Publications by authors named "Arun S Oinam"

Purpose: Optical surface monitoring systems (OSMSs) have gained substantial attention in modern radiation therapy, specifically in the context of surface guided radiation therapy, which offers real-time patient surface monitoring, ensuring accurate and effective radiation therapy treatments. The aim of this article is to evaluate the OSMS camera sensitivity toward different skin tones, categorized according to the Fitzpatrick scale, a universal classification of human skin tones, using a phantom.

Methods And Materials: This study used Catalyst and Sentinel OSMSs (C-RAD).

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Purpose: The purpose of this study was to develop a predictive model to evaluate pretreatment patient-specific quality assurance (QA) based on treatment planning parameters for stereotactic body radiation therapy (SBRT) for liver carcinoma.

Materials And Methods: We retrospectively selected 180 cases of liver SBRT treated using the volumetric modulated arc therapy technique. Numerous parameters defining the plan complexity were calculated from the DICOM-RP (Radiotherapy Plan) file using an in-house program developed in MATLAB.

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Perioperative high dose rate brachytherapy involves insertion of brachytherapy catheter over the tumor bed during surgical removal of disease followed by radiation in the postoperative period. It has applications in radiotherapy dose escalation or reirradiation and for extending the surgical margins. We report here initial results of treatment in five cases of locally advanced head and neck cancers.

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Introduction: Total skin electron beam therapy, commonly known as TSET, is a good choice of treatment for patients suffering from mycosis fungoides. The aim of this study was to introduce a new approach to the beam profile measurement using diodes and to calculate the monitor units required for the TSET treatment by the use of a simple setup of output measurement. Dosimetric measurements required for the treatment were taken to establish the Stanford technique in the department, and the measured data was compared with the published data.

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Introduction: Linear accelerator (LINAC) embedded with kV source-imager system is capable to do image-guided radiotherapy. The only disadvantage of cone-beam computed tomography image acquisition during treatment is the extra radiation dose to the patient. The aim of this study is to optimize the CBCT imaging doses likely to be received by the patient undergoing radiotherapy without affecting image quality.

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Article Synopsis
  • The study evaluated the safety and feasibility of using a 2-dimensional (2-D) radiotherapy technique for hypofractionated treatment in breast cancer patients, comparing a 2-week schedule to a traditional 3-week schedule.
  • Conducted as an open-label, randomized phase 3 trial with 1121 patients, it aimed to see if the shorter treatment duration could be effective using 2-D methods when 3-dimensional techniques weren't available.
  • Findings indicated the research was approved ethically, followed for a median of 35 months, and included assessments for acute toxicity and cosmetic outcomes post-treatment.
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Purpose: Concurrent chemoradiation is the standard of care for the treatment of anal cancer. Radiation can be delivered by sequential or simultaneous integrated boost (SIB) approach. The present study was conducted to compare the treatment outcomes and toxicity profile of patients with anal cancer treated with sequential boost and SIB approach.

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Purpose: The purpose of the study was to estimate the fitting parameters of the sigmoidal dose response (SDR) curve of radiation-induced acute dermatitis in breast cancer patients treated with intensity-modulated radiation therapy for calculation of normal tissue complication probability (NTCP).

Materials And Methods: Twenty-five breast cancer patients were enrolled to model the SDR curve for acute dermatitis. The acute radiation-induced (ARI) dermatitis toxicity was assessed weekly for all the patients, and their scores were determined using the common terminology criterion adverse events version 5.

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Purpose: To estimate the fitting parameters of the sigmoidal dose response (SDR) curve of radiation-induced acute proctitis in prostate cancer patients treated with intensity modulated radiation therapy (IMRT) for the calculation of normal tissue complication probability (NTCP).

Materials And Methods: Twenty-five prostate cancer patients were enrolled and evaluated weekly for acute radiation-induced (ARI) proctitis toxicity. Their scoring was performed as per common terminology criteria for adverse events version 5.

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Purpose: This study aimed to estimate the fitting parameters of sigmoidal dose-response (SDR) curve of radiation-induced acute rectal mucositis in pelvic cancer patients treated with Intensity Modulated Radiation Therapy (IMRT) for the calculation of normal tissue complication probability (NTCP).

Materials And Methods: Thirty cervical cancer patients were enrolled to model the SDR curve for rectal mucositis. The patients were evaluated weekly for acute radiation-induced (ARI) rectal mucositis toxicity and their scoring was performed as per Common Terminology Criteria for Adverse Events (CTCAE) version 5.

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Purpose/objective(s): This study aimed to estimate the fitting parameters of sigmoidal dose-response (SDR) curve of radiation-induced acute oral and pharyngeal mucositis in head-and-neck (H and N) cancer patients treated with Intensity Modulated Radiation Therapy (IMRT) for the calculation of normal tissue complication probability (NTCP).

Materials And Methods: Thirty H-and-N cancer patients were enrolled to model the SDR curve for oral and pharyngeal mucositis. The patients were evaluated weekly for acute radiation-induced (ARI) oral and pharyngeal mucositis toxicity, and their scoring was performed as per the common terminology criteria adverse events version 5.

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Article Synopsis
  • The study addresses the challenge of accurately measuring doses in brachytherapy, particularly in areas with high dose gradients and proximity to organs at risk, by introducing a new calibration method for GafChromic EBT3 films irradiated by an Ir-192 source.
  • Two exposure setups (single and dual catheter-based) were compared, and EBT3 films were analyzed using a flatbed scanner and Image J software, resulting in dose calibration graphs based on third-order polynomial equations.
  • The research found varying levels of agreement between the TPS calculated doses and the measured doses from both calibration methods, with maximum dose differences observed in the high dose range, highlighting the potential for improved accuracy in dose reporting through the dual catheter setup.
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Introduction: Chemoradiation therapy (CRT) remains the treatment of choice for inoperable locally advanced esophageal cancer (LAEC). Several CRT regimens are existent in esophageal cancer, but definitive conclusions are lacking. We performed a pilot study to compare treatment outcome, survival, and toxicities in inoperable upper and middle third esophageal cancer patients undergoing CRT using either paclitaxel/carboplatin or cisplatin/5FU based regimen.

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Purpose: To assess the feasibility of accelerated hypofractionated radiotherapy with simultaneous integrated boost (SIB) in patients with breast cancer.

Materials And Methods: A total of 27 patients after breast-conserving surgery were included in this study. Patients were planned on a four-dimensional computerized tomogram, and contouring was done using RTOG guidelines.

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Perioperative high dose rate brachytherapy is a radiotherapy treatment technique which involves intraoperative insertions of brachytherapy catheters into the tumor bed during the surgical resection followed by treatment in the post-operative period. We report here two cases to highlight its use in the primary treatment and reirradiation of head and neck cancers.

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. This study aimed to analyze the degree of reduction in normal liver complication probability (NTCP) from free-breathing (FB) to breath-hold (BH) liver SBRT. The effect of the radiation dose-volume on the mean liver dose (MLD) was also analyzed due to dose prescription, normal liver volume (NLV), and PTV.

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Purpose: To evaluate the clinical outcomes in patients with cervical cancer with limited residual disease at brachytherapy (BT) treated with point-based dose prescription.

Methods: Patients with locally advanced squamous cell carcinoma of the cervix treated with computed tomography (CT)-based intracavitary BT were considered for analysis. Patients with good response to external beam radiotherapy and limited residual disease suitable for intracavitary BT alone were included.

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Background: A purpose of the study was to investigate the dosimetric impact of contrast media on dose calculation using average 4D contrast-enhanced computed tomography (4D-CECT) and delayed 4D-CT (d4D-CT) images caused by CT simulation contrast agents for stereotactic body radiation therapy (SBRT) of liver cases.

Materials And Methods: Fifteen patients of liver SBRT treated using the volumetric modulated arc therapy (VMAT) technique were selected retrospectively. 4D-CECT, and d4D-CT were acquired with the Anzai gating system and GE CT.

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Objective: To prospectively analyze the effect of three-dimensional chemoradiation on the bone mineral density of pelvic bones and its association with low back pain and disability in patients with locally advanced cervical cancer.

Methods: In biopsy proven locally advanced cervical cancer patients, bone mineral density and T scores for lumbar vertebrae 5, dorsal thoracic vertebrae 12, and T scores for the femoral neck were analyzed. Low back pain was scored using the visual analog scale while disability scoring was done using the Oswestry low back pain disability scale.

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. The present study aims to investigate the dosimetric and radiobiological impact of patient setup errors (PSE) on the target and organs at risk (OAR) of the cervix carcinoma stage IIB patients treated with volumetric-modulated arc therapy (VMAT) delivery technique using plan uncertainty parameters module of Varian Eclipse treatment planning system and in-house developed DVH Analyzer program..

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To model the interplay effect and minimize it by a selection of optimum parameters value using a predictive model for SBRT of liver cancers. Ten cases of liver tumors treated with the VMAT technique were selected retrospectively. The dosimetric error due to the interplay effect was measured with a micro ionization chamber (0.

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Introduction: The impact of dose heterogeneity within the tumor on TCP and NTCP was studied using various radiobiological models. The effect of the degree of heterogeneity index (HI) on TCP was also analyzed.

Materials And Methods: Thirty-seven pre-treated liver SBRT cases were included in this study.

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The development of a stringent derivative-based gamma (DBG) index for patient-specific QA in stereotactic radiotherapy treatment planning (SRTP) to account for the spatial change in dose.Twenty-five patients of liver SBRT were selected retrospectively for this study. Deliberately, two different kinds of treatment planning approaches were used for each patient.

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Aim: Development of bidirectional non-monotonic segmented leaf sequence (NSLS) MLC delivery technique compatible with Varian MLC for non-split IMRT fields reducing total monitor units (TotalMU) and the number of segments (NS) simultaneously and assessment of its efficiency using a plan scoring index (PSI).

Materials And Methods: The optimal fluence of IMRT plans of ten patients of lung carcinoma, calculated using Eclipse TPS version 11.0 (Varian Medical Systems, Palo Alto, CA, USA), was used to generate the segmented MLC fields using our newly developed equally spaced (ES) reducing level and NSLS algorithms in MATLAB® version 2011b for 6-10 intensity levels.

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Objective: This study presents a methodology for voxel-based evaluation of two phase sequential radiotherapy treatment plans having conventional dose scheme in the first phase and subsequent hypofractionation dose scheme in the second phase based upon different priority [planning target volume (PTV), clinical target volume (CTV) and organs at risk (OAR)] of display modes.

Methods: A case of carcinoma prostate was selected for demonstration. Varian Eclipse treatment planning system (TPS) was used for contouring and planning.

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