در هنگام جستجو کلمه در قسمت عنوان میتوانید کلمات مورد جستجو را با کاراکتر (-) جدا کنید.
کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Iranian Journal of Medical Physics
- نوع مقاله: Journal Article
- کلمات کلیدی: Glioma,volumetric modulated arc therapy,Computer-Assisted Radiotherapy Planning,Three-Dimensional Conformal Radiotherapy
- چکیده:
- چکیده انگلیسی: Introduction: We aimed to dosimetrically compare three-dimensional conformal radiotherapy (3D-CRT) and volumetric modulated arc therapy (VMAT) in terms of planning target volume (PTV) coverage, organ at risk (OAR) sparing, and conformity index (CI).
Material and Methods: Planning data of 26 high grade glioma (HGG) patients were used. Prescribed dose for 3D-CRT was 46Gy in 23 fractions to low-risk PTV (LR-PTV) and 14 Gy in 7 fractions to high-risk PTV (HR-PTV). VMAT plans were conducted using 46 Gy in 30 fractions to LR-PTV and 60 Gy in 30 fractions to HR-PTV.
Results: Tumor locations were frontal, parietal, temporal, and multi-lobed in 27%, 15%, 23%, and 35% of cases, respectively. Histology was glioblastoma multiform in 89% of patients. Mean values of PTV D95 (dose received by 95% volume) in 3D-CRT and VMAT were 96.6% and 98.8% for the LR-PTV and 97.3% and 99% for HR-PTV (p <0.001), respectively. Mean values of CI in 3D-CRT were 0.96 and 0.97 for LR-PTV and HR-PTV and 0.98 and 0.99 for LR-PTV and HR-PTV of VMAT (both p <0.001), respectively. Mean Dmax of right optic nerve (maximum point dose received by the organ) for 3D-CRT and VMAT were 31.59 and 25.57Gy (P=0.02). Mean Dmax for left optic nerve and optic chiasm were 28.81 and 22.14 Gy (P=0.019) and 42.24 and 37.12 Gy (P=0.055) respectively for 3D-CRT versus VMAT. Doses to other OARs were not statistically different between 3D-CRT and VMAT.
Conclusion: VMAT achieved better coverage of the PTV and delivered fewer doses to bilateral optic nerve and chiasm.- انتشار مقاله: 23-08-1397
- نویسندگان: Harikesh Bahadur Singh,Ajeet Kumar Gandhi,Shantanu Sapru,Rohini Khurana,Rahat Hadi,Sambit Swarup Nanda,Satyajeet Rath,Avinav Bharati,Anoop Kumar Srivastava,Surendera P Mishra,Kamal Sahni,Nuzhat Husain,Madhup Rastogi
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Medical Physics
- نوع مقاله: Journal Article
- کلمات کلیدی: Dose Volume Histogram,Tumor control probability,Normal tissue complication probability
- چکیده:
- چکیده انگلیسی: Introduction: The ultimate goal of radiation treatment planning is to yield a high tumor control probability (TCP) with a low normal tissue complication probability (NTCP). Historically dose volume histogram (DVH) with only volumetric dose distribution was utilized as a popular tool for plan evaluation hence present study aimed to compare the radiobiological effectiveness of the cobalt-60 (Co-60) gamma photon and 6MV X-rays of linear accelerators (Linac) in the radiotherapy of head and neck tumors.
Materials and Methods: TCP and NTCP were calculated using DVH through the BIOPLAN software developed by Sanchez-Nieto and Nahum . The treatment planning was performed for all the patients using both treatment modalities (i.e., Co-60 and 6 MV Linac). The TCP was also manually calculated using a mathematical formula proposed by Brenner’s et al.
Results: The average TCP calculated by the BIOPLAN for Co-60 and 6 MV X-rays were 44.6% and 60.8%, respectively. Furthermore, the average NTCPs obtained for the organ at risk, namely optic nerve, for Co-60 and 6 MV X-ray were 0.24 % and 0.03 %, respectively. Regarding the spinal cord, the average NTCPs for Co-60 gamma photon and 6 MV X-ray of Linac were 0.05 % and 0.002%, respectively.
Conclusion: As the findings of the present study indicated, Co-60 unit could provide comparable TCP along with minimal NTCP, compared to the high-cost technologies of Linac. The design of treatment plans based on the radiobiological parameters facilitated the judicious choice of physical parameters for the achievement of high TCP and low NTCP.- انتشار مقاله: 17-11-1395
- نویسندگان: Anoop Kumar Srivastava,MADHUP RASTOGI,SURENDRA PRASAD MISHRA
- مشاهده
- جایگاه : پژوهشی
- مجله: Asian Pacific Journal of Cancer Prevention
- نوع مقاله: Journal Article
- کلمات کلیدی: Radiotherapy,high grade glioma,1p/19q codeletion,IDH 1 mutation,Molecular markers
- چکیده:
- چکیده انگلیسی: Background: The standard of care in high grade glioma (HGG) is maximal safe surgical resection followed by adjuvant radiotherapy (RT) with/without chemotherapy. For anaplastic gliomas, studies have shown use of procarbazine, lomustine, vincristine (PCV) improves overall survival (OS) and progression free survival (PFS). Currently, there is substantial evidence that molecular markers strongly predict prognosis and response to treatment. Methods: Between January 2016 to January 2018, 42 patients were accrued and followed up till April 2019. The primary end points were to correlate molecular markers with response to therapy in terms of OS and PFS in HGG. The secondary end point was to evaluate frequency of 1p/19q codeletion, IDH 1 mutation, ATRX deletion and p53 in HGG patients. Results: The median age was 46 years (range 18-67) with M:F ratio 30:12. The frequency of IDH1 mutation,1p/19q codeletion, p53 mutation and ATRX mutation were 42.8%, 16.6%, 42.8% and 14.2% respectively. All the seven patients with 1p/19q codeletion had IDH1 mutation. Median follow up was 22 months. The 20-months PFS for different mutations were as follows; IDH1-mutated vs wild type: 53.6% vs 29.8%; p-0.035, 1p/19q codeleted vs non-codeleted: 85.7% vs 62.3%; p-0.011, p53 wild type vs mutated 32.1% vs 35.6%; p-0.035 and ATRX lost vs retained: 55.6% vs 53.3%; p- 0.369. The 20-months OS for IDH1 mutated vs wild type: 82.4% vs 30.6%; p-0.014, 1p/19q codeleted vs non-codeleted: 85.7% vs 65.8%; p-0.104, p53 wild-type vs mutated 45.5% vs 73.9%; p-0.036 and ATRX lost vs retained: 100% vs 60.3%; p-0.087. Conclusion: Codeletion of 1p/19q with IDH1 mutation in HGG is associated with a significantly favourable PFS. However, larger studies with longer follow up are required to evaluate OS and PFS in all the molecular subgroups.
- انتشار مقاله: 01-09-1398
- نویسندگان: Rohini Khurana,Satyajeet Rath,Harikesh Bahadur Singh,Madhup Rastogi,Sambit Swarup Nanda,Abhishek Chauhan,Mohammad Kaif,Nuzhat Hussain
- مشاهده
- جایگاه : پژوهشی
- مجله: Asian Pacific Journal of Cancer Prevention
- نوع مقاله: Journal Article
- کلمات کلیدی: DNA damage,Q-PCR,Low Dose Radiation (LDR),DNA Lesions
- چکیده:
- چکیده انگلیسی: Background: Radiation causes oxidative lesions and strand breaks in DNA of exposed cells. Extended length
PCR is a reliable method for assessing DNA damage. Longer DNA strands with DNA damage are difficult to amplify
compared to smaller DNA strands by PCR. The present study was aimed to evaluate DNA damage caused by ionising
radiation exposure in therapeutic and diagnostic medicine. Materials and Methods: The study group comprised 50
cases with low dose single exposure (LDS), low dose multiple exposure (LDM) and low dose angiography (LDA)
which were compared with 25 high dose controls (HDC) and 25 controls with no exposure (NEC). Blood samples were
collected within 1 hour of radiation exposure. DNA was isolated using a kit based protocol, 50 ng aliquots of DNA
were used to amplify a long 13kbp DNA fragment of the β-actin gene by conventional PCR and band intensity was
then quantified. Relative amplification was calculated and damage was expressed in terms of lesions per kilobase (kbp)
by assuming a Poisson distribution. Result: Relative amplification was found to be 1.0, 0.87, 0.86, 0.72 and 0.69 with
NEC, LDS, LDM, LDA and HDC groups, respectively. Cases undergoing angiography as well as high dose controls
had high values, compared to NEC. The lesions/kbp calculated for LDS was 0.13, for LDM 0.15, for LDA 0.32 and
for HDC 0.37 suggesting a linear increase in quantity with increasing radiation dose. Conclusion: DNA damage, even
at low doses of radiation can be assessed by quantitative extra long PCR.- انتشار مقاله: 26-10-1396
- نویسندگان: Kainat Khan,Shikha Tewari,Madhup Rastogi,Gaurav Raj Agarwal,Surendra Prasad Mishra,Nuzhat Husain
- مشاهده