Cardiac Safety with High Cumulative Dose of Pegylated Liposomal Doxorubicin in Patients with Metastatic Breast Cancer Previously Treated with Conventional Anthracyclines

Introduction: The treatment of metastatic breast cancer (MBC) is still challenging. Many studies documented the efficacy of pegylated liposomal doxorubicin (PLD) in patients with MBC, but there is a limited data about the cardiac safety with high cumulative dose (HCD) of PLD. Aim of the work: We conducted this trial to outline the cardiac safety of HCD of PLD in patients with MBC who previously received conventional anthracyclines. Methods: During the period of nine years (January 2011 to December 2019). We extracted the data of the patients with MBC receiving PLD at Medical Oncology Department, South Egypt Cancer Institute, Assiut University. These included patients’ demographics and therapeutic data including the full data of PLD, prior conventional anthracyclines, prior trastuzumab, and prior radiotherapy. Also, data about comorbidities as well as cardiac and other toxicities of PLD were obtained. The data was analysed using SPSS v. 21. Results: For all 81 eligible patients, the mean age was 43.9 years (±standard deviation (SD) 13.2). The mean cumulative dose of PLD was 378.4 mg/m2 (± SD of 250.2) and a range of 100 - 1200 mg/m2. About thirty-one (38.3%) patients received high cumulative dose (400 mg/m2 or more), while the remaining 50 patients did not. The decline in left ventricular ejection fraction (LVEF) was relatively rare;and of low grade. Grade 2 decline in LVEF occurred in only two patients who received high cumulative dose of PLD, and only one patient who did not reach HCD (p = 0.555). Grade 3 or 4 decline in LVEF did not occur in patients either with or without HCD. Regarding other toxicities, there was a significant increase in incidence of all grades palmar plantar erythrodysesthesia (PPE) in patients who received HCD of PLD when compared to those who did not reach the HCD (38.7% versus 16% respectively;p = 0.021). Conclusion: Our study concluded that the use of PLD seems to be a justified agent in the treatment of MBC who previously treated by conventional anthracyclines in the adjuvant, metastatic or both settings, even in patients reaching the cumulative dose of conventional anthracycline.

Preliminary study on protection of synchrotron radiation damage in CEPC main ring

Background The Circular Election–Positron Collider has been proposed by Institute of High Energy Physics(IHEP,CAS).The beam in the main ring with energy up to 120 GeV would produce intense synchrotron radiation(SR)with photon energy up to several MeV.Without shielding,this radiation would be harmful to the accelerator components.Purpose To clarify the radiation damage,analyze the source of SR,and design the shielding system to protect the accelerator.Methods The theoretical formula has been used to estimate the spectrum and distribution of SR.Several ways of designing or shielding vacuum chamber with different geometries and various materials are put forward to protect sensitive facility components.The Monte Carlo program FLUKA has been introduced to calculate cumulative dose and heat deposition in all designing cases.Results The SR in CEPC main ring would be harmful to the coil used in dipole magnets.The design based on LEP with aluminum and lead would need 23 mm lead to make the coil safe.The design based on LEP with copper would need 28 mm of outer copper.And the copper chamber and lead shield design would need 16 mm of Lead.Conclusion The theoretical formula has been used in source generation of Monte Carlo program to get the distribution of SR in CEPC main ring.The program was also used to simulate SR problems in the vacuum chamber with designs of different geometries and materials.Among these designs,the elliptical pipe with lead shield is preferred in CEPC.