Safety and Efficacy of Stereotactic Ablative Radiotherapy for Ultra-Central Lung Cancer.

Background: Ultra-central lung cancer (UCLC) is difficult to achieve surgical treatment. Over the past few years, stereotactic ablative radiotherapy (SABR) or stereotactic body radiotherapy (SBRT) obviously improved the clinical efficacy and survival of UCLC patients. However, the adapted scheme of radiation therapy is still controversial. For this, a single arm retrospective analysis was performed on UCLC patients treated with SBRT. Material and Methods: We retrospectively studied primary UCLC patients who were treated with SBRT of 56 Gy/6-8f between 2010 and 2018. UCLC was defined as planning target volume (PTV) touching or overlapping the proximal bronchial tree, trachea, esophagus, heart, pulmonary vein, or pulmonary artery within 2 cm around the bronchial tree in all directions. Results: A total of 58 patients whose median age was 68 years (range, 46-85) were included in our study, 79.3% of whom did not undergo any previous therapy. The median dose of the PTV was 77.8 Gy (range, 43.3-91.8), and the median PTV of tumors was 6.2 cm3 (range, 12.9-265.0). With a median follow-up of 57 months (range, 6-90 months), the median cumulative overall survival (OS) rate was 58 months (range, 2-105). In addition, the 1-year, 2-year and 5-year OS rates were 94.7%, 75.0% and 45.0%, respectively. In our univariable analysis (p=0.020) and multivariate analysis (p=0.004), the OS rate was associated with the PTV. The 5-year OS rates for PTV <53.0 cm3 and PTV ≥53.0 cm3 were 61.6% and 37.4%, respectively. Regarding toxicity after SBRT, there were two cases (3.5%) with grade ≥3 adverse events, of which 1 case died of sudden severe unexplained hemoptysis. Conclusions: Patients with UCLC can benefit from SBRT at a dose of 56 Gy/6-8f. On the other hand, smaller PTV was associated with superior outcomes, and the cure difference needs to be validated by prospective comparative trials.

Single-Cell Profiling Reveals Heterogeneity of Primary and Lymph Node Metastatic Tumors and Immune Cell Populations and Discovers Important Prognostic Significance of CCDC43 in Oral Squamous Cell Carcinoma.

Although substantial progress has been made in biological research and clinical treatment in recent years, the clinical prognosis of oral squamous cell carcinoma (OSCC) is still not satisfactory. Tumor immune microenvironment (TIME) is a potential target, which plays an essential role in the response of anti-tumor immunity and immunotherapy. In this study, we used scRNA-seq data, revealing the heterogeneity of TIME between metastatic and primary site. We found that in the metastatic site, the content of cytotoxic T cells and classical activated macrophages (M1 macrophages) increases significantly, while alternately activated macrophages (M2 macrophages) and inflammatory cancer-associated fibroblasts (iCAFs) decrease, which may be due to the increased immunogenicity of OSCC cells in the metastatic site and the changes in some signal pathways. We also found that iCAFs may recruit alternately activated macrophages (M2 macrophages) by secreting CXCL12. Then, we described a regulatory network for communication between various TIME cells centered on OSCC cells, which can help to clarify the possible mechanism of lymph node metastasis in OSCC cells. By performing pseudotime trajectory analysis, we found that the expression CCDC43 is upregulated in more advanced OSCC cells and is an independent prognostic factor for poor living conditions. Other than this, the high expression of CCDC43 may impair the antitumor immunity of the human body and promote the metastasis of OSCC cells. Our research provides a profound insight into the immunological study of OSCC and an essential resource for future drug discovery.

Microsurgery vs. radiosurgery for the treatment of multiple metastases in the brain: a retrospective cohort study.

OBJECTIVE: Multiple brain metastases are a severe condition for cancer patients. To date, no general consensus exists regarding the optimal treatment procedure for multiple brain metastases. Radiotherapy is the most commonly used treatment option. The role of surgical resection for multiple brain metastases is unclear. The aim of this study was to compare the outcomes of patients with multiple brain metastases treated with either surgery or stereotactic radiosurgery (SRS). METHODS: The medical records of 279 consecutive adult patients with multiple brain metastases treated with either surgery (26 patients) or SRS (253 patients) were retrospectively reviewed. Propensity score matching was conducted to correct for discrepancies in the baseline characteristics, and 78 patients (26 receiving surgery and 52 receiving SRS) were chosen for comparison of outcomes, such as overall survival, local tumor control rate, and symptom improvement. RESULTS: The tumor size in the surgery group was significantly greater than that in the SRS group after propensity score matching. However, the neurological recovery rate, incidence of leptomeningeal metastasis after surgery, 1-year local tumor control rate, and overall survival were not significantly different between groups. CONCLUSIONS: Our data demonstrate that surgery and radiosurgery have identical overall survival and local tumor control rates in patients with 2 to 4 brain metastases. Although SRS remains the primary and standard option for patients with brain metastasis, surgery offers several distinct advantages, such as establishing a diagnosis or relieving mass effects, and may additionally be beneficial in carefully selected patients with 2-4 brain metastases.

Is lymph node dissection mandatory among early stage endometrial cancer patients? A retrospective study.

BACKGROUND: Whether routine lymph node dissection for early endometrial cancer is beneficial to survival is still controversial. However, surgeons usually perform lymph node dissection on all patients with early endometrial cancer. This study aimed to prove that the risk of lymph node metastasis, as defined by our standard, is very low in such patients and may change the current surgical practice. METHODS: 36 consecutive patients who had staged surgery for endometrial cancer were collected. All eligible patients meet the following very low risk criteria for lymph node metastasis, including: (1) preoperative diagnosis of endometrial cancer (preoperative pathological diagnosis), (2) tumors confined to the uterine cavity and not beyond the uterine body, (3) PET-MRI lymph node metastasis test is negative. PET-MRI and pathological examination were used to assess the extent and size of the tumor, the degree of muscular invasion, and lymph node metastasis. RESULTS: The median age at diagnosis was 52 years (range 35-72 years). The median tumor size on PET-MRI was 2.82 cm (range 0.66-6.37 cm). Six patients underwent robotic surgery, 20 underwent laparoscopic surgery, 8 underwent Laparoscopic-assisted vaginal hysterectomy, and 2 underwent vaginal hysterectomy. 23% (63.9%) patients had high-grade (i.e. 2 and 3) tumors. Among the 36 patients who underwent lymph node sampling, the median number of lymph nodes retrieved was 32 (range 9-57 nodules). No patient (0%) was diagnosed with lymph node metastasis. According to the policy of each institution, 8 patients (22.2%) received adjuvant therapy, and half of them also received chemotherapy (4 patients; 50%). CONCLUSIONS: None of the patients who met the criteria had a pathological assessment of lymph node metastasis. Omitting lymph node dissection may be reasonable for patients who meet our criteria.

Risk-adapted stereotactic body radiation therapy for central and ultra-central early-stage inoperable non-small cell lung cancer.

To determine the therapeutic efficacy and safety of risk-adapted stereotactic body radiation therapy (SBRT) schedules for patients with early-stage central and ultra-central inoperable non-small cell lung cancer. From 2006 to 2015, 80 inoperable T1-2N0M0 NSCLC patients were treated with two median dose levels: 60 Gy in six fractions (range, 48-60 Gy in 4-8 fractions) prescribed to the 74% isodose line (range, 58%-79%) for central lesions (ie within 2 cm of, but not abutting, the proximal bronchial tree; n = 43), and 56 Gy in seven fractions (range, 48-60 Gy in 5-10 fractions) prescribed to the 74% isodose line (range, 60%-80%) for ultra-central lesions (ie abutting the proximal bronchial tree; n = 37) on consecutive days. Primary endpoint was overall survival (OS); secondary endpoints included progression-free survival (PFS), tumor local control rate (LC), and toxicity. Median OS and PFS were 64.47 and 32.10 months (respectively) for ultra-central patients, and not reached for central patients. Median time to local failure, regional failure, and any distant failures for central versus ultra-central lesions were: 27.37 versus 26.07 months, 20.90 versus 12.53 months, and 20.85 versus 15.53 months, respectively, all P < .05. Multivariate analyses showed that tumor categorization (ultra-central) and planning target volume ≥52.76 mL were poor prognostic factors of OS, PFS, and LC, respectively (all P < .05). There was one grade 5 toxicity; all other toxicities were grade 1-2. Our results showed that ultra-central tumors have a poor OS, PFS, and LC compared with central patients because of the use of risk-adapted SBRT schedules that allow for equal and favorable toxicity profiles.

Identification of Floral Scent Profiles in Bearded Irises.

Bearded irises are ornamental plants with distinctive floral fragrance grown worldwide. To identify the floral scent profiles, twenty-seven accessions derived from three bearded iris, including Iris. germanica, I. pumila and I. pallida were used to investigate the composition and relative contents of floral scent components by headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). A total of 219 floral scent components were detected in blooming flowers. The scent profile varied significantly among and within the three investigated species. Principal component analysis (PCA) indicated that terpenes, alcohols and esters contributed the most to the floral scent components and 1-caryophyllene, linalool, citronellol, methyl cinnamate, ß-cedrene, thujopsene, methyl myristate, linalyl acetate, isosafrole, nerol, geraniol were identified as the major components. In a hierarchical cluster analysis, twenty-seven accessions could be clustered into six different groups, most of which had representative scent components such as linalool, citronellyl acetate, thujopsene, citronellol, methyl cinnamate and 1-caryophyllene. Our findings provide a theoretical reference for floral scent evaluation and breeding of bearded irises.

Cystic brain metastases had slower speed of tumor shrinkage but similar prognosis compared with solid tumors that underwent radiosurgery treatment.

PURPOSE: Traditionally, radiosurgery was considered less effective for patients with cystic brain metastases. However, comparisons of prognosis between cystic and solid brain metastases in cancer patients have been seldom reported. We aimed to compare the survival between cystic and solid brain metastases and assess risk factors for overall survival after brain metastases (BMOS) in patients who underwent radiosurgery treatment. PATIENTS AND METHODS: The Kaplan-Meier method and multivariate Cox regression analysis were used to compare survival time and evaluate risk factors for BMOS. RESULTS: A total of 356 patients (including 498 brain metastases) were analyzed in our study, including 67 patients (67/356, 18.8%) with 75 cystic brain metastases. There is no statistical significance in BMOS between patients with cystic (17 months, range: 3-64 months) and solid (17.5 months, range: 1-65 months) brain metastases (P=0.148). However, the volume of cystic brain metastases decreased more slowly than solid brain metastases (P<0.05). The results indicated that high recursive partitioning analysis classification (P=0.006), large volume of brain metastases (P=0.006), and different primary lesion (especially gastrointestinal tract tumor) (P=0.001) were associated with poor prognosis in patients with brain metastases. CONCLUSION: There is no difference in prognosis and local control between patients with cystic and solid brain metastases who underwent radiosurgery. However, the rate and speed of tumor shrinkage were lower in cystic brain metastases after radiotherapy. Patients with larger brain metastases had shorter survival time, regardless of cystic or solid brain metastases.

A Second Course of Stereotactic Image-Guided Robotic Radiosurgery for Patients with Cerebral Metastasis.

OBJECTIVES: The purpose of this research was to study the outcome of brain metastases in a cohort of patients undergoing a second course of stereotactic image-guided robotic radiosurgery and to identify predictors corelated with survival. METHODS: A total of 63 patients with primary malignancies underwent a second course of CyberKnife radiosurgery for intracranial progression, including recurrence and new metastases after initial stereotactic radiosurgery (SRS). Overall survival (OS) and control rate were calculated by the Kaplan-Meier method. A Cox proportional hazards model was used to analyze predictive factors for survival. RESULTS: With a median follow-up duration of 12 months after second SRS, the median OS of the second course of radiosurgery was 18 months. On multivariate analysis, the sum of total planned target volume (hazard ratio, 2.112; 95% confidence interval, 1.069-4.173) and minimum dose (hazard ratio, 1.990, 95% confidence interval, 1.017-3.892) were significantly associated with OS. Median intracranial progression-free survival was 23 months. The 6-month and 12-month local control rates of the targets were 97.0% and 94.4%, respectively. Univariate analysis showed that only tumor number significantly influenced intracranial progression-free survival (P = 0.012). Nine patients (14.2%) developed brain necrosis. Median time to brain necrosis in regions in which brain necrosis occurred after a single course of SRS was not reached, compared with 16 months for those treated with repeat SRS (P = 0.041). CONCLUSIONS: A second course of CyberKnife radiosurgery seems to be an effective salvage option for brain progression after initial SRS. The total planned target volume shows prediction for OS. Tumor volume of initial SRS may influence selection of the potential population that may benefit from salvage radiosurgery.

Clinical study on the influence of motion and other factors on stereotactic radiotherapy in the treatment of adrenal gland tumor.

BACKGROUND: The aim of this study was to investigate the adrenal tumor motion law and influence factors in the treatment of adrenal gland tumor and provide a reference value basis for determining the planning target volume margins for therapy. MATERIALS AND METHODS: The subjects considered in this study were 38 adrenal tumor patients treated with CyberKnife with the placement of 45 gold fiducials. Fiducials were implanted into each adrenal tumor using ß-ultrasonic guidance. Motion amplitudes of gold fiducials were measured with a Philips SLS simulator and motion data in the left-right, anterior-posterior, and cranio-caudal directions were obtained. Multiple linear regression models were used to analyze influencing factors. t-Test was used for motion amplitude comparison of different tumor locations along the z-axis. RESULTS: The motion distances were 0.1-0.4 cm (0.27±0.07 cm), 0.1-0.5 cm (0.31±0.11 cm), and 0.5-1.2 cm (0.87±0.21 cm) along the x-, y-, and z-axes, respectively. Motion amplitude along the z-axis may be affected by tumor location, but movement along the other axes was not affected by age, height, body mass, location, and size. CONCLUSION: The maximum motion distance was along the z-axis. Therefore, this should be the main consideration when defining the planning target volume safety margin. Due to the proximity of the liver, adrenal gland tumor motion amplitude was smaller on the right than the left. This study analyzed adrenal tumor motion amplitude data to evaluate how motion and other factors influence the treatment of adrenal tumor with a goal of providing a reference for stereotactic radiotherapy boundary determination.

Stereotactic body radiation therapy for patients with recurrent pancreatic adenocarcinoma at the abdominal lymph nodes or postoperative stump including pancreatic stump and other stump.

BACKGROUND AND AIM: The aim of this study is to evaluate the efficacy and safety of stereotactic body radiation therapy (SBRT) using CyberKnife in the treatment of patients with recurrent pancreatic adenocarcinoma at the abdominal lymph node or stump after surgery. PATIENTS AND METHODS: Between October 1, 2006 and May 1, 2015, patients with recurrent pancreatic adenocarcinoma at the abdominal lymph node or stump after surgery were enrolled and treated with SBRT at our hospital. The primary end point was local control rate after SBRT. Secondary end points were overall survival, time to symptom alleviation, and toxicity, assessed using the Common Terminology Criteria for Adverse Events version 4.0. RESULTS: Twenty-four patients with 24 lesions (17 abdominal lymph nodes and seven stumps) were treated with SBRT, of which five patients presented with abdominal lymph nodes and synchronous metastases in the liver and lung. The 6-, 12-, and 24-month actuarial local control rates were 95.2%, 83.8%, and 62.1%, respectively. For the entire cohort, the median overall survival from diagnosis and SBRT was 28.9 and 12.2 months, respectively. Symptom alleviation was observed in eleven of 14 patients (78.6%) within a median of 8 days (range, 1-14 days) after SBRT. Nine patients (37.5%) experienced Common Terminology Criteria for Adverse Events version 4.0 grade 1-2 acute toxicities; one patient experienced grade 3 acute toxicity due to thrombocytopenia. CONCLUSION: SBRT is a safe and effective treatment for patients with recurrent pancreatic adenocarcinoma at the abdominal lymph node or stump after surgery. Further studies are needed before SBRT can be recommended routinely.

Stereotactic radiation therapy for oligometastases or oligorecurrence within mediastinal lymph nodes.

AIMS: This study evaluated the safety and efficacy of stereotactic radiation therapy (SRT) for the treatment of patients with oligometastases or oligorecurrence within mediastinal lymph nodes (MLNs) originating from different tumors. METHODS: Between October 2006 and May 2015, patients with MLN oligometastases or oligorecurrence were enrolled and treated with SRT at our hospital. The primary endpoint was MLN local control (LC). Secondary endpoints were time to symptom alleviation, overall survival (OS) after SRT, and toxicity using the Common Terminology Criteria for Adverse Events (CTCAE v4.0). RESULTS: Eighty-five patients with 98 MLN oligometastases or oligorecurrences were treated with SRT. For the entire cohort, the 1-year and 5-year actuarial LC rates were 97% and 77%, respectively. Of 53 symptomatic patients, symptom alleviation was observed in 47 (89%) after a median of 5 days (range, 3-30 days). The median OS was 27.2 months for all patients. For patients with non-small cell lung cancer, univariate and multivariate analyses revealed that a shorter interval between diagnosis of primary tumors and SRT and larger MLN SRT volume were associated with worse OS. CTCAE v4.0 ≥ Grade 3 toxicities occurred in six patients (7%), with Grade 5 in three patients (all with RT history to MLN station 7). CONCLUSIONS: SRT is a safe and efficacious treatment modality for patients with oligometastases or oligorecurrence to MLNs originating from different tumors, except for patients who received radiotherapy to MLN station 7. Further investigation is warranted to identify the patients who benefit most from this treatment modality.

Early diagnosis, treatment and prognosis of epilepsy with continuous spikes and waves during slow sleep.

The study is to investigate the importance of early diagnosis and treatment to the prognosis of epilepsy with continuous spikes and waves during slow sleep (CSWS). A total of 8 cases of CSWS children were followed up for 6 months to 4 years. Retrospective analysis of the clinical and electroencephalographic (EEG) characteristics, treatment and prognosis was performed in these 8 cases. Of the 8 cases of CSWS patients, 5 were males and 3 were females. Epilepsy onset ages were from 3 years and 1 month to 10 years and 6 months. Five cases of the patients were with brain lesions while the other 3 cases appeared normally by imaging detection. After treatment with valproic acid, clonazepam, lamotrigine and hormone for 3 months, clinical symptoms and EEG were improved significantly in 7 cases. Two cases relapsed at 6 months after comprehensive treatment. For atypical early performance of CSWS, early diagnosis and regular treatment could improve the condition of children with seizures and effectively inhibit the epileptic activity with good prognosis.

Analysis of clinical efficacy of CyberKnife(®) treatment for locally advanced pancreatic cancer.

OBJECTIVE: To evaluate the efficacy and safety of CyberKnife(®) treatment for locally-advanced pancreatic cancer (LAPC). METHODS: The efficacy of CyberKnife(®) treatment was analyzed in 59 LAPC patients treated between October 2006 and September 2014. The median tumor volume was 27.1 mL (13.0-125.145 mL). The median prescribed dose was 45 Gy (35-50 Gy), delivered in 5 fractions (3-8 fractions). The overall survival (OS) rates and freedom from local progression (FFLP) rates were estimated using the Kaplan-Meier survival curve. RESULTS: The median follow-up for all patients was 10.9 months (3.2-48.7 months) and 15.6 months (3.9-37.6 months) among surviving patients. The median OS was 12.5 months, and the 1-year and 2-year survival rates were 53.9% and 35.1%, respectively. The 1-year FFLP rate was 90.8% based on the computed tomography (CT) evaluation. Grade 1-2 acute and late-stage gastrointestinal (GI) reactions were observed in 61% of the patients. One patient experienced grade 3 toxicity. CONCLUSION: Excellent clinical efficacy was obtained after treatment of LAPC using CyberKnife(®), with minimal toxicity.

Clinical evaluation of stereotactic radiation therapy for recurrent or second primary mediastinal lymph node metastases originating from non-small cell lung cancer.

AIMS: To evaluate the safety and efficacy of stereotactic radiotherapy (SRT, both stereotactic body RT [SBRT] and fractionated stereotactic RT [FSRT]) in the treatment of patients with recurrent or second primary mediastinal lymph node metastases (R/SP-MLNMs) originating from non-small cell lung cancer (NSCLC). METHODS: Between 10/2006 and 7/2013, patients with R/SP-MLNMs originating from NSCLC were enrolled and treated with SRT at our hospital; their data was stored in prospectively-collected database. The enrolled patients were divided into Group A (without prior RT) and Group B (with prior RT). The primary end-point was overall survival (OS). The secondary end-points were the MLNM local control (LC), the time to symptom alleviation, and toxicity using the Common Terminology Criteria for Adverse Events (CTCAE v4.0). RESULTS: Thirty-three patients were treated (16 in Group A with 19 R/SP-MLNMs and 17 in Group B with 17 R/SP-MLNMs). For the entire cohort, the median OS was 25.5 months with a median follow-up of 20.9 months (range, 3.2-82). The 1-year and 3-year actuarial LC rates were 100% and 86%, respectively. Symptom alleviation was observed in 52% of patients, after a median of 6 days (range, 3-18). CTCAE v4.0 ≥ Grade 3 toxicities occurred in 5 patients (15%; all in Group B); among them, Grade 5 in 2 patients. CONCLUSIONS: We recommend exercising extreme caution in using SRT for R/SP-MLNMs in patients who received prior RT (particularly to LN station 7). For patients without previous RT, SRT appears to be safe and efficacious treatment modality; prospective studies are warranted.

Stereotactic body radiation therapy using the CyberKnife(®) system for patients with liver metastases.

The aim of this study was to evaluate the efficacy and toxicity of stereotactic body radiation therapy (SBRT) in the treatment of patients with liver metastases. Between August 2006 and July 2011, patients with 1-4 liver metastases were enrolled and treated with SBRT using the CyberKnife(®) system at Tianjin Medical University Cancer Institute and Hospital. The metastases were from different primary tumors, with a maximum tumor diameter of less than 6 cm. The primary endpoint was local control. Secondary endpoints were overall survival, progression-free survival, distant progression-free survival, and adverse events. Fifty-seven patients with 80 lesions were treated with SBRT. The 1-year and 2-year local control rates were 94.4% and 89.7%, respectively. The difference in local control between patients who received adjuvant treatment before SBRT and those who did not reached statistical significance (P=0.049). The median overall survival for the entire cohort was 37.5 months. According to the primary tumor sites, the median overall survival was not reached. The 2-year overall survival rate was 72.2% in the favorable group (primary tumors originating from the colon, breast, or stomach, as well as sarcomas); however, in the unfavorable group (primary tumors originating from the pancreas, lung, ovary, gallbladder, uterus, hepatocellular carcinoma, as well as olfactory neuroblastoma), the median overall survival and 2-year overall survival rates were 37.5 months and 55.9%, respectively (P=0.0001). Grade 1-2 fatigue, nausea, and vomiting were the most common adverse events, and no grade 3 and higher adverse events were observed. With excellent local control in the absence of severe toxicity, SBRT provides an alternative for patients with 1-4 liver metastases who cannot undergo surgery or other treatments.

Robotic stereotactic irradiation and reirradiation for spinal metastases: safety and efficacy assessment.

BACKGROUND: Spine is the most common site of bone metastases in patients with cancer. Conventional external beam radiotherapy lacks precision to allow delivery of large fraction radiation but simultaneously limit the dose to spinal cord. The purpose of this study was to evaluate the safety and efficacy of CyberKnife(®) radiation therapy for spinal metastases. METHODS: Seventy-three lesions in 62 patients treated with CyberKnife radiotherapy from September 2006 to June 2010 for spinal metastases were retrospectively reviewed. Thirteen tumors in 12 patients had received prior radiation. Patients were followed clinically and radiographically for at least 12 months or until death. In all patients, the spinal cord and thecal sac were contoured for dose-volume constraints, and maximum doses to 0.1, 0.5, 1, 2, and 5-ml volumes were analyzed. RESULTS: Using the CyberKnife System, 20-48 Gy in one to five fractions for unirradiated patients, and 21-38 Gy in one to five fractions for the previously irradiatied patients, were delivered. Median 2-Gy normalized Biological Equvalent Dose (nBED) of unirradiated targets and irradiated targets were 49.6 Gy10/2 (range, 31.25-74.8 Gy10/2) and 46.9 Gy10/2 (range, 29.8-66 Gy10/2), respectively. With a median follow-up of 9.4 months (range, 2.5-45 months), twenty-nine patients (46.7%) were alive, whereas the others died of progressive disease. Fifty-six patients (93.3%) reported complete or partial reduction of pain after CyberKnife radiotherapy at one-month follow-up, 17 patients (28.3%) reported some degree of pain relief after first fraction of the treatment course. Two patients experienced local recurrence at fifth and ninth months post-radiotherapy. Median maximum nBED for spinal cord and thecal sac of naive targets were 68.6 Gy2/2 (range, 8.3-154.5 Gy2/2) and 83.5 Gy2/2 (range, 10.5-180.5 Gy2/2), respectively. Median maximum nBED for spinal cord and thecal sac for the re-irradiated targets were 58.6 Gy2/2 (range, 17.7-140 Gy2/2) and 70.5 Gy2/2 (range, 21.7-141.3 Gy2/2), respectively. No patient developed radiation related myelopathy during the follow-up period. CONCLUSION: Cyberknife radiotherapy is clinically effective and safe for spinal metastases, even in previously irradiated patients.

[An initial report of cyberknife radiosurgery for primary hepatic carcinoma].

OBJECTIVE: To study the efficacy and toxicity of cyberknife radiosurgery for primary hepatic carcinoma. METHODS: From September 2006 to March 2008, 17 patients with clinical stage I-III primary hepatic carcinoma were treated with cyberknife at Tianjin Cancer Hospital. 12 patients received previous treatment of surgery, or interventional therapy or radiofrequency therapy before the cyberknife radiosurgery. Totally 23 lesions in the liver were treatment. The median planning target volume (PTV) was 75 ml (13 - 351 ml). Fiducials were placed in or adjacent to the tumor one week before the CT scan simulation. The median total prescription dose was 45 Gy (range: 39 - 52 Gy) at 3-8 fractions and the median prescription isodose lines was of 78.0% (range: 75.0% - 81.0%. RESULTS: The follow-up time was 3-30 months (median: 14 months). All patients finished the treatment and slightly fatigue was the most common complain. There were 12 patients alive and 5 patients died. All the lesions in liver treated by the cyberknife radiosurgery achieved local control. CONCLUSION: The cyberknife radiosurgery for primary hepatic carcinoma showed a high rate of local control and minimal toxicity. Long time follow-up is necessary to evaluate the survival data and late toxicity.

[Simulation of SAR and temperature distribution for tumor RF thermotherapy with double-frequencies and double-plates].

The model establishment and numerical simulation of specific absorption rate (SAR) and the unsteady-state temperature distribution for radio frequency (RF) thermotherapy with double-frequencies and double-plates are presented in this paper. The model can correctly reflect the attenuation of electromagnetic wave in the biotissue. The variation of perfusion with temperature and the lower perfusion in tumor tissue are fully considered in the simulation of unsteady-state temperature profiles. Also presented are detailed analyses and discussions on the characteristics of SAR and temperature profiles, and the effects of the plates location and power as well as of the perfusion on the depth of effective treatment.

[The simulation of SAR and temperature distribution and parameters analysis for tumor RF thermotherapy].

In this paper are reported the model establishment and numerical simulation of specific absorption rate(SAR) and the unsteady temperature distribution for the non-invasive tumor RF thermotherapy. The model can correctly reflect the attenuation of electromagnetic wave in the biotissue, the variation of perfusion with temperature and lower perfusion of the tumor tissue are fully considered in the simulation. These measures made simulation results more close to the clinical results. Also presented in the paper are detailed analyses and discussions on the characteristics of SAR of electromagnetic energy and the temperature profiles, the effects of the frequency and the perfusion on the depth for effective treatment. The simulation results are of great significance for directing the clinical application of tumor RF thermotherapy.