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Objective:According to 2013 updated consensus guidelines of neck node levels, the distribution characteristics of cervical lymph nodes of nasopharyngeal carcinoma (NPC) were analyzed, aiming to provide preliminary reference for the clinical target volume (CTV) delineation of level Ⅴ in NPC.Methods:A total of 1110 patients pathologically diagnosed with NPC from 2012 to 2020 were retrospectively recruited for further analysis. All patients’ MRI and contrast-enhanced CT simulation scan imageswere retrospectively reviewed, metastatic lymph nodes were mapped using the 2013 International Consensus Guidelines. Then, the correlation between Ⅴa, Ⅴb and Ⅴc metastatic lymph nodes and other lymph nodes was analyzed. An NPC case diagnosed with T 1N 0M 0 was selected as the baseline standard for the normal anatomical structure and proportion of Ⅴc area. The metastatic lymph nodes in Vc were delineated on the CT simulation scan image of sample case, and the distribution characteristics of the metastatic lymph nodes inⅤc were analyzed. Results:Among the 1110 patients, 1004(90.5%) patients had lymph node metastases. The most common area of metastatic lymph node levels were level Ⅶa (74.7%) and level Ⅱb(70.7%), and the skip metastasis of lymph nodes was rare (1.0%). The multivariate analysis showed lymph node metastasis in level Va was correlated with levels Ⅱb, Ⅲ, Ⅳa, Ⅴb, and Ⅷ region ( P=0.010, 0.001, 0.001, 0.001, 0.037). Lymph node metastasis in level Ⅴb was correlated with levels Ⅲ, Ⅳa, Ⅴa and Ⅴc region ( P=0.006, 0.001, 0.001, 0.001). Lymph node metastasis in level Ⅴc was correlated with levels Ⅳb and Ⅴb region ( P=0.008, 0.001). There were 28 cases of lymph node metastasis in levelⅤc. A total of 38 metastatic lymph nodes were counted in level Vc. Among them, 33(86.8%) lymph nodes were located in the medial of the omohyoid muscle (Ⅴc-1 region), and 5(13.2%) were located in the lateral of the omohyoid muscle (Ⅴc-2 region). Conclusions:This study reflects the principle of individualized CTV delineation, which is based on the levels of nodal spread in NPC patients. When correlation is observed among different level V, V should be delineated as the moderate risk lymphatic drainage (CTV n2). It is recommended to individualized delineate level Vc when the CTV n2 covers Vc. The Ⅴc-2 region should be delineated as CTV n2 only when there is nodal spread in the ipsilateral Ⅴc-1 region.
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Objective To explore the value of MRI simulation in the pre-operative radiotherapy for locally advanced low rectal carcinoma.Methods A total of 40 patients diagnosed with locally advanced low rectal carcinoma by endoscopic biopsy and radiological staging examinations were included in this study.There were 22 male and 18 female with nedian age 58 years (range 31-80).Patients underwent CT and MRI simulation scanning in the same position and fixing device.GTV under CT images and MRI inages were delineated respectively by two experienced radiologists.Primary tumor length,tumor volume and distance of distal tumor from the anal verge were calculated by treatment planning system(TPS).The two groups of data were compared.Results The distance of distal tumor to the anal verge were all no more than 5 cm on digital examination.The mean length of GTVcT was remarkably longer than that of GTVMRI [(5.21 ±1.65) cm vs.(4.46 ± 1.51) cm,t =5.059,P ＜0.05].The mean volume of GTVcTWaS significantly larger than that of GTVMRI[(55.71 ±31.57) cm3vs.(44.02 ±25.11) cm3,t=6.977,P＜ 0.05)].The mean distance of distal tumor to the anal verge was (3.72 ± 0.93) cm,significantly longer than that of lower bounds of GTVCT to the anal verge,which had a high consistency with GTVMRI.The IMRT plan was based on CT-MRI fusion images.There were no 3-4 grade adverse effects of radiotherapy.The overall pCR rate was 32.5％.Conclusions MRI simulation could define smaller GTV and more precise lower bounds than CT.With improved accuracy of target volumes contours,the application of MRI simulation may promote the efficacy of radiotherapy and result in a reduction in the incidence of toxicities.
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Objective To investigate the pattern of nodal recurrence after curative resection in adenocarcinoma of the gastroesophageal junction ( AGE ) , and to provide a basis for delineation of the radiation range in the high-risk lymphatic drainage area.Methods A retrospective analysis was performed in 78 patients with locally advanced AGE who were newly treated in our hospital from January 2009 to December 2013 and had complete clinical data.All patients received curative resection and were pathologically diagnosed with stage T3/T4 or N (+) AGE.Those patients were also diagnosed with SiewertⅡor Ⅲ AGE by endoscopy, upper gastroenterography, macroscopic examination during operation, and pathological specimens.None of the patients received preoperative or postoperative radiotherapy.All patients were diagnosed by imaging with postoperative nodal recurrence.The computed tomography images of those patients were accessible and had all the recurrence sites clearly and fully displayed.Results The median time to recurrence was 10 months ( 1-48 months) , and 90%of the recurrence occurred within 2 years after surgery.The lymph nodes with the highest risk of recurrence were No.16b1( 39%) , No.16a2( 37%) , No.9 (30%), and No.11p (26%), respectively.There was no significant difference in the recurrence rate within each lymphatic drainage area between patients with SiewertⅡandⅢAGE ( P=0.090-1.000) .The lymph nodes with the most frequent recurrence were No.16b1, No.16a2, No.9, No.16b2, No.11p, and No.7 in patients with stage N3 AGE and No.11p, No.16b1, No.16a2, No.9, No.8, and No.7 in patients with stage non-N3 AGE.Patients with stage N3 AGE had a significantly higher recurrence rate in the para-aortic regions (No.16a2-b2) than those with stage non-N3 AGE (67%vs.33%, P=0.004, OR=4.00, 95% CI=1.54-10.37) .Conclusions The lymph nodes with the highest risk of recurrence are located in the celiac artery, proximal splenic artery, and retroperitoneal areas ( No.16a2 and No.16b1) in patients with SiewertⅡorⅢlocally advanced AEG.Moreover, patients with stage N3 AGE have a higher risk of retroperitoneal recurrence.The above areas should be involved in target volume delineation for postoperative radiotherapy.
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Objective To investigate the role of large-diameter magnetic resonance imaging (MRI) simulation in target volume delineation in radiotherapy for nasopharyngeal carcinoma (NPC).Methods Eighteen patients with NPC underwent computed tomography (CT) simulation and MRI simulation scans and localization in the same body position,with SOMATOM Sensation Open 40-row 82-cm large-diameter CT simulator and Siemens 3T MRI MAGNETOM Skyra 70-cm large-diameter simulator,respectively.The gross tumor volume (GTV) and parotid glands were delineated on all images according to the ICRU Report 50/62,and MRI was applied to observe the changes in GTV and parotid volume during radiotherapy.Paired t-test was applied to analyze the differences between GTVCT and GTVMRI and between GTVnx-CT and GTVnx-MRI.Results GTVMRI decreased significantly compared with GTVCT,and the average volume decreased from (213.64±84.59) cm3 to (199.68±84.69) cm3(p=0.006).As for the volume of primary lesions in the nasopharynx,GTVnx-MRI was significantly smaller than GTVnx-CT,and the volume decreased from (95.75± 24.76) cm3 to (88.12±26.25) cm3 (P =0.001);as for the volume of cervical lymph nodes,GTVnd-MRI was significantly smaller than GTVnd-CT,and the volume decreased from (117.89± 72.69) cm3 to (111.56± 70.69) cm3 (P=0.018).The targets delineated by CT and MRI did not overlap completely,with major differences in skull base bone and cervical soft tissue.The volume of both parotid glands delineated on MRI image was higher than that delineated on CT image,with a major difference in the deep lobe.MRI showed that GTV was reduced by 82.64± 16.87％ during radiotherapy,and the volumes of the left and right parotid glands were reduced by (32.7± 23.95) ％ and (34.7± 21.72) ％,respectively.Conclusions The delineation of target volume based on MRI simulation is more accurate than that based on CT simulation and can achieve a smaller volume range,which helps to guide target volume delineation in radiotherapy for NPC accurately.
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Objective To compare target volume and dosimetry between computed tomography (CT)?and magnetic resonance imaging (MRI)?guided three?dimensional (3D) conformal brachytherapy for locally advanced cervical cancer, and to provide evidence for optimization of the image?guided approach and improvement of treatment regimen. Methods Thirteen patients with locally advanced cervical cancer who were treated with radical radiotherapy in our hospital in 2014 were enrolled as subjects. All patients received MRI?guided 3D conformal intracavitary/ interstitial brachytherapy. All patients received MRI and CT scans for each brachytherapy fraction, based on which the target volume delineation, intracavitary/ interstitial regimen design, and intracavitary?only treatment regimen design were performed. Comparison of data between MRI and CT scans was performed using paired t test. Results The width and volume of the high?risk clinical target volume ( HR?CTV) were significantly smaller in the MRI simulation than in the CT simulation ((38.0±9?? 4) mm vs. (45.1±8?? 7) mm, P= 0?? 000;(34.2±15?? 3) cm3 vs. (42.9±20?? 4) cm3 , P= 0?? 002), and the width, thickness, and volume of the intermediate?risk clinical target volume (IR?CTV) were also significantly smaller in the MRI simulation than in the CT simulation ((58.8±9?? 4) mm vs. (65.4±10?? 3) mm, P= 0?? 000;(34.8±6?? 3) mm vs. (37.5±6?? 3) mm, P= 0?? 001;(90.9±28?? 5) cm3 vs. (109.0±36?? 4) cm3 , P= 0?? 000). The D90 values for HR?CTV and IR?CTV were significantly higher in the MRI simulation than in the CT simulation (87?? 6 Gy vs. 85?? 8 Gy, P= 0?? 013;67?? 7 Gy vs. 66?? 3 Gy, P= 0?? 005), while the average D2 cm3 values for the bladder and rectum were significantly lower in the MRI simulation than in the CT simulation ( 73?? 1 Gy vs . 75?? 5 Gy , P= 0?? 011 ; 61?? 0 Gy vs . 65?? 7 Gy , P= 0?? 000 ) . Conclusions Compared with the MRI simulation, the CT simulation overestimates the width of target volume. MRI has substantial advantages in dosimetry for target volume and normal tissues. The intracavitary/ interstitial treatment can make up the reduced dose for the target volume resulting from the CT simulation.
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ObjectiveTo investigate the delineation of gross tumor volume (GTV) in locally advanced nasopharyngeal carcinoma (LANC) according to imageological changes before and after induction chemotherapy (IC) in order to decrease high dose area and protect normal tissue better.MethodsBetween Mar 2010 to Jan 2011,11 patients with LANC were enrolled and treated with TPF regimen followed by intensity-modulated radiotherapy (IMRT) with concurrent chemotherapy,target volumes were delineated based on fused CT imaging before and after IC following project determination.Tumor target volumes after and before IC were respectively delineated according to imaging tumor residues and were overlaid by CTVnx in order to ensure radical doses for the imaging tumor volume before IC,the resulting differences of tumor target volumes of IC before and after were measured and analyzed by paired t-test.ResultsBefore and after IC,the average volumes of GTVnx were respectively 44.72 cm3 and 28.87 ( t =3.89,P =0.003 ),the average volumes of GTVnd were respectively 32.76 cm3 and 19.82 cm3 ( t =2.47,P =0.033 ),the volumes of maximum dose area in brainstem and spinal cord as well as eyeball decreased ( t =2.93-4.59,all P ＜0.05).ConclusionsLANC treated by 3 cycle TPF regimen followed by IMRT with concurrent chemotherapy showes significant shrinkage of tumor volume.The volume of high dose region which caused by normally recovered tissues were decreased by re-delineation of target volume in brainstem and spinal cord as well as eyeball of CT images after IC.
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ObjectiveTo explore the application of diffusion-weighted magnetic resonance imaging (DWMRI) in precise radiotherapy of esophageal carcinoma.MethodsThirty-seven patients with biopsy proven esophageal cancer from March 2010 to January 2011 were included.To delineate the gross tumor volume (GTV) using CT and DWMRI images,each patient was examined by DWMRI and CT scan using the same position before radiotherapy.To compare the maximum diameters and volumes of tumor between CT and DWMRI. The tumor lengths measured by esophagogram,esophagoscope,CT and DWMRI were compared.ResultsTumor lengths under esophagogram,esophagoscope,CT and DWMRI were 5.70 cm,6.06 cm,7.97 cm and 5.79 cm respectively. The lengths between CT and esophagogram,CT and esophagoscope,CT and DWMRI had statistical significance respectively (F=4.88,P=0.003).The maximum diameters of tumor shown on CT and DWMRI were 3.79 cm and 3.81 cm respectively ( t =-0.32,P=0.751 ).The GTV were 45.75 cm3 and 38.05 cm3 in CT and DWMRI respectively (t=5.30,P =0.001 ).53 lymph nodes were assessed positive on both CT and DWMRI.DWMRI excluded 25 positive lymph nodes assesed by CT; also confirmed 15 negative lymph nodes excluded by CT,6 of which were paraesophageal lymph nodes.The addition of DWMRI information altered the clinical stage in 6 patients.ConclusionsTumor lengths measured on DWMRI and esophagogram had the optimal approximation.It was easy to find paraesophageal lymph nodes via DWMRI.With the addition of DWMRI information,the target range and clinical stage were alerted in some patients.
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Objective The frequency and the anatomic distribution of involved regional nodes in recurrent and locally advanced breast cancer were analyzed, in order to evaluate the rational of conventional regional node radiation technique and provide evidence for target definition of breast cancer . Methods Patients with recurrent or locally advanced breast cancer who were treated in our hospital from August 2003 to December 2009 were included in this study. 111 patients had contrast enhanced chest CT images of the whole regional nodes before treatment. The regional nodes were categorized into 8 anatomical substructures including medial and lateral supraclavicular nodes ( SC-M, SC-L), axilla nodes ( ALN )- Ⅰ , Ⅱ , Ⅲ,infraclavicular nodes (IFN), Rotter's nodes (RN) and internal mammary nodes (IMN). The frequency of involvement and anatomical distribution of the involved nodes on CT images were analyzed. Results A total of 111 patients were enrolled this study and 199 anatomical substructures with involved nodes were identified. The frequency of involvement were :SC-M 33, SC-L 21, ALN- Ⅰ 30, ALN-Ⅱ 25, ALN-Ⅲ + IFN 35, RN 27, IMN 28. Supraclavicular region and axilla were the most frequently involved area (72. 3% ).The average depth of the SC-M and SC-L nodes was 33.48 mm ± 10. 57 mm and 45.62 mm ±20. 45 mm,and 51.5% and 71.4% of the SC-M and SC-L nodes were located more than 3 cm deep from the skin. The axilla nodes were located cranial and caudal to the axillary vein in 5 and 20 locally advanced breast cancer patients and in 64 and 28 patients who received prior axillary dissection. The majority of involved IMN was located within the first 3 intercostal spaces (26/28). The average distance between the center of involved IMN and chest skin was 24. 23 mm ± 10. 28 mm. The average distance between the center of involved IMN and midline of the body was 29. 38 mm ±6. 7 mm. The center of involved IMN was 6.19 mm ±5.73 mm lateral and 5.73 mm ± 4. 56 mm posterior to the internal mammary vessels. Conclusions Conventional field design is unlikely to provide sufficient dose to the entire risk region because of individual differences.Individualized treatment planning based on CT would become feasible with increasing knowledge of natural risk of nodal involvement.
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Objective To define the patterns of local extension and nodal involvement in patients with early stage nasal NK/T-cell lymphoma, and to improve the delineation of clinical target volume.Methods Two hundred and twenty-two patients consecutively diagnosed with nasal NK/T-cell lymphoma were reviewed.All patients had stage Ⅰ E/Ⅱ E diseases.CT/MRI images were reviewed to determine the local invasion of adjacent organs or structures and involvement of lymph node.Results 143 of 222(64%) patients had primary tumor extended into adjacent organs or structures from nasal cavity.According to the incidence rates of tumor extension, the involved organs or structures were subclassified into three subgroups:high risk (≥40%):ethmoid sinus (60%) and maxillary sinus (55%);intermediate risk (5%-40%):nasopharynx (39%), skin (22%), oropharynx (12%), orbit (10%), and hard palate (10%);and low risk (≤5%):sphenoid sinus (3%), soft plate (3%),frontal sinus (3%) and skull base (1%).Cervical lymph node metastasis occurred in 16%(36/222) of the patients and these patients were staged as Ⅱ E.Thirty-three patients with stage Ⅱ E disease had available images and were analyzed for the pattern of nodal involvement.Submandibular or submental (57%) and the upper cervical lymph nodes (57%) were the most commonly involved sites of nodal region.For the 24 patients with primary tumor located in the unilateral nasal cavity, 54% presented with contralateral cervical lymph node metastasis.Whereas for the 9 patients with primary tumor located in the bilateral nasal cavity, 57% had bilateral cervical lymph node metastasis.For the 88 patients with extensive stage Ⅰ E disease who did not receive irradiation to the cervical lymph node, only one patient (1%) had disease relapse in cervical lymph node.Furthermore, all patients with disease extended to nasopharynx (n= 23) or oropharynx (n= 8) did not receive prophylactic cervical lymph node irradiation, and none of them developed cervical lymph node relapse.Conclusions The delineation of clinical target volume for early stage nasal NK/T-cell lymphoma should be determined by the risk of involvement of paranasal structures and cervical lymph node.Prophylactic neck irradiation is not recommended for patients with stage Ⅰ disease.
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Objective To evaluate the accuracy, of different threshold segmentation of 18FDG PET for target volume delineation of non-small cell lung cancer(NSCLC) and the potential influence on radiotherapy treatment planning. Methods Eight NSCLC patients who had tumor with clear margin on CT scan and the amplitude of tumor movements not more than 5 mm were enrolled. PET scans were carried out at 1 h after intravenous injection of 18FDG with CT image for attenuation revisement. Gross target volume (GTV) delineated on CT image ( GTVCT ) was used as the standard. Then, GTVs were delineated on PET image with three different threshold segmentation of 42% Imax(total) (42% of maximum voxel intensity within the tumor) ,Iback + 20% Imax-back(max) (mean background intensity + 20% of normalized background-subtracted maximum voxel intensity within the tumor) and Iback -20% Imax-back(slice) (mean background intensity + 20% of normalized background-subtracted maximum voxel intensity of each slice within the tumor) ,the corresponding GTV was named as GTV42%, GTV20%max and GTV20%slice. Both the size of GTV42%, GTV20%max, GTV20%slice and GTVCT,and the coverage over GTVCT for each GTV were compared. A three dimensional margin of 1 cm were added to GTVCT, GTV42%, GTV20%max and GTV20%slice to form corresponding PTVCT, PTV42%, PTV20%max and PTV20%slic e. Three dimensional conformal radiotherapy treatment plans were designed based on PTVCT,PTV42% , PTV20%max and PTV20%slice respectively for each patient. The prescription dose of all PTVs was 66 Gy in 33 fractions in 6.6 weeks. Both the volume accepting dose less than 95% of prescription dose within PTVCT ( VPTV ) and the lung V20 were compared among the four plans based on different PTVs. Tumor control probability(TCP) as well as lung normal tissue complication probability (NTCP) were also compared. Resuits Eight patients were enrolled in this study. Median deviation of volume between GTVPET and GTVCT were -54.1% , -21.5 % and 5.3 % for GTV42% , GTV20%max and GTV20%slice, respectively. Median coverage over GTVCT of GTV42% , GTV20%max and GTV20%slice was 45.9% ,78.0% and 95.3% respectively( F = 57.50,P＜0.01). Median 7.5% of VPTV was observed for radiotherapy treatment plan based on PTV42% ,which meant that it might induce median 1% decrease of TCP comparing with that of radiotherapy treatment plan based on PTVCT. Whereas,there were only 1.3% and 0.0% of VPTV for treatment plans based on PTV20%max and PTV20%slice respectively. As far as TCP was concemed, both PTV20%max group and PTV20%slice group were superior to PTV42% group,there was no significant difference among PTV20%max group, PTV20%slice group and PTVCT group. Lung V20 and lung NTCP showed no significant difference among all groups. Conclusions The threshold segmentation of Iback + 20% Imax-back(slice) , being slice specialized, might be an optimal threshold segmentation for target volume delineation of lung caner. Independent of information of target volume provided by CT scan in advance,it is recommended to use for the target volume delineation of NSCLC with atelectasis.
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Molecular imaging, in particular, positron emission tomography(PET) has brought an additional dimension to management for patients with cancer. It may lead to a change in staging and treatment management. In radiotherapy, the PET or PET-CT has a crucial role in treatment planning and patient management, specifically, its use in disease staging, patient selection, treatment planning and evaluation. The purpose of radiotherapy is radical or palliative depending on the staging of tumor; thus, PET(-CT) may actually change the course of disease. The methodological and technological aspects of PET(-CT) in radiotherapy are discussed, focusing on the problem of target volume definition and tumor motion with respect to imaging and dose delivery. In addition, tissue hypoxia is an important factor in radiotherapy as a resistance factor in treatment; thus, we mention the concept of hypoxia-directed therapy.