International Journal of Cancer Therapy and Oncology
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High Impact Papers from September – October, 2013 (Issue 1)
Get PDFHigh impact papers from a particular Issue are selected based on the quality of the article and the number of citations. High impact papers are typically recognized once the Issue completes the publication time period of 12 months.Full text is available in PD
A real-time virtual delivery system for photon radiotherapy delivery monitoring
Get PDFPurpose: Treatment delivery monitoring is important for radiotherapy, which enables catching dosimetric error at the earliest possible opportunity. This project develops a virtual delivery system to monitor the dose delivery process of photon radiotherapy in real-time using GPU-based Monte Carlo (MC) method.Methods: The simulation process consists of 3 parallel CPU threads. A thread T1 is responsible for communication with a linac, which acquires a set of linac status parameters, e.g. gantry angles, MLC configurations, and beam MUs every 20 ms. Since linac vendors currently do not offer interface to acquire data in real time, we mimic this process by fetching information from a linac dynalog file at the set frequency. Instantaneous beam fluence map (FM) is calculated based. A FM buffer is also created in T1 and the instantaneous FM is accumulated to it. This process continues, until a ready signal is received from thread T2 on which an in-house developed MC dose engine executes on GPU. At that moment, the accumulated FM is transferred to T2 for dose calculations, and the FM buffer in T1 is cleared. Once the dose calculation finishes, the resulting 3D dose distribution is directed to thread T3, which displays it in three orthogonal planes in color wash overlaid on the CT image. This process continues to monitor the 3D dose distribution in real-time.Results: An IMRT and a VMAT cases used in our patient-specific QA are studied. Maximum dose differences between our system and treatment planning system are 0.98% and 1.58% for the IMRT and VMAT cases, respectively. The update frequency is >10Hz and the relative uncertainty level is 2%.Conclusion: By embedding a GPU-based MC code in a novel data/work flow, it is possible to achieve real-time MC dose calculations to monitor delivery process.------------------------------Cite this article as: Shi F, Gu X, Graves YJ, Jiang S, Jia X. A real-time virtual delivery system for photon radiotherapy delivery monitoring. Int J Cancer Ther Oncol 2014; 2(2):020222. DOI: 10.14319/ijcto.0202.2
Skeletal muscle lipid quantification in lean and diabetic subjects using in vivo proton MR spectroscopy
Get PDFPurpose: To quantify and compare the intramyocellular (IMCL), extramyocellular (EMCL) lipids and total fat fraction in human vastus lateralis muscle between lean and type 2 diabetic (T2DM) subjects using long echo time (TE) STEAM proton MR spectroscopy (1H-MRS). Methods: 1H-MRS using single voxel (15 × 15 × 15 mm3) stimulated acquisition mode (STEAM) was performed in right vastus lateralis m. on 10 lean controls (age: 28.3 ± 3.94 yo, BMI: 24.25 ± 3.20 kg/m2) and 7 type 2 diabetic (age: 54.28 ± 6.42 yo, BMI: 31.34 ± 3.13 kg/m2) subjects with Siemens 3T MRI and a four-channel flex coil. Unsuppressed water spectra (NSA = 16) with TR/TE = 3000/30 ms, TM = 10 ms BW = 2000 Hz, and water-suppressed spectra (NSA = 128) with TR/TE = 3000/270 ms, TM = 10 ms, fixed water suppression BW = 50 Hz were acquired. Spectral intensity ratios of IMCL-CH2, EMCL-CH2 and total lipid (IMCL + EMCL) with unsuppressed water signal (W) were converted into absolute concentrations expressed in mmol/kg. Fat fraction (100 × F/(W+F)) was also calculated, where F includes the signal intensities of IMCL and EMCL methylene (CH2)n, peaks only.Results: Comparison of IMCL (controls: 11.70 ± 6.7, T2DM: 21.74 ± 10.2, p < 0.01), EMCL (controls: 22.89 ± 18.42, T2DM: 77.21 ± 33.4, p < 0.001) and total lipid (64.35 mmol/kg less in controls, p < 0.001) showed statistical significance using two-tailed student’s t-test. Mean fat fraction (%) exhibited considerable inter-individual variability for controls (3.14 ± 2.09; range: 1.34 – 7.04) and T2DM (9.34 ± 2.88; range: 4.15 – 13.67) and deemed significant (p < 0.05). Conclusion: Single voxel STEAM 1H-MRS at long TE provides a robust non-invasive method for characterizing lipids within localized muscle regions, with well-resolved IMCL/EMCL peak separation. Regional lipid estimate and fat fraction in vastus lateralis muscle is significantly different in T2DM compared to normal lean controls.------------------------------Cite this article as: Valaparla SK, Boone GRE, Ripley EM, Giuseppe D, Duong TQ, Abdul-Ghani M, Clarke GD. Skeletal muscle lipid quantification in lean and diabetic subjects using in vivo proton MR spectroscopy. Int J Cancer Ther Oncol 2014; 2(2):020239. DOI: 10.14319/ijcto.0202.3
Consideration of therapeutic approach to advanced colorectal cancer in elderly patients
Get PDFColorectal cancer (CRC) is predominantly a disease of elderly and is a major cause of morbidity and mortality in the elderly population. The increased availability of treatment options for CRC has made it more difficult for clinicians to decide on the optimal therapeutic approach in elderly patients, because of the potential for poorer outcomes due to an increased burden of comorbidities, functional dependency, and limited life expectancy. It is necessary to determine which elderly patients are likely to benefit from active cancer therapy, and the establishment of treatment markers for multimodality approaches is eagerly awaited. Elderly cancer patients are at risk of exposure to various intrinsic inflammatory mediators, such as tumor-generating cytokines and surgery-induced pro-inflammatory cytokines. It is therefore important to understand the immunological changes occurring in the elderly and to adjust treatment strategies accordingly to reduce the morbidity and mortality associated with multimodality therapy for CRC that induce systemic inflammation. Several inflammation-based factors such as the Glasgow Prognostic Score (GPS) may reflect the balance between tumor progression and host-related immunity, especially in elderly CRC patients. Appropriate selection criteria for multimodality therapy in elderly CRC patients may include not only tumor characteristics, but also host- and/or treatment-related factors such as comorbidities or surrogate markers using inflammation-based factors.----------------------------------------------Cite this article as: Inoue Y, Toiyama Y, Tanaka K, Mohri Y, Kusunoki M. Consideration of therapeutic approach to advanced colorectal cancer in elderly patients. Int J Cancer Ther Oncol 2014; 2(1):02014.DOI: http://dx.doi.org/10.14319/ijcto.0201.
Evaluation of three commercial metal artifact reduction methods for CT simulations in radiation therapy
Get PDFPurpose: To evaluate the success of three commercial metal artifact reduction methods (MAR) in the context of radiation therapy treatment planning.Methods: Three MAR strategies were evaluated: Philips O-MAR, monochromatic imaging using Gemstone Spectral Imaging (GSI) dual energy CT, and monochromatic imaging with metal artifact reduction software (GSI-MARs). The Gammex RMI 467 tissue characterization phantom with several metal rods and two anthropomorphic phantoms (pelvic phantom with hip prosthesis and head phantom with dental fillings), were scanned with and without metals (baseline). Each MAR method was evaluated based on CT number accuracy, metal size accuracy, and reduction in the severity of streak artifacts. CT number difference maps between the baseline and metal scan images were calculated, and the severity of streak artifacts was quantified using the percentage of pixels with > 40 HU error (“bad pixels”).Results: Philips O-MAR generally reduced HU errors in the RMI phantom. However, increased errors and induced artifacts were observed for lung materials. GSI monochromatic 70keV images generally showed similar HU errors as conventional 120kVp imaging, while 140keV images reduced HU errors. All the imaging techniques represented the diameter of a stainless steel rod to within ±1.6mm (2 pixels). For the hip prosthesis, O-MAR reduced the average % bad pixels from 47% to 32%. For GSI 140keV imaging, the % bad pixels was reduced from 37% to 29% compared to 120kVp imaging, and GSI-MARs further reduced it to 12%. For the head phantom, none of the MAR methods was particularly successful.Conclusion: O-MAR resulted in consistent artifact reduction but exhibited induced artifacts for metals located near lung tissue. GSI imaging at 140keV gave consistent reduction in HU errors and severity of artifacts. GSI-MARs at 140keV was the most successful MAR method for the hip prosthesis but exhibited induced artifacts at the edges of metals in some cases.---------------------------------Cite this article as: Huang JY, Kerns JR, Nute JL, Liu X, Stingo FC, Followill DS, Mirkovic D, Howell RM, Kry SF. Evaluation of three commercial metal artifact reduction methods for CT simulations in radiation therapy. Int J Cancer Ther Oncol 2014; 2(2):020224. DOI: 10.14319/ijcto.0202.2
Rate of EGFR mutation in patients with pulmonary adenocarcinoma
Get PDFPurpose: Contemporary literature on lung adenocarcinoma has demonstrated a genetic difference of the epidermal growth factor receptor (EGFR) pathway conferring to ethnicity, such as higher frequency of activated EGFR mutations in East Asian population. This information is missing in some developing countries, and we intend to address this gap in the literature. Methods: We examined the rate of EGFR mutations among Pakistani patients with adenocarcinoma of the lung. Fine-needle aspiration samples were gathered from 73 patients. Polymerase chain reaction was performed on extracted DNA for mutational analysis of EGFR exons 19 and 21. Results: EGFR mutations were discovered in 18 of 73 (24.6%) patients. We did not find any significant difference in EGFR mutation rate with regard to patient's age, sex, smoking history, clinical stage of lung cancer, subtypes of adenocarcinoma, and tumor differentiation. Conclusion: Our investigation shows that the EGFR mutation rate in our patient population with adenocarcinoma of the lung was higher than in African-American, Arabian, and white Caucasian patients, and was lower than the East Asian population
Non-invasive pre-clinical MR imaging of prostate tumor hypoxia for radiation therapy prognosis
Get PDFPurpose: To investigate the usefulness of Oxygen-Enhanced Magnetic Resonance Imaging (OE-MRI) changes in signal intensity related to oxygen challenge for predicting tumor response to radiation therapy.Methods: Dynamic MR signal changes were acquired using Varian 4.7T small animal MR scanner prior to image-guided radiation therapy (IGRT) of small (n = 6) and large subcutaneous (n = 5) prostate tumors in adult male rats. An interleaved blood-oxygen level dependent (BOLD) and tissue-oxygen level dependent (TOLD) data acquisition or (IBT) was performed using a baseline of medical air as positive control and using medical oxygen as a breathing challenge. BOLD used a 2-D multi-slice spoiled gradient-echo with multi-echo sequence. TOLD used a 2-D multi-slice spoiled gradient-echo sequence. Voxel changes in signal intensity were determined by a correlation coefficient mapping technique. Irradiation technique planned consisted of 1F × 15 Gy AP/PA or 2F × 7.5 Gy AP/PA to the gross tumor volume (GTV). Tumor growth measurements were recorded over time to assess the response to IGRT.Results: BOLD and TOLD signals variously illustrated positive or negative impulse responses in the tumor ROI due to inhaling medical oxygen. Correlation coefficient mapping demonstrated heterogeneity in tumors after inhaling medical oxygen. BOLD and TOLD signals exhibited increased changes in signal intensities after the first fraction of dose. Multi-fractionation had minimum effect until the second fraction of dose was applied. Tumor growth delays were observed when inhaling medical oxygen during IGRT.Conclusion: OE-MRI is a non-invasive imaging modality that can provide insight to the oxygen status of tumors. Observed increase percent changes in BOLD and TOLD signal intensities after the first fraction of dose suggest tumors experienced reoxygenation. OE-MRI could be used for predicting tumor response to IGRT when using medical oxygen for increasing GTV radiosensitivity, suggesting patient stratification for clinical implementation.------------------------------Cite this article as: White DA, Mason RP. Non-invasive pre-clinical MR imaging of prostate tumor hypoxia for radiation therapy prognosis. Int J Cancer Ther Oncol 2014; 2(2):020243. DOI: 10.14319/ijcto.0202.4
Treatment of skin and subcutaneous cancer diseases by hyperthermic methods
Get PDFPurpose: The present work pursues perfection of highly efficient anticancer, principally new methodology and technology. It deals with the comparative study of anticancer activity of controlled local hyperthermia in animals and determination-de- velopment of optimal regimes and schemes. Furthermore, it also presents the work on new clinical device of high anticancer effect. Methods: Authors used controlled local hyperthermia for this study. In our experiments, we used 3 to 3.5 months-old non-pedigree (nonlinear) white mice (mass: 18-30 gram). After mice selection for the experiments, animals were placed in vivarium, in quarantine regime for 10 to 4 days. Individual protocols were drawn for each animal. Similar feeding and handling regimes were created for all animals. Transplantable malignant cancer strain, Erlich adenocarcinoma, was used. Results: Experiments on animals were successful. There are positive conclusions of pathological-anatomy laboratory “PathGeo”: Form # IV -200- 6A, for the examination # 3119-12 and # 15/02 and macro-morphological and micro-morphological description of the study # 15272-13. On the basis of the results of morphological study, it was proved that liver and lungs (the main target bodies) were intact, and secondary cancer injuries were not fixed. After three sessions of hyperthermia treatment, the decrease in sizes of cancer formations and necrosis of diseased sections were visualized, while massive necrosis was observed after seven sessions. In all cases, necrosis and ulceration of diseased places were observed, which refers to transition of cancer into phase of healing. After eight-ten sessions, necrosis of cancer and ulceration were observed, which refers to irreversibility of the process and efficiency of the applied method of hyperthermia. Conclusion: Anticancer effect of hyperthermia conditioned by temperature fields was proved, which was expressed in inhibition of cancer growth, resorption and increase of life length of experimental animals. The method of treatment was selected with maximum anticancer effect free of side effects and was offered as a new, perspective alternative or additional means for treatment of malignant cancers
A case of endometrial carcinoma with age related hyperkyphosis treated with definitive radiotherapy
Get PDFThis report describes a simple brachytherapy procedure in a patient with endometrial cancer with age related hyperkyphosis. Sixty-eight year-old postmenopausal woman with age related hyperkyphosis presented with endometrial carcinoma, and the patient was not operated on due to associated pelvic deformity. The patient received whole pelvic radiation followed by uterovaginal brachytherapy. Patient was supported with soft pillows to support her exaggerated anterior concavity during brachytherapy procedure and execution. The brachytherapy dose was 6 Gy per fraction per week for 3 weeks using image guidance. This is probably the first reported case of endometrial cancer with age related hyperkyphosis. In spite of the associated skeletal problems, a simple brachytherapy procedure is possible and provides good result.
Clinical dosimetric impact of Acuros XB and analytical anisotropic algorithm (AAA) on real lung cancer treatment plans : review
Get PDFPhoton dose calculation algorithms in treatment planning system could affect the accuracy of dose delivery when tissue heterogeneity is involved along the beam path. Treatment planning for lung cancer is challenging, especially in the case of treatment plan involving small fields. The combination of low-density (air) medium and small fields cause charge particle disequilibrium nears the air/tissue interface. Beam modeling within the dose calculation algorithms must also employ an accurate method of accounting tissue heterogeneity corrections in order to avoid dose overestimation or underestimation. Analytical anisotropic algorithm (AAA) is one of the widely tested and validated dose calculation algorithms in external beam photon radiation therapy. Recently, Acuros XB (AXB) was made available for photon dose calculations, and several studies have demonstrated better dose prediction accuracy of the AXB over AAA. This article reviews the results from the treatment planning studies, which have investigated the clinical dosimetric impact of the AXB and AAA on real lung cancer treatment plans.--------------------------------------Cite this article as: Rana S. Clinical dosimetric impact of Acuros XB and analytical anisotropic algorithm (AAA) on real lung cancer treatment plans: review. Int J Cancer Ther Oncol 2014; 2(1):02019.DOI: http://dx.doi.org/10.14319/ijcto.0201.