검색
검색 팝업 닫기

Ex) Article Title, Author, Keywords

Articles

Archives
  • Original Article 2021-09-30 2021-09-30 \ 0 \ 1032 \ 354

    The Crucial Role of the Establishment of Computed Tomography Density Conversion Tables for Treating Brain or Head/Neck Tumors

    Shu-Chin Yang1,2 , Su-Hua Lo3 , Li-Tsuen Shie1 , Sung-Wei Lee1 , Sheng-Yow Ho1,4,5

    https://doi.org/10.14316/pmp.2021.32.3.59

    Abstract
    Purpose: The relationship between computed tomography (CT) number and electron density (ED) has been investigated in previous studies. However, the role of these measures for guiding cancer treatment remains unclear.
    Methods: The CT number was plotted against ED for different imaging protocols. The CT number was imported into ED tables for the Pinnacle treatment planning system (TPS) and was used to determine the effect on dose calculations. Conversion tables for radiation dose calculations were generated and subsequently monitored using a dosimeter to determine the effect of different CT scanning protocols and treatment sites. These tables were used to retrospectively recalculate the radiation therapy plans for 41 patients after an incorrect scanning protocol was inadvertently used. The gamma index was further used to assess the dose distribution, percentage dose difference (DD), and distance-to-agreement (DTA).
    Results: For densities <1.1 g/cm3, the standard deviation of the CT number was ±0.6% and the greatest variation was noted for brain protocol conditions. For densities >1.1 g/cm3, the standard deviation of the CT number was ±21.2% and the greatest variation occurred for the tube voltage and head and neck (H&N) protocol conditions. These findings suggest that the factors most affecting the CT number are the tube voltage and treatment site (brain and H&N). Gamma index analyses for the 41 retrospective clinical cases, as well as brain metastases and H&N tumors, showed gamma passing rates >90% and <90% for the passing criterion of 2%/2 and 1%/1 mm, respectively.
    Conclusions: The CT protocol should be carefully decided for TPS. The correct protocol should be used for the corresponding TPS based on the treatment site because this especially affects the dose distribution for brain metastases and H&N tumor recognition. Such steps could help reduce systematic errors.
  • Original Article 2021-09-30 2021-09-30 \ 2 \ 3705 \ 421

    Dosimetric Evaluation of Low-Dose Spillage Volumes for Head and Neck Cancer Using Intensity-Modulated Radiation Therapy and Volumetric Modulated Arc Therapy Treatment Techniques

    Gourav Kumar1 , Manindra Bhushan1 , Lalit Kumar1 , Vimal Kishore2 , Kothanda Raman1 , Pawan Kumar1 , Soumitra Barik1 , Sandeep Purohit1

    https://doi.org/10.14316/pmp.2021.32.3.70

    Abstract
    Purpose: This study was designed to investigate the dosimetric difference between intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) in head and neck cancer (HNC). The study primarily focuses on low-dose spillage evaluation between these two techniques.
    Methods: This retrospective study involved 45 patients with HNC. The treatment plans were generated using the IMRT and VMAT techniques for all patients. Dosimetric comparisons were performed in terms of target coverage, organ-at-risk (OAR) sparing, and various parameters, including conformity index, uniformity index, homogeneity index, conformation number, low-dose volumes, and normal tissue integral dose (NTID).
    Results: No significant (P>0.05) difference in planning target volume coverage (D95%) was observed between IMRT and VMAT plans for supraglottic larynx, hard palate, and tongue cancers. A decrease in dose volumes ranging from 1 Gy to 30 Gy was observed for VMAT plans compared with those for IMRT plans, except for V1Gy and V30Gy for supraglottic larynx cancer and V1Gy for tongue cancer. Moreover, decreases (P<0.05) in NTID were observed for VMAT plans compared with that for IMRT plans in supraglottic larynx (4.50%), hard palate (12.80%), and tongue (7.76%) cancers. In contrast, a slight increase in monitor units for VMAT compared with those for IMRT in supraglottic larynx (0.46%), hard palate (2.54%), and tongue (7.56%) cancers.
    Conclusions: For advanced-stage HNC, both IMRT and VMAT offer satisfactory clinical plans. VMAT offers a conformal and homogeneous dose distribution with comparable OAR sparing and higher dose falloff outside the target volume than IMRT, which provides an edge to reduce the risk of secondary malignancies for HNC over IMRT.
  • Erratum 2021-09-30 2021-09-30 \ 0 \ 530 \ 238

    Erratum: Proton Therapy Review: Proton Therapy from a Medical

    Se Byeong Lee

    https://doi.org/10.14316/pmp.2021.32.3.82

Korean Society of Medical Physics

Vol.35 No.2
2021-09-30

pISSN 2508-4445
eISSN 2508-4453
Formerly ISSN 1226-5829

Frequency: Quarterly

Current Issue   |   Archives

Most Keyword ?

What is Most Keyword?

  • It is most registrated keyword in articles at this journal during for 2 years.

Archives