International Journal of Cancer Therapy and Oncology
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Human epidermal keratinocytes death and expression of protein markers of apoptosis after ionizing radiation exposure
Get PDFPurpose: Knowledge of the pathophysiology of the irradiated skin is important to understand the tolerance and cosmetic response of the human skin to radiation. There are limited studies on the effect of radiotherapy dosage and fraction size in inducing apoptotic cell death in human skin. The expression of apoptotic biomarkers within a controlled population in different fractionation schemes has also never been studied. This study aims to investigate radiation induced apoptotic cell death in human skin cells after fractionated radiation exposure and the expression of unique biomarkers that reflect cell death or biology using multiplexed immunoassays.Methods: Breast skin biopsies were obtained from a single individual and divided into small pieces. Each piece was irradiated under different radiotherapy treatment fractionation schedules to a total dose of 50Gy. The irradiated skin tissues were analysed using Tunnel, immunohistochemistry and Western blot assays for expression of apoptotic keratinocytes and biomarkers (p53, p21, and PCNA). Haematoxylin and eosin (H&E) immunostaining was performed to study the morphological changes in the skin cells. Results: Radiation is mostly absorbed by the epidermal layers and observed to damage the epidermal keratinocytes leading to the activation of apoptotic proteins. Apoptotic proteins (p53, p21 and PCNA) were confirmed to be up-regulated in radiation exposed skin cells as compared to normal skin cells with no radiation. There is strong correlation of apoptotic protein expressions with increased radiation dosage and dose fractionation. Statistical analysis with ANOVA revealed a significant increase of PCNA and p21 expression with increased radiation dosage and dose fractionation (p < 0.05). Immunohistochemically, 14 % (range 10.71% to 17.29%) of the keratinocytes were positive for PCNA and 22.5% (range 18.28% to 27.2%) for p21 after 2Gy of irradiation. The most widespread, intense and uniform staining for PCNA and p21 was observed in skin that had received 50Gy of irradiation. The maximum expression of p53 (range 37.09% to 50.91%) was reached at 10Gy.Conclusion: Findings from this study will assist clinicians in predicting radiation induced skin toxicity with the current changes in radiation fractionation protocols.-----------------------------------Cite this article as: Wong S, Chor HH, Moothy S, Ong CT, Phan TT, Lu JJ. Human epidermal keratinocytes death and expression of protein markers of apoptosis after ionizing radiation exposure. Int J Cancer Ther Oncol 2013; 1(2):01027.DOI: http://dx.doi.org/10.14319/ijcto.0102.
Getting the right balance in treatment of ductal carcinoma in situ (DCIS)
Get PDFAs a result of mammographic detection, ductal carcinoma in situ (DCIS) is an increasing problem in breast clinics. Both histopathology and molecular profiling can identify subtypes likely to progress to invasive disease, but there is no subgroup with a zero likelihood of subsequent invasion. In patients with low/intermediate grade DCIS, if breast irradiation is not being carried out after free margins have been achieved the patient should be aware of the risks of withholding and the benefits and morbidity of adjuvant radiotherapy. Either tamoxifen or an aromatase inhibitor may be of value in those with low/intermediate ER+ve disease if radiotherapy is being withheld. For those patients with extensive or multicentric DCIS, mastectomy is the appropriate treatment. This is best combined with sentinel node biopsy and all such cases should be offered immediate reconstruction.----------------------------Cite this article as:Fentiman IS. Getting the right balance in treatment of ductal carcinoma in situ (DCIS). Int J Cancer Ther Oncol 2013; 1(2):01029.DOI: http://dx.doi.org/10.14319/ijcto.0102.9
Impact of heterogeneities on lateral penumbra in uniform scanning proton therapy
Get PDFPurpose: In the treatment planning of uniform scanning proton therapy, an aperture block is designed for each beam with a margin, which typically includes the lateral penumbra measured in water (homogenous) medium. However, during real proton therapy treatment, protons may pass through tissues of different densities within the patient's body before they are stopped. The main aim of this study was to investigate the dependency of lateral penumbra on low- and high-density heterogeneities placed in the plateau and spread-out Bragg peak (SOBP) regions.Method: The measurements were performed by placing radiographic films at the isocenter (center of SOBP), and each proton beam was delivered with 150 monitor units using standard beam conditions of the institution. Results and Conclusion: The preliminary results from this study showed that the lateral penumbra of uniform scanning proton beams was less sensitive to the inhomogeneities introduced in the protons beam path. The low-density heterogeneity in the plateau region had more impact on the lateral penumbra when compared to the low-density in the SOBP region. In contrast, the placement of high-density heterogeneity (whether in the plateau or SOBP region) produced a very minimal difference. The overall difference in lateral penumbra among different phantoms was within ±1 mm.----------------------Cite this article as:Rana S, Singh H. Impact of heterogeneities on lateral penumbra in uniform scanning proton therapy. Int J Cancer Ther Oncol 2013; 1(2):01026.DOI: http://dx.doi.org/10.14319/ijcto.0102.
Dose prediction accuracy of collapsed cone convolution superposition algorithm in a multi-layer inhomogenous phantom
Get PDFPurpose: Dose prediction accuracy of dose calculation algorithms is important in external beam radiation therapy. This study investigated the effect of air gaps on depth dose calculations computed by collapsed cone convolution superposition (CCCS) algorithm. Methods: A computed tomography (CT) scan of inhomogenous phantom (30 × 30 × 30 cm3) containing rectangular solid-water blocks and two 5 cm air gaps was used for central axis dose calculations computed by CCCS in Pinnacle treatment planning system. Depth dose measurements were taken using a cylindrical ionization chamber for identical beam parameters and monitor units as in the depth dose computations. The calculated and the measured percent depth dose (PDDs) were then compared. The data presented in this study included 6 MV photon beam and field sizes of 3 × 3 cm2, 5 × 5 cm2, 10 × 10 cm2, and 15 × 15 cm2.Results: The results of CCCS were within ±1.4% in the first water medium. However, upon traversing the first air gap and re-entering the water medium, in comparison to the measurements, the CCCS under-predicted the dose, with difference ranged from -1.6% to -3.3% for 3 × 3 cm2, from -2.4% to -4.2% for 5 × 5 cm2, from -2.4% to -6.7% for 10 × 10 cm2, and from -1.6% to -6.3% for 15 × 15 cm2. After the second air gap, the CCCS continued to under-predict the dose, and the difference ranged from -3.2% to -3.9% for 3× 3cm2, from -2.4% to -5.6% for 5 × 5 cm2, from -2.3% to -6.0% for 10 × 10 cm2, and from -1.5% to -5.6% for 15 × 15 cm2. Conclusion: The CCCS under-predicted the dose in water medium after the photon beam traversed the air gap. Special attention must be given during the patient set-up since large air gap between the patient body and immobilization devices may lead to unacceptable dose prediction errors.----------------------------------------------Cite this article as:Oyewale S. Dose prediction accuracy of collapsed cone convolution superposition algorithm in a multi-layer inhomogenous phantom. Int J Cancer Ther Oncol 2013; 1(1):01016.DOI: http://dx.doi.org/10.14319/ijcto.0101.
Current status of robotic training in the UK – a trainees perspective
Get PDFThe validation of robotic surgery in a growing number of operative procedures has increased its acceptance nationwide and its usage is becoming widespread. Training needs to reflect this fast paced environment to ensure that surgeons continue to progress competently and safely. Current surgical training in the UK is validated through the Intercollegiate Surgical Curriculum Programme (ISCP) with progression assessed through an Annual Review of Curriculum Progress (ARCP). There has been some resistance to this since its introduction and many trainees remain dissatisfied with this programme. Training in robotic surgery is currently focused through fellowships with little regular exposure to urology trainees at more junior levels. Robotic simulation provides a useful adjunct to training for both technical and non-technical skills. Its usage is particularly valuable to more inexperienced trainees but may be of limited benefit in those with more advanced skills. Training programmes such as the fundamental skills in robotic surgery (FSRS) have been created to facilitate robotic training and it is likely that the future of robotic surgery training will include a combination of theoretical learning, training programmes and fellowship training.-------------------------------------------------------Cite this article as: Chan KE, Vasdev N. Current status of robotic training in the UK – a trainees perspective. Int J Cancer Ther Oncol 2014; 2(1):02013.DOI: http://dx.doi.org/10.14319/ijcto.0201.
Recent advances in treatment of childhood cancer : role of targeted therapy
Get PDFThis article is an editorial, and it doesn't include an abstract. Full text of this article is also available in HTML and PDF.Cite this article as: Al-Tonbary Y. Recent advances in treatment of childhood cancer: role of targeted therapy. Int J Cancer Ther Oncol 2013; 1(2):01028.DOI: http://dx.doi.org/10.14319/ijcto.0102.
Dosimetric study of SIB-IMRT versus SIB-3DCRT for breast cancer with breath-hold gated technique
Get PDFBackground and Purpose: 3-dimensional conformal therapy (3DCRT) is widely employed radiation therapy technique for breast cancer, but there is still need to minimize the doses to organ at risk (OAR) using 3DCRT. A few clinical studies have discussed using intensity modulated radiation therapy (IMRT) to address this shortfall. Simultaneous integrated boost (SIB) has been used in head and neck and prostate cancer, and there is a growing interest in using SIB for breast cancer too. This study aimed to compare SIB-IMRT versus SIB-3DCRT for breast cancer patients. Materials and Methods: SIB-3DCRT treatment plans were created for 36 consecutive patients. Dose was prescribed as 45 Gy in 25 fractions to the planning target volume (PTV)-1 and 60 Gy in 25 fractions to PTV-2. Treatment plans were normalized to 95% of PTV volume receiving 95% of the prescription dose. The conformity index (CI), homogeneity index (HI), lung dose, heart dose, left anterior descending artery(LAD) dose, and low dose volume and integral dose of normal healthy tissue were recorded and analyzed. Results: With the use of IMRT technique, there was an improvement in CI (0.14) when compared to CI of 3DCRT (0.18; p = 0.01). However, there was no significant difference in the HI (p = 0.45). On average, the V20Gy of ipsilateral lung was 37.9 % for 3DCRT and 22.4 % (p < 0.01) for IMRT, whereas the V20Gy of total lung (ipsilateral + contralateral) was 21.8% for 3DCRT and 12.14 (p < 0.01) for IMRT. Similarly, average V40Gy of heart was 7.5 % for 3DCRT and 2.13 % (p = 0.01) for IMRT. The LAD maximum dose to left side breast patients, on average, was 39.5 Gy for 3DCRT and 29.17 Gy (p = 0.03) for IMRT. The average number of monitor units was about 180 for 3DCRT and 1441 (p < 0.01) for IMRT. Conclusion: IMRT for breast cancer treatment is feasible. In comparison to 3DCRT, IMRT can reduce the maximum dose to the target volume, and dose to the OAR. However, 3DCRT technique is superior in terms of low dose volume, integral dose, and treatment time. With the use of breath-hold gated technique in IMRT, it can further improve the target coverage and reduction of doses to the heart, lung, and LAD. SIB technique could reduce the overall treatment duration by about one week.----------------------------------Cite this article as:Moorthy S, Sakr H, Hasan S, Samuel J, Al-Janahi S, Murthy N. Dosimetric study of SIB-IMRT versus SIB-3DCRT for breast cancer with breath-hold gated technique. Int J Cancer Ther Oncol 2013;1(1):010110. DOI: http://dx.doi.org/10.14319/ijcto.0101.1
2nd Annual Conference of Bangladesh Medical Physics Society
Get PDFFollowing abstracts proceedings are available in PDF:Challenges in brachytherapy dosimetryEssentials of periodic QA in radiation therapyInterventional radiotherapy or brachytherapy: new challenges for a successful techniqueExternal beam radiotherapy and high dose rate (HDR) brachytherapy treatment for carcinoma cervix practice in BPKMCH, Bharatpur, NepalTransition from 2D to 3D-CRT (NICRH experience)Conformal HDR brachytherapy for prostate cancer: comparison between boost and monotherapyImportance and procedures of quality control of diagnostic CT and CT simulator using for modern radiation therapyMedical physics and biomedical engineering education in Gono UniversityPlan verification in tomotherapy using 3D semiconductor detectorComparison of the miniaturized Co-60 and Ir-192 sources in HDR brachytherpy applicationsA Supine based cranio-spinal irradiation technique using moving field junctions radiotherapyStatistical variation and significance in the responses of thyroid follicular cells of two areas of Bangladesh due to radiotherapy into head and neck regionDetermining proper patient’s set-up parameters like IFD, gantry angles, and field width in Ca. breast to achieve precise treatment, in a center where TPS & simulators are not availableAccidental exposure of cancer patient and its preventionComparison of physical and enhanced dynamic wedges beam characteristics for 6 MV photon energy using pencil-beam convolution (PBC) algorithmProcedure to set up a radiotherapy unit & low cost unit analysisPatient setup verification and quality control (QC) of electronic portal imaging device (EPID
Notes of the editorial board on the role of medical physics in radiotherapy
Get PDFoai:ojs.ijcto.org:article/13This article is an editorial, and it doesn't include an abstract. Full text of this article is available in HTML or PDF.Cite this article as:Ulmer W. Notes of the editorial board on the role of medical physics in radiotherapy. Int J Cancer Ther Oncol 2013;1(1):01014. DOI: 10.14319/ijcto.0101.
Radiation exposure for coronary artery calcium score at prospective 320 row multi-detector computed tomography
Get PDFPurpose:To date there is extensive data on the radiation dose for assessing coronary artery calcium scores (CACS) with 4-64 row multidetector MDCT. However with the advent of 320 row MDCT, the entire heart can be imaged in one beat and thus potentially reduce the radiation dose. The aim of this study was to evaluate radiation dose for CACS on low-dose prospective EKG-triggered 320 row MDCT.Materials and Methods: Informed consent for this retrospective HIPAA-compliant study was waived and approved by our institution’s institutional review board IRB. One hundred and sixty eight consecutive patients (Male 133 (79%): female 35 (21%), mean body mass index BMI 29±5 and mean heart rate 58± bpm) underwent coronary calcium scoring with prospective gating. The scan parameters were 300 mA, 120 kVp, volume scan length (VSL) 160 mm, gantry rotation 0.350 msec and 320 x 0.5 mm detectors at 320 MDCT. Beta blockers were given to patients in a case heart rate HR > 65 bpm. The effective dose (ED) estimates were calculated for all patients from the dose length product and the conversion factor k (0.014 mSv/mGy/cm) as recommended by current guidelines.Results: The mean SD radiation was 1.89±0.79 mSv. Overall the range varied from 0.28-2.48 mSv. The radiation was significantly less in females as compared to males (2.02±0.73 vs. 1.41±0.87, p<0.0001). No differences were noted whether HR was <60 vs. >=60 bpm (1.87±0.79 vs. 1.77±0.84 mSv, p=0.45). On the other hand a higher radiation was noted among obese individuals as compared to those with BMI<30 (1.84±0.82 vs. 1.91±0.80 mSv, p=0.62).Conclusion: Radiation dose obtained from 320-MDCT is similar to those obtained with 4-64 row MDCT. Further studies are needed to assess the feasibility of further lowering the tube current and tube voltage.------------------------------------------------Cite this article as:Khosa F, Khan A, Shuaib W, Clouse M, Budoff M, Blankstein R, Nasir K. Radiation exposure for coronary artery calcium score at prospective 320 row multi-detector computed tomography. Int J Cancer Ther Oncol 2013; 1(2):01023.DOI: http://dx.doi.org/10.14319/ijcto.0102.