Yongchun Song

Comparative research on the efficacy of CyberKnife ® and surgical excision for Stage I hepatocellular carcinoma

Objective To retrospectively analyze and compare the outcomes of patients with hepatocellular carcinoma treated with either surgical excision or CyberKnife® from September 2006 to August 2011. Materials and methods Local control and toxicity were the primary endpoints, followed by local progression-free survival, progression-free survival, and overall survival as the secondary endpoints. Response Evaluation Criteria In Solid Tumors were the evaluation criteria for efficacy; Common Toxicity Criteria 3.0 were the evaluation criteria for adverse events. Local control was calculated using the direct method (nonactuarial). The survival curves were drawn using the Kaplan–Meier method along with log-rank test analysis. Results The research included 26 patients treated with tumor-free cutting edge (R0) surgical excision and 22 patients treated with CyberKnife treatment. The results showed that the adverse effects of CyberKnife were milder, with 1-, 2-, and 3-year local control rates of 92.9%, 90.0%, and 67.7%, respectively. The overall survival rates of the surgical treatment were 88.5%, 73.1%, and 69.2% for the same periods, while those of CyberKnife treatment were 72.7%, 66.7%, and 57.1%, respectively. In this study, surgical excision appeared to prolong overall survival to a greater extent, but with no statistical significance; no statistical difference was observed in the tumor-specific overall survival and progression-free survival between the two cohorts. Conclusion According to this preliminary study, with its mild toxicity, the efficacy of CyberKnife treatment for early hepatocellular carcinoma was on par with that of surgical resection.

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 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 β-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.

A preliminary probe into the movement of pancreatic lesions and factors that influence it

The aim of this study was to investigate the movement, and the factors that influence such movement, of pancreatic lesions and to provide a reference for determination of planning target volume (PTV) during stereotactic radiotherapy. We implanted 19 gold markers into the inner pancreatic tumours of 16 pancreatic carcinoma patients percutaneously under B-ultrasonographic guidance. The marked motion of pancreatic lesions in the x (right-left), y (superoinferior) and z (anteroposterior) directions was measured using an X-ray simulator system. Based on the statistical analysis of the detected movements, we investigated the relevant influencing factors of pancreatic lesions with multinomial linear regression. Data showed that the mean motion amplitudes of pancreatic lesions were 0.16 cm +/- 0.06 (range 0.1-0.3 cm) in the x direction, 0.25 cm +/- 0.12 (range 0.1-0.4 cm) in the y direction and 0.88 cm +/- 0.24 (0.5-1.6 cm) in the z direction. Motion amplitude was not correlated with the height, weight or age of the patients nor with the location or size of the tumour. The motion of pancreatic lesions was mainly influenced by the respiratory motion and has maximal amplitude in the z direction. Therefore, motion in the z direction should be given a priority consideration while determining the PTV.

Exploration of the recurrence in radiation brain necrosis after bevacizumab discontinuation

Objective: The aim of the paper was to investigate the recurrence and its causes of radiation brain necrosis following bevacizumab discontinuation. Methods: This study included 14 patients with radiation brain necrosis (confirmed through imaging) after stereotactic radiotherapy for a primary or metastatic brain tumor and who received bevacizumab treatment from June 2011 through December 2014. The patients received bevacizumab at 5 mg/kg, q3-4w, for at least 3 cycles. The T1 signal intensity from enhanced MRI images was used as the evaluation criteria for the brain necrosis treatment efficacy. Results: brain necrosis improved in 13 of the 14 cases (92.9%). However, during follow-up, 10 of the 13 responsive patients (76.9%) exhibited a recurrence in brain necrosis, and a multiple linear regression analysis shows that brain necrosis recurrence was related to the follow-up time after the initial bevacizumab treatment discontinuation. Conclusion: bevacizumab produced good short-term effects for radiation brain necrosis; however, most of the patients would recurrence after bevacizumab is discontinued. Thus, brain necrosis was irreversible.

Clinical observation on the efficacy of CyberKnife for primary or metastatic retroperitoneal tumours

The aim of the paper is to evaluate the efficacy of CyberKnife® for the treatment of primary or metastatic retroperitoneal tumours. Twenty-eight patients were treated. The prescription isodose line (median, 78%; range, 70-84%) covered the planning target volume at a total dose of 2000-6000 cGy (median, 4500 cGy) and a biologically effective dose of 3750-10,080 cGy (median, 7680 cGy) in 2-10 fractions (median, five fractions). The results showed that the complete response, partial response, stable disease, and progressive disease rates were 43% (12/28), 36% (10/28), 18% (5/28), and 4% (1/28) respectively. The overall response rate was 96%. The 1-, 2- and 3-year local control rates were 92%, 86%, and 86% respectively. The 1-, 2- and 3-year overall survival rates were 60%, 49%, and 49% respectively. No significant difference was found between local progression-free survival and overall survival. Moreover, if a patient only had metastases in the retroperitoneum and local control was effective, there was no significant difference between local progression-free survival and overall progression-free survival. In conclusion, CyberKnife treatment for retroperitoneal tumours resulted in high response rates with minimal side effects. All radiation-induced side effects were well tolerated.