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Objective:Partial stereotactic ablative boost radiotherapy(P-SABR)is a method to deliver SABR boost to the gross tumor boost volume(GTVb), followed by conventionally fractionated radiotherapy to the whole tumor area(GTV). GTVb is the max volume receiving SABR while ensuring the critical organ-at-risk(OAR)falloff to 3 GyE/f. We investigated the potential advantage of proton therapy in treating bulky non-small cell lung cancer(the tumor length greater than 8 cm).Methods:Nine patients with bulky NSCLC treated with photon P-SABR in our institute were selected. For the treatment planning of proton therapy, the GTVb target area was gradually outwardly expanded based on the photon GTVb target area until the dose to critical OARs reached 3 GyE/f. The GTV and CTV areas remained the same as photon plan. A proton intensity-modulated radiation treatment plan(proton-IMPT), a photon intensity-modulated radiation treatment plan(photon-IMRT)and a photon volumetric modulated arc therapy(photon-VMAT)were created for each patient, respectively. The dosimetric parameters of different treatment plans were compared.Results:The volume ratio of GTVb-photon and GTVb-proton to GTV was(25.4±13.4)% and(69.7±30.0)%,respectively( P<0.001). In photon-IMRT, photon-VMAT, and proton-IMPT plan groups, the mean dose of CTV was(76.1±4.9)Gy, (78.2±3.6)Gy, and(84.7±4.9)Gy, respectively; the ratio of tumor volume with Biologic Effective Dose(BED)≥ 90 Gy to GTV volume was(70.7±21.7)%, (76.8±22.1)%,and(97.9±4.0)%,respectively. The actual dose and BED to the tumor area of the proton-IMPT plan group were significantly higher than those of the photon plan group(both P<0.05). Besides, the OARs dose was significantly decreased in the proton-IMPT group, with(49.2±22.0)%, (56.8±19.0)% and(16.1±6.3)% of the whole lung V5 for photon-IMRT, photon-VMAT and proton-IMPT, respectively(all P<0.001). Conclusions:Larger GTV boost target volume, higher BED and reduced OARs dose can be achieved in proton plans compared with photon plans. Proton P-SABR is expected to further improve the local control rate of bulky NSCLC with fewer adverse effects.
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Objective:To analyze the failure patterns and influencing factors of stereotactic ablative radiotherapy (SABR) for early-stage non-small cell lung cancer (ES-NSCLC).Methods:113 cases of ES-NSCLC treated with SABR from 2012 to 2020 in our hospital were retrospectively analyzed. The failure patterns, recurrence time, recurrence site and influencing factors were analyzed. Kaplan-Meier method was used to calculate the local recurrence rate, regional lymph node recurrence rate and distant metastasis rate. Univariate analysis was performed by Log-rank test, and multivariate analysis was performed by Cox model.Results:The median follow-up time was 58 months (range: 6-108 months), and a total of 45 patients (39.8%) recurred. The median recurrence time was 36 months. Distant metastasis (DM) occurred in 31 patients (27.4%) and DM alone in 24 patients (21.2%). Local recurrence (LR) was developed in 12 patients (10.6%) and LR alone in 7(6.2%). Regional lymph node recurrence (RR) occurred in 11 patients (9.7%) and RR alone in 6 patients (5.3%). LR combined with RR was observed in 1 case (0.9%), LR combined with DM in 3(2.7%), LR combined with RR and DM in 1(0.9%), and RR combined with DM in 3(2.7%). The 1-, 2-, 3-, 4-and 5-year recurrence rates were 5.4%, 16.6%, 27.5%, 44% and 51.2%, respectively. Univariate and multivariate analyses suggested that EGFR mutation was an influencing factor of high recurrence rate.Conclusion:ES-NSCLC patients treated with SABR alone have a high recurrence rate, and DM is the most common mode of failure. Follow-up consolidation therapy is recommended, especially for EGFR mutation-positive NSCLC patients.
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Systemic treatment and local treatment of metastatic lesion can improve the survival of patients with colorectal cancer liver metastasis (CRLM). Stereotactic body radiotherapy, also known as stereotactic ablative radiotherapy (SABR), is an effective method for local treatment of metastatic lesion and also has a certain impact on systemic immune status. SABR can directly kill tumor cells and change tumor immune microenvironment through influence on tumor cells and non-tumor cells. SABR combined with immunotherapy may increase the incidence rate of abscopal effect outside the irradiated area by affecting different links of immune response. Stereotactic ablative brachytherapy (SABT) is an independent minimally invasive treatment system with the characteristics of short treatment course, high accuracy, and definite therapeutic effect. This article reviews the application of SABR and SABT in CRLM.
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For the treatment of early non-small cell lung cancer, surgery is still one of the most important curative treatments. Lung segment or subsegment resection under video-assisted thoracoscopic surgery is becoming more and more popular. With the development of radiotherapy technology, Stereotactic Body Radiotherapy (SBRT) has achieved the similar or the same curative effect as surgery. It has become an indisputable curative treatment for patients who can not or refuse surgery, and there are still some disputes among those who can operate. Therefore, this review will elaborate on these treatment methods in order to help update the concept and provide more treatment methods and obtain more benefits for patients. Although it is no randomized clinical trial to compare SBRT with surgery, we suggest that SBRT is the curative treatment for patients who can not or refuse surgery. Especially for the elderly, or patients with cardiopulmonary diseases, diabetes and other high-risks. SBRT should become the main treatment methods, because its curative effect is not inferior to surgery and its complications are fewer and lighter. Therefore, for the treatment of non-small cell lung cancer in the early stage, it is more importent to choose individualized treatment methods so as to more benefit.
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In metastatic non-small cell lung cancer (NSCLC), the role of radiotherapy (RT) has been limited to palliation to alleviate the symptoms. However, with the development of advanced RT techniques, recent advances in immuno-oncology therapy targeting programmed death 1 (PD-1) and programmed death ligand 1 (PD-L1) and targeted agents for epidermal growth factor receptor (EGFR) mutation or anaplastic lymphoma kinase (ALK) translocation allowed new roles of RT in these patients. Within this metastatic population, there is a subset of patients with a limited number of sites of metastatic disease, termed as oligometastasis that can achieve long-term survival from aggressive local management. There is no consensus on the definition of oligometastasis; however, most clinical trials define oligometastasis as having 3 to 5 metastatic lesions. Recent phase II randomized clinical trials have shown that ablative RT, including stereotactic ablative body radiotherapy (SABR) and hypofractionated RT, to primary and metastatic sites improved progression-free survival (PFS) and overall survival (OS) in patients with oligometastatic NSCLC. The PEMBRO-RT study, a randomized phase II study comparing SABR prior to pembrolizumab therapy and pembrolizumab therapy alone, revealed that the addition of SABR improved the overall response, PFS, and OS in patients with advanced NSCLC. The efficacy of RT in oligometastatic lung cancer has only been studied in phase II studies; therefore, large-scale phase III studies are needed to confirm the benefit of local ablative RT in patients with oligometastatic NSCLC. Local intensified RT to primary and metastatic lesions is expected to become an important treatment paradigm in the near future in patients with metastatic lung cancer.
Subject(s)
Humans , Carcinoma, Non-Small-Cell Lung , Consensus , Disease-Free Survival , Lung Neoplasms , Lymphoma , Phosphotransferases , Radiotherapy , ErbB ReceptorsABSTRACT
For the treatment of early non-small cell lung cancer,surgery is still one of the most important curative treatments.Lung segment or subsegment resection under video-assisted thoracoscopic surgery is becoming more and more popular.With the development of radiotherapy technology,Stereotactic Body Radiotherapy (SBRT) has achieved the similar or the same curative effect as surgery.It has become an indisputable curative treatment for patients who can not or refuse surgery,and there are still some disputes among those who can operate.Therefore,this review will elaborate on these treatment methods in order to help update the concept and provide more treatment methods and obtain more benefits for patients.Although it is no randomized clinical trial to compare SBRT with surgery,we suggest that SBRT is the curative treatment for patients who can not or refuse surgery.Especially for the elderly,or patients with cardiopulmonary diseases,diabetes and other high-risks.SBRT should become the main treatment methods,because its curative effect is not inferior to surgery and its complications are fewer and lighter.Therefore,for the treatment of non-small cell lung cancer in the early stage,it is more importent to choose individualized treatment methods so as to more benefit.
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With the technical advances, radiotherapy has ushered in a new era of 3-D and 4D, which are associated with significantly improved therapy precision and profound change in fractionation pattern. The radiotherapy with focused rays, represented by both 3D-conformal radiotherapy (3D-CRT) and intensity modulated radiation therapy ( IMRT ) , involves the delivery of high doses to the target volume, with a less attendant potential for damages to surrounding normal tissue. Radiotherapy has been able to deliver precise, efficient, low toxic access to therapeutic effects thanks to the advance in image-guided techniques, the combination of radiotherapy equipment with image-guided system, the availability of target position information before radiotherapy with 3D or 4D image modality, the stereotactic body radiation therapy (SBRT)/the stereotactic ablation radiosurgery (SABR). Conventional fractionated radiation has seen the therapeutic effect of convincing and promising. The conventional theory of radiobiology, which deems the tumor not sensitive to radiotherapy to have good reaction with SABR, has been unable to explain the mechanism of antitumor effects arising from such exposure modes. Therefore, it is now urgent to create new radiobiological theory and system for radiotherapy in order to better illustrate the principle and mechanism of new technologies, to establish its internal relation with conventional radiobiology and to lay theoretical groundwork for popularization and dissemination of SABR in clinical medicine.
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Background and purpose:Radiomics is an emerging field that generates large amounts of valuable clinical information through extracting quantitative imaging features. The purpose of this study was to use the radiomics approach to assess the value of features captured from PET and CT in predicting the therapeutic effect in stageⅠ non-small cell lung cancer (NSCLC) after stereotactic ablative radiotherapy (SABR).Methods:Patients with stageⅠ NSCLC conifrmed by pathology and treated with SABR were included retrospectively. The gross tumor volume (GTV) was deifned by two radiologists. PET and CT scan images were collected, and radiomic features were further extracted and analyzed. Non-negative matrix factorization was used to distinguish patients with or without local control.Results:Sixteen patients were eligible for analysis. This study identiifed two PET features (LL_GLCM_Maximal_Correlation_Coeffcient and HL_GLRMS_LRE) captured from PET/CT as having signiifcance in classifying patients with or without disease development. This study not ifnd similar results in CT scans.Conclusion:It seems feasible to use radiomics information effects from PET/CT to predict therapeutic effects of SABR in stageⅠ NSCLC. Further investigation is needed.
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Objective To measure the volumetric changes precisely during stereotactic ablative radiotherapy for early-stage and oligo-metastatic lung tumors and optimize the treatment plan timely.Methods From October 2011 to October 2014, 66 patients with 71 early-stage or oligo-metastatic lung tumors received SABR.Median age was 66 years.To measure the volume of tumors, the verification images were registered before each treatment fraction with stimulation images by reference to bone structure.Tumors volume was measured by the first verification images, and were defined as the reference when evaluating the trend of tumors volume change during SABR treatment.Generalized estimated equations were used to analyze the trend of the change of tumors volume over time with several possible predictors.The primary plan (P-plan) was modified when the biological effective dose (BED) of a tumor reached 60 Gy and volume change reached 25％.The modified plan was named as M-plan.Paired t-test was used to compare the dose of organs at risk (OAR) between M-plan and P-plan.Results In 71 tumors, 49 (69％) tumors showed volumetric shrinkage, 21 (30％) tumors showed enlargement and 1 tumor showed invariance.Generalized estimated equation showed no statistical significance (P =0.281) for the volumetric shrinkage of lung tumors.M-plan was made in 26 tumors.Of these tumors, 21 tumors decreased over 25 ％ and the result of paired t-test showed V5 of lung, Dmax and D1.2 cm3 of spinal cord, Dmax and D5 cm3 of esophagus and D30 cm3 of chest wall were statistically different between two plans(t =3.139 ～11.939 ,P＜0.05).5 tumors enlarged over 25％ and the result of paired t-test showed V5 and V20 of lung,Dmax and D1.2cm3 of spinal cord, Dmax of esophagus and D30cm3 of chest wall were statistically different between the two plans(t =-10.436--2.518, P ＜ 0.05).Conclusions Size of lung tumors changed dynamically during SABR, but it is unnecessary to modify treatment plans for all tumors.The tumors which showed obvious volumetric change may benefit from modifying treatment plans.
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The role of radiotherapy in practice is mainly palliative. According to the Practice Guidelines for Management of Hepatocellular Carcinoma (2009) developed by the Korean Liver Cancer Study Group and the National Cancer Center, Korea, radiotherapy can be applied for 1) refractoriness to trans-catheter hepatic arterial chemo-embolization, 2) portal vein tumor thrombosis, and 3) palliative therapy to reduce the symptoms caused by hepatocellular carcinoma. Radiotherapy is one of the most rapidly developing fields of medical research. Recent advances in intensity-modulated radiotherapy, image-guided radiotherapy, and respiratory-gated radiotherapy technologies have enabled more accurate and precise radiation delivery for the treatment of hepatocellular carcinoma. Proton therapy is also emerging as a candidate therapy for ablative measures for patients ineligible for other curative local therapies. Due to recent advances in radiotherapy technologies, radiotherapy for hepatocellular carcinoma has been evolving into stereotactic ablative radiotherapy, which delivers an ablative dose of radiation in 1 to 4 sessions. Clinical series have confirmed that it is safe in Child-Pugh A patients and local control is sustained. The possibility for performing phase 3 randomized clinical trials involving the radiotherapy modality has increased with those advances. Not merely palliative, the role of radiotherapy in the treatment of hepatocellular carcinoma will be expanded to potentially curative therapy in patients who are ineligible for other curative local therapies.
Subject(s)
Humans , Carcinoma, Hepatocellular , Korea , Liver Neoplasms , Palliative Care , Portal Vein , Proton Therapy , Radiotherapy , Radiotherapy, Image-Guided , Radiotherapy, Intensity-Modulated , ThrombosisABSTRACT
Stereotactic body radiation therapy (SBRT) is a newly developed technique currently in clinical use. SBRT originated from stereotactic radiosurgery for intracranial tumors. SBRT has been widely used clinically for lung cancer. The practice of SBRT demands different kinds of patient fixation, breathing control, target determination, treatment planning, and verifications. The history and current standard technique are reviewed. Clinical studies of lung cancer showed high local control rates with acceptable toxicities. Past and on-going clinical trials are reviewed.