative patients who were subsequently validated through sentinel lymph node biopsy,confirming the absence of axillary lymph node metastasis or the presence of 1-2 positive axillary lymph nodes.The accurate preoperative prediction and selection of axillary lymph node-negative patients,with the aim of minimizing unnecessary sentinel lymph node biopsy,continues to be a pertinent concern within the realm of breast cancer surgery.Diverse imaging modalities,including mammography,ultrasound imaging,CT,MRI,and PET-CT,have been widely adopted in the evaluation of breast cancer patients,showing substantial potential in the preoperative assessment of axillary lymph node status.This review provides an overview of the advancement in preoperative axillary lymph node status assessment for breast cancer patients using these imaging techniques.
10.Advances in imaging examinations for axillary lymph node status assessment in breast cancer patients
Tumor 2024;44(3):296-305
The reduction in surgical axillary lymph node dissection has emerged as a notable trend in the surgical management of breast cancer.In the recent years,with the release of the ten-year data from prospective randomized controlled clinical trials,such as Z0011,NSABP B-32,and AMAROS,in which surgical intervention was primarily utilized,an increasing number of breast cancer patients have been spared from axillary lymph node dissection.Nevertheless,the inclusion criteria employed in these studies rooted in the clinical assessment of axillary lymph node-negative patients who were subsequently validated through sentinel lymph node biopsy,confirming the absence of axillary lymph node metastasis or the presence of 1-2 positive axillary lymph nodes.The accurate preoperative prediction and selection of axillary lymph node-negative patients,with the aim of minimizing unnecessary sentinel lymph node biopsy,continues to be a pertinent concern within the realm of breast cancer surgery.Diverse imaging modalities,including mammography,ultrasound imaging,CT,MRI,and PET-CT,have been widely adopted in the evaluation of breast cancer patients,showing substantial potential in the preoperative assessment of axillary lymph node status.This review provides an overview of the advancement in preoperative axillary lymph node status assessment for breast cancer patients using these imaging techniques.

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