A comprehensive study of lateral fall-off (penumbra) optimisation for pencil beam scanning (PBS) proton therapy.

In conclusion, collimated edge-enhancement combined with the variable pre-absorber is the recommended setting to minimize the lateral penumbra for PBS. Without collimator, it would be favourable to use a variable pre-absorber for large air gaps and an automatic pre-absorber for small air gaps. PMID: 29256441 [PubMed - as supplied by publisher]
Source: Physics in Medicine and Biology - Category: Physics Authors: Tags: Phys Med Biol Source Type: research

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eier Sairos Safai The Pencil Beam Scanning (PBS) technique in proton therapy uses fast magnets to scan the tumor volume rapidly. Changing the proton energy allows changing to layers in the third dimension, hence scanning the same volume several times. The PBS approach permits adapting the speed and/or current to modulate the delivered dose. We built a simple prototype that measures the dose distribution in a single step. The active detection material consists of a single layer of scintillating fibers (i.e., 1D) with an active length of 100 mm, a width of 18.25 mm, and an insignificant space (20 μm) between the...
Source: Sensors - Category: Biotechnology Authors: Tags: Article Source Type: research
Wilms ’ tumour (WT) and neuroblastoma (NBL) are two of the most common abdominal solid tumours diagnosed in children. Depending on the risk stratification, the treatment involves a combination of surgery, chemotherapy and radiotherapy [1,2]. During radiotherapy treatment planning (RTP), magnetic resonan ce imaging (MRI) scans are commonly acquired to define the target volume thanks to their superior soft-tissue contrast [3]. In addition, computed tomography (CT) images are used for the computation of patient-specific dose deposition maps [4] using the conversion of the CT Hounsfield units (HU) to r elative electron d...
Source: Radiotherapy and Oncology - Category: Radiology Authors: Tags: Original Article Source Type: research
In conclusion, proton beam matching was quantified for three beam-matched rooms of an IBA ProteusPLUS system with a PBS dedicated nozzle. It is feasible to match the spot size and absolute dose within ± 5% and ± 2%, respective ly. Proton range can be matched within ± 0.5 mm.
Source: Australasian Physical and Engineering Sciences in Medicine - Category: Biomedical Engineering Source Type: research
Proton pencil beam scanning (PBS) represents an interesting option for the treatment of breast cancer (BC) patients with nodal involvement. Here we compare tangential 3D-CRT and VMAT to PBS proton therapy (PT)...
Source: Radiation Oncology - Category: Cancer & Oncology Authors: Tags: Research Source Type: research
Hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinomas (ICC) are the most prevalent intrahepatic primary cancer and the second leading cause of cancer death [Petrick2016], [Hong2016], [Igaki2017]. Although biologically and clinically distinct entities, both share common management issues.
Source: Radiotherapy and Oncology - Category: Radiology Authors: Tags: Original Article Source Type: research
CONCLUSION: We designed and clinically applied a technique for the treatment of liver cancer with proton pencil beam scanning in forced deep expiration breath-hold. The initial data on plan robustness and patient positioning suggest that the choices in terms of planning technique and treatment margins are able to reach the desired balance between target coverage and organ at risk sparing. PMID: 32976870 [PubMed - as supplied by publisher]
Source: Radiotherapy and Oncology : journal of the European Society for Therapeutic Radiology and Oncology - Category: Radiology Authors: Tags: Radiother Oncol Source Type: research
Pencil beam scanning (PBS) proton therapy is an increasingly used radiation modality for childhood malignancies due to its ability to minimise dose to surrounding organs. However, the dosimetry is extremely sensitive to anatomical and density changes. The aims of this study were to investigate if there is a dosimetric benefit or detriment with PBS for paediatric abdominal neuroblastoma, assess gastrointestinal air variability and its dosimetric consequences, plus identify if there are factors that could assist case selection for PBS referral.
Source: Clinical Oncology - Category: Radiology Authors: Tags: Original Article Source Type: research
CONCLUSION: Robustly optimized PBS-PT for cervical cancer patients shows equivalent target robustness against inter- and intra-fraction variability compared to VMAT, and offers significantly better OAR sparing. PMID: 32956707 [PubMed - as supplied by publisher]
Source: Radiotherapy and Oncology : journal of the European Society for Therapeutic Radiology and Oncology - Category: Radiology Authors: Tags: Radiother Oncol Source Type: research
Weber L, Høyer M Abstract The beneficial effects of protons are primarily based on reduction of low to intermediate radiation dose bath to normal tissue surrounding the radiotherapy target volume. Despite promise for reduced long-term toxicity, the percentage of cancer patients treated with proton therapy remains low. This is probably caused by technical improvements in planning and delivery of photon therapy, and by high cost, low availability and lack of high-level evidence on proton therapy. A number of proton treatment facilities are under construction or have recently opened; there are now two operatio...
Source: Acta Oncologica - Category: Cancer & Oncology Authors: Tags: Acta Oncol Source Type: research
CONCLUSION: The results of this study indicate that margin reduction below 3 mm/3% is possible but requires a larger cohort to substantiate clinical introduction. PMID: 32898561 [PubMed - as supplied by publisher]
Source: Radiotherapy and Oncology : journal of the European Society for Therapeutic Radiology and Oncology - Category: Radiology Authors: Tags: Radiother Oncol Source Type: research
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