Assessment of dosimetric impact of interfractional 6D setup error in tongue cancer treated with IMRT and VMAT using daily kV-CBCT

Background: This study aimed to evaluate the dosimetric influence of 6-dimensional (6D) interfractional setup error in tongue cancer treated with intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) using daily kilovoltage cone-beam computed tomography (kV-CBCT).  Materials and methods: This retrospective study included 20 tongue cancer patients treated with IMRT (10), VMAT (10), and daily kV-CBCT image guidance. Interfraction 6D setup errors along the lateral, longitudinal, vertical, pitch, roll, and yaw axes were evaluated for 600 CBCTs. Structures in the planning CT were deformed to the CBCT using deformable registration. For each fraction, a reference CBCT structure set with no rotation error was created. The treatment plan was recalculated on the CBCTs with the rotation error (RError), translation error (TError), and translation plus rotation error (T+RError). For targets and organs at risk (OARs), the dosimetric impacts of RError, TError, and T+RError were evaluated without and with moderate correction of setup errors. Results: The maximum dose variation ΔD (%) for D98% in clinical target volumes (CTV): CTV-60, CTV-54, planning target volumes (PTV): PTV-60, and PTV-54 was –1.2%, –1.9%, –12.0%, and –12.3%, respectively, in the T+RError without setup error correction. The maximum ΔD (%) for D98% in CTV-60, CTV-54, PTV-60, and PTV-54 was –1.0%, –1.7%, –9.2%, and –9.5%, respectively, in the T+RError with moderate setup error correction. The dosimetric impact of interfractional 6D setup errors was statistically significant (p < 0.05) for D98% in CTV-60, CTV-54, PTV-60, and PTV-54. Conclusions: The uncorrected interfractional 6D setup errors could significantly impact the delivered dose to targets and OARs in tongue cancer. That emphasized the importance of daily 6D setup error correction in IMRT and VMAT.

Combustion synthesis of KZnPO

In this work, KZnPO4:Dy3+ and KZnPO4:Sm3+ phosphors are synthesized using the Combustion technique. The phosphor XRD and photoluminescence properties were studied. The XRD was used to confirm the orthorhombic phase with the space group P n a 21. The PL emission spectra of the synthesized KZnPO4:Dy3+ phosphor shows a strong emission at 482 and 574 nm under 350 nm excitation, which is ascribed due to 4F9/2→6H15/2 and 4F9/2→6H13/2 electronic transitions of the Dy3+ ions, respectively. When the KZnPO4:Sm3+ phosphor was excited at 402 nm, the emission spectra exhibited prominent bands located at 562 and 597 nm. The CIE coordinates show that the current phosphors have high colour purity. The KZnPO4:Dy3+ and Sm3+ phosphors provide an excellent candidate for n-UV-based w-LEDs

Energy Transfer Mechanisms and Optical Thermometry of BaMgF4:Yb3+,Er3+ Phosphor

Motivated from our previous studies on the upconversion properties of BaMgF4:Yb3+,Tb3+ phosphor, here we investigated the upconversion properties of BaMgF4:Yb3+,Er3+ phosphor. We demonstrate a two-way versatile approach for the fine-tuning of emission from green to the red region, by varying the dopant concentration and adjusting the pulse width of an infrared laser. The mechanism involved in tuning the emission color by laser power and pulse width variation was illustrated in detail. The temperature dependent upconversion spectra were studied by analyzing the fluorescence intensity ratio of the thermally coupled levels. The maximum sensitivity obtained is 83.29 x 10(-4) K-1 at 583 K, which is much higher than the temperature sensitivity reported for other fluoride based materials. Moreover, the influence of the excitation power density on the ability of the phosphor for temperature sensing was also investigated. We obtained a maximum (similar to 415 K) temperature detection at 2563 mW laser power. The obtained results illustrate the potential use of BaMgF4:Yb3+,Er3+ phosphor in an optical thermometer due to its highly sensitive temperature detection ability

Two-Dimensional Double Hydroxide Nanoarchitecture with High Areal and Volumetric Capacitance

The development of high volumetric or areal capacitance energy storage devices is critical for the future electronic devices. Hence, the hunting for next-generation electrode materials and their design is of current interest. The recent work in the two-dimensional metal hydroxide nanomaterials demonstrates its ability as a promising candidate for supercapacitor due to its unique structure and additional redox sites. This study reports a design of freestanding high-mass-loaded copper-cobalt hydroxide interconnected nanosheets for high-volumetric/areal-performance electrode. The unique combination of hydroxide electrode with high mass loading (26 mg/cm(2)) exhibits high areal and volumetric capacitance of 20.86 F/cm(2) (1032 F/cm(3)) at a current density of 10 mA/cm(2). This attributes to the direct growth of hydroxides on porous foam and conductivity of copper, which benefits the electron transport. The asymmetric supercapacitor device exhibits a high energy density of 21.9 mWh/cm(3), with superior capacitance retention of 96.55% over 3500 cycles

Energy Transfer Mechanisms and Optical Thermometry of BaMgF₄:Yb³⁺,Er³⁺ Phosphor

Motivated from our previous studies on the upconversion properties of BaMgF₄:Yb³⁺,Tb³⁺ phosphor, here we investigated the upconversion properties of BaMgF₄:Yb³⁺,Er³⁺ phosphor. We demonstrate a two-way versatile approach for the fine-tuning of emission from green to the red region, by varying the dopant concentration and adjusting the pulse width of an infrared laser. The mechanism involved in tuning the emission color by laser power and pulse width variation was illustrated in detail. The temperature dependent upconversion spectra were studied by analyzing the fluorescence intensity ratio of the thermally coupled levels. The maximum sensitivity obtained is 83.29 × 10^–4 K^–1 at 583 K, which is much higher than the temperature sensitivity reported for other fluoride based materials. Moreover, the influence of the excitation power density on the ability of the phosphor for temperature sensing was also investigated. We obtained a maximum (∼415 K) temperature detection at 2563 mW laser power. The obtained results illustrate the potential use of BaMgF₄:Yb³⁺,Er³⁺ phosphor in an optical thermometer due to its highly sensitive temperature detection ability