Epidemiological and Clinical Profile of Breast Cancer at Bamako Radiotherapy Center

Breast cancer is a major public health problem because of its incidence and mortality. Purpose: To establish the epidemiological and clinical characteristics of breast cancer seen at the radiotherapy center at the Mali Hospital of Bamako. Patients and methods: It was a retrospective, descriptive study of data from patients seen for breast cancer at the Center of Radiotherapy of Mali Hospital between April 2014 and December 2016. The parameters studied were: age, sex, family history of breast cancer, menopausal status, parity, breast tumor location, histological type, histological grade, cancer classification stage. Results: 134 cases of breast cancer were collected, with a frequency of 15%. The sex ratio (H/F) of 0.007. The patient’s mean age was 47 ± 11 years old. The most represented age groups were 33 - 47 years old with 45.5% and 48 - 62 years old with 39%. Three percent (3%) of patients had a family history of breast cancer. Fifty (50%) of the patients were menopausal. The main clinical signs found were : mammary nodules (98%), mastodynia (65%), nodes (67%). Invasive ductal carcinomas were found in 94% of patients, followed by infiltrating lobular carcinomas with 3.7% and metaplastic carcinomas with 1.7%. SBR Grades II and III were mostly found with 37% and 23%. The average tumor size was 87 mm ± 43. Stage III was predominantly represented with 72%, followed by Stage II with 24% and Stages I and IV with 2% each. Conclusion: Breast cancer is common and reaches both before and after 50 years;the diagnosis is usually late;hence it is the importance of raising awareness and screening before the age of 50 and popularizing some complementary tests to better understand the prognosis of this disease and promote more targeted and conservative treatments that will improve survival.

Epidemiological and Clinical Profile of Cervix Cancer at Bamako Radiotherapy Center

Cervical cancer remains a major public health problem in Africa, particularly in Mali. The goal of this work was to investigate the epidemiological and clinical aspects of cervix cancer seen at the radiation therapy center. This was a descriptive study on the retrospective collection of data on patients found in the Radiation Therapy Centre of Bamako, for invasive cervical cancer be-tween April 2014 and April 2017. The average age of our population was 52 ± 12.5 years with extremes ranges from 18 to 95 years. The most represented age group was [50 - 65 years] with 44.2%. The predominant histological type was squamous carcinoma (CE) with 94.2%. Bleeding were found in almost all patients, most often associated with foul smelling hydrorrhea;80.3% of our patients were stage III and 12.9% of stage IV according to the IFGO classifi-cation. Cervix cancer remains a major public health problem in Mali. The di-agnosis is often late, therefore, resulting in late care and unfavorable progno-sis. Sensitization, vulgarization of vaccination and systematization of screen-ing could be helpful in the fight against this cancer.

Phase II Clinical Study of Three-Dimensional Printed Coplanar Template Combined with CT-Guided Percutaneous Core Needle Biopsy of Pulmonary Nodules in Elderly Patients

Background: As the population age structure gradually ages, more and more elderly people were found to have pulmonary nodules during physical examinations. Most elderly people had underlying diseases such as heart, lung, brain and blood vessels and cannot tolerate surgery. Computed tomography (CT)-guided percutaneous core needle biopsy (CNB) was the first choice for pathological diagnosis and subsequent targeted drugs, immune drugs or ablation treatment. CT-guided percutaneous CNB requires clinicians with rich CNB experience to ensure high CNB accuracy, but it was easy to cause complications such as pneumothorax and hemorrhage. Three-dimensional (3D) printing coplanar template (PCT) combined with CT-guided percutaneous pulmonary CNB biopsy has been used in clinical practice, but there was no prospective, randomized controlled study. Methods: Elderly patients with lung nodules admitted to the Department of Oncology of our hospital from January 2019 to January 2023 were selected. A total of 225 elderly patients were screened, and 30 patients were included after screening. They were randomly divided into experimental group (Group A: 30 cases) and control group (Group B: 30 cases). Group A was given 3D-PCT combined with CT-guided percutaneous pulmonary CNB biopsy, Group B underwent CT-guided percutaneous pulmonary CNB. The primary outcome measure of this study was the accuracy of diagnostic CNB, and the secondary outcome measures were CNB time, number of CNB needles, number of pathological tissues and complications. Results: The diagnostic accuracy of group A and group B was 96.67% and 76.67%, respectively (P = 0.026). There were statistical differences between group A and group B in average CNB time (P = 0.001), number of CNB (1 vs more than 1, P = 0.029), and pathological tissue obtained by CNB (3 vs 1, P = 0.040). There was no statistical difference in the incidence of pneumothorax and hemorrhage between the two groups (P > 0.05). Conclusions: 3D-PCT combined with CT-guided percutaneous CNB can improve the puncture accuracy of elderly patients, shorten the puncture time, reduce the number of punctures, and increase the amount of puncture pathological tissue, without increasing pneumothorax and hemorrhage complications. We look forward to verifying this in a phase III randomized controlled clinical study. .

Is there a place for optimizing thoracic radiotherapy in limited-stage small cell lung cancer after twenty years?

Thoracic radiotherapy(TRT)is one of the main treatments in limited-stage small cell lung cancer(LS-SCLC).Hyperfractionated TRT(45 Gy,1.5 Gy twice daily)has been the standard of care(SOC)since Turrisi and colleagues published the results of their clinical trial in 1999.Two meta-analyses have demonstrated the benefits of concurrent chemotherapy and TRT in terms of intrathoracic disease control at 2 years and 3-year overall survival(OS).The phase 2 trial by Grønberg et al(2016)comparing once-daily hypofractionated TRT to twice-daily hyperfractionated TRT in LS-SCLC found similar outcomes in both groups in terms of response rate,progression-free survival(PFS),grade 3-4 adverse effects,and OS.The CONVERT trial,published in 2017,failed to demonstrate the superiority of the conventional scheme(once-daily TRT)vs twice-daily radiotherapy,despite the application of modern radiotherapy techniques and a quality assurance programme,thus confirming the twice-daily hyperfractionated regimen as the SOC.At the 2020 American Society of Clinical Oncology(ASCO)annual meeting,Grønberg et al reported preliminary findings from a phase 2 trial comparing two different TRT dose regimens(45 Gy vs 60 Gy),both administered twice daily.Those data demonstrated a marked improvement in 2-year survival rates in the high dose arm(70.2%vs 46.1%,P=0.002),despite similar objective response rates and PFS outcomes.Those findings provide a new treatment alternative to consider:Hyperfractionated,high-dose TRT.However,the results of that trial will need to be validated in a large,randomized phase 3 study.The results of the phase 2 CALCG 30610 trial will help to clarify the optimal dose and regimen.The potential role of upfront immunotherapy,which early data suggest may improve OS,also needs to be determined.

Clinical Effects of Lianbai Liquid in Prevention and Treatment of Dermal Injury Caused by Radiotherapy

Objective: To observe the effect of Lianbai liquid (连柏液) in prevention and treatment of acute radiation dermal injury. Method: From May 2000 to December 2005, 126 cancer patients were randomly divided into a prevention group of 75 cases given externally topical application of Lianbai liquid since the first radiotherapy, and a control group Ⅰ of 51 cases given only advice after radiotherapy; while the other 92 cancer patients who had already had grade Ⅲ acute radiation-induced dermal injury were randomly divided into a treatment group of 54 cases treated by externally topical use of Lianbai liquid, and a control group Ⅱ of 38 cases treated by topical use of norfloxacin. Clinical evaluation was carried out according to the CTC.V2.0 standard stipulated by NCI for classifying acute radiation dermal injury. Results: The incidence of skin reaction was 32.0% in the prevention group and 92.2% in the control group Ⅰ, with an obvious difference between the two groups (χ2=54.163, P<0.01). Mild radioactive reaction (grade Ⅰ and Ⅱ) was 28.0% (21/75) in the prevention group and 70.6% (36/51) in the control group Ⅰ, with a remarkable difference between the two groups (χ2=22.226, P<0.01). The effective rate for grade Ⅲ dermal injury was 92.6% (50/54) in the treatment group and 65.9% (25/38) in the control group Ⅱ, with a remarkable difference between the two groups (χ2=6.018, P=0.024). The wound-healing time was 11.07±2.21 days in the treatment group and 18.08±1.76 days in the control group Ⅱ, with a remarkable difference between the two groups (u=16.932, P<0.01). Conclusion: Lianbai liquid can effectively prevent the radiation dermatitis, and treat grade Ⅲ acute radiation dermal injury with obvious curative effect.

Influences of Motion Artifacts on Three-Dimensional Reconstruction Volume and Conformal Radiotherapy Planning

Objective ：To investigate the influences of motion artifacts on three-dimensional （3D） reconstruction volume and conformal radiotherapy planning. Methods： A phantom which can mimic the clip motion of lung tumor along the cranial-caudal direction is constructed by step motor, small ball of polyethylene and potato. Ten different scan protocols were set and CT data of the phantom were acquired by using a commercial GE LightSpeedl6 CT scanner. The 3D reconstruction of the CT data was implemented by adopting volume-rendering technology of GE AdvantageSim 6.0 system. The reconstructed volumes of each target in different scan protocols were measured through 3D measuring tools. Thus, relative deviations of the reconstruction volumes between moving targets and static ones were determined. The three-dimensional conformal radiation therapy （3D- CRT） plans and conformal fields were created and compared for a static/moving target with the WiMRT treatment planning system （TPS）. Results：For a static target, there was no obvious difference among the 3D reconstruction volumes when the CT data were acquired with different pitches and slices. The appearance of 3D reconstruction volume and 3D conformal field of a moving target was quite different from that of static one. The maximum relative deviation is nearly 90% for a moving target scanned with different scan protocols. The relative deviations are variable among the different targets, about from -39.8% to 89.5% for a smaller target and from - 18.4% to 20.5% for a larger one. Conclusion ：The motion artifacts have great effects on 3 D-CRT planning and reconstruction volume, which will greatly induce distorted conformal radiation fields and false DVHs for a moving target.

Complex Target Volume Delineation and Treatment Planning in Radiotherapy for Malignant Pleural Mesothelioma (MPM)

Introduction: Radiotherapy alone or combined with surgery and/or chemotherapy is being investigated in the treatment of malignant pleural mesothelioma (MPM). This study aimed to simulate a Volumetric Modulated Arc Therapy (VMAT) treatment of a patient with MPM. Materials and Methods: CT images from a patient with intact lungs were imported via DICOM into the Pinnacle3 treatment planning (TP) system (TPS) and used as a model for MPM to delineate organs at risk (OAR) and both clinical and planning target volumes (CTV and PTV) with a margin of 5 mm. Elekta Synergy with 6 MV photons and 80 leafs MLCi2 was employed. VMAT plans were generated using two coplanar arcs with gantry rotation angles of 178° - 182°, the collimator angles of each arc were set to 90°, Octavius® 4D 729 was employed for quality assurance while the calculated and measured doses were compared using VeriSoft. Results: A TP was achieved. The Gamma volume analysis with criteria of 3 mm distance to agreement and 3% dose difference yielded the gamma passing rate = 99.9%. The reference isodose was 42.75 Gy with the coverage constraints for the PTV D95 and V95 = 95.0% of 45 Gy. The remaining dosimetric parameters met the recommendations from the clinically acceptable guidelines for the radiotherapy of MPM. Conclusion: Using well-defined TV and VMAT, a consistent TP compared to similar ones from publications was achieved. We obtained a high agreement between the 3D dose reconstructed and the dose calculated.

Analysis of the Prognosis for Patients with Stage T3N0-1M0 Nasopharyngeal Carcinoma Treated by Chemotherapy Combined with Radiotherapy

OBJECTIVE To investigate the relationship between the therapeutic modality and prognostic factors for the patients with T3N0-1M0 nasopharyngeal carcinoma. METHODS The clinical data from 127 cases of T3N0-1M0 nasopharyngeal carcinoma patients with initial treatment, during the period from January 4th, 2000 to November 12th, 2001, were retrospectively analyzed. The cases were divided into Group A with simple radiotherapy (90) and Group B with the radiation therapy combined with chemotherapy (37), based on various patients' conditions. In group B, inductive chemotherapy was conducted for 18 cases, inductive chemotherapy plus homochronous chemotherapy for 5 and homochronous chemotherapy for 14. RESULTS The 5-year overall survival (OS) in the groups A and B was 73.4% and 72.3% respectively (P>0.05); the cancer-correlated survival (CCS) in the 2 groups was 76.4% and 72.3% respectively (P>0.05); the disease-free survival (DFS) in group A and B was 65.5% and 71.7% respectively (P<0.05). A multiple analysis showed that the mode of radiation therapy plus chemotherapy was a favorable independent impact factor for DFS. CONCLUSION Chemotherapy plus radiotherapy can improve the DFS of patients with T3N0-1M0 nasopharyngeal carcinoma, but fails to prolong the survival time of the patients. The modality of chemotherapy plus radiotherapy is not the necessary choice in treatment of patients with T3N0-1M0 nasopharyngeal carcinoma.

Immunosuppressive treatment and radiotherapy in kidney transplant patients:A systematic review

BACKGROUND Immunosuppression(IS)therapy may contribute to cancer development.Some authors have proposed to reduce immunosuppression drugs dose in case of viral infections,in immunosuppression-related diseases,and in patients undergoing radiotherapy.The present analysis reports the results of a systematic review on kidney transplant recipients undergoing immunosuppression and radiotherapy.AIM To define if it is necessary reduce immunosuppression drugs during radiotherapy.METHODS The literature search was based on three electronic databases(Pubmed,Scopus,and Web of Science)using selected keywords linked through the"AND"and"OR"Boolean operators to build specific strings for each electronic search engine.Two researchers independently screened the citations,and disagreement was resolved by discussion or through the intervention of a third author.The review was conducted and reported according to the PRISMA statement.Extracted data were narratively synthesized,and,where possible,frequencies,percentages,and ranges were calculated.RESULTS The literature search resulted in 147 citations.After abstracts screening,21 records were selected for full-text evaluation.Fifteen of these were excluded,leaving six papers considered suitable for analysis.There is still no clear evidence that withdrawing antimetabolites and/or calcineurin inhibitors and/or mammalian target of rapamycin-inhibitors,as opposed to continuing maintenance IS,improves patient survival in kidney transplant recipients with cancer undergoing radiotherapy.Only few retrospective studies on small cancer patient cohorts are available in this setting,but without comparison of different immunosuppression treatments.Even where immunosuppression therapy was described,patient survival seemed to be correlated only with cancer stage and type.CONCLUSION The results of this systematic review do not support the reduction of immunosuppression dose in patients undergoing radiotherapy.

Circular RNA PIP5K1A promotes colon cancer development through inhibiting mi R-1273a

BACKGROUND Circular RNAs (circRNAs) are considered to be highly stable due to the closed structure, which are predominately correlated with the development and progression of a wide variety of cancers. Colon cancer is one of the most common malignancies worldwide. A recent study demonstrated the upregulated expression of circPIP5K1A in non-small cell lung cancer. However, few studies have investigated the relationship between circ_0014130 level and colon cancer. Therefore, elucidating the underlying mechanisms of circPIP5K1A’s role may help with the identification of novel diagnostic and therapeutic targets for colon cancer. AIM To investigate the status of circPIP5K1A in colon cancers and its effects on the modulation of cancer development. METHODS The expression level of circPIP5K1A in tissue and serum samples from colon cancer patients, as well as human colonic cancer cell lines was detected by realtime quantitative reverse transcription-polymerase chain reaction. Following the transfection of specifically synthesized small interfering RNA (siRNA) into colon cell lines, we used Hoechst staining assay to measure the ratio of cell death in the absence of circPIP5K1A. Moreover, we also used the Transwell assay to assess the migratory function of colon cells overexpressing circPIP5K1A. Additionally, we employed a series of bioinformatics prediction programs to predict the potential of circPIP5K1A-targeted miRNAs and mRNAs. The miR-1273a vector was constructed, and then transfected with or without circPIP5K1A vector into colon cancer cells. Afterwards, the expression of activator protein 1 (AP-1), interferon regulating factor 4 (IRF-4), caudal type homeobox 2 (CDX-2), and zinc finger of the cerebellum 1 (Zic-1) was detected by western blotting. RESULTS CircPIP5K1A was significantly upregulated in colon cancer tissue relative to their adjacent normal tissues. Knockdown of circPIP5K1A in colon cancer cells impaired cell viability and suppressed cell invasion and migration, while enforced expression of circPIP5K1A exhibited the opposite effects on cell migration. Bioinformatics prediction program predicted that the association of circPIP5K1A with miR-1273a, as well as AP-1, IRF-4, CDX-2, and Zic-1. Subsequent studies showed that overexpression of circPIP5K1A augmented the expression of AP-1 but attenuated the expression of IRF-4, CDX-2, and Zic-1. Reciprocally, overexpression of miR-1273a abrogated the oncogenic function of circPIP5K1A in colon cancers. CONCLUSION Overall, our data demonstrate the oncogenic role of circPIP5K1A-miR-1273a axis in regulation of colon cancer development, which provides a novel insights into colon cancer pathogenesis.

Two outward potassium current types are expressed during the neural differentiation of neural stem cells

The electrophysiological properties of potassium ion channels are regarded as a basic index for determining the functional differentiation of neural stem cells. In this study, neural stem cells from the hippocampus of newborn rats were induced to differentiate with neurotrophic growth factor, and the electrophysiological properties of the voltage-gated potassium ion channels were observed. Immunofluorescence staining showed that the rapidly proliferating neural stem cells formed spheres in vitro that expressed high levels of nestin. The differentiated neurons were shown to express neuron-specific enolase. Flow cytometric analysis revealed that the neural stem cells were actively dividing and the percentage of cells in the S ＋ G2/M phase was high. However, the ratio of cells in the S ＋ G2/M phase decreased obviously as differentiation proceeded. Whole-cell patch-clamp re- cordings revealed apparent changes in potassium ion currents as the neurons differentiated. The potassium ion currents consisted of one transient outward potassium ion current and one delayed rectifier potassium ion current, which were blocked by 4-aminopyridine and tetraethylammonium, respectively. The experimental findings indicate that neural stem cells from newborn rat hippo- campus could be cultured and induced to differentiate into functional neurons under defined condi- tions in vitro. The differentiated neurons expressed two types of outward potassium ion cur＇ents similar to those of mature neurons in vivo.

A method for direct conversion of EPID images to incident fluence for dose reconstruction

A direct incident fluence measurement method based on amorphous silicon electronic portal imaging device(a-Si EPID) has been developed for pretreatment verification of intensity-modulated radiation therapy(IMRT).The EPID-based incident fluence conversion method deconvolves EPID images to the primary response distribution based on measured lateral scatter kernels in the EPID detector using Conjugate Gradient algorithm.The primary response is converted to the incident fluence based on measured fluence conversion matrix which corrects for off-axis position dependence of the a-Si EPID response and the "horn" beam profile caused by flatting filter. To verify feasibility and accuracy of this method, square fields of various sizes and two IMRT plans were delivered. The dose distributions computed based on EPID-derived incident fluence were compared with the measurement data. For all square field sizes except the smallest field(2 cm), the mean dose differences in cross-line dose profiles were within 1% excluding the penumbra region, and gamma passing percentages with a 2%/2 mm criterion were about 99%. For two IMRT plans, the least gamma passing percentage for all eight IMRT fields was 98.14% with 2%/3 mm criteria. It can be concluded that our direct EPID-based incident fluence conversion method is accurate and capable of being applied to pretreatment dose verification in clinical routines.

Four-Dimensional Computerized Tomography (4D-CT) Reconstruction Based on the Similarity Measure of Spatial Adjacent Images

Objective:To investigate the feasibility of a 4D-CT reconstruction method based on the similarity principle of spatial adjacent images and mutual information measure. Methods:A motor driven sinusoidal motion platform made in house was used to create one-dimensional periodical motion that was along the longitudinal axis of the CT couch. The amplitude of sinusoidal motion was set to an amplitude of ±1 cm. The period of the motion was adjustable and set to 3.5 s. Phantom objects of two eggs were placed in a Styrofoam block, which in turn were placed on the motion platform. These objects were used to simulate volumes of interest undergoing ideal periodic motion. CT data of static phantom were acquired using a multi-slice general electric (GE) LightSpeed 16-slice CT scanner in an axial mode. And the CT data of periodical motion phantom were acquired in an axial and cine-mode scan. A software program was developed by using VC++ and VTK software tools to resort the CT data and reconstruct the 4D-CT. Then all of the CT data with same phase were sorted by the program into the same series based on the similarity principle of spatial adjacent images and mutual information measure among them, and 3D reconstruction of different phase CT data were completed by using the software. Results:All of the CT data were sorted accurately into different series based on the similarity principle of spatial adjacent images and mutual information measures among them. Compared with the unsorted CT data, the motion artifacts in the 3D reconstruction of sorted CT data were reduced significantly, and all of the sorted CT series result in a 4D-CT that reflected the characteristic of the periodical motion phantom. Conclusion:Time-resolved 4D-CT reconstruction can be implemented with any general multi-slice CT scanners based on the similarity principle of spatial adjacent images and mutual information measure.The process of the 4D-CT data acquisition and reconstruction were not restricted to the hardware or software of the CT scanner and has the feasibility ,which extensive applicability.

High Dose-Volume SBRT Following TACE Improves Clinical Outcomes of Patients with Unresectable Hepatocellular Carcinoma

This study aimed to investigate the dose-volume effects of γ-ray stereotactic body radiotherapy (SBRT) on clinical outcomes of patients with huge-size (≥10 cm) unresectable hepatocellular carcinoma (HCC). A total of 59 patients with huge-size unresectable HCC were treated with SBRT following TACE between May 2006 and Dec. 2009. The analyzed parameters included fractional dose, marginal dose, maximal dose, and mean dose that the target received, as well as percentages of tumor volume encompassed by 60% (P60), 70% (P70), and 80% (P80) of isodose curves in entire tumor. The clinical outcomes included objective response rate (ORR), disease-free survival (DFS), overall survival (OS), and adverse event (AE). During median follow-up of 18.4 months, 81.4% of ORR (8.5% CR and 72.9% PR) was achieved, higher than 28.9% of ORR recently reported for TACE alone. 1- and 3-year DFS rates were 31.1% and 2.6% with median DFS of 8.7 months;1-, 3-, and 5-year OS rates were 46.5%, 13.7%, and 2.9%, with median OS of 11.8 months. P70 was the only factor significantly correlating to DFS (P = 0.009) and OS (P = 0.01). Neither severe radiation-related liver disease nor > grade 3 AE was observed. In conclusion, SBRT was a safe and effective option for treatment of huge-size unresectable HCC. P70 represented a parameter for predicting DFS and OS, and high dose-volume (e.g., P70) might be required to achieve improved clinical outcomes of patients with this type of HCC.

Observation of intratumoral injection of radiosensitizer

The present study made in 92 mice showed that hydrogen peroxide com-pound injected directly into the tumor could to some extent sensitize the hypoxiccells of S180 solid tumor to radiate,for example,both the tumor regression rateand the mouse survival rate 40d after radiation in the hydrogen peroxide com-pound group were significantly greater than those in the radiation alone group.The increasing rate of tumor diameter in 10d was 77.10%,47.09%,and 47.47%-10.4% in groups of control,radiation alone,radiosensitizer alone,radiationand hydrogen peroxide compound,respectively.Some of the problems aboutthe intratumoral injection of radiosensitizer were discussed.

Comparative Study on the Surface Dose of Some Bolus Materials

In order to investigate the possibility of using different materials as bolus in radiotherapy, five samples denoted by S2 - S6 were prepared and analyzed by comparison with one available commercial bolus denoted by S1. Sample S1 was a thermoplastic material from Qfix;S2 was a moldable silicon rubber (RTV-530 from Prochima);S3 and S4 were obtained by adding micrometric particles of Al and Cu respectively (at the same mass concentration of 5.5%);S5 was another moldable silicon rubber (GSP400 from Prochima) and S6 was a mixture of GSP400 and micrometric particles of Cu (at the mass concentration of 5.5%). The measurements of normalized transmitted dose as a function of sample thickness were performed for all samples (S1 - S6) at two values of electron beam energy (6 and 9 MeV) produced by a linear accelerator VARIAN 2100SC. The results showed that the maximum of the normalized transmitted dose of manufactured samples (S2 - S6) is registered at smaller sample thicknesses than for the analyzed commercial bolus (sample S1). The smallest sample thickness corresponding to normalized maximum point dose is obtained for sample S2 (RTV-530). Measurements performed for electron beam energy of 6 and 9 MeV have proven the possibility of using the manufactured samples as bolus in radiotherapy.

Postoperative glioma extracranial metastasis:A case report

A case with intracranial glioma after the surgery metastasizing to the spine was described. A 28-year-old female patient who underwent surgery and radiation therapy for glioma in the left frontal lobe and was diagnosed as having extracranial metastasis to L2–L4 vertebral body by MRI, PET-CT and pathological examination. The clinical, imaging and pathologic features of the case are described and discussed.

Experience of implanting fiducial markers for 504 cases with body malignant solid tumors

Objective:The purpose of the study is to investigate the technical points,effects and complications of fiducial marker implantation within target areas before the CyberKnife treatment on body malignant solid tumors.Methods:Five hundred and four cases of patients with body malignant solid tumors accepted fiducial implantation within target areas under CT guidance before the treatment of CyberKnife.Observe the complications and effect.Results:Among the 504 cases,500 cases successfully accepted the implantation(a success rate of 99.2%).158 patients felt pain at the punctured sites and 3 patients had tachycardia.33 patients had abdominal pain after the surgery due to a small amount of bleeding in the needle passage during liver puncturing process.Among the 19 lung cancer patients who accepted lung paracentesis,1 case had light pneumothorax and 1 case got light haemothorax.Among the 453 patients who accepted liver paracentesis,6 had fiducial migration.Conclusion:The method of fiducial implantation within target areas before treating body malignant solid tumor with CyberKnife is minimally invasive and comparatively secure.

Beam Characteristics at Low Dose Monitor Unit Settings for Vero4DRT

The stability of delivery of low monitor unit (MU) setting is important especially for step-and-shoot intensity-modulated radiotherapy (IMRT), because the nature of the technique is inherent to repeat beam on/off according to the number of the segments. This study evaluates the dose linearity and profile flatness/symmetry under low MU settings for Vero4DRT, a new linear-accelerator based irradiation system that currently implements step-and-shoot IMRT. To evaluate the dose linearity and flatness/symmetry, the point doses and beam profiles were measured as functions of MU and dose rates. The accuracy of dose delivery depended on the dose rate. Under all dose rates, the dose was linear within 1% above 5 MU and within 2% above 3 MU. The beam symmetry was degraded in-line compared with crossline, although both profiles were symmetric within 2% at all dose settings. The profile flatness was also within 2% above 5 MU at any dose rate and showed no significant variation among the low MU settings. To ensure stable beam delivery without increasing the treatment time of Vero4DRT, we recommend a delivery of 5 MU per segment at a dose rate of 500 MU/min.

Dataset for Beam Commissioning of the Vero4DRT System

We present the results of measurements made using the Vero4DRT radiation therapy system, which is not yet widely used, to assist technicians in achieving reliable and safe radiotherapy to the patient. We measured percent depth dose, beam profile, and relative scatter factor under water and air conditions. The Vero4DRT system has a 150 × 150-mm fixed secondary collimator. Its multileaf collimator (MLC) design is a single-focus type, with 30 pairs of 5 mm thick leaves at the isocenter, and produces a maximum field size of 150 × 150 mm. Profile measurements were performed using a 0.016-cm3 ionization chamber (PTW31016 pinpoint chamber;PTW, Freiburg GmbH Germany). A brass build-up cap was used for measurements obtained in air conditions. We present a useful measurement dataset for users of the Vero4DRT system.