Application of artificial intelligence in the target delineation of radiotherapy / 国际肿瘤学杂志

Artificial intelligence is the use of computer algorithms to copy or simulate human behavior, giving machines human-like ability. With the rapid development of radiotherapy technology, artificial intelligence has great potential value in all stages of radiotherapy. Image segmentation is the premise of target delineation using artificial intelligence. The commonly used methods in clinic mainly include automatic segmentation based on deep learning and atlas library. The technology of artificial intelligence in organs at risk delineation is relatively mature, which can significantly shorten the delineation time and improve the efficiency. The delineation of tumor targets has achieved some success, the accuracy still needs to be further improved. Artificial intelligence technology makes the target delineation more and more efficient, and the consistency and repeatability have been significantly improved. It is expected to provide more accurate and individualized treatment for patients.

Application of diffusion tensor imaging to brain tumors radiotherapy / 中华放射医学与防护杂志

Diffusion tensor imaging (DTI) uses the diffusion motion of water molecules to describe the spatial structure of brain.DTI,which can obtain the infiltration of brain tumors into normal physiological structures,makes the diagnosis of diseases change from macroscopic to microscopic,from morphology to both morphology and metabolism,bringing new opportunities for the diagnosis and treatment of brain tumors.In this review,we outlined the theoretical basis and current technical limitations of DTI,and comprehensively discussed its research values in brain tumors radiotherapy treatment and its prognostic value.We believe that DTI can provide important imaging information for radiotherapy planning of brain tumors.

The feasibility of involved-field irradiation in old patients with esophageal squamous-cell carcinoma / 中华放射医学与防护杂志

Objective To assess the outcomes of involved field irradiation (IFI) and elective nodal irradiation (ENI) in patients older than 70 years with esophageal squamous-cell carcinoma(SCC) receiving radical IMRT,and to determine whether IFI is feasible in these patients.Methods Totally 79 patients older than 70 years diagnosed with SCC of esophagus without distant metastases were collected.48 patients were received IFI,and the other 31 patients were treated with ENI.With a median follow-up time of 24 months,disease-free survival,overall survival,patterns of failure,irradiated lung dose and radiation pneumonitis were observed and compared between IFI and ENI groups.Results In IFI and ENI arm,the disease-free survival rates of 1,2,3 years were 60.4％,34.9％,29.7％ and 64.5％,54.0％,35.0％,respectively(P ＞0.05).The 1-,2-,and 3-year survival rates were 72.9％,43.4％,31.5％ for the IFI arm,and 73.0％,53.0％,38.3％ for the ENI arm(P ＞ 0.05).The ENI arm had a tendency to expand survival,but the two arms had no significant difference (P ＞ 0.05).The patterns of failure also had no difference between the two arms.Distant failure,local failure,uninvolved nodal failure in IFI arm were 22.9％,27.0％,4.2％,while in ENI arm were 25.8％,0,19.4％,all of them had no significant difference (P ＞ 0.05).However,the lung V5,V20,mean lung dose in ENI arm were higher than that in IFI and all of them had a significantly difference (t =4.66,29.90,15.63,P ＜ 0.05).The radiation pneumonitis rates were higher in ENI than in IFI arm.The rates of degree 1-2 and degree 3 were 22％,19％,and 13％ and 4％ in the two arms,respectively,with a significantly difference(x2 =4.55,4.77,P ＜ 0.05).Conclusions It is feasible that IFI for definitive IMRT in the elderly patients older than 70 years with SCC,because it got similar disease-free survival and overall survival but with less lung doses along with decreased radio-pulmonary lesion when compared with ENI.

Comparison of quality of life in patients with nasopharyngeal carcinoma receiving conventional external beam radiation therapy versus intensity modulated radiation therapy / 中华放射医学与防护杂志

Objective To compare the acute and late adverse events and quality of life (QOL) in patients with nasopharyngeal carcinomas receiving conventional external beam radiation therapy (RT) versus intensity modulated radiation therapy (IMRT).Methods Ninety-one patients with newly diagnosed nasopharyngeal carcinoma treated in our institution between August 2008 and September 2010 were systemically reviewed,including 35 cases administered with conventional RT ( RT group) and 56 cases with IMRT (IMRT group).Conjoint facio-cervical fields plus tangential lower neck-supraclavicular field initially,and then shrinking preauricular portals plus electron beams to the neck were adopted in RT groups,with a total dose of 70 Gy/35 fractions.Nine coplanar fields were conducted in IMRT group with a total dose of 69.96 Gy/33 fractions.Acute and late adverse reactions were observed and compared between RT and IMRT groups,including acute reactions as xerostomia,odynophagia,dermatitis/mucositis and late events as dysphagia,trismus,hypothyroidism,optic/acoustic impairments,skin injury,hypodermal fibrosis,spinal myelitis and brain injury.Results Compared with RT group,IMRT group showed less acute reactions in xerostomia,odynophagia,dysphagia and dermatitis and mucositis(x2 =85.73,56.03,26.58,69.28,55.99,P ＜ 0.05 ),and less late reactions in xerostomia,dysphagia,trismus,taste loss and skin injury (x2 =37.95,7.48,9.49,9.49,11.87,P ＜ 0.05 ),whereas the degree of acoustic/optic impairments and brain injury showed no difference in both groups.Conclusions As compared to conventional RT,IMRT could decrease acute and some late side events,and improve the quality of life in patients with nasopharyngeal carcinoma.

Use of diffusion-weighted magnetic resonance imaging in cervical lymph node metastasis from nasopharyngeal carcinoma patients receiving intensity modulated radiation therapy / 中华放射医学与防护杂志

Objective To investigate the value of diffusion-weighted magnetic resonance imaging (DWI) and apparent diffusion coefficients (ADC) in detecting metastatic lymph nodes from nasopharyngeal carcinoma (NPC),and predicting the response of these nodes to concurrent chemoradiation (CRT).Methods Eighteen patients with pathologically proven NPC received conventional magnetic resonance imaging (MRI) and DWI before treatment,weekly during treatment,and one month after treatment.DWI was performed using a single-shot echo-planar (SSEPI) MR imaging sequence with b values of 0 and 1500 s/mm2.ADC maps were reconstructed for all patients and ADC values were calculated for each lymph node and tongue muscle.Totally fifty-two morphologically abnormal lymph nodes were analyzed.The ADC values of the metastatic lymph nodes before treatment were compared between those with the short axis≥10 mm (n=32) and those with the short axis<10 mm (n=20),and the dynamic changes in ADC values of the lymph nodes before,during,and after therapy were observed and recorded.Results The average ADC of the 32 lymph nodes with the short axis ≥ 10 mm was (0.71±0.12) x 10-3mm/s,not significantly different from that of the 20 lymph nodes with the short axis < 10 mm [(0.73±0.16) x 10-3mm/s,t = 1.11 ,P =0.27].The average ADC values of these lymph nodes before treatment was significantly lower than that of the tongue muscle (t = 19.35,P < 0.0001).During CRT,the ADC values of the lymph nodes increased gradually,with the most evident change in the first two weeks before reaching a relatively flat plateau thereafter.The ADC value of the residual lymph nodes after CRT was significantly higher than that before treatment (t = 12.72,P < 0.0001),however,not statistically significant different from that of the normal tongue muscle (t = 0.34,P = 0.73).Conclusions DWI plays an important role in diagnosing the metastatic lymph nodes from NPC and is feasible for observation of the early response of the lymph nodes to IMRT,thus helping the clinicians make appropriate treatment planning and replanning in the course of radiotherapy.

Therapeutic effects and quality of life in 37 glioma patients with postoperative intensity-modulated radiotherapy / 中华放射医学与防护杂志

Objective To evaluate treatment outcomes and quality of life (QOL) in glioma patients treated with postoperative intensity-modulated radiotherapy (IMRT), and to explore the possible clinical factors of affecting QOL. Methods From 2007 to 2009, 37 patients with low or high grade glioma were analyzed retrospectively. All patients were operated by tumor resection below microscopy. IMRT began at 2-4 week postoperstion with 2.0 Gy/fractior, 5 fractions/week and to shrink portal and to add dose to 50-60 Gy/25-30 fractions after 40-50 Gy. The gross tumor volume (GTV) was defined as preoperation T2WI MRI high sign area and postoperation tumor cavity for low grade glioma, and with preoperation T1WI MRI enhanced abnormity area and postoperation tumor cavity for high grade glioma. The clinical target volume ( CTV ) was defined as GTV with a margin of 1.5 cm for low grade glioma and a margin of 2.5 cm for high grade ghoma, the planning target volume (PTV) with CTV plus 0.4 cm margin for setup errors according to the European Organization for Research and Treatment of Cancer ( EORTC ).The treatment outcomes and QOL were assessed. Results The half-year and one-year survival rates for all the patients were 100% and 79.2%, respectively. The median progression-free survival time was 10 months. The main side-responses after postoperative IMRT were fatigue and mild memory decline or cognitive disabilities, which were radiation dose-dependent. Conclusions Postoperative IMRT is an effective and safe modality of therapy for glioma patients.