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Compared with conventional radiotherapy, FLASH radiotherapy has advantages in protecting normal tissues, while the dose rate is increased by more than 100 times. If the shielding design of the treatment room is carried out according to the existing standard, the thickness and cost of the shielding wall will be significantly increased, or even hardly to meet the requirement of the standards, resultsing in the failure of the application of FLASH radiotherapy. By investigating the domestic and foreign standards and literature, this paper analyzes the challenges brought by FLASH radiotherapy technology to the shielding design of radiotherapy treatment room in China. Dose rate control standards adopted by different countries in the shielding design are emphatically compared as well. In several countries, the average dose rate under the actual treatment conditions was considered in the shielding design. In China, the method of instantaneous dose rate taking acount of occupancy factor is adopted. However, if FLASH radiotherapy technology is applied, the requirement of instantaneous dose rate will be difficult to meet. In order to improve the high dose rate radiotherapy technology such as FLASH radiotherapy, the revision of the existing standards is advised if the authorized limits are not changed. To use the average dose rate limit within a certain period of time for control, or to raise the control standard in the case of flash radiotherapy, are also avaliable.
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Hepatocellular carcinoma (HCC) is the most common liver malignancy, where HCC segmentation and prediction of the degree of pathological differentiation are two important tasks in surgical treatment and prognosis evaluation. Existing methods usually solve these two problems independently without considering the correlation of the two tasks. In this paper, we propose a multi-task learning model that aims to accomplish the segmentation task and classification task simultaneously. The model consists of a segmentation subnet and a classification subnet. A multi-scale feature fusion method is proposed in the classification subnet to improve the classification accuracy, and a boundary-aware attention is designed in the segmentation subnet to solve the problem of tumor over-segmentation. A dynamic weighted average multi-task loss is used to make the model achieve optimal performance in both tasks simultaneously. The experimental results of this method on 295 HCC patients are superior to other multi-task learning methods, with a Dice similarity coefficient (Dice) of (83.9 ± 0.88)% on the segmentation task, while the average recall is (86.08 ± 0.83)% and an F1 score is (80.05 ± 1.7)% on the classification task. The results show that the multi-task learning method proposed in this paper can perform the classification task and segmentation task well at the same time, which can provide theoretical reference for clinical diagnosis and treatment of HCC patients.
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Humans , Carcinoma, Hepatocellular , Liver Neoplasms , LearningABSTRACT
Objective:To observe the efficacy and safety of radium-223 in metastatic castration resistant prostate cancer (mCRPC) with bone metastasis.Methods:The clinical data of 48 patients with mCRPC treated with radium-223(55 kBq/kg, once every 4 weeks, planned to use for 6 cycles)from February 2021 to May 2022 were analyzed retrospectively. All patients had symptomatic bone metastasis without visceral metastasis, which the number of bone metastasis was more than one site.They were all classified as IVb stage. The average age was 70.5 (ranging 49-90) years. The median PSA was 44.70(ranging 0.15-1 864.00) ng/ml. The median ALP was 162 (ranging 43-1 589) U/L. The median time from mCRPC diagnosis to radium-223 use was 10 (ranging 3-47) months. 9, 18 and 11 patients had received first-line, second-line and third-line treatment for mCRPC before enrollment respectively, 10 patients had received at least fourth-line treatment. 38 (79.1%), 31 (64.5%), 30 (62.5%) and 7 (14.6%) patients had used abiraterone, enzalutamide, docetaxel and olaparib before enrollment. The probability of PSA level decrease >30%, ALP level decrease >30%, symptom improvement rate, median overall survival (OS), as well as the occurrence of treatment-related adverse reactions and the reasons for withdraw treatment were analyzed.Results:The median follow-up time was 8 (ranging 1-16) months. 11 patients completed all 6 courses of treatment. The median number of completed courses was 4 (ranging 1-6). 27 patients (56.2%) received radium-223 and bone protection drugs (Bisphosphate/ Denosumab). PSA decreased by >30% was recorded in 10 patients (20.8%) and ALP decreased by >30% was recorded in 25 patients (52.1%). 23 cases (47.9%) reported bone pain relief during treatment. Among the 9 patients who had received first-line of mCRPC previously, 6 cases (66%) had relief of bone pain symptoms, and 4 cases (44%) had a decrease of PSA >30%. Among the 18 patients who had previously received second-line mCRPC treatment, 11 cases (61%) had relief of bone pain symptoms, and 4 cases (22%) had a decrease of PSA >30%. Among the 21 patients who had received third-line or more mCRPC treatment in the past, 6 (28.5%) had symptom relief, and 2 (9.5%) had PSA decrease >30%. The median overall survival (OS) was not reached, and the OS was estimated to be 12.5 months using the Kaplan-Meier method. The most common hematological adverse effects were thrombocytopenia (15 cases, 31.2%; grade 3 in 6 cases and grade 4 in 0), followed by leucopenia (11 cases, 22.9%; grade 3 in 4 cases and grade 4 in 1 case) and anemia (8 cases, 16.7%; grade 3 in 3 cases and grade 4 in 0). Non-hematological adverse reactions included fever in 1 case (2.1%), constipation in 4 cases (8.3%), nausea and vomiting in 10 cases (20.8%), diarrhea in 7 cases (14.6%), dizziness in 1 case (2.1%) and fatigue in 11 cases (22.9%). Seven cases were discontinued due to intolerable adverse reactions (median 2 courses), 14 cases were discontinued due to disease progression or death (median 2 courses), and 5 cases were discontinued due to other reasons (median 1 course).Conclusions:Radium-223 has a good performance in symptom control for mCRPC patients who have previously received first-line or second-line therapy. Due to the high incidence of hematological adverse reactions, more attention should be paid to the changes of hemogram during the treatment, and timely treatment should be carried out to improve the drug tolerance of patients.
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Objective:To explore clinical value of prostate target biopsy guided by multiparametric magnetic resonance imaging (mpMRI) and 68Ga-labeled prostate specific membrane antigen ligand imaging positron emission tomography/X-ray computed tomography ( 68Ga-PSMA PET/CT) image fusion. Methods:The data of 50 patients admitted to Fudan University Shanghai Cancer Center from January 2021 to February 2022 who underwent mpMRI and 68Ga-PSMA PET/CT to guide prostate biopsy were retrospectively analyzed. The median age was 70 (63-79) years, the median serum tPSA value was 8.1 (6.8-83.0) ng/ml, and the prostate volume was 45.5 (30-80) ml. 36 cases were positive by mpMRI, including PI-RADS score 3 in 5 cases, 4 score in 19 cases, 5 score in 12 cases. 32 cases were positive by 68Ga-PSMA PET/CT examination, of which 30 cases were double positive and the fusion of both imaging techniques was positive, referred to as PET/CT-MRI. The patient's mpMRI and 68Ga-PSMA PET/CT images were imported into the MIM fusion software, and the outline of the prostate and the target area were outlined respectively. When PET/CT and MRI double positive cases were biopsied, the two images were alternately fused, calibrated and locked with the real-time prostate ultrasound interface(PET/CT-MRI). Single-positive cases were guided by positive images to complete targeted biopsy, and 12-needle systematic biopsies were completed after targeted biopsy and double-negative cases. The advantages of targeted biopsy and systematic biopsy was evaluated, and the diagnostic performance (sensitivity, specificity, positive predictive value, and negative predictive value) was analyzed. Results:Among the 50 biopsy patients in this group, 31 (62%) had prostate cancer, of which 22 (44%) were CsPCa. There was no significant difference in the detection rate of prostate cancer between targeted biopsy and systematic biopsy [78.9% (30/38) and 62.0% (31/50), P=0.088], and there was no significant difference in the detection rate of CsPCa [57.9% (22/38) and 40.0% (20/50), P=0.096]. The positive rate of the biopsy needles number was significantly different [86.3% (69/80) and 19.0% (114/ 600), P<0.001]. The detection rates of prostate cancer in mpMRI positive, PET/CT positive and PET/CT-MRI positive cases were 83.3% (30/36), 90.6% (29/32) and 96.6% (29/30) respectively, the detection rates of CsPCa were 61.1% (22/36), 68.8% (22/32) and 73.3% (22/30) respectively.The sensitivity, specificity, positive predictive value and negative predictive value of mpMRI in the diagnosis of prostate cancer were 96.8%(30/31), 68.4%(13/19), 83.3%(30/36)and 92.9%(13/14), respectively.Those values in 68Ga-PSMA PET/CT were 93.5%(29/31), 84.2%(16/19), 90.6%(29/32)and 88.9%(16/18), respectively.Those values in PET/CT-MRI were 93.8%(29/31), 94.7%(18/19), 96.7%(29/30)and 90.0%(18/20), respectively. The above four indicators of mpMRI diagnosis of CsPCa were 100.0%(22/22), 50.0%(14/28), 61.1%(22/36)and 100.0%(14/14), respectively.Those indicators in 68Ga-PSMA PET/CT were 100.0%(22/22), 64.3%(18/28), 68.8%(22/32)and 100.0%(18/18), respectively.Those indicators in PET/CT-MRI was 100.0%(22/22), 71.4%(20/28), 73.2%(22/30)and 100.0%(20/20), respectively. The detection efficiency of PET/CT-MRI was better than that of mpMRI (Kappa value was 0.737, P=0.031). Conclusions:PET/CT-MRI image fusion-guided targeted prostate biopsy can effectively improve the detection efficiency of prostate cancer and clinically significant prostate cancer, and increase the positive rate.
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Objective:To introduce the clinical dosimetry commissioning methods and results of the 1.5 T MR-linac.Methods:In May, 2019, an Elekta Unity 1.5 T MR-linac was installed in Cancer Hospital, Chinese Academy of Medical Sciences and dosimetry commissioning was performed with magnetic field compatible measuring instruments. Commissioning items include absolute dose calibration, data acquisition and planning system model verification.Results:Absolute dose calibration in magnetic field should be corrected by magnetic field correction factor. The standard output dose of Unity was 87 cGy. Gamma analysis (3%/2 mm) was performed on the beam collection data and the planning system calculation data. The average pass rate of dose verification of standard field test cases was 96.41%, and the TG119 test case was 98.24%. The IROC end to end test case was 97.5%(7%/4 mm).Conclusions:The planning system model and the beam collection data have good consistency. The dose verification results of the standard field and TG119 test cases meet the general tolerance limit requirements of the AAPM TG218 report, and the verification results of the IROC end-to-end test cases meet the IROC center standards.
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Retrospectively analyze the clinicopathological data of a patient with metastatic hormone sensitive prostate cancer, and review relevant literature. The patient was male, 68 years old. Complaints of dysuria and urgency for half a year. Blood PSA>100 ng/ml, magnetic resonance showed that the prostate was occupying space, the boundary with the seminal vesicle gland was not clear, and the pelvic cavity had multiple bone lesions. Bone scan revealed multiple bone metastases. The prostate biopsy showed adenocarcinoma, Gleason score 5+ 5. The clinical stage was T 3N 0M 1b.A palliative transurethral resection of the prostate was performed due to urination obstruction, and endocrine therapy with medical castration combined with abiraterone and prednisone. PSA was continuously controlled at <0.006 ng/ml. After half a year of treatment, the prostate-specific membrane antigen single-photon emission computerized tomography and magnetic resonance examination revealed sternal and parasternal soft tissue lesions. Local radiotherapy and continuous endocrine therapy were given. The disease was under long-term control.There are various treatment options for metastatic hormone sensitive prostate cancer. Medical castration treatment combined with abiraterone and prednisone can effectively control the disease with mild adverse reactions. Palliative transurethral resection of the prostate can improve the symptoms of urinary obstruction and may also improve the prognosis of patients.
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Objective:To observe the clinical effect and safety of regional lymph node dissection in metastatic castration resistant prostate cancer(mCRPC).Methods:The clinical data of 22 patients with mCRPC who underwent regional lymph node dissection in our hospital from August 2015 to May 2021 were retrospectively analyzed. All patients had undergone radical prostatectomy and entered mCRPC, metastatic lymph nodes limited to pelvic or retroperitoneal without other metastasis were determined by PSMA-PET in 5 cases and PSMA-SPECT in 17 cases. The median time from radical surgery to mCRPC was 32 (4-96) months, and the median time from discovery of mCRPC to regional lymph node dissection was 4 (1-43) months. The median PSA before regional lymph node dissection was 4.44 (2.00-22.15) ng/ml. Image of local examination showed pelvic lymph node metastasis in 16 cases, retroperitoneal lymph node metastasis in 3 cases, pelvic together with retroperitoneal lymph node metastasis in 3 cases. Before regional lymph node dissection, 18 patients were treated with drug castration combined with first-generation antiandrogens, and 4 patients were treated with drug castration combined with abiraterone. The lymph node dissection range was determined according to the location of metastatic lymph nodes. Obturator lymph nodes and lymph node metastasis around external iliac and internal iliac vessels: the range of dissection includes fibrous adipose tissue around external iliac vein and internal iliac vein, and obturator lymph adipose tissue. Common iliac and pelvic floor lymph node metastasis: dissect lymphoid adipose tissue around common iliac vessels on the basis of the original dissection range as far as the aortic bifurcation. Retroperitoneal lymph node metastasis: remove all lymph node adipose tissue located between the bifurcation of renal artery and aorta. The PSA remission rate, PSA remission time, surgical complications and other relevant clinicopathological features were analyzed.Results:Among the 22 cases, 6 cases underwent unilateral pelvic lymph node dissection, 10 cases underwent bilateral pelvic lymph node dissection, 3 cases underwent retroperitoneal lymph node dissection, and 3 cases underwent pelvic and retroperitoneal lymph node dissection at the same time. 19 cases (86.3%) showed positive lymph nodes by pathology. An average of 9.8 (3-29) lymph nodes were dissected in each patient, with an average of 4.1 (0-12) positive lymph nodes. All 22 cases continued to use the previous anti-androgen therapy after lymph node dissection. 17 cases (77.3%) achieved PSA remission after operation, of which 9 cases developed PSA progression, and the median PSA progression time was 12 (2-36) months. Univariate analysis showed that PSA value during radical operation ( P=0.029), N stage during radical operation ( P=0.057), the number of positive lymph nodes during regional lymph node dissection ( P=0.069) and the location of lymph node metastasis during regional lymph node dissection ( P =0.005) were related to the progression time of PSA. Postoperative complications: lymphatic leakage in 7 cases; 5 cases of postoperative fever, of which 1 case was confirmed to have pelvic bacterial infection. One patient suffered from massive intra-operative bleeding due to the invasion of blood vessels by metastatic lymph nodes. After timely hemostasis during the operation, the patient returned to the ward and was discharged 6 days later. One case of intestinal obstruction, and 1 case of body surface wound infection. 6 cases of lymphatic leakage healed within 1 month after operation, and 1 case of lymphatic leakage healed within 3 months after operation. Conclusions:For mCRPC patients with lymph node metastasis which could be surgically removed, regional lymph node dissection may further delay the starting time of posterior drugs, and the complications are relatively controllable.
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Objective:To explore the clinical value of cryoablation technology in the treatment of patients with primary tumor recurrence after radical radiotherapy for prostate cancer.Methods:The clinical data of 21 patients with prostate cancer recurrence after radical radiotherapy in the Fudan University Affiliated Cancer Hospital from August 2017 to February 2021 was retrospectively analyzed. The average age was 73.1 (57.3-85.0) years old, and the Gleason score was 6 in 5 cases, 7 in 8 cases, and ≥8 in 8 cases. The clinical stage of the first diagnosis: 13 cases of cT 2 stage; 8 cases of cT 3 stage. The baseline PSA before radiotherapy was 35.3 (6.4-78.5) ng/ml, and the lowest PSA after radiotherapy was 1.8 ng/ml. After a median follow-up of 8 (3-12) months, all patients were detected with persistently elevated PSA. Pelvic MRI and PSMA SPECT showed that the primary prostate lesion had recurred. PSA before cryoablation was 4.1 (1.8-14.4) ng/ml. Comprehensive assessment of preoperative examination showed that the patient only had a recurrence of the primary tumor, and no lymph node or distant metastasis was seen. An argon-helium cryogenic surgical treatment system was used to place 1 to 3 cryo-needles for recurring lesions, and cryoablation was performed using two cold and hot cycles. Observation indicators include prognostic indicators such as PSA, recurrence and metastasis, and the occurrence of adverse reactions. Results:Complications after cryoablation include: 2 cases of urinary retention, 1 case of urinary tract infection, and 2 cases of urination with tissue shedding. The PSA of 11 cases decreased rapidly 2 to 3 months after operation, and dropped to the lowest median value of 0.4 (0.003 to 2.8) ng/ml. After cryoablation, the median follow-up was 18 (6-51) months. Imaging examinations in 1 case showed that the prostate still had limited diffusion or increased PSMA uptake, and 4 cases had PSA progression but no recurrence or metastasis. The median recurrence time for advanced patients was 13 (4-36) months. Larger prostate volume ( P<0.001) and higher blood PSA before ablation( P=0.021) were related to biochemical recurrence. Conclusions:Prostate cryoablation could delay the progression of the primary tumor after radical radiotherapy for prostate cancer. The incidence of complications such as urinary retention and urinary tract infection is not high, and it is generally safe and controllable.
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Background and purpose:The association between metabolic syndrome (MS) and renal cell carcinoma (RCC) is still unknown. The aim of this study was to elucidate how MS correlates with the prevalence and malignancy of RCC.Methods:This study enrolled 398 RCC patients (350 clear cell RCC patients, 5 XP11.2 transloca-tion RCC patients, 16 papillary RCC patients and 27 chromophobe RCC patients), 160 normal persons, and 32 benign renal tumor patients. The metabolic status of the patients was assessed, and the link between MS and the prevalence or malignancy of RCC was calculated.Results:Clear cell RCC patients had signiifcantly higher rates of hypertension, higher body mass index (BMI) and longer waist circumference. Forty-eight percent clear cell RCC patients had MS, while the number was 33% for papillary RCC, 26% for chromophobe RCC, 0% for XP11.2, 17% for AML, and 25%for normal people. MS patients had signiifcant higher rates of having clear cell RCC than no-MS patients, however this kind of difference was not seen in other types of RCC. Clear cell RCC patients with higher Furhman grade had lower rates of MS.Conclusion:Patients with MS are more likely to develop clear cell RCC. Patients with high Furhman grade tumors have low MS rates, indicating that high grade tumor may have other originating mechanisms other than metabolic disorders.
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Objective To explore high concentrations of urea-induced human brain microvascular endothelial cell line( HBMECs) to produce inflammatory cytokines and possible mechanism .Methods HBMECs were incubated in high concentrations of urea or mannitol ( as osmotic control ) for 3,6,12 and 24 hours.Expression of TNF-αand iNOS was observed by immunofluorescence .Western blot analysis was employed to assess the protein expressions of TNF-α, iNOS, COX-2, NF-κB/P65 and p-P65.NO concentration was determined by a commercial NO assay kit . Results Immunofluorescence showed high positive immunostaining of TNF-αand iNOS after incubation in high concentration of urea stimulued as compared with control group .The protein expressions of TNF-α, COX-2 and p-P65 were significantly increased at 3 and 6 hours after high urea treatment (P<0.01), and iNOS was continued to increase from 3 to 24 hours ( P<0.01 ) .Moreover , NO content was increased at 3 hours after high urea treatment ( P<0.05 ) .Conclusions High concentration of urea can induce HBMECs to produce inflammatory cytokines .
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Background and purpose:Papillary renal cell carcinomas (PRCC) is relatively infrequent, and there are few related researches in China. This study aimed to summarize the clinical and pathological features of PRCC, and evaluate prognostic factors for patients treated with surgery.Methods:A total of 64 patients who under-went surgery for PRCC were retrospectively assessed. PRCC tissue slides from each patient were reviewed for type (ⅠorⅡ), grade, TNM stage, coagulative tumor necrosis and microvascular invasion. We estimated overall survival using the Kaplan-Meier method. Multivariate analysis was done according to the Cox proportional hazards model of factors statistically signiifcant on univariate analysis. Results:The incidence rate of ENE was 6.04%in RCC, the median age was 55 (range 22 to 78) years. The comparison of the 22 (534.4%) typeⅠPRCCs and 42 (65.6%) typeⅡPRCCs revealed that typeⅡtumors were associated with a greater stage and grade more often. The median follow-up was 46 months (range 19 to 133). Of the 64 patients, 14 died, (4.5%) with typeⅠand 13 (31.0%) with typeⅡtumors (P=0.018). The overall survival rate was 85.7%in typeⅠtumors and 55.8%in typeⅡtumors, respectively. Univariate analysis identiifed symptoms at presentation, tumor type, TNM stage and grade as prognostic factors. On multivariate analysis only metastatic RCC remained associated with decreased overall survival (HR:14.78, P=0.004). Conclusion:The per-centage of PRCC is lower and typeⅡPRCC is relatively common compared with foreign data. Metastasis at diagnosis is an independent predictive parameter of overall survival in Chinese patients with PRCC.
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To develop a method of evaluating bone mass with CT numbers (Hounsfield unit, HU), volumetric mean of CT numbers (HUm) was defined to describe bone mass for the study of bone loss caused by microgravity. Ten femurs in the tail-suspended rats experiment were scanned by CT scanner. And the RUm of the intact, proximal, middle and distal femurs were obtained from these CT data. Then regressive analysis was performed between HUm and bone mineral density (BMD) measured by DXA in those regions. When HU threshold is equal to 400, the correlation between BMD and HUm of the intact femur is the best in all cases (R = 0.887, P <0.001), and the correlation between BMD and HUm of the proximal femur (R = 0.833, P <0.01) is better than those of the middle femur (R=0.683, P<0.05) and distal femur (R = 0.744, P<0.05). Volumetric mean of CT numbers has a good linear relationship with BMD; it can accurately describe bone mass and can be used to evaluate the results of the tail-suspended rats experiment.
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Animals , Rats , Bone Density , Femur , Diagnostic Imaging , Radiographic Image Interpretation, Computer-Assisted , Tomography, X-Ray Computed , MethodsABSTRACT
Objective To find an efficient and practical reconstruction algorithm for the fluorescence molecular tomography basing on total leastsquares rule as well as the normalized conjugate gradient method.Methods The finite element method was used to get the weighting matrix from the forward diffusion model.For the inverse reconstruction problem,the total least-squares rule was employed.The normalized conjugate gradient method was applied to find the fluorochrome information in the objective area.Results The simulation experiments showed that images reconstructed by the total least-squares rule were more accurate than those reconstructed by the least-squares rule under the same circumstances when noise existed.The presented algorithm could also give consistent results when the initial guesses varied in a wide range.Conclusion The algorithm presented in this paper offers a practical and efficient reconstruction for the fluorescence molecular tomography.