Dosimetric impact of MLC positional errors on dose distribution in IMRT.

Optimizing the positional accuracy of multileaf collimators (MLC) for radiotherapy is important for dose accuracy and for reducing doses delivered to normal tissues. This study investigates dose sensitivity variations and complexity metrics of MLC positional error in volumetric modulated arc therapy and determines the acceptable ranges of MLC positional accuracy in several clinical situations. Treatment plans were generated for four treatment sites (prostate cancer, lung cancer, spinal, and brain metastases) using different treatment planning systems (TPSs) and fraction sizes. Each treatment plan introduced 0.25-2.0 mm systematic or random MLC leaf bank errors. The generalized equivalent uniform dose (gEUD) sensitivity and complexity metrics (MU/Gy and plan irregularity) were calculated, and the correlation coefficients were assessed. Furthermore, the required tolerances for MLC positional accuracy control were calculated. The gEUD sensitivity showed the highest dependence of systematic positional error on the treatment site, followed by TPS and fraction size. The gEUD sensitivities were 6.7, 4.5, 2.5, and 1.7%/mm for Monaco and 8.9, 6.2, 3.4, and 2.3%/mm (spinal metastasis, lung cancer, prostate cancer, and brain metastasis, respectively) for RayStation. The gEUD sensitivity was strongly correlated with the complexity metrics (r = 0.88-0.93). The minimum allowable positional error for MLC was 0.63, 0.34, 1.02, and 0.28 mm (prostate, lung, brain, and spinal metastasis, respectively). The acceptable range of MLC positional accuracy depends on the treatment site, and an appropriate tolerance should be set for each treatment site with reference to the complexity metric. It is expected to enable easier and more detailed MLC positional accuracy control than before by reducing dose errors to patients at the treatment planning stage and by controlling MLC quality based on complexity metrics, such as MU/Gy.

Emergency intensive care unit pharmacist's intervention may reduce time to four-factor prothrombin complex concentrate administration: a retrospective study.

BACKGROUND: Four-factor prothrombin complex concentrate (4F-PCC) must be administered as soon as possible, and in our emergency intensive care unit (EICU), pharmacists are available on weekdays for consultation on expediting 4F-PCC administration. Although recent reports have described a reduction in time to 4F-PCC administration, few studies have addressed if this is because of EICU pharmacist's intervention, and there are no such studies in Japan. Therefore, we aimed to examine whether EICU pharmacist's intervention reduced time to 4F-PCC administration. METHODS: This single-center retrospective cohort study was conducted from December 2017 to May 2019. We enrolled patients who received 4F-PCC due to major bleeding or requirement of urgent surgical/invasive procedures (n = 10). Patients were divided into two groups, namely, the intervention group (n = 5), in which EICU pharmacists consulted on weekdays, and the nonintervention group (n = 5), in which an intervention was not possible because of the absence of the EICU pharmacist. RESULTS: The median time from patient presentation to the EICU to 4F-PCC administration (103 min vs. 111 min, p = 0.4) was similar between the two groups; however, the median time from 4F-PCC prescription ordering to administration was significantly shorter in the intervention group than in the nonintervention group (21 min vs. 60 min, p = 0.02). CONCLUSIONS: EICU pharmacist's intervention improves the process from 4F-PCC prescription to administration and can reduce time to 4F-PCC administration.

[Effectiveness of Topical NSAIDs in a Gastric Cancer Patient with Bone Metastasis Pain during Therapy with Opioids and Oral NSAIDs].

Cancer patients often suffer from severe pain related to bone metastasis. We encountered a patient in whom the addition of topical non-steroidal anti-inflammatory drugs (NSAIDs) for persistent pain related to bone metastasis during therapy with opioids and oral NSAIDs reduced pain, improving activities of daily living (ADL). Fentanyl patches, celecoxib, denosumab, and topical NSAIDs (loxoprofen tape, felbinac) were administered to a 72-year-old patient with gastric cancer and pain related to bone metastasis. Pain control was favorable, with a numerical rating scale (NRS) score of 2 and Japanese version Support Team Assessment Schedule (STAS-J) score of 1. Intervention by pharmacists for the use of topical NSAIDs decreased both the NRS and STAS-J scores to zero, improving ADL. The results suggest that topical NSAIDs relieve bone-metastasis-related pain, improving ADL. When bone-metastasis-related pain is localized, the prescription of topical NSAIDs should be considered, and positive intervention by pharmacists regarding their usage should be promoted.