The dose data produced by treatment plan system (TPS) in intensity-modulated radiation therapy (IMRT) has many gradient edge points. Considering this feature we proposed a new interpolation algorithm called treatment plan dose interpolation algorithm based on gradient feature in intensity-modulated radiation therapy (TDAGI), which improves the Canny algorithm to detect the gradient edge points and non-edge points by using the gradient information in the dose data plane. For each gradient edge point, the corresponding gradient profile was traced and the profile's sharpness was calculated, and for each non-edge point, the dispersion was calculated. With the sharpness or dispersion, the kernel coefficients of bi-cubic interpolation can be obtained and can be used as the central point to complete the bi-cubic interpolation calculation. Compared with bi-cubic interpolation and bilinear interpolation, the TDAGI algorithm is more accurate. Furthermore, the TDAGI algorithm has the advantage of gradient keeping. Therefore, TDAGI can be used as an alternative method in the dose interpolation of TPS in IMRT.
ObjectiveTo discuss the clinical value of internal radiation therapy with hepatic intraarterial iodine131 labeled material for the treatment of hepatocellular carcinoma (HCC). MethodsThis summarized paper was made on literature review. ResultsIodine131lipiodol and several reported iodine131labeled antibodies to HCC associated antigens were concentrated in the foci of HCC with a high tumortonormaltissue absorbed dose ratios. No severe side effects occurred. It was used in various kinds of HCC patients, and mostly showed a significant tumor response. Survival rate of HCC patients was raised in several clinical trials.Conclusion Internal radiotherapy with hepatic intraarterial iodine131 labeled material may be considered as an effective method to treat HCC.
Objective To evaluate the effectiveness and prognosis of patients in advanced hepatocellular carcinoma (HCC) with portal vein (PV) tumor thrombus received external-beam radiation therapy (EBRT). Methods The clinical data of 126 HCC patients with PV tumor thrombus who were referred for EBRT at our institution from January 2000 to November 2009 were analyzed retrospectively. EBRT was designed to focus on the tumor thrombus with or without primary intrahepatic tumors， to deliver a median total conventional dose of 50 Gy (range of 30-60 Gy). Predictors of survival were identified using univariate and multivariate analysis. Results Unfavorable pretreatment predictors were associated by multivariate analysis with lower albumin and higher α-fetoprotein levels, poorer Child-Pugh liver function classification, poorer intrahepatic tumor control， lymph node metastases， and the two-dimensional EBRT technique. The dose of EBRT showed no significant in both univariate and multivariate survival analysis. Conclusions In patients with HCC， EBRT is effectively prevents progression in cases of PV tumor thrombus， but palliative dose of EBRT is not related to survival.EBRT is not related to survival.
ObjectiveTo compare the static intensity-modulated radiation therapy (IMRT) plans using different beams sets and segments number, and find the better static IMRT plan sets on beams and segments in gastric surgical adjuvant radiotherapy.MethodsFifteen patients who underwent adjuvant radiotherapy for gastric cancer between February 1st and August 30th, 2013 were chosen as subjects through random sampling. Based on the 5 beams static IMRT plans already used in clinical practice, four different static IMRT plans used diverse beams sets for each patient were designed in the same treatment planning system (Pinnacle 9.2). The beams sets of static IMRT plans were as follows: 7 coplanar equal beams; 5 coplanar equal beams; 4 coplanar beams of 310, 20, 90 and 180°; 3 coplanar beams of 310, 65 and 180°. Sufficient segments 65 was set as the max segments number in order to compare the plans’ difference just resulting from beams. In the second step, the max segments number was changed from 65 to 45 and 25 to design two different static IMRT plans for the 4 coplanar beams static IMRT plans. The dosimetric parameters were compared for the planning target volume (PTV) and organs at risk (OARs). The monitor units and treatment times of the different static IMRT plans were also evaluated.ResultsWhen the max segments number was set to 65, the 4 coplanar beams static IMRT plans were a little better on PTV conformability than the 5 coplanar beams static IMRT plans used in clinical practice (0.74±0.04 vs. 0.73±0.05, P<0.01). Meanwhile, better OARs dose sparing especially for liver and kidneys were gained by the 4 coplanar beams static IMRT plans, for example, the percent volume gained 30 Gy for liver [(22.71±6.10)%vs. (24.03±6.84)%, P<0.01] and the percent volume gained 20 Gy for the right kidney [(14.97±6.72)%vs. (19.41±6.14)%, P<0.01]. The PTV conformability of the 4 coplanar beams static IMRT plans reduced as the max segments number became smaller (0.74±0.04vs. 0.73±0.04 vs. 0.71±0.04, P<0.05). However, they were still acceptable in clinical practice. And the better dose sparing for liver and kidneys were retained. The average reductions of 1.8 and 4.3 minutes on the irradiation time were get by the 4 coplanar beams static IMRT plans with the max segments number 45 and 25 compared to that with the max segments number 65 [(494.66±26.79)vs. (384.26±14.99) vs. (235.00±9.21) s, P<0.01]. And the raises of treatment efficiency were 22.3% and 52.4%, respectively (P<0.05).ConclusionsThe 4 coplanar beams static IMRT plans with fewer segments could ensure plan quality, and protect the OARs better in the meanwhile, especially for liver and kidneys. The treatment time is reduced as well. The 4 coplanar beams static IMRT plans could improve the treatment efficiency.
We reported three cases of stageⅢ/N2 non-small cell lung cancer (NSCLC) treated with neoadjuvant immunotherapy and stereotactic body radiation therapy (SBRT) in our hospital, including 2 males and 1 female with a mean age of 65.7 years. The patients received two doses of the programmed cell death protein-1 inhibitor toripalimab after 1 week of SBRT. Thereafter, surgery was planned 4-6 weeks after the second dose. One patient achieved pathologic complete response, one achieved major pathologic response (MPR), and one did not achieve MPR with 20% residual tumor. There were few side effects of toripalimab combined with SBRT as a neoadjuvant treatment, and the treatment did not cause a delay of surgery.
ObjectiveTo summarize clinical application progress of stereotactic radiotherapy for primary hepatocellular carcinoma. MethodsThe literatures about the research progress of the stereotactic radiotherapy for primary hepatocellular carcinoma were reviewed. ResultsRadiotherapy for hepatocellular carcinoma is importantly based on the radiation biology of the liver and the radiophysics of the liver cancer. Stereotactic precision radiotherapy is an effective and low toxic treatment for early hepatocellular carcinoma, moreover, it alone or in combination with microwave ablation, hepatic artery chemoembolization for unresectable hepatocellular carcinoma is safe and effective method for the treatment. ConclusionsThe optimal dose model for hepatocellular carcinoma, hepatocellular carcinoma radical dose level are problems that need further exploration, and radiobiology, radiation physics research must be strengthened to explore it, stereotactic precision radiotherapy treatment modalities in the treatment of hepatocellular carcinoma position will become increasingly people attention.
Objective To overview the systematic reviews of the effectiveness and safety of the charged-particle radiation therapy. Methods Databases including CNKI, WanFang Data, PubMed, and EMbase were electronically searched from January 2007 to November 2020. Two investigators independently screened literature, extracted data, and assessed the quality of the included studies by AMSTAR 2, and then reported results through a narrative synthesis of outcomes. Results A total of 6 systematic reviews were identified. One systematic review demonstrated moderate quality and the other 5 demonstrated critically low quality. The charged-particle radiation therapy had a wide range of applications. Its effectiveness was superior to traditional radiotherapy methods on various types of tumors in various regions of the body, with acceptable side effects. Specifically, the effectiveness and safety outcomes of carbon ion radiotherapy was superior to those of proton radiotherapy. Conclusions Current evidence shows that the charged-particle radiation therapy has superior effectiveness and limited toxicity, though the studies are of relatively low quality. High quality and larger sample size researches are required in the future.
ObjectiveTo evaluate the effect of post mastectomy radiation therapy (PMRT) on breast reconstruction after mastectomy in breast cancer patients, in order to provide evidence support for clinical treatment decision.MethodsFive databases searched in the current study include the Cochrane Library, PubMed, CNKI, VIP and WanFang database. A systematic search for control trials was performed in each database from the starting date of each database to March 1, 2021. After the two evaluators independently selected literatures, extracted data and conducted quality evaluation according to the inclusion and exclusion criteria, the meta analysis was carried out by Revman 5.3 software.ResultsA total of 9 cohort studies (3 447 cases) were included, including 699 cases in PMRT group and2 748 cases in non-radiotherapy group. The results of meta-analysis showed that: PMRT was associated with significant increase in capsular contracture. The incidence of capsular contracture increased from 4.34% in the non-radiotherapy group to 34.10% in patients receiving PMRT [OR=9.25, 95%CI (3.76, 22.78), P<0.000 01]. In addition, PMRT was associated with a significant increase in incidences of reconstructive failure [OR=2.55, 95%CI (1.74, 3.74), P<0.000 01] and revisional surgery [OR=2.24, 95%CI (1.58, 3.18), P<0.000 01]. Moreover it was associated with a significant reduction in patient satisfaction [OR=0.29, 95%CI (0.15, 0.57), P=0.000 30] and cosmetic outcome [OR=0.26, 95%CI (0.15, 0.43), P<0.000 01].ConclusionThis meta-analysis demonstrates that breast cancer patients who received PMRT after breast reconstruction, the rate of adverse events is increased and patients’ satisfaction and cosmetic outcome are decreased.
Image-guided radiation therapy using magnetic resonance imaging (MRI) is a new technology that has been widely studied and developed in recent years. The technology combines the advantages of MRI imaging, and can offer online real-time tracking of tumor and adjacent organs at risk, as well as real-time optimization of radiotherapy plan. In order to provide a comprehensive understanding of this technology, and to grasp the international development and trends in this field, this paper reviews and summarizes related researches, so as to make the researchers and clinical personnel in this field to understand recent status of this technology, and carry out corresponding researches. This paper summarizes the advantages of MRI and the research progress of MRI linear accelerator (MR-Linac), online guidance, adaptive optimization, and dosimetry-related research. Possible development direction of these technologies in the future is also discussed. It is expected that this review can provide a certain reference value for clinician and related researchers to understand the research progress in the field.
Lobectomy and systematic nodules resection has been the standard surgical procedure for non-small cell lung cancer (NSCLC). However, increased small-size lung cancer has been identified with the widespread implementation of low-dose computed tomography (LDCT) screening, and it is controversial whether it is proper to choose lobar resection for the pulmonary nodules. Numerous retrospective researches and randomized clinical trials, such as JCOG0201, JCOG0804/WJOG4507L, JCOG0802 and CALGB/Alliance 140503, revealed that the sublobar resection was safe and effective for NSCLC with maximum tumor diameter≤2 cm and with consolidation tumor ratio (CTR)≤0.25, and that segmentectomy was superior to lobectomy with significant differences in 5-year overall survival rate and respiratory function for patients with small-size (≤2 cm, CTR>0.5) NSCLC and should be the standard surgical procedure. It is the principle for multiple primary lung cancer that priority should be given to primary lesions with secondary lesions considered, and it is feasible to handle the multiple lung nodules based on the patients' individual characteristics.