Physical and Engineering Sciences in Medicine最新文献

{"title":"Retearing of type B blind cystic aortic dissection: computational fluid dynamics analysis.","authors":"Hongbing Chen, Yujing Huang, Tong Su, Qi Wang, Minzhu Zhao, Shangyu Zhang, Ruijiao Lin, Jianbo Li","doi":"10.1007/s13246-025-01552-y","DOIUrl":"https://doi.org/10.1007/s13246-025-01552-y","url":null,"abstract":"<p><p>Aortic dissection (AD) is a serious life-threatening vascular disease. However, research on type B blind cystic AD is still insufficient. This type of AD involves only one proximal intimal tear, and the distal end of the aortic false lumen (FL) is a blind sac. The purpose of this study was to explore the haemodynamic indicators of retearing and high-risk areas for FL rupture in type B blind cystic AD patients. This study included 4 cases of type B blind cystic AD rupture death, which revealed the pathological characteristics of the aorta. In addition, imaging data from one deceased and four patients with type B AD (TBAD) with multiple intimal tears were collected, and two groups of models (n = 10) were constructed. The pressure, velocity, time-averaged wall shear stress (TAWSS), and relative residence time (RRT) were compared to interpret our autopsy results. In type B blind cystic AD patients, the FL is characterized by high pressure, a low TAWSS, and high RRT. There was a relatively high TAWSS in the FL adjacent to the proximal intimal tear; at the same time, both the blood flow velocity and the pressure difference in the true lumen (TL) significantly changed. In addition, the greater the curvature of the aorta is, the more drastic the change in the luminal pressure difference. In type B blind cystic AD, high pressure may be the main reason for FL rupture, and the FL adjacent to the proximal intimal tear may be a high-risk rupture area. In addition, alterations in blood flow velocity and differential pressure may cause distal intimal retears. Tortuosity is an important indicator for studying pressure changes.</p>","PeriodicalId":48490,"journal":{"name":"Physical and Engineering Sciences in Medicine","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143991198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improving patient specific quality assurance for image registration: clinical use case of target contouring for PET deformable image registration.","authors":"Johnson Yuen, Joel Poder, Michael Jameson, Laurel Schmidt, Ryan Brown, Charlotte Atkinson, Shrikant Deshpande, Anna Ralston, Lois Holloway","doi":"10.1007/s13246-025-01541-1","DOIUrl":"https://doi.org/10.1007/s13246-025-01541-1","url":null,"abstract":"<p><p>Deformable image registration (DIR) has proven to be an invaluable tool to maximize the clinical benefits of multimodality imaging in radiation oncology. In contrast to rigid image registration (RIR), which is employed at all stages of diagnosis and treatment, the uptake of DIR has been constrained by concerns over the potential for unsafe use. The AAPM Task Group 132 (TG132) published a report on the use of image registration, including many recommendations on clinical integration of registration in treatment planning and delivery. There is a remaining uncertainty on incorporating registration uncertainties into treatment margins (Sect. 6.A, TG 132), a challenge in clinical practice. The aim of this work was to report our experience in implementing a practical, patient specific quality assurance process based on the AAPM Task Group 132 report recommendations. This work includes refining our process of target contouring using PET with deformable image registration based on our experience of addressing vulnerabilities identified during implementation. A multidisciplinary team created a flowchart for patient specific quality assurance for image registration (RIR or DIR) based on use cases defined in the AAPM TG132 Report on the use of image registration in radiotherapy. Vulnerabilities identified from this implementation were assessed relative to AAPM TG132 recommendations. These findings were used to adapt our patient specific quality assurance to mitigate vulnerabilities. The main vulnerabilities were identified in the last steps of image registration. There was potential for inappropriate use of the registration for clinical use, such as target contouring where the image registration accuracy level was poor. Vulnerabilities were addressed by an adaptation in our quality assurance process. A new physics image registration QA task was introduced that independently checks registration accuracy and appropriateness of target contouring, addressing the vulnerability in the last steps of the AAPM TG132 flowchart. A multi-disciplinary team implemented the image registration process outlined by AAPM TG132. An improved patient specific quality assurance process was developed by introducing an independent physics image registration review that considers the acceptable registration uncertainty for the specific clinical use case in question.</p>","PeriodicalId":48490,"journal":{"name":"Physical and Engineering Sciences in Medicine","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143992663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biomechanics-driven dose stress metrics for radiation-induced acute xerostomia prediction among head and neck radiation therapy.","authors":"Yusuke Kawazoe, Takehiro Shiinoki, Koya Fujimoto, Yuki Yuasa, Wataru Mukaidani, Yuki Manabe, Miki Kajima, Hidekazu Tanaka","doi":"10.1007/s13246-025-01558-6","DOIUrl":"https://doi.org/10.1007/s13246-025-01558-6","url":null,"abstract":"<p><p>Xerostomia is a condition commonly affecting patients subjected to radiation therapy (RT) for head and neck cancer (HNC) treatment. We propose dose metrics that consider the stress of parotid glands (PGs) during RT by using finite element analysis (FEA) of structural changes captured via computed tomography (CT) images acquired before and during RT to evaluate their effectiveness in predicting acute xerostomia. Thirty patients treated for HNC via in volumetric modulated arc therapy were enrolled. Patient complaints were considered by radiation oncologists based on the common terminology criteria for adverse events and scored as xerostomia grade 0 (XG-0), XG-1, or XG-2. All patients underwent CT both before and during RT (CT_ini and CT_bst, respectively). FE-based deformable image registration was performed from the CT_ini images to the CT_bst images, following which the stress of PGs was calculated and generate the dose-stress histograms (DSH). Four classical indices (volume change, mean dose, CT value change in PGs, and weight change), the mean stress, dose-volume histogram (DVH), and DSH metrics were used to evaluate the effectiveness of our approach. No significant differences among patients w/wo acute xerostomia groups were noted based on the four classical indices, mean stress, or DVH metrics; however, DSH metrics presented significant differences (p < 0.05) and demonstrated good predictive performance in distinguishing patients w/wo acute xerostomia (AUC > 0.70). The proposed metrics can analyze stress values without additional examinations and demonstrate significant differences between groups w/wo acute xerostomia and between different XGs.</p>","PeriodicalId":48490,"journal":{"name":"Physical and Engineering Sciences in Medicine","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144022834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bppv nystagmus signals diagnosis framework based on deep learning.","authors":"ZhiChao Liu, YiHong Wang, MingZhu Zhu, JianWei Zhang, BingWei He","doi":"10.1007/s13246-025-01542-0","DOIUrl":"https://doi.org/10.1007/s13246-025-01542-0","url":null,"abstract":"<p><p>Benign Paroxysmal Positional Vertigo (BPPV) is a prevalent vestibular disorder encountered in clinical settings. Diagnosis of this condition primarily relies on the observation of nystagmus, which involves monitoring the eye movements of patients. However, existing medical equipment for collecting and analyzing nystagmus data has notable limitations and deficiencies. To address this challenge, a comprehensive BPPV nystagmus data collection and intelligent analysis framework has been developed. Our framework leverages a neural network model, Egeunet, in conjunction with mathematical statistical techniques like Fast Fourier Transform (FFT), enabling precise segmentation of eye structures and accurate analysis of eye movement data. Furthermore, an eye movement analysis method has been introduced, designed to enhance clinical decision-making, resulting in more intuitive and clear analysis outcomes. Benefiting from the high sensitivity of our eye movement capture and its robustness in the face of environmental conditions and noise, our BPPV nystagmus data collection and intelligent analysis framework has demonstrated outstanding performance in BPPV detection.</p>","PeriodicalId":48490,"journal":{"name":"Physical and Engineering Sciences in Medicine","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144045457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improved commissioning of lung stereotactic body radiotherapy using a customized respiratory motion Phantom: a single- institutional study.","authors":"Ashlesha Gill, Mohamed Nawar, Pejman Rowshanfarzad, Andrew Hirst, Malgorzata Skorska, Tom Milan, Nicholas Bucknell, Mahsheed Sabet","doi":"10.1007/s13246-025-01550-0","DOIUrl":"https://doi.org/10.1007/s13246-025-01550-0","url":null,"abstract":"<p><p>Stereotactic body radiation therapy (SBRT) involves delivering high doses of radiation with geometric precision in a few hypofractionated schedules. In lung SBRT, respiratory motion is an additional concern as it could cause the delivered dose distribution to deviate from the treatment plan. Therefore, it is crucial to conduct accurate commissioning tests on a dynamic phantom. In this study, the QUASAR™ Respiratory Motion Phantom was customized using 3D-printed parts to minimize motion-induced errors in measurements. The customisations included a specialized ion chamber insert designed to move with the tumour and measure the average dose at its centre. A film insert was also developed for secure fixation, enabling precise dose verification on a static plane while minimizing the risk of friction-related damage. The quality assurance (QA) tests were performed on the plans created for phantom studies indicated that ion chamber measurements were within 1.9% of the planned dose, and film gamma analysis demonstrated pass rates over 95% using the 3%/1 mm criteria. A set of SBRT volumetric modulated arc therapy (VMAT) plans were created for a suite of test patients using both flattened and flattening filter free (FFF) 6 MV beams and utilising robust optimization. A standardized patient-specific QA protocol was used to evaluate the treatment plans of 20 test patients, yielding film gamma pass rates above 98.8%. The suggested approach, using the 3D-printed inserts, effectively mitigated dose-blurring, providing a robust tool for lung SBRT commissioning and ensuring the reliability of lung cancer treatment with SBRT.</p>","PeriodicalId":48490,"journal":{"name":"Physical and Engineering Sciences in Medicine","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144041504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A 2D electrocardiogram signal compression algorithm using 1D discrete wavelet transform.","authors":"Hardev Singh Pal, A Kumar, Amit Vishwakarma, Girish Kumar Singh","doi":"10.1007/s13246-025-01556-8","DOIUrl":"https://doi.org/10.1007/s13246-025-01556-8","url":null,"abstract":"<p><p>Electrocardiogram (ECG) signals are frequently acquired nowadays to detect various heart diseases. Nowadays, IoT-enabled wearable devices are in demand for distant or telemedicine-based healthcare applications. However, the acquisition process of ECG signals generates a huge amount of data, which negatively impacts the storage and transmission efficiency of these devices. As a result, an efficient compression algorithm is needed for effective ECG data management. Therefore, a compression algorithm for 2D ECG signals is proposed that employs the 1D Cohen-Daubechies-Feauveau 9/7 wavelet transform on 2D ECG signals. The proposed method effectively improves compression performance by increasing sparsity among the transform coefficients. Following that, obtained coefficients are quantized, and significant ones are retained using the target-based reconstruction error. The adaptive Huffman encoding is used to further enhance the compression once the quantized coefficients have been encoded. The experimental work is tested on MIT-BIH arrhythmia database, and the effect of different anomalies on compression performance is also assessed. The compression efficacy is evaluated in comparison to existing compression methods, and other wavelet transforms such as sym2, sym4, haar, db5, coif4, and beta wavelets. The proposed algorithm's performance is assessed in terms of quality score, percent root-mean-square difference, signal-to-noise ratio, and compression ratio. These factors were averaged out to get values of 30.23, 5.07, 26.78 dB, and 7.21, respectively. Results are evident that the proposed method can significantly improve storage efficiency and may also improve bandwidth utilization during real-time data transfer.</p>","PeriodicalId":48490,"journal":{"name":"Physical and Engineering Sciences in Medicine","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144051294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the dosimetric advantages of a novel multi-modality radiotherapy platform in prostate cancer.","authors":"Jie Duan, Qinghui Yun, Zhongfei Wang, Te Zhang, Xiaohuan Sun, Hua Yang, Weiwei Li, Wei Wang, Hongfei Sun, Liting Chen, Yue Gao, Zhiwei Wei, Zhe Wang, Lina Zhao","doi":"10.1007/s13246-025-01544-y","DOIUrl":"https://doi.org/10.1007/s13246-025-01544-y","url":null,"abstract":"<p><p>The present research aims to explore the dosimetric advantages associated with a novel multi-modality radiotherapy platform TaiChiB, which integrates a medical linac and a focused ⁶⁰Co γ-ray system. The primary focus of this investigation is to assess the efficacy of this platform in the treatment of prostate cancer. A retrospective study was conducted involving fifteen prostate patients. Each patient had two different treatment plans: a Varian linac x-ray plan (group A), and a TaiChiB plan combined with linac x rays and focused γ rays (group B). In both plan groups, the prescribed dose to the planning target volume (PTV) was 50 Gy, with a boost dose of 20 Gy to the gross tumor volume (GTV). In the TaiChiB plan, the primary plan was delivered using linac x rays and the boost dose plan was delivered using γ rays. Different criteria were used to evaluate the plan quality and results from the two plan groups were compared through statistical analysis (p < 0.05 as significantly different). All plans from these two groups met the clinical requirements for treatment, and Gamma passing rates were above 95% using the 3%/2 mm criterion suggested by TG-218. Regarding the dose coverage to targets, the TaiChiB plan group had a higher mean dose to the GTV (77.46 ± 1.04 Gy (B) vs. 71.40 ± 0.33 Gy (A), p < 0.01), whereas it maintained a comparable mean dose to the PTV (55.33 ± 1.76 Gy (B) vs. 55.23 ± 1.92 Gy (A), non-significant). In terms of dose to organs-at-risk (OARs), the TaiChiB plan group showed a lower or comparable mean value. In detail, bladder V_45Gy (43.90 ± 6.34% (B) vs. 49.83 ± 6.31% (A), p < 0.01); rectum V_45Gy (38.45 ± 14.38% (B) vs. 51.46 ± 17.18%(A), p < 0.01); intestine V_45Gy (163.88 ± 18.85 cm³ (B) vs. 177.18 ± 18.20 cm³ (A), p < 0.01); left femoral head V_30Gy (5.63 ± 1.97% (B) vs. 11.83 ± 2.56% (A), p < 0.01); and right femoral head V_30Gy (4.64 ± 1.94% (B) vs. 10.38 ± 2.73% (A), p < 0.01). The comparison of plan evaluation results showed the superiority of the novel multi-modality radiotherapy platform TaiChiB in dosimetric characteristics by harnessing the physical advantages of γ rays as a supplement to x rays in radiotherapy.</p>","PeriodicalId":48490,"journal":{"name":"Physical and Engineering Sciences in Medicine","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144051235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accelerated inference for thyroid nodule recognition in ultrasound imaging using FPGA.","authors":"Wei Ma, Xiaoxiao Wu, Qing Zhang, Xiang Li, Xinglong Wu, Jun Wang","doi":"10.1007/s13246-025-01548-8","DOIUrl":"https://doi.org/10.1007/s13246-025-01548-8","url":null,"abstract":"<p><p>Thyroid cancer is the most prevalent malignant tumour in the endocrine system, with its incidence steadily rising in recent years. Current central processing units (CPUs) and graphics processing units (GPUs) face significant challenges in terms of processing speed, energy consumption, cost, and scalability in the identification of thyroid nodules, making them inadequate for the demands of future green, efficient, and accessible healthcare. To overcome these limitations, this study proposes an efficient quantized inference method using a field-programmable gate array (FPGA). We employ the YOLOv4-tiny neural network model, enhancing software performance with the K-means + + optimization algorithm and improving hardware performance through techniques such as 8-bit weight quantization, batch normalization, and convolutional layer fusion. The study is based on the ZYNQ7020 FPGA platform. Experimental results demonstrate an average accuracy of 81.44% on the Tn3k dataset and 81.20% on the internal test set from a Chinese tertiary hospital. The power consumption of the FPGA platform, CPU (Intel Core i5-10200 H), and GPU (NVIDIA RTX 4090) were 3.119 watts, 45 watts, and 68 watts, respectively, with energy efficiency ratios of 5.45, 0.31, and 5.56. This indicates that the FPGA's energy efficiency is 17.6 times that of the CPU and 0.98 times that of the GPU. These results show that the FPGA not only significantly outperforms the CPU in speed but also consumes far less power than the GPU. Moreover, using mid-to-low-end FPGAs yields performance comparable to that of commercial-grade GPUs. This technology presents a novel solution for medical imaging diagnostics, with the potential to significantly enhance the speed, accuracy, and environmental sustainability of ultrasound image analysis, thereby supporting the future development of medical care.</p>","PeriodicalId":48490,"journal":{"name":"Physical and Engineering Sciences in Medicine","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144034761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Visualization and evaluation of the quality variations of EBT4 Gafchromic film using multidimensional scaling and Lie derivative image analysis.","authors":"Yusuke Anetai, Yasuhiro Tsutsui, Shinji Kinami, Masanori Yokoi, Yuji Tomita, Yuhei Koike, Hideki Takegawa, Kentaro Doi, Ken Yoshida, Satoaki Nakamura, Yuji Yamada, Mitsuhiro Nakamura","doi":"10.1007/s13246-025-01545-x","DOIUrl":"https://doi.org/10.1007/s13246-025-01545-x","url":null,"abstract":"<p><p>Film-specific uniformity variations in packages are known to significantly diminish the effectiveness of the one-scan protocol, a commonly used film dosimetry method. This method universally adopts the reference dose-response with rescaling linearly from the relationship of the known dose and the unexposed state. This study aims to visualize and quantify the variation in unexposed film-specific uniformity in a package to evaluate the suitability of the reference dose response using machine-learning method. Fourteen EBT4 films (#00-#13) were selected from two lot packages. Nine grid-spaced 100 × 100 pixel (72 dpi) patches were obtained from the color images of EBT4 film sheet using a single scanner with landscape (scan A) and portrait (scan B) scan orientations. The reference patch was set at the center of film #00. For this study, multidimensional scaling (MDS) and Lie derivative image analysis (LDIA) were applied to the patch data with respect to the red (R)/green (G)/blue (B) channels. MDS is a suitable method for analyzing non-linear data with similarity, which provides a map of data objects according to a distance metric. LDIA directly detects the deviation vector field between image gradients. The film-specific uniformity was measured at 1/10000 scaled pixel value as a scalar distribution. The image flow field was obtained as a negative gradient of the scalar distribution. Two similarity metrics were defined for comparison with the reference patch: (1) MDSr (the distance parameter in the MDS map from the origin) and (2) Stot (summed S-value in each patch, where S-value represents the vorticity of the deviation vector field obtained via the Lie derivative). MDSr highly correlated with the absolute pixel value difference from the reference patch except for the blue channel in which a favorable package was detected for the reference dose response. Stot quantified the film-uniformity variation from the reference, independent of the dataset, and detected the unfavorable film state as Stot < 0.8 in the blue channel. We visualized and quantified the variation in film-specific uniformity in a lot package using MDS and LDIA, thereby quantitatively determining the unfavorable condition for applying the reference dose-response.</p>","PeriodicalId":48490,"journal":{"name":"Physical and Engineering Sciences in Medicine","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144006990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Feasibility of individual dosimetry using RT-PHITS for patients with SPECT/CT imaging after ¹⁷⁷Lu-DOTATATE peptide receptor radionuclide therapy.","authors":"Kenta Miwa, Ryo Kakino, Tatsuhiko Sato, Takuya Furuta, Noriaki Miyaji, Tensho Yamao, Kosuke Yamashita, Takashi Terauchi","doi":"10.1007/s13246-025-01551-z","DOIUrl":"https://doi.org/10.1007/s13246-025-01551-z","url":null,"abstract":"<p><p>A radiotherapy package based on the Particle and Heavy Ion Transport code System (RT-PHITS) can calculate internal 3-dimensional dose distribution from SPECT/CT images of individual patients coupled with Monte Carlo radiation transport simulation. This study aims to determine the feasibility of individual dosimetry using RT-PHITS for patients after ¹⁷⁷Lu-DOTATATE peptide receptor radionuclide therapy (PRRT). We acquired SPECT/CT images from two patients from the ¹⁷⁷Lu SNMMI Dosimetry Challenge (patients A and B) and one from our institute (patient C) at various time points. The images were converted to source/geometry information in the PHITS input format using RT-PHITS. The 3D dose-rate distribution in each patient was calculated using Monte Carlo radiation transport simulation. The output data from the PHITS simulation were converted to DICOM RT-dose format and analyzed using 3D Slicer to identify dose rates in lesions and organs at risk. The time variations of the calculated dose rates were linearly interpolated, considering the physical decay constant. The absorbed dose was evaluated as the integration of the time variation of the dose rate. Agreements between the absorbed doses obtained from RT-PHITS and ¹⁷⁷Lu Dosimetry Challenge Task 4 were generally satisfactory (< 20%), although discrepancies were noted in some normal organs of patient A. This was likely due to difficulties in estimating the tail of the dose rate curve after the last imaging time point. The EQD2 was slightly, but not significantly increased compared with the absorbed dose in patient C. Individual dosimetry using RT-PHITS is feasible for assessing the effects of ¹⁷⁷Lu-DOTATATE PRRT.</p>","PeriodicalId":48490,"journal":{"name":"Physical and Engineering Sciences in Medicine","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144032519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}