European validation of the classification for the anticipated difficulty of liver transplantation.

Background: Appropriate risk stratification for the difficulty of liver transplantation (LT) is essential to guide the selection and acceptance of grafts and avoid morbidity and mortality.

Methods: Based on 987 LTs collected from 5 centers, perioperative outcomes were analyzed across the 3 difficulty levels. Each LT was retrospectively scored from 0 to 10.

Determination of consensus k values for megavoltage photon beams for the update of IAEA TRS-398.

The IAEA is currently coordinating a multi-year project to update the TRS-398 Code of Practice for the dosimetry of external beam radiotherapy based on standards of absorbed dose to water. One major aspect of the project is the determination of new beam quality correction factors, k , for megavoltage photon beams consistent with developments in radiotherapy dosimetry and technology since the publication of TRS-398 in 2000. Specifically, all values must be based on, or consistent with, the key data of ICRU Report 90.

Feasibility of using a dose-area product ratio as beam quality specifier for photon beams with small field sizes.

Purpose: To investigate the feasibility of using the ratio of dose-area product at 20 cm and 10 cm water depths (DAPR) as a beam quality specifier for radiotherapy photon beams with field diameter below 2 cm.

Methods: Dose-area product was determined as the integral of absorbed dose to water (D) over a surface larger than the beam size. 6 MV and 10 MV photon beams with field diameters from 0.

Using a dose-area product for absolute measurements in small fields: a feasibility study.

To extend the dosimetric reference system to field sizes smaller than 2 cm × 2 cm, the LNE-LNHB laboratory is studying an approach based on a new dosimetric quantity named the dose-area product instead of the commonly used absorbed dose at a point. A graphite calorimeter and a plane parallel ion chamber with a sensitive surface of 3 cm diameter were designed and built for measurements in fields of 2, 1 and 0.75 cm diameter.