Proton (Malaysia)

This article explores the MRI-guided proton therapy (MRiPT) integrated technology, which is magnetic resonance imaging-guided radiation therapy. By precisely controlling dose distribution, MRiPT has the potential to enhance the efficacy of radiotherapy. This article reviews the development of MRiPT, analyzes its potential for clinical application, and discusses technical challenges and potential solutions. MRiPT technology offers significant advantages in improving treatment precision and reducing side effects, especially showing exceptional potential in the treatment of complex tumors. This article concludes by looking forward to the future development of MRiPT technology, emphasizes the importance of optimizing electromagnetic compatibility and reducing inter-system interference.

Objective.Upright positioning has seen a surge in interest as a means to reduce radiotherapy (RT) cost, improve patient comfort, and, in selected cases, benefit treatment quality. In particle therapy (PT) in particular, eliminating the need for a gantry can present massive cost and facility footprint reduction. This review discusses the opportunities of upright RT in perspective of the open challenges.Approach.The clinical, technical, and workflow challenges that come with the upright posture have been extracted from an extensive literature review, and the current state of the art was collected in a synergistic perspective from photon and particle therapy. Considerations on future developments and opportunities are provided.Main results.Modern image guidance is paramount to upright RT, but it is not clear which modalities are essential to acquire in upright posture. Using upright MRI or upright CT, anatomical differences between upright/recumbent postures have been observed for nearly all body sites. Patient alignment similar to recumbent positioning was achieved in small patient/volunteer cohorts with prototype upright positioning systems. Possible clinical advantages, such as reduced breathing motion in upright position, have been reported, but limited cohort sizes prevent resilient conclusions on the treatment impact. Redesign of RT equipment for upright positioning, such as immobilization accessories for various body regions, is necessary, where several innovations were recently presented. Few clinical studies in upright PT have already reported promising outcomes for head&neck patients.Significance.With more evidence for benefits of upright RT emerging, several centers worldwide, particularly in PT, are installing upright positioning devices or have commenced upright treatment. Still, many challenges and open questions remain to be addressed to embed upright positioning firmly in the modern RT landscape. Guidelines, professionals trained in upright patient positioning, and large-scale clinical studies are required to bring upright RT to fruition.

zfit is a highly scalable and customizable model manipulation and likelihood fitting library. It uses the same computational backend as TensorFlow and is optimised for simple and direct manipulation of probability density functions.

In this chapter, we will consolidate the concluding remarks presented throughout the preceding chapters, with a specific emphasis on the technical and methodological advancements in image-guided particle therapy, as well as elucidating the future trajectory of this field.

Radiation therapy (RT) is commonly used for the treatment of prostate cancer, with intensity-modulated radiation therapy (IMRT) and proton beam therapy (PBT) being the utilized modalities. This case report outlines the treatment course of a recurrent prostate cancer lesion in the right perineal musculature managed with proton therapy following IMRT. A 64-year-old Japanese man, diagnosed with prostate cancer and categorized as high risk according to the National Comprehensive Cancer Network guidelines, underwent six months of androgen deprivation therapy, which included bicalutamide and degarelix acetate. Six months after completing 78 Gy in 39 fractions of IMRT, the patient reported perineal to anal pain. Laboratory tests showed an elevated serum prostate-specific antigen (PSA) level, and pelvic MRI showed a mass lesion in the right perineal musculature. Consequently, the patient was diagnosed with recurrent prostate cancer. Thereafter, the patient underwent eight cycles of systemic chemotherapy with docetaxel; however, his pain progressively worsened. Subsequently, the treatment was switched to 12 cycles of cabazitaxel, which led to gradual pain relief. The patient received PBT at 60 Gy relative biological effectiveness in 30 fractions for the recurrent lesion. Five years after PBT, pelvic MRI showed no mass lesions in the prostate or surrounding tissues. The PSA levels remained low, less than 0.008 ng/ml, and there were no apparent late complications.

This study aimed to determine the optimal bladder volume (BV) for hypofractionated proton therapy in prostate cancer (PC). Two hundred patients with PC were enrolled in this study and classified into low-, intermediate-, and highrisk groups. Treatment planning was performed by assuming a hypofractionated schedule of 63 Gy (relative biological effectiveness) in 21 fractions. The dose indices of the bladder (V 60 and V 50 ) were calculated and classified into four groups according to the BV. A cutoff value with a 95% confidence interval was calculated on the basis of the mean and standard deviation of the dose indices. These values were compared with the dose constraints (V 60 < 15 % and V 50 < 30 %). The dose indices were higher in the high-risk group than in the other risk groups. The cutoff value exceeded dose constraints in the low-and intermediate-risk groups with a BV of ≦ 149 cc. Additionally, the cutoff value exceeded the dose constraint in the high-risk group with a BV of ≦ 199 cc. In all the cases, the group with a BV of ≧ 200 cc was below the dose constraint. In this study, the relationship between the dose and volume of the bladder in hypofractionated PT for PC was evaluated using a 95% CI to determine the optimal BV. The BV should be changed for each risk group, and a larger BV is required for a high-risk group than for other risk groups.

Heating, ventilation and air conditional (HVAC) system provides a cold ventilation for the comfort of the driver and passengers in a vehicle. However, the vibration induced by the HVAC contributes to a reasonable level of noise emission, and hissing is one of the critical noises. So far, the characterization of hissing noise from the vehicle is least to be reported compared to other type of noises. Hence, this paper investigates the occurrence of hissing noise from several HVAC components. A lab-scale HVAC system was developed to imitate the real-time operations of the vehicle HVAC system. Two engine conditions, namely as ambient and operating conditions, were tested at speed of 850 rpm and 850–1400 rpm, with the blower speed maintained constantly at one level. The result shows that the hissing noise from the labscale HVAC was produced at frequency range of 4000–6000 Hz. The finding also highlights that the main component contributors of noise emission are an evaporator and a thermal expansion valve. The validation with a real vehicle system showed a good consensus whereby the hissing noise was produced at the similar operating frequency ranges. Also, the hissing noise was found to be louder when in an operating condition which could be taken into consideration by the vehicle manufacturers to improve the HVAC design.

Matlamat utama kajian ini adalah untuk meneroka hubungan burnout terhadap stres, kebimbangan, dan kemurungan dalam kalangan anggota payung terjun Batalion Ke-8 Rejimen Renjer Diraja, yang ditempatkan di Kem Terendak, Melaka. Kajian ini menggunakan alat psikometrik yang disahkan seperti Maslach Burnout Inventory (MBI) dan DASS-21 untuk mengukur burnout, stres, kebimbangan dan kemurungan dalam kalangan anggota. Seramai 371 orang anggota pasukan payung terjun menyertai kajian ini. Dapatan kajian menunjukkan terdapat hubungan korelasi positif dan signifikan antara burnout dengan stres, kebimbangan, dan kemurungan dalam kalangan anggota payung terjun Batalion ke-8 Rejimen Renjer Diraja. Berdasarkan ujian Maslach Burnout Inventory (MBI), anggota pasukan payung terjun menunjukkan mereka mengalami gejala burnout yang rendah. Manakala keputusan ujian DASS-21 menunjukkan anggota mengalami tahap stress yang normal, kebimbangan yang serdahana dan kemurungan yang ringan. Persekitaran dan bidang kerja yang berisiko mendorong kepada wujudnya tekanan secara fizikal dan mental dalam kalangan anggota tentera payung terjun. Seterusnya menyebabkan gejala burnout terjadi dan ia memberi kesan yang buruk kepada kesejahteraan psikologi anggota tentera payung terjun di Kem Terendak, Melaka. Kajian ini mendedahkan kepentingan pengesanan awal dan strategi intervensi untuk mengesan gejala burnout dalam kalangan pasukan payung terjun. Tambahan pula, penemuan mencadangkan keperluan untuk program kesihatan mental yang komprehensif dalam menghadapi cabaran psikologi yang dihadapi oleh pasukan payung terjun di Malaysia amnya.

Risk factors predicting distant metastasis (DM) in extrahepatic bile duct cancer (EHBDC) patients treated with curative resection were investigated. Medical records of 1,418 EHBDC patients undergoing curative resection between Jan 2000 and Dec 2015 from 14 institutions were reviewed. After resection, 924 patients (67.6%) were surveilled without adjuvant therapy, 297 (21.7%) were treated with concurrent chemoradiotherapy (CCRT) and 148 (10.8%) with CCRT followed by chemotherapy. To exclude the treatment effect from innate confounders, patients not treated with adjuvant therapy were evaluated. After a median follow-up of 36.7 months (range, 2.7 to 213.2 months), the 5-year distant metastasis-free survival (DMFS) rate was 57.7%. On multivariate analysis, perihilar or diffuse tumor (hazard ratio [HR], 1.391; p=0.004), poorly differentiated histology (HR, 2.014; p < 0.001), presence of perineural invasion (HR, 1.768; p < 0.001), positive nodal metastasis (HR, 2.670; p < 0.001) and preoperative carbohydrate antigen (CA) 19-9 ≥ 37 U/mL (HR, 1.353; p < 0.001) were significantly associated with inferior DMFS. The DMFS rates significantly differed according to the number of these risk factors. For validation, patients who underwent adjuvant therapy were evaluated. In patients with ≥ 3 factors, additional chemotherapy after CCRT resulted in a superior DMFS compared with CCRT alone (5-year rate, 47.6% vs. 27.7%; p=0.001), but the benefit of additional chemotherapy was not observed in patients with 0-2 risk factors. Tumor location, histologic differentiation, perineural invasion, lymph node metastasis, and preoperative CA 19-9 level predicted DM risk in resected EHBDC. These risk factors might help identifying a subset of patients who could benefit from additional chemotherapy after resection.