Assessment of Uncertainty in Volume Estimation of Non-Static Target: A Phantom Study using Racemosa Wood.

INTRODUCTION: CT information of the target undergoing motion/movement during its scanning has been questioned by many researchers for its preciseness as well as accuracy. The present study was taken with aim to validate the racimosa wood as lung equivalent and to assess the uncertainty in volume estimation during virtual simulation of non-static target of known dimension such as in lung cancer radiotherapy. MATERIALS AND METHODS: The racemosa wood was validated as lung equivalent material with the help of two methods. Wood insert with tumor model was put into the hollow cylinder space of dimension 6.4 cm in diameter provided in CIRS phantom. First CT image of rest position was taken and given name "No Movement". Subsequently the tumor was shifted +/-5mm, +/-15mm and +/-25 mm with respect to "Rest Position". CT images of the CIRS phantom containing tumor in wood cylinder were acquired after each movement given to wood cylinder. RESULTS: The relative electron density of racemosa wood corresponding to HU value -724 was found to be 0.275 gm/cm3. The true volume of the target was 7.8.cm3 however variation up to 9.5 cm3 was observed in CT produced volume of the target over the range of different movements. DISCUSSION: The racemosa wood was found to be having range of density (- 850 HU to - 400 HU) similar to real human lung density variation. Various studies have been performed using uniform density lung structures in their experimental setups to assess the accuracy in lung cancer radiation delivery. However, in the present work approximately real clinical setting was reproduced by putting the wood cylinder with density variation from 0.2 gm/cm3- 4.5 gm/cm3in hollow space provided in one lung structure the phantom used in this study. CONCLUSIONS: The racemosa wood was found to be lung equivalent which is available locally and cost-effective as well. Overestimation in the target volume (by CT imaging) showed a trend of increase with 3 directional movement amplitudes. The results of this study can be utilised in lung cancer radiotherapy as the same were derived from setup having clinical settings in terms of lung density variation, shape, compositions of the phantom maximally as found during the real patient radiotherapy.

Expression of miR-145 and miR-18b in Peripheral Blood Samples of Head and Neck Cancer Patients.

Head and neck squamous cell carcinomas (HNSCC) is one of the most prevalent type of cancer known in Indian population. Studies are needed to identify the early biomarkers for HNSCC. MicroRNAs (miRNAs) are non-coding RNA molecules, expression of which can be used as biomarker for early diagnosis of HNSCC. For miRNA profiling total RNA, which also contained small RNAs were isolated from ten HNSCC tissue samples and adjacent control. Purity and concentration of eluted RNA was assessed using the NanoDrop1000® spectrophotometer, Reverse Transcription reaction was carried out with megaplex RT primers of pool A and pool B and the expression of selected miRNAs (miR-143/145 and miR-18a/b) was measured using TaqMan primers specific for mature miRNAs. Our study showed dramatic downregulation in expression of two miRNAs, miR-18b and miR-145 in blood samples of HNSCC patients, which are inhibitor of tumorigenesis and can be targeted as biomarker of HNSCC pathogenesis therefore developing avenues for miRNA role in prognosis and therapeutics. Supplementary Information: The online version contains supplementary material available at 10.1007/s12291-023-01119-2.

Feasibility, efficiency & effectiveness of pooled sample testing strategy (pooled NAAT) for molecular testing of COVID-19.

BACKGROUND & OBJECTIVES: During the current COVID-19 pandemic, a large number of clinical samples were tested by real-time PCR. Pooling the clinical samples before testing can be a good cost-saving and rapid alternative for screening large populations. The aim of this study was to compare the performance characteristics, feasibility and effectiveness of pooling nasal swab and throat swab samples for screening and diagnosis of SARS-CoV-2. METHODS: The pool testing was applied on a set of samples coming from low COVID-19 positivity areas. A total of 2410 samples were tested in pools of five samples each. A total of five pools of five samples each were generated and tested for E gene. RESULTS: Of the total of 482 pools (2410 samples) 24 pools flagged positive. Later on pool de-convolution, a total of 26 samples were detected as positive for COVID-19, leading to positivity of about one per cent in the test population. For the diagnosis of individual samples, the pooling strategies resulted in cost savings of 75 per cent (5 samples per pool). INTERPRETATION & CONCLUSIONS: It was observed that testing samples for COVID-19 by reverse transcription (RT)- PCR after pooling could be a cost-effective method which would save both in manpower and cost especially for resource-poor countries and at a time when test kits were short in supply.

Short-course radiotherapy with consolidation chemotherapy versus conventionally fractionated long-course chemoradiotherapy for locally advanced rectal cancer: randomized clinical trial.

BACKGROUND: The trial hypothesis was that, in a resource-constrained situation, short-course radiotherapy would improve treatment compliance compared with conventional chemoradiotherapy for locally advanced rectal cancer, without compromising oncological outcomes. METHODS: In this open-label RCT, patients with cT3, cT4 or node-positive non-metastatic rectal cancer were allocated randomly to 5 × 5 Gy radiotherapy and two cycles of XELOX (arm A) or chemoradiotherapy with concurrent capecitabine (arm B), followed by total mesorectal excision in both arms. All patients received a further six cycles of adjuvant chemotherapy with the XELOX regimen. The primary endpoint was treatment compliance, defined as the ability to complete planned treatment, including neoadjuvant radiochemotherapy, surgery, and adjuvant chemotherapy to a dose of six cycles. RESULTS: Of 162 allocated patients, 140 were eligible for analysis: 69 in arm A and 71 in arm B. Compliance with planned treatment (primary endpoint) was greater in arm A (63 versus 41 per cent; P = 0.005). The incidence of acute toxicities of neoadjuvant therapy was similar (haematological: 28 versus 32 per cent, P = 0.533; gastrointestinal: 14 versus 21 per cent, P = 0.305; grade III-IV: 2 versus 4 per cent, P = 1.000). Delays in radiotherapy were less common in arm A (9 versus 45 per cent; P < 0.001), and overall times for completion of neoadjuvant treatment were shorter (P < 0.001). The rates of R0 resection (87 versus 90 per cent; P = 0.554), sphincter preservation (32 versus 35 per cent; P = 0.708), pathological complete response (12 versus 10 per cent; P = 0.740), and overall tumour downstaging (75 versus 75 per cent; P = 0.920) were similar. Downstaging of the primary tumour (ypT) was more common in arm A (P = 0.044). There was no difference in postoperative complications between trial arms (P = 0.838). CONCLUSION: Reduced treatment delays and a higher rate of compliance were observed with treatment for short-course radiotherapy with consolidation chemotherapy, with no difference in early oncological surgical outcomes. In time- and resource-constrained rectal cancer units in developing countries, short-course radiotherapy should be the standard of care.

Prospective evaluation of XRCC-1 Arg194Trp polymorphism as bio-predictor for clinical outcome in locally advanced laryngeal cancer undergoing cisplatin-based chemoradiation.

BACKGROUND: To determine X-ray repair cross-complementing 1 gene (XRCC-1) Arg194Trp polymorphism as bio-predictor for clinical outcome in advanced laryngeal squamous cell carcinoma undergoing cisplatin-based chemoradiation (CRT). METHODS: A total of 150 patients were enrolled in this prospective study. XRCC-1 Arg194Trp genotyping categorized patients as wild (C/C) and polymorphic (C/T or T/T). The primary endpoint was to assess acute radiation-induced toxicity (ARIT). RESULTS: A significant correlation of skin (P- .04) and oral mucosal ARIT (P- .01) was noticed in the XRCC-1 polymorphic variant. A higher treatment response was noted in the polymorphic variant, and it shows a trend toward significance (P- .08). With 33 months of median follow-up, 2-year progression-free survival (PFS) and overall survival (OS) of wild vs polymorphic variant were 34.6% vs 46.9% (P- .066) and 50.6% vs 62.2% (P- .12). CONCLUSION: XRCC-1 polymorphic variants have significantly higher grade of >2 ARIT and may have improved trend for treatment response and PFS.

Evaluation of Lung Density and Its Dosimetric Impact on Lung Cancer Radiotherapy: A Simulation Study.

BACKGROUND: The dosimetric parameters required in lung cancer radiation therapy are taken from a homogeneous water phantom; however, during treatment, the expected results are being affected because of its inhomogeneity. Therefore, it becomes necessary to quantify these deviations. OBJECTIVE: The present study has been undertaken to find out inter- and intra- lung density variations and its dosimetric impact on lung cancer radiotherapy using Monte Carlo code FLUKA and PBC algorithms. MATERIAL AND METHODS: Density of 100 lungs was recorded from their CT images along with age. Then, after PDD calculated by FLUKA MC Code and PBC algorithm for virtual phantom having density 0.2 gm/cm3 and 0.4 gm/cm3 (density range obtained from CT images of 100 lungs) using Co-60 10 x10 cm2 beams were compared. RESULTS: Average left and right lung densities were 0.275±0.387 and 0.270±0.383 respectively. The deviation in PBC calculated PDD were (+)216%, (+91%), (+)45%, (+)26.88%, (+)14%, (-)1%, (+)2%, (-)0.4%, (-)1%, (+)1%, (+)4%, (+)4.5% for 0.4 gm/cm3 and (+)311%, (+)177%, (+)118%, (+)90.95%, (+)72.23%, (+)55.83% ,(+)38.85%, (+)28.80%, (+)21.79%, (+)15.95%, (+)1.67%, (-) 2.13%, (+)1.27%, (+)0.35%, (-)1.79%, (-)2.75% for 0.2 gm/cm3 density mediums at depths of 1mm, 2mm, 3mm, 4mm, 5mm, 6 mm, 7 mm, 8mm, 9mm,10mm, 15mm, 30mm, 40mm, 50mm, 80mm and 100 mm, respectively. CONCLUSION: Large variations in inter- and intra- lung density were recorded. PBC overestimated the dose at air/lung interface as well as inside lung. The results of Monte Carlo simulation can be used to assess the performance of other treatment planning systems used in lung cancer radiotherapy.

Alteration of the Risk of Oral Pre-Cancer and Cancer in North India Population by CYP1A1 Polymorphism Genotypes and Haplotype

Background: The aim of this study was to evaluate any association between CYP1A1 (T6235C and C4887A, A4889G) gene polymorphisms and the risk of oral pre-cancer and cancer. Methods: In the present study, 250 patients with oral pre-cancer and/or cancer and 250 healthy controls were genotyped for CYP1A1 T6235C, C4887A and A4889G polymorphisms by the PCR-RFLP method. Results: None of the CYP1A1 polymorphisms were associated with the risk of either oral cancer or pre cancer. Nor were any links with clinical parameters of oral cancer found. However, among the consumers of areca nut/pan masala the TC, CA and AG genotypes respectively for the CYP1A1 T6235C,C4887Aand A4889G polymorphisms were significantly more frequent in controls compared to cases (p values for cases vs. controls of 0.0032, 0.0019 and 0.0009, respectively). Similarly, compared to the haplotype TCA, TAG constituted by CYP1A1 T6235C and C4887A and A4889G was more common in controls (6.88%) than in cases (4.07%). Conclusion: Our results suggest that genotypes regarding CYP1A1 polymorphisms may modulate the risk of oral cancer and pre-cancer among the areca nut/pan masala consumers. The haplotype may also exert an influence in our north Indian population.

Evaluation of Volumetric Doses of Organs at Risk in Carcinoma Cervix Patients with HDR Intracavitary Brachytherapy and Comparison of CT-based and Conventional Plans.

BACKGROUND: Brachytherapy treatment planning in cervix carcinoma patients using two dimensional (2D) orthogonal images provides only point dose estimates while CT-based planning provides volumetric dose assessment helping in understanding the correlation between morbidity and the dose to organs at risk (OARs) and treatment volume. OBJECTIVE: Aim of present study is to compare International Commission on Radiation Units and Measurements Report 38 (ICRU 38) reference point doses to OARs with volumetric doses using 2D images and CT images in patients with cervical cancer. MATERIAL AND METHODS: In this prospective study, 20 patients with cervical cancer stages (IIB-IIIB) were planned for a brachytherapy dose of 7Gy per fraction for three fractions using 2D image-based treatment plan and CT-based plan. ICRU 38 points for bladder and rectum were identified on both 2D image-based plan and CT-based plan and doses (DICRU) at these points were compared to the minimum dose to 2cc volume (D2cc) of bladder and rectum receiving the highest dose. RESULTS: D2cc bladder dose was 1.60 (±0.67) times more than DICRUb bladder dose whereas D2cc rectum dose was 1.13±0.40 times DICRUr. Significant difference was found between DICRUb and D2cc dose for bladder (p=.0.016) while no significant difference was seen between DICRUr and D2cc dose for rectum (p=0.964). CONCLUSION: The study suggests that ICRU 38 point doses are not the true representation of maximum doses to OARs. CT-based treatment planning is more a reliable tool for OAR dose assessment than the conventional 2D radiograph-based plan.

Validation of the Gel & Wax Boluses and Comparison of their Dosimetric Performance with Virtual Bolus.

BACKGROUND: In general, radiotherapy treatment planning is performed using the virtual bolus. It is necessary to investigate physical bolus in comparison to virtual one. OBJECTIVES: In the present study, first, radiological properties of superflab Gel bolus and Paraffin wax bolus was investigated in terms of their relative electron density. Then, dosimetric performance of both the bolus (i.e. Gel and Parafin wax) was compared with Virtual bolus. MATERIAL AND METHODS: In This experimental study, the radiological property of Wax and Gel boluses was investigated using two methods. In one, the relative electron density of both the Gel and Wax boluses was calculated by measuring their linear attenuation coefficient where in another method relative electron density was calculated by recording their CT No directly from their CT scan. Later CT scan of solid water slab phantom (dimension 30x30x15 cm3), with physical boluses (i.e. Gel and Wax bolus) of appropriate thicknesses required to deliver a dose of 200 cGy at Dmax using 4 MV, 6 MV and 15 MV photon beams, was taken. These CT data sets were retrieved to TPS. A plan was done to deliver a dose of 200 cGy at Dmax using Single 4 MV, 6 MV and 15 MV photon beams. Dose at depths Dmax, 1 cm, 2 cm, 3 cm, 4 cm and 5 cm was recorded. Using this similar method, doses at depths viz Dmax, 1 cm, 2 cm, 3 cm, 4 cm and 5 cm was recorded for the Gel and Wax boluses. The differences in dose of gel and wax bolus from virtual bolus were recorded for comparison of their dosimetric performance. RESULTS: The measured (calculated) relative electron density of wax and Gel bolus was found to be 0.958 (0.926) and 0.923 (0.907), respectively. Variation in dosimetric performance of Gel and Wax with reference to Virtual bolus was studied. However, on average, Gel bolus was more consistent with virtual bolus. CONCLUSION: To avoid any dose difference between, delivered (using physical bolus) and planned (using virtual bolus), the physical boluses should be investigated for their dosimetric performance in comparison to virtual bolus. The results obtained and methodology used in this study can be applied in routine radiotherapy practices.

Correction: Tissue and serum expression of TGM-3 may be prognostic marker in patients of oral squamous cell carcinoma undergoing chemo-radiotherapy.

[This corrects the article DOI: 10.1371/journal.pone.0199665.].

Tissue and serum expression of TGM-3 may be prognostic marker in patients of oral squamous cell carcinoma undergoing chemo-radiotherapy.

Radioresistance is one of the main determinants of treatment outcome in oral squamous cell carcinoma (OSCC), but its prediction is difficult. Several authors aimed to establish radioresistant OSCC cell lines to identify genes with altered expression in response to radioresistance. The development of OSCC is a multistep carcinogenic process that includes activation of several oncogenes and inactivation of tumour suppressor genes. TGM-3 is a tumour suppressor gene and contributes to carcinogenesis process. The aim of this study was to estimate serum and tissue expression of TGM-3 and its correlation with clinico-pathological factors and overall survival in patients of OSCC undergoing chemo-radiotherapy. Tissue expression was observed in formalin fixed tissue biopsies of 96 cases of OSCC and 32 healthy controls were subjected to immunohistochemistry (IHC) by using antibody against TGM-3 and serum level was estimated by ELISA method. mRNA expression was determined by using Real-Time PCR. Patients were followed for 2 year for chemo radiotherapy response. In OSCC, 76.70% cases and in controls 90.62% were positive for TGM-3 IHC expression. TGM-3 expression was cytoplasmic and nuclear staining expressed in keratinized layer, stratum granulosum and stratum spinosum in controls and tumour cells. Mean serum TGM-3 in pre chemo-radiotherapy OSCC cases were 1304.83±573.55, post chemo-radiotherapy samples were 1530.64±669.33 and controls were 1869.16±1377.36, but difference was significant in pre chemo-radiotherapy samples as compared to controls (p<0.018). This finding was also confirmed by real- time PCR analysis in which down regulation (-7.92 fold change) of TGM-3 in OSCC as compared to controls. TGM-3 expression was significantly associated with response to chemo-radiotherapy treatment (p<0.007) and overall survival (p<0.015). Patents having higher level of TGM-3 expression have good response to chemo-radiotherapy and also have better overall survival. TGM-3 may serve as a candidate biomarker for responsiveness to chemo-radiotherapy treatment in OSCC patients.

Evaluation of dose calculation accuracy of various algorithms in lung equivalent inhomogeneity: Comparison of calculated data with Gafchromic film measured results.

AIM: To evaluate dose calculation accuracy of various algorithms in lung equivalent inhomogeneity comprising tumor within it and comparison with Gafchromic film data. MATERIALS AND METHODS: Gafchromic film measured central axis absorbed dose in lung insert (-700 Hounsfield unit [HU]), in racemosa wood cylindrical inhomogeneity (-725 HU) and at three surfaces of tumor (-20 HU) created in cylindrical inhomogeneity, put in the cavity of computerized imaging reference systems (CIRS) thorax phantom were compared with convolution (CON), superposition (SP), fast SP (FSP), and X-ray voxel Monte Carlo (XVMC) algorithms calculated dose using 6 MV beams of field size 2 cm × 2 cm, 3 cm × 3 cm, 4 cm × 4 cm, 5 cm × 5 cm, and 8 cm × 8 cm. RESULTS: XVMC was in good agreement with film measured results for all selected field sizes except 3 cm × 3 cm. SP under estimated by 5.7% at the center of the lung insert while deviation up to 6% was found at the cent of wood inhomogeneity in 2 cm × 2 cm. Except CON, increase in dose from proximal to the central surface of the tumor and then dose falloff from central to the distal surface for field size 2 cm × 2 cm to 4 cm × 4 cm was recorded. The change in film measured percentage depth dose from 2 cm × 2 cm to 3 cm × 3 cm field sizes was found -8% however for consecutive field size(s) larger than 3 cm × 3 cm this difference was less. CON and FSP produced overestimated results. CONCLUSION: Out of four algorithms, XVMC found consistent with measured data. The electronic disequilibrium within and at the interface of inhomogeneity make the accurate dose predictions difficult. These limitations results in deviations from the expected results of the treatments.

Physical interaction of estrogen receptor with MnSOD: implication in mitochondrial O2.- upregulation and mTORC2 potentiation in estrogen-responsive breast cancer cells.

Augmented reactive oxygen species levels consequential to functional alteration of key mitochondrial attributes contribute to carcinogenesis, either directly via oxidative DNA damage infliction or indirectly via activation of oncogenic signaling cascades. We previously reported activation of a key oncogenic signaling cascade via mammalian target of rapamycin (mTOR) signaling complex-2 (mTORC2) owing to estrogen receptor (ER-α)-dependent augmentation of O2.- within the mitochondria of 17-ß-estradiol (E2)-stimulated breast cancer cells. Manganese superoxide dismutase (MnSOD) is the principal mitochondrial attribute governing mitochondrial O2.- homeostasis, raising the possibility that its functional alteration could be instrumental in augmenting mitochondrial O2.- levels in breast cancer cells. Here we show ER-dependent transient inhibition of MnSOD catalytic function in breast cancer cells. Catalytic function of MnSOD is tightly regulated at the post-translational level. Post-translational modifications such as phosphorylation, nitration and acetylation represent key regulatory means governing the catalytic function of MnSOD. Acetylation at lysine-68 (K68) inhibits MnSOD catalytic activity and thus represents an important post-translational regulatory mechanism in human cells. Using reciprocal immunoprecipitation and proximity ligation assay, we demonstrate the occurrence of direct physical interaction between ER-α and MnSOD in human breast cancer cells, which in turn was associated with potentiated acetylation of MnSOD at K68. In addition, we also observed diminished interaction of MnSOD with sirtuin-3, the key mitochondrial deacetylase that deacetylates MnSOD at critical K68 and thereby activates it for scavenging O2.-. Consequently, compromised deacetylation of MnSOD at K68 leading to its inhibition and a resultant buildup of O2.- within the mitochondria culminated in the activation of mTORC2. In agreement with this, human breast cancer tissue specimen exhibited a positive correlation between acetyl-MnSODK68 levels and phospho-Ser2481 mTOR levels. In addition to exposing the crosstalk of ER-α with MnSOD post-translational regulatory mechanisms, these data also unravel a regulatory role of ER/MnSOD interaction as an important control switch for redox regulation of ER-α-responsive oncogenic signaling cascades. Furthermore, our study provides a mechanistic link for ER-α-dependent O2.- potentiation and resultant mTORC2 activation in breast cancer cells.

Understanding molecular markers in recurrent oral squamous cell carcinoma treated with chemoradiation.

INTRODUCTION: Oral cancer accounts for approximately 2.1% of all cancers worldwide. In India, oral squamous cell carcinoma (OSCC) is the most common cancer with half a million new cases diagnosed every year. More than 50% of patients eventually develop local recurrence or metastasis usually within the first 2-years following completion of treatment. It is beneficial to analyze the prognostic significance of Cyclin D1, p53 and EGFR which are critical mediators in the pathogenesis of OSCC. The objective of this study was to assess the association of expression of these markers with recurrence and pattern of recurrence in OSCC patients undergoing chemoradiation. MATERIALS AND METHODS: A Total 290 OSCC cases of locally advanced stage (III, IV) oral cancer with World Health Organization (W.H.O.) performance status of grade 0/1 in the year 2009-2012 were enrolled in the study. Treatment response was assessed according to W.H.O. criteria. Cyclin D1, EGFR and p53 expression in tumor tissue was estimated by immunohistochemical (IHC) method and quantified as percentage positive nuclei. RESULTS: During the 2-years follow up, 56 (19.3%) patients recurred, out of which, 47 (83.9%) were locoregional and 9 (16.1%) distant sites. On correlating, χ2 test showed significant (P < 0.05 or P < 0.01 or P < 0.001) association of marker expressions (Cyclin D1, EGFR and p53) with recurrence. The strong positive expressions of all three markers showed significant association with early time of recurrence. The multivariate logistic regression analysis showed significant (P < 0.05 or P < 0.01 or P < 0.001) association of recurrence with primary site, differentiation, Cyclin D1 and p53 expressions indicating these as an independent predictors of recurrence in OSCC. The Cyclin D1, EGFR and p53 expressions also showed significant (P < 0.001) poor survivals (OS, DFS and RFS) in patients with positive/strong positive expressions than negative expression suggesting their prognosis in OSCC. CONCLUSION: Our results signifies that tumors over expressing Cyclin D1, EGFR and p53 are resistant to chemoradiation and are associated with increased risk of locoregional recurrence and metastasis in OSCC patients undergoing chemoradiation.

Performance Evaluation of Algorithms in Lung IMRT: A comparison of Monte Carlo, Pencil Beam, Superposition, Fast Superposition and Convolution Algorithms.

BACKGROUND: Inclusion of inhomogeneity corrections in intensity modulated small fields always makes conformal irradiation of lung tumor very complicated in accurate dose delivery. OBJECTIVE: In the present study, the performance of five algorithms via Monte Carlo, Pencil Beam, Convolution, Fast Superposition and Superposition were evaluated in lung cancer Intensity Modulated Radiotherapy planning. MATERIALS AND METHODS: Treatment plans for ten lung cancer patients previously planned on Monte Carlo algorithm were re-planned using same treatment planning indices (gantry angel, rank, power etc.) in other four algorithms. RESULTS: The values of radiotherapy planning parameters such as Mean dose, volume of 95% isodose line, Conformity Index, Homogeneity Index for target, Maximum dose, Mean dose; %Volume receiving 20Gy or more by contralateral lung; % volume receiving 30 Gy or more; % volume receiving 25 Gy or more, Mean dose received by heart; %volume receiving 35Gy or more; %volume receiving 50Gy or more, Mean dose to Easophagous; % Volume receiving 45Gy or more, Maximum dose received by Spinal cord and Total monitor unit, Volume of 50 % isodose lines were recorded for all ten patients. Performance of different algorithms was also evaluated statistically. CONCLUSION: MC and PB algorithms found better as for tumor coverage, dose distribution homogeneity in Planning Target Volume and minimal dose to organ at risks are concerned. Superposition algorithms found to be better than convolution and fast superposition. In the case of tumors located centrally, it is recommended to use Monte Carlo algorithms for the optimal use of radiotherapy.

Clinico-epidemiological study of oral squamous cell carcinoma: A tertiary care centre study in North India.

INTRODUCTION: Oral squamous cell carcinoma (OSCC) ranks 12th most common cancer in the world. OBJECTIVE: The aim of this study was to retrospectively evaluate the OSCC. METHODS: A retrospective study of 611 OSCC patients from January 2010 to December 2013 was carried out in Department of Surgical Oncology, King George's Medical University, Lucknow, India. Details of patient's sex, age, tobacco habit and site of cancer were noted. Data were analyzed by Student's t test and chi-squire (χ (2)) test. RESULTS: The prevalence of OSCC was significantly (p < 0.001) higher in males (75.9%) than females (24.1%). The mean age of female patients was higher than males (p < 0.001). In both the genders, the buccal mucosa and gingivobuccal sulcus were found to be the most affected sites. Moreover, the smokeless form of tobacco was found to be significantly associated with OSCC, especially in females. CONCLUSION: The study concluded that OSCC is more common in men as compared to women, probably due to habit of tobacco consumption. Smokeless tobacco use is an important risk factor, especially in females.