RESUMO
Objective:To explore the clinical value of 18F-fluoromisonidazole (FMISO) PET/CT hypoxia imaging in early response to heavy ion radiotherapy in patients with non-small cell lung cancer(NSCLC). Methods:From April 2018 to January 2021, the 18F-FMISO PET/CT images of 23 NSCLC patients (19 males, 4 females; age (64.9±10.3) years) who received heavy ion radiotherapy in Shanghai Proton and Heavy Ion Center were retrospectively analyzed. The evaluation parameters included tumor volume (TV), tumor to background ratio (TBR) before and after radiotherapy. Patients were divided into hypoxia group and non-hypoxia group with the baseline TBR value≥1.4 as hypoxia threshold. Wilcoxon signed rank test was used to compare the differences of TV and TBR before and after radiotherapy in 2 groups. Results:Of 23 NSCLC patients, 17 were hypoxia and 6 were non-hypoxia. Compared with the baseline, TV after the radiotherapy (59.44(22.86, 99.43) and 33.78(8.68, 54.44) cm 3; z=-3.05, P=0.002) and TBR after the radiotherapy (2.25(2.09, 2.82) and 1.42(1.24, 1.67); z=-3.39, P=0.001) of the hypoxia group were significantly lower, while TV (16.19(6.74, 36.52) and 8.59(4.38, 25.47) cm 3; z=-1.57, P=0.120) and TBR (1.19(1.05, 1.27) and 1.10 (0.97, 1.14); z=-1.89, P=0.060) of the non-hypoxia group decreased with no significant differences. Conclusions:Hypoxic NSCLC tumors are sensitive to heavy ion radiation. Compared with non-hypoxic tumors, hypoxic tumors respond more quickly, and a significant reduction in TV can be observed early after radiotherapy. Heavy ion radiation can significantly improve tumor hypoxia.
RESUMO
Objective@#To analyze the spatial distribution of brain metastases in EGFR-mutant lung cancer and the risk of hippocampal metastasis.@*Methods@#Patients with lung cancer brain metastases diagnosed and treated in the Shanghai Cancer Center Fudan University from 2006 to 2016 were enrolled. The brain metastasis with positive mutation of EGFR gene was screened. The magnetic resonance images of the patients were reviewed and the distribution characteristics of brain metastasis were analyzed.@*Results@#A total of 920 lung cancer patients with brain metastases were screened, 266 of whom had EGFR gene mutation detection, and 131(49%) were identified as EGFR gene mutations. Excluding 17 patients who did not have a head magnetic resonance examination in our hospital, a total of 114 patients and 738 lesions were enrolled in this study. The proportion of brain metastases distributed in each brain region was 22.8%, 19.5%, 22.0%, 13.4%, 3.3%, 16.7%, and 2.2% for frontal, temporal, parietal, occipital lobe, insula, cerebellum, and brainstem, respectively. The number of metastases and cases located in the hippocampus, <5 mm from the hippocampus, <10 mm from the hippocampus, and<15 mm from the hippocampus were 6(0.8%), 10(1.3%), 11(1.4%), and 14(1.8%), 5 cases (4.4%), 8 cases (7.0%), 9 cases (7.9%), and 11 cases (9.6%), respectively.@*Conclusion@#EGFR-mutant lung cancer brain metastasis is low risk in the hippocampus and its surrounding 15 mm.
RESUMO
Regulatory T cells ( Treg) play important role in immune homeostasis in physics and hamper the anti-tumor immunity. Depletion of intra-tumor Treg is a critical step to boost the anti-tumor effect in immune therapy. Radiotherapy can induce secretion of TGF-βand IL33 from tumor cells and then increase Treg proliferation and recruitment into tumor through Langerhans cell. Depletion of Treg could increase the local control and abscopal effect of radiotherapy.
RESUMO
Background and purpose:Radiotherapy is one of the main treatment methods for brain tumor patients, but neurotoxicity was observed frequently. Because of the confounding factors in clinical data, it’s hard to summarize the characteristic of neurological changes after brain irradiation. This study used the brain irradiation injury model of rats to test whether brain irradiation change the mood and memory.Methods:Whole brain of SD rats (6-8 weeks old) was exposed to 22 Gy radiation. Open ifeld and elevated plus maze was used to assess the anxiety of rats, passive avoidance was used to assess the mood memory, and novel place recognition was used to assess the spatial memory at 1 month or 10 months after brain irradiation.Results:At 1 month post irradiation, rats moved with less distance and entrance to the central zone of open ifeld with less time, explored the open and closed arms with less time and the exploration of open arms also decreased, entered the darkroom more rapidly during the test phase of passive avoidance, and lose the interest to explore the novel place during novel place recognition. At 10 months post irradiation, rats exhibited similarly with control group during open ifeld and elevated plus maze test, but still entered the darkroom more rapidly during the test phase of passive avoidance, and lose the interest to explore the novel place during novel place recognition.Conclusion:Brain irradiation could decrease the locomotor activity, increase the anxiety mood, reduce the mood and spatial memory; mood dysfunction induced by brain irradiation could restore, but memory impairments would be long-standing.
RESUMO
Objective To investigate whether the change of beam set-up methods will influence the dosimetric quality of intensity modulated radiation therapy (IMRT) for non-small cell lung cancer (NSCLC).Methods Twenty-one stage Ⅰ-Ⅲ NSCLC patients were selected for this study.The technique of step and shoot was used and three different beam set-up methods were chosen for IMRT planning,including IMRT-7 with nine equal-spaced beams angled 0°,51°,102°,153°,204°,255°and 306°; IMRT-5 with five equal-spaced beams angled 0°,72°,144°,216°and 288°; and IMRT-5m which was created from IMRT-7 but excluded 2 fields (51°and 102° were omitted if there was lesion in the right lung,while 255°and 306° were excluded if there was lesion in the left lung).The dose constrains ofnormal lungs for IMRT were set according to V5-V60 of normal lungs obtained from the same patient's actually treated 3D-CRT dose volume histogram.The prescription dose for IMRT started from 65 Gy,and then escalated or decreased step by step by 2 Gy once a time until the best plan was obtained.Results For normal lung dose,IMRT-5m had lower V5-V25 than the other two groups; but there was no significant difference in V30-V40.IMRT-5 was the worst for V45-V60; and mean lung dose was lowest in IMRT-5m.Dose parameters of esophagus and spinal cord,target conformity index,and total monitor units were all similar among difference plans.IMRT-5m had lowest heart V40 compared to the other two groups.For target heterogeneity index,IMRT-5 was higher than IMRT-7,but there were no significant differences among IMRT-5m,IMRT-5 and IMRT-7.Compared to 3D-CRT,the prescription dose could be increased by (5.1 ±4.6) Gy for IMRT-7,(3.1 ±5.3) Gy for IMRT-5,and (5.5 ±4.8)Gy for IMRT-5m.Conclusion Fewer beams and modified beam angles could result in similar,even better plan quality.
RESUMO
SCLC can spare more volume of the normal lungs and e-sophagus, and has the ability of dose escalation.
RESUMO
Objective To reasonably confirm the target of 3-dimensional conformal radiation therapy (3DCRT) for lung cancer. Methods While a patient was breathing, the motion of the primary lesion in the lung was observed by fluoroscopy. The extent of motion of the primary lesion during irradiation was evaluated by portal films. Three 3DCRT plannings for lung cancer, in which gross tumor volume (GTV) decided by a group of radiation oncologists and implemented, were taken as the standard. The GTV delineated by five radiation oncologits was compared with the standard by computing the radial line measurement variation (RLMV). Results From fluoroscopic observation in fifty-nine patients, the extent of lesion motion was the largest in cephalo-caudal direction, with 14.3 mm for lesions in the lower and 7.1 mm (median) for middle part of the lung. In lateral and antero-posterior directions, it was within 4. 0 mm. The motion error during irradiation was 4. 2 mm in lateral direction and 4.6 mm in cephalo-caudal direction. The random error, system error and total error for set-up uncertainty were 3.4 mm, 6.0 mm, and 6.9 mm. Compared to the standard, the discrepancy of GTV could be as large as 150% . The largest RLMV was observed in the area of lung hilar nodes. Conclusions The target of 3-dimensional conformal radiation therapy for lung cancer should be confirmed individually and delineated by a group of radiation oncologists. A more efficient fixing device is needed owing to the large total error for set-up.
RESUMO
Objective To assess and delineate the dosimetric shortcomings of conventional radiotherapy planning,as compared with the three dimensional treatment planning system, and to obtain a better technique in the treatment of lung cancers.Methods Thirteen patients with stage ⅢA ⅢB non small cell lung cancer were chosen in the present study. Using the Cadplan 6.0.8 treatment planning system , three different methods of radiotherapy planning: conventional planning, conventional and conformal planning, and conformal planning were designed for each patient. The total radiation dose was 66 ?Gy and DVHs were used to assess the dosimetric distribution in the gross tumor volume and the surrounding organs at risk. Results No significant dosimetric disparity in the target volume was found among the three designs, according to anticipated therapeatic requirements. The conformity indices were 0.13,0.24 and 0.35 for these three radiotherapy designs. The mean lung volumes which received radiation dose of≥20?Gy were 32%,26% and 25%.The mean maximum dose at the spinal cord were 42?Gy,49?Gy and 33?Gy.The mean esophageal volume which received radiation of ≥50?Gy were 32%,34% and 22%, and the mean radiation dose to the heart were 18?Gy,15?Gy and 12?Gy,respectively. Conclusions Conventional radiotherapy planning is able to meet the demands of dosimetric requirements for radiation treatment of lung cancers. The three dimensional conformal radiation therapy planning system is able to provide superior delivery of high dose to the target volume without inflicting too high a risk to the surrounding normal tissues and organs.