Nonrigid registration of 3D tomographic images of di erent modalities (e.g., CT and MR images) is a key issue for neurosurgery and radiotherapy planning. Here, we consider image registration based on a set of corresponding anatomical point landmarks and approximating thin-plate splines. With this approach it is possible to take into account landmark localization errors and thus to control the i...

Dose verifications for intensity-modulated radiation therapy (IMRT) are generally performed once before treatment. A 39-fraction treatment course for prostate cancer delivers a dose prescription of 78 Gy in eight weeks. Any changes in multileaf collimator leaf position over the treatment course may affect the dosimetry. To evaluate the magnitude of deviations from the predicted dose over an ent...

Background: Salivary glands (SGs) are usually irradiated during radiotherapy for head and neck cancers, which may lead to radiation-induced changes. These changes could be evaluated safely by ultrasonography; however, there have been few studies in this regard. Thus, we aimed to investigate the changes in post-radiotherapy submandibular glands using ultrasonography in patients undergoing head-n...

Chen AM , Farwell DG , Luu Q , Donald PJ , Perks J , Purdy J . [20] Evaluation of the planning target volume in the treatment of head and neck cancer with intensity-modulated radiotherapy: What is the appropriate expansion margin in the setting of daily image guidance? Int J Radiat Oncol Biol Phys 2011 ; 81 : 943 – 9 . Van Herk M , Remeijer P , Rasch C , Lebesque JV . The [21] probability of co...

Due to its vast number of occurrences, cancer has caused an economic impact on the public and supplementary health care sectors. It is estimated that more than 50% patients diagnosed with malignant neoplasms need radiotherapy at some stage their treatment, most them treated photon and/or electron beams. build-up effect (increase in dose matter from deposition surface a point maximum dose) by in...

background: in treating patients with radiation, the degree of accuracy for the delivery of tumor dose is recommended to be within ± 5% by icru in report 24. the experimental studies have shown that the presence of low-density inhomogeneity in areas such as the lung can lead to a greater than 30% change in the water dose data. therefore, inhomogeneity corrections should be used in treatment pla...

background : tongue cancer is one of the most common cancers of the oral cavity, excluding lip, and the median age of the patients is approximately 60 years. methods : treatment results of a total of 110 patients with oral tongue cancer admitted to cancer institute of tehran university between1999-2003 were retrospectively analyzed. the patients were treated by surgery or radiotherapy or chemot...

Abstract Introduction: Radiotherapy is an ever-changing field with constant technological advances. It for this reason that risk management strategies are regularly updated in order to remain optimal. Methodology: A retrospective audit of all reported incidents and near misses the audited department between 1 November 2020 30 April 2021 was performed. The root cause each radiotherapy error (RTE...