Application of deep learning-based multimodal imaging to the automatic segmentation of glioblastoma targets for radiotherapy / 中华放射医学与防护杂志

Objective:To explore the effects of multimodal imaging on the performance of automatic segmentation of glioblastoma targets for radiotherapy based on a deep learning approach.Methods:The computed tomography (CT) images and the contrast-enhanced T1 weighted (T1C) sequence and the T2 fluid attenuated inversion recovery (T2- FLAIR) sequence of magnetic resonance imaging (MRI) of 30 patients with glioblastoma were collected. The gross tumor volumes (GTV) and their corresponding clinical target volumes CTV1 and CTV2 of the 30 patients were manually delineated according to the criteria of the Radiation Therapy Oncology Group (RTOG). Moreover, four different datasets were designed, namely a unimodal CT dataset (only containing the CT sequences of 30 cases), a multimodal CT-T1C dataset (containing the CT and T1C sequences of 30 cases), a multimodal CT-T2-FLAIR dataset (containing the CT and T2- FLAIR sequences of the 30 cases), and a trimodal CT-MRI dataset (containing the CT, T1C, and T2- FLAIR sequences of 30 cases). For each dataset, the data of 25 cases were used for training the modified 3D U-Net model, while the data of the rest five cases were used for testing. Furthermore, this study evaluated the segmentation performance of the GTV, CTV1, and CTV2 of the testing cases obtained using the 3D U-Net model according to the indices including Dice similarity coefficient (DSC), 95% Hausdorff distance (HD95), and relative volume error (RVE).Results:The best automatic segmentation result of GTV were achieved using the CT-MRI dataset. Compared with the segmentation result using the CT dataset (DSC: 0.94 vs. 0.79, HD95: 2.09 mm vs. 12.33 mm, and RVE: 1.16% vs. 20.14%), there were statistically significant differences in DSC ( t=3.78, P<0.05) and HD95 ( t=4.07, P<0.05) obtained using the CT-MRI dataset. Highly consistent automatic segmentation result of CTV1 and CTV2 were also achieved using the CT-MRI dataset (DSC: 0.90 vs. 0.91, HD95: 3.78 mm vs. 2.41 mm, RVE: 3.61% vs. 5.35%). However, compared to the CT dataset, there were no statistically significant differences in DSC and HD95 of CTV1 and CTV2 ( P>0.05). Additionally, the 3D U-Net model yielded some errors in predicting the upper and lower bounds of GTV and the adjacent organs (e.g., the brainstem and eyeball) of CTV2. Conclusions:The modified 3D U-Net model based on the multimodal CT-MRI dataset can achieve better segmentation result of glioblastoma targets and its application potentially benefits clinical practice.

Analysis on volume modulated arc therapy for spinal metastases / 中华放射医学与防护杂志

Objective To evaluate clinical effect of volume modulated arc therapy ( VMAT) for spinal metastases .Methods Twenty patients with spinal metastases who had been treated with VMAT were chosen to participate in the study .The prescribed dose varied from 45 to 60 Gy within 15 -20 fractions, 3 Gy per fraction, and one fraction per day of VMAT .Pain and quality of life were measured before VMAT and at several time points up to 6 months after treatment , by the numerical rating scale (NRS) and verbal rating scale (VRS) and the quality of life scale for bone metastases (EORTC QLQ-BM22) questionnaire.In addition, Frankel grading was used to evaluate the neurological function of spinal cord.The primary endpoint was frequency and duration of complete pain relief , and the secondary endpoint was death.Results At the end of the follow-up, the number of patients reporting no pain from spinal metastases, as measured by the NRS, increased from 0 of 20 before VMAT to 10 of 14 ( t =20.24, P0.05).After VMAT, the patients who suffered from nerve function impairment recovered to different extent . No one had radiation-induced injury , such as radiation myelitis , radiation pneumonitis , etc.Median survival time was 10 month.Conclusions VMAT is a safe and effective treatment method for spinal metastases .Significant reductions in patient-reported pain were observed , along with nerve dysfunction improved .The patients′quality of life was significantly improved .VMAT has no late spinal cord toxicities .

Paired observation of californium-252 neutron intraluminal brachytherapy combined with external-beam radiotherapy with and without lead shielding for cervical cancer / 中华放射肿瘤学杂志

Objective To compare the efficacy between californium?252 ( 252 Cf ) neutron intraluminal brachytherapy combined with external?beam radiotherapy with lead?shielding pelvic parallel opposing field technique and non?lead?shielding four?field box technique for cervical cancer. Methods A total of 52 patients with stage Ⅱa?Ⅲb cervical squamous cell carcinoma who were admitted to our hospital from 2004 to 2007 were enrolled as subjects and paired by clinical stage, age, tumor size, and degree of anemia. The 26 pairs of patients were divided into lead?shielding pelvic parallel opposing field group (lead?shielding group) and non?lead?shielding four?field box group (non?lead?shielding group). For all patients in both groups, 252 Cf neutron brachytherapy was added in external?beam radiotherapy. The local control (LC), overall survival (OS), and disease?free survival (DFS) rates were calculated using the Kaplan?Meier method and analyzed using the log?rank test. The difference in the incidence of late complications was analyzed using the McNemar method. Results There were significant differences in 5?year LC, OS, and DFS rates between the lead?shielding group and the non?lead?shielding group (85% vs. 81%, P= 0?? 014;89% vs. 73%, P=0?? 013; 89% vs. 73%, P= 0?? 013 ). There was also significant difference in the incidence of late complications between the lead?shielding group and the non?lead?shielding group ( 12% vs. 23%, P=0?? 008). Conclusions When intraluminal brachytherapy combined with external?beam radiotherapy is used to treat cervical cancer, the centers of the front and back fields should be shielded by lead, regardless of whether the parallel opposing field technique or the four?field box technique is used.

Clinical application of stereotactic body radiation therapy for colorectal cancer with liver metastases / 中华放射医学与防护杂志

Objective To evaluate the efficacy of stereotactic body radiation therapy (SBRT) for hepatic metastases from colorectal cancer,and to collect data for the application of this technique.Methods A total of 28 patients from No.306 Hospital of PLA,including 17 male and 11 female with median age of 63.8 (range from 31 to 86),were treated with SBRT for colorectal cancer with liver metastases with 54 lesions in total.The GTV,CTV and PTV were delineated above the enhanced CT scans acquired during normal quiet respiration.CTV was obtained by adding 5 mm isotropic margin from GTV,and PTV was obtained by adding 5 to 10 mm isotropic margin from CTV.Prescription dose line covered 50％-60％ of isodose curve at 3-6 Gy/fraction.The total dose was 39-45 Gy and the biologically equivalent doses(BED)was 50.7-65.3 Gy.The patients were followed-up beginning at 3 months after SBRT.The change in size of the lesion based on enhanced CT or MR scans was evaluated.Toxicity was evaluated and scored according to the RTOG criteria.Local control rate and survival rate were analysed.Results All patients completed the treatment.With median follow-up of 15.1 months (range frome 3 to 30 months),7 patients survived at the end of follow-up.The local control rate (LC) was 79.2％,and 1-and 2-year overall survival rate(OS) were 82.7％ and 48.6％,respectively.There was a close corelation between the size of lesion and the LC.The LC (PR + CR) was much better at the size of lesion less than 14 cm3 than that at the size more than 65 cm3(x2 =4.17,P＜0.05).When the size was more than 180 cm3,the LC was zero.Toxicity included fatigue (60.7％),grade 1 and 2 digestive system toxicity (28.6％),a transient grade 1 and 2 bone marrow suppression (46.4％) and a transient increase in transaminase(17.8％).No grade 3 toxicity and above and late toxicity were observed.Conclusions Stereotactic body radiation therapy could be suggested as the first choice for the selected patients who suffer form colorectal liver metastases,especially for those who cannot undergo surgery.

Therapeutic efficacy of stereotactic radiotherapy with gamma knife on early-stage non-small-cell lung cancer and life quality of patients / 中华放射医学与防护杂志

Objective To evaluate the therapeutic efficacy of stereotactic body radiotherapy (SBRT) with gamma knife on stage Ⅰ-Ⅱ non-small-cell lung cancer(NSCLC)and the quality of life of the patients undergoing this therapy.Methods Twenty NSCLC patients with the median age of 76,10 at stage Ⅰ and 10 at stage Ⅱ who were unable or unwilling to undergo surgery were given SBRT with gamma knife at the doses of 3-6 Gy in 8-15 fractions,finished within 2 to 3 weeks.The prescription isodose line was 50％,the marginal dose was 39-56 Gy,the central dose was 78-112 Gy,and the total biologically effective dose was 51-83 Gy.The patients were observed after admission and followed up by chest CT 1,3,6,and 12 months after treatment until progressive disease or death.EORTC QLQ-LC43 questionnaire was used to investigate the changes in quality of life.Results The 20 patients were followed up for 24 (12-46) months.At six months after the treatment,the overall response rate was 80％,and the complete response rate was 35％.The 1,2 and 3-year local control rates were 100％,95％ and 95％,respectively.The 1,2 and 3-year overall survival rates were 95％,80％ and 50％ respectively; The 1,2,and 3-year progression free survival rates were 85％,64％ and 33％,respectively.The failure rate was 20％ and the rate of progress within the planning target volume was 5％.No acute toxicity at grade 3 and over occurred in any patient during the treatment.15％ of the patients developed grade 1-2 radiation pneumonia.Age,gender,pathologic index or not were weakly correlated with the overall survival.The emotional function was improved significantly after treatment (P ＜ 0.05),dyspnea and cough were improved at different degrees,however,not significantly.There were no significant changes in the physical function and symptoms,such as fatigue,lack of appetite,insomnia,etc.Conclusions Significantly improving the motional function and maintaining the quality of life,SBRT with gamma knife is effective for elderly NSCLC patients with high local control rate fair overall survival rate and few side effects.

Efficacy of gamma knife stereotactic radiotherapy and whole-brain radiotherapy in treatment of brain metastases / 中华放射医学与防护杂志

Objective To analyze the efficacy and prognosis of stereotactic radiotherapy (SRT) and whole-brain radiotherapy (WBRT) in treatment of brain metastases,and to observe the influence of temozolomide (TMZ) on survival rate during the period of radiotherapy.Methods A total of 52 patients with brain metastases were divided into two groups according to treatment methods,including 35 patients treated with WBRT plus SRT and 17 patients treated with SRT alone.WBRT dose was 1.8 - 3.0 Gy per fraction,one fraction a day,five fractions per week,with total dose of 30 - 40 Gy.After WBRT,gamma knife was performed with prescription isodose line of 45％ -70％ surrounding the planned target volume in WBRT + SRT group.The marginal dose was 12 - 15 Gy and the center dose was 20-30 Gy.In SRT group,the prescription isodosc line was 45％ - 70％ and the marginal dose was 36 - 40 Gy while the center up to 70 - 80 Gy.The follow up time was 1 - 2 years.Besides 20 patients in this study took temozolomide capsule during and after radiotherapy.The schedule of concomitant chemotherapy was temozolomide of 75 mg/m2 by oral administration every day until radiotherapy was over,and then temozolomide of 150 mg/m2 was taken for 3 -6 months after radiotherapy.Results The efficiency during 1 -3 months after treatment was 84.62％ in this study.In the WBRT + SRT group,the efficiency was 88.57％ and declined to 76.47％ in the SRT group.The six month-and one year-local control rate were 92.10％ and 85.20％,respectively.The average survival time of WBRT + SRT was 13.2 months and median survival time was 11 months.Six month-,one year-and eighteen months-survival rate were 71.40％,54.30％ and 14.30％,respectively.In the SRT group,the average survival time was 10.2 months and median survival time was 9 months.Six month-,one year- and eighteen month-survival rate were 41.20％,23.50％ and 5.88％,respectively,while those for RT + TMZ group were 80.00％,60.00％ and 10.00％.In comparison,those in RT group were 56.30％,37.50％ and 12.50％,respectively.Conclusions Effect of gamma knife stereotactic radiotherapy combined with WBRT is better than GK stereotactic radiotherapy alone in treatment of brain metastases.Compared with radiotherapy alone,concomitant temozolomide chemotherapy could improve the survival rate of the patients with brain metastases without increasirg adverse reactions significantly.