Low-Intensity Light Detection with a High Detectivity Using 2D-Sb2Se3 Nanoflakes on 1D-ZnO Nanorods as Heterojunction Photodetectors.

Multifunctional photodetectors (PDs) with broadband responsivity (R) and specific detectivity (D*) at low light intensities are gaining significant attention. Thus, we report a bilayer PD creatively fabricated by layering two-dimensional (2D) Sb2Se3 nanoflakes (NFs) on one-dimensional (1D) ZnO nanorods (NRs) using simple thermal transfer and hydrothermal processes. The unique coupling of these two layers of materials in a nanostructured form, such as 2D-Sb2Se3 NFs/1D-ZnO NRs, provides an effective large surface area, robust charge transport paths, and light-trapping effects that enhance light harvesting. Furthermore, the combination of both layers can effectively facilitate photoactivity owing to proper band alignment. The as-fabricated device demonstrated superior overall performance in terms of a suitable bandwidth, good R, and high D* under low-intensity light, unlike the single-layered 1D-ZnO NRs and 2D-Sb2Se3 NF structures alone, which had poor detectivity or response in the measured spectral range. The PD demonstrated a spectral photoresponse ranging from ultraviolet (UV) to visible (220-628 nm) light at intensities as low as 0.15 mW·cm-2. The PD yielded a D* value of 3.15 × 1013 Jones (220 nm), which reached up to 5.95 × 1013 Jones in the visible light region (628 nm) at a 3 V bias. This study demonstrated that the 2D-Sb2Se3 NFs/1D-ZnO NRs PD has excellent potential for low-intensity light detection with a broad bandwidth, which is useful for signal communications and optoelectronic systems.

Photocatalytic Activity of BaAl2O4 for Water Purification.

Degradation of dyes under natural light sources is one of the most active research areas in basic science for greener technology. In this context, the photocatalytic activity of semiconductors has received massive attention in solving water treatment-related issues as these possess enormous potential for degrading organic impurities. Here, we report that barium aluminate (BaAl2O4, BAO), which has been extensively studied for photoluminescence applications, is found to be a highly potent candidate for photocatalytic activities. We have explored the degradation of dyes (meant for water purification) by using the photocatalytic properties of pure and Dy- and Yb-codoped BAO. Crystal structure, electron microscopy, and Raman analysis of the autocombustion-synthesized pure and codoped BAO samples revealed significant morphological changes such as increased particle size and stabilization of rod-like structures. UV-vis absorbance measurements confirm the presence of multiple bandgaps in the BAO samples, which is substantiated by X-ray absorption spectroscopy measurements. Photocatalytic degradation studies of methylene blue (MB) dye (with different catalyst concentrations, dopings, and MB dye concentrations) have been carried out by using BAO. The kinetics of the photocatalytic degradation measurements has been explained by the Boltzmann distribution function, and the fastest (in less than 40 min), with more than 99% degradation of MB impurity, is reported here for the first time in BAO compounds. Synthesized BAO samples show excellent cyclic stability, which is essential for their potential applications in environmental remediation. The trade-off between the enhancement of surface area and increased particle size is considered the key parameter for controlling the photocatalytic performance of the BAO catalyst after Dy and Yb codopings.

Comparative analysis of trace elements in the saliva and serum of patients with oral submucous fibrosis and squamous cell carcinoma.

Of note, one third of oral cancer or oral tissue dysfunction cases are from India, primarily resulting from the consumption of Gutkha, a type of smokeless tobacco prevalent among several Indian populations. Gutkha is a mixture of tobacco, areca nut, slaked lime, catechu, spices, sweeteners and essences. Oral submucous fibrosis (OSMF), which is linked to the consumption of areca nut products and tobacco, is a chronic, precancerous condition of the submucosal tissues. OSMF transforms into oral squamous cell carcinoma (OSCC) at a rate of 7-13%. Gutkha also contains various trace elements, such as copper (Cu), zinc (Zn), selenium (Se) and molybdenum (Mo). Alterations in trace element levels in the body are associated with cancer progression. The present study aimed to determine the levels of serum and salivary trace elements in patients with OSMF and OSCC. A total of 80 patients were selected for the study and were divided into four groups of 20 patients in each (Group A, gutkha intake without OSMF; group B, gutkha intake with OSMF; group C, OSCC; and group D, control). The level of Cu was found to be increased and the levels of Zn, Se and Mo were decreased in the serum of patients with OSMF and OSCC compared with the controls. The salivary levels of these elements were lower compared with those in the serum. Age and sex had no significant effect on the levels of these trace elements. The results of the present study affirm the fact that serum and salivary trace elements are altered in pre-malignant and malignant lesions as the disease progresses. As the composition of saliva often varies, monitoring serum trace element levels as diagnostic and prognostic markers may aid in the early detection of the disease and in the management of the treatment efficacy.

Comparison of fracture resistance of simulated immature teeth using four different commercially available apexification materials - An in vitro study.

Introduction: The aim of this study was to compare the fracture resistance of simulated immature teeth using four different apical plug materials, i.e. Pro- Root MTA, Neo- MTA Plus, Biodentine, and Bioactive Glass. Materials and Methods: 80 extracted human maxillary anterior teeth were divided into 4 groups for this study. They were prepared using Peeso reamers to simulate immature teeth and to mimic Cvek's stage 3 of root development. A 5 mm apical barrier was placed using different materials. The remaining canal was obturated using gutta-percha and AH plus sealer. The final samples were stored at 37°C and 100% humidity for 4 weeks. Fracture resistance of the teeth was measured in Newtons using a universal testing machine. The comparison of fracture resistance between the four groups was done using Kruskal Walis ANOVA followed by post hoc Mann Whitney U test for pairwise comparison. Results: Biodentine group showed the highest fracture resistance as compared to the other three groups and the difference was highly significant (P < 0.001). Conclusions: Biodentine can be advocated over MTA as an effective material for the management of teeth with wide open apex. Bioactive glass also has shown promising results in increasing the fracture resistance of simulated immature teeth.

DFT stimulation and experimental insights of chiral Cu(II)-salen scaffold within the pocket of MWW-zeolite and its catalytic study.

A Cu(II)-salen complex encapsulated in MWW-framework as an efficient chiral organocatalyst was developed for the synthesis of 3,4-dihydropyrimidin-2-(1H)-one (DHPMs) derivatives via an asymmetric pathway. In order to confirm its structural properties, single-crystal X-ray diffraction, powder XRD, BET, XPS, FE-SEM, EDX, UV-Vis, and FTIR spectra were used. Using computer-assisted DFT calculations, the Cu(II)-salen complex has been fine-tuned to fit into the pocket of the porous MWW support while keeping its chirality. This organocatalyst was shown to be a potent catalyst for the formation of the desired DHPMs product under short reaction times. Furthermore, this green protocol allows rapid and simple isolation of active MWW-trapped Cu(II)-salen scaffolds and its reusability in at least five consecutive runs without losing much of its activity.

Hypohidrotic ectodermal dysplasia: A rare entity.

Hypohidrotic ectodermal dysplasia (HED) is a genetic disorder which involves a complex group of inherited conditions. This condition is characterised by the failed development of two or more ectodermal derived anatomic structure; for example, the skin, hair, nails, teeth, and sweat glands. It is a phenotypically heterogenous group of illnesses including anodontia with conical teeth, generalised spacing, reduced ability to sweat, very less hair growth, etc. The pattern of inheritance of HED varies from person to person depending on the type of ectodermal dysplasia (ED). The patterns include X-linked recessive, X-linked dominant, autosomal dominant, autosomal recessive, and spontaneous mutation. There is one such common type of ED more in female than male. It is an X-linked HED (XLHED), characterised by hypohidrosis, sparse hair, and teeth abnormalities. The other type can affect both male and female equally and may be inherited in different ways. The present case is a 21-year-old male who presented with hair, teeth, and sweat gland abnormalities.

A study to evaluate the effectiveness of various disinfectants for extracted human teeth - A comparative study.

Objectives: The aim of this study was to evaluate the effectiveness of various disinfectants for extracting human teeth. The objectives were to assess the effectiveness of 5% vinegar, 3% hydrogen peroxide, 70% alcohol, and 5.25% sodium hypochlorite for disinfection of extracted human teeth. Methods: The teeth were divided into one of the following four groups consisting of 10 teeth in each group. All teeth were immersed in separate bottles containing 10 ml of the disinfectant for 7 days at 25°C. No visible growth in the broth was considered effective disinfection. The Institutional Ethics Committee (IEC) Number is SVIEC/ON/DENT/SRP/15186, and the IEC Clearance number is SVIEC/ON/DENT/SRP/15040. Results: Vinegar was most effective for bacterial disinfection, and 5.25% sodium hypochlorite was most effective for fungal disinfection. The result was statistically significant with Chi-square values of 0.015 and 0.057, respectively, and P < 0.001. Conclusions: Extracted teeth should be handled with extreme care as these are a potential source of infection. The present study documented the role of various disinfectants. Vinegar can be used as an effective disinfectant medium for extracting human teeth. Sterilisation and autoclaving are superior options while vinegar is cheap, readily available, and relatively non-toxic. All these qualities plus the fact that it has given encouraging results as an antibacterial disinfectant should necessitate its usage on a more regular basis than it is used at present.

Rickets - A case report.

Rickets is a disorder caused by a lack of vitamin D, calcium or phosphate. It leads to softening and weakening of the bones. Dental manifestation of rickets includes enamel hypoplasia and delayed tooth eruption. The most important oral findings are characterised by spontaneous gingival and dental abscesses occurring without a history of trauma or caries. Radiographic examination revealed large pulp chambers, short roots, poorly defined lamina dura and hypoplastic alveolar ridge. These dental abscesses are common, and therefore, extraction and pulpectomy are the treatment of choice. Oral manifestations of rickets should be diagnosed early by both physicians and dentists to prevent severe dental complications. This article aims to report a case of rickets in a 3-year-old girl, describing the dental findings and the treatment to be performed in these cases.

Maxwell-Wagner Relaxation-Driven High Dielectric Constant in Al2O3/TiO2 Nanolaminates Grown by Pulsed Laser Deposition.

Multilayer nanolaminates (NLs) of alternate ultrathin sublayers of Al2O3 and TiO2 (ATA) with the thickness ranging ∼2 to 0.5 nm were fabricated by optimized pulsed laser deposition (PLD). Maxwell-Wagner (M-W) relaxation-induced interfacial polarization was realized and engineered by precisely controlling the sublayer thicknesses and the number of interfaces. X-ray reflectivity and cross-sectional transmission electron microscopy measurements of ATA NLs revealed an artificial periodicity with well-defined uniformly thick amorphous sublayers with chemically and physically distinct interfaces down to a sublayer thickness of ∼0.8 nm. The dielectric constants and loss of ATA NLs were found to increase from ∼60 to 670 and decrease from ∼0.9 to 0.16, respectively, as sublayer thicknesses reduced from ∼2 to 0.8 nm. However, for a sublayer thickness below 0.8 nm, the trend was reversed. Furthermore, temperature-dependent impedance spectroscopy studies revealed two distinct thermally activated relaxation processes, corresponding to TiO2 and Al2O3 sublayers, corroborating the M-W relaxation. The conductivity contrast between the sublayers of ATA NLs enhanced with reducing sublayer thickness and plateaued at a sublayer thickness of ∼0.8 nm, resulting in dominant M-W interfacial polarization and a high cut-off frequency of ∼50 kHz. These results demonstrate that ATA NLs grown by PLD may find application as potential high-k materials for next-generation nanoelectronic devices.

A comparative survival analysis of high viscosity glass ionomer restorations using conventional cavity preparation and atraumatic restorative treatment technique in primary molars: A randomized clinical trial.

BACKGROUND: This randomized clinical trial (RCT) aimed to compare the 3-year survival rates of high viscosity glass ionomer restorations (HVGIC) using conventional cavity preparation and atraumatic restorative technique (ART) in primary molars. MATERIALS AND METHODS: In this RCT, 139 schoolchildren aged 6-9 years with dentinal caries in primary molars were randomly allocated to groups, i.e. the ART group and the conventional group, utilizing a random number generator. Adequate allocation concealment was done. Intervention was delivered using standard procedure and GC Fuji IX ART HVGIC was used as restorations in both the groups. Analysis was carried in 92 participants, and survival rates in both the groups were compared at 12, 24, and 36-month intervals. IBM SPSS software was utilized to analyze the time taken for the procedure and the Kaplan-Meier estimate was used to assess the survival rates. P value of 0.05 was considered statistically significant. RESULTS: The ART took longer to complete (16.48 ± 2.02 min) versus conventional rotary instrumentation (13.15 ± 1.32 min). The conventional method was slightly superior as compared to ART; excellent survival rates (i.e. >90%) were achieved in both groups at the end of 12-month follow-up with no significant differences at the end of 24 and 36 months as evident from Kaplan-Meier estimate (P = 0.255). CONCLUSION: Three-year follow-up showed that GIC restorations with ART and conventional method carried out using GC Fuji IX ART HVGIC were acceptably successful, substantiating the use of ART for the primary dentition in areas with high caries prevalence and limited access to dental care.

Sub-nanograin metal based high efficiency multilayer reflective optics for high energies.

The present finding illuminates the physics of the formation of interfaces of metal based hetero-structures near layer continuous limit as an approach to develop high-efficiency W/B4C multilayer (ML) optics with ML periodicity varying d = 1.86-1.23 nm at a fixed number of layer pairs N = 400. The microstructure of metal layers is tailored near the onset of grain growth to control the surface density of grains resulting in small average sizes of grains to sub-nanometers. This generates concurrently desirable atomically sharp interfaces, high optical contrast, and desirable stress properties over a large number of periods, which have evidence through the developed ML optics. We demonstrate significantly high reflectivities of ML optics measured in the energy range 10-20 keV, except for d = 1.23 nm due to quasi-continuous layers. The reflectivities at soft gamma-rays are predicted.

Castleman's disease.

Castleman's disease, a type of lymph node hyperplasia, usually occurs in the mediastinum and rarely presents in the cervical region as an asymptomatic solitary mass. Clinically, they are of two types-solitary and multi-centric. Most of the solitary types are asymptomatic with no associated symptoms, whereas the multi-centric type is associated with systemic symptoms and has a poor prognosis. Histologically, they can be classified as-Hyaline vascular, plasma cell, transitional and stromal rich type. We report a case of Castleman's disease involving the submandibular lymph node in a 75-year-old male patient whose definitive diagnosis was made only on histological examination. Isolated Castleman's disease of the submandibular node is rare and a thorough clinical and histological examination is necessary to rule out the systemic form of the disease and other diseases with manifestations as a cervical lymph node enlargement.

Immunohistochemical Detection of Proliferative Marker Ki-67 in Benign and Malignant Salivary Gland Tumors.

Introduction: Salivary gland tumors are the most histologically heterogeneous group of tumors with the greatest diversity of morphologic features among their cells and tissues. The present study was aimed at assessing the validity of Ki-67, a cell proliferation marker, as a prognostic factor in benign and malignant salivary gland tumors and to study whether it is related to age, sex, anatomical site, and size of the lesion in salivary gland tumors. Materials and methods: A retrospective study consisted of benign salivary gland tumors (BSGTs) (n = 15), malignant salivary gland tumors (n = 18), and normal salivary gland parenchyma (n = 15). Results: There was a significant difference of Ki-67 labeling index (LI, %) in normal salivary gland parenchyma, BSGTs, and malignant salivary gland tumors. The Ki-67 LI (%) in normal salivary gland parenchyma is negligible (0.27 ± 0.31%), whereas malignant salivary gland tumors showed very high Ki-67 LI (%) of 18.79 ± 18.06% compared with BSGTs being 0.76 ± 2.02%. There was a significant correlation statistically of mean ± standard deviation (SD) of Ki-67 LI (%) with the age of the patients being the maximum (32.68 ± 15.87%) in the 50 to 59 years age group, whereas sex, site of the lesion, and size of the lesion in salivary gland tumors had no significant correlation. Conclusion: The Ki-67 is a useful marker for assessing prolif-erative potential of tumors. Clinical significance: The Ki-67 LI% can be used as a reliable adjuvant diagnostic tool to differentiate between the subtypes and grading of certain malignant tumors, such as mucoepi-dermoid carcinoma (MEC), adenoid cystic carcinoma (AdCC), and acinic cell carcinoma (AcCC), which are usually difficult to diagnose on histopathological criteria alone. Keywords: Immunohistochemistry, Ki-67, Salivary gland neoplasms.

Adjuvant Radiation Therapy and Temozolomide in Gliosarcoma: Is It Enough? Case Series of Seven Patients.

OBJECTIVE: We present our experience of gliosarcoma (GSM) in oncology tertiary care center over the last 5 years. MATERIALS AND METHODS: We carried out a retrospective analysis of seven patients with GSM diagnosed between April 2008 and December 2012. Demographic data, clinicopathological data, treatment strategies employed, details of recurrence, and survival patterns were reviewed. RESULTS: The median age at diagnosis was 54 years, ranging between 34 and 63 years with a female predominance (57.1% females). Headache and neurological deficit were the most common symptoms with parietal region being the most common site of lesion. Subtotal resection followed by concurrent chemoradiation therapy was delivered to six patients. The results following completion of planned schedule of concurrent chemoradiotherapy were quite disappointing with two patients having no evidence of disease, one patient was lost to follow-up, and other three had progressive disease. One patient with progressive disease subsequently received eight cycles of bevacizumab on a clinical trial protocol. Fifteen-month posttreatment, she had stable disease on follow-up. CONCLUSIONS: Our experience suggests that despite treatment, the diagnosis of GSM portends a poor prognosis and the use of bevacizumab could represent a treatment approach to improve outcome in these patients. Although the role of targeted therapy in GSM remains unclear because of paucity of experience, the treatment decision should be according to patient's performance status, ability, and willingness to receive additional treatment.

Pattern of Gustatory Impairment and its Recovery after Head and Neck Irradiation.

INTRODUCTION: The majority of patients receiving concurrent chemoradiotherapy frequently complain of changes in their taste perception, and other distressing symptoms affecting their quality of life. This study was undertaken to determine the pattern of gustatory impairment and its recovery in irradiated head and neck cancer patients in India. MATERIALS AND METHODS: Thirty patients undergoing radical head and neck irradiation were enrolled and assessed for the four basic taste quality (sweet, salt, sour and bitter) by a forced three-choice stimulus drop technique measuring their taste recognition thresholds at baseline, weekly during radiation therapy (RT) and every month for 6 months following completion of RT. RESULTS: The maximum taste loss for any taste quality developed after the third week of RT. Irrespective of the taste quality, the majority of patients developed their maximum taste loss in the fourth to sixth week. The maximum taste loss was highest (100%) for the bitter taste and least (40.7%) for the sweet taste. Taste recovery for sweet, salt and sour taste qualities started from the first month onwards, but not for bitter taste. All taste qualities were severely affected in patients with primary involvement of the oral cavity and oropharynx as compared with nasopharynx, hypopharynx and laryngeal tumors. CONCLUSIONS: Taste dysfunction is a frequently ignored adverse effect of head and neck cancer treatment, seriously affecting the patient's quality of life. Clinicians must make patients aware of this specific gustatory dysfunction and its pattern of recovery. Future efforts should be directed towards minimizing this dysfunction, specifically in tumors arising from the oral cavity and oropharynx.

Impact on Radiological and Pathological Response with Neoadjuvant Chemoradiation and Its Effect on Survival in Squamous Cell Carcinoma of Thoracic Esophagus.

BACKGROUND: Neoadjuvant chemoradiation (NCRT) has been shown to improve survival in patients with locally advanced esophageal squamous cell carcinoma (SCC). The aim of the present study was to evaluate the role of 18-FDG PET-CT in predicting pathological response to NCRT. MATERIAL AND METHODS: We assessed 70 patients of esophageal SCC who underwent NCRT and were evaluated with baseline and post chemoradiation 18F-FDG PET-CT scan. Receiver operating characteristic (ROC) curve was generated by analyzing the sensitivity and specificity of different cut-off points for defining a positive test and their ability to predict pathological complete response. Univariate and multivariate analysis were performed using log-rank and Cox proportional hazards models, and survival curves were estimated using the Kaplan-Meier method. RESULTS: Radiological and pathological complete response was achieved in 44.3 % (n = 31) and 34.3 % (n = 24) patients, respectively. Using ROC curves, post-treatment standardized uptake value (SUV) max [3.25, area under curve (AUC) 0.752] and % change in SUVmax cut-off value (72.32 %, AUC 0.705) was used to predict pathological response. Significant associations between pathological response in primary tumor and post chemotherapy/radiotherapy SUVmax values (p = 0.016), % change in SUVmax (p = 0.006), radiological response in primary (p = 0.006), and grade of dysphagia at presentation (p = 0.041) were observed. Mean overall survival and relapse free survival was 83 and 58 %, respectively at 34 months. CONCLUSION: 18F-FDG PET-CT can be used to predict pathological response to NCRT in locally advanced SCC.

A Comparative Analysis of Cytokeratin 18 and 19 Expressions in Odontogenic Keratocyst, Dentigerous Cyst and Radicular Cyst with a Review of Literature.

INTRODUCTION: Odontogenic cysts viz Odontogenic Keratocyst (OKC), Dentigerous Cyst (DC) and Radicular Cyst (RC) occur commonly in the oral and maxillofacial region. Cytokeratin (CK) expression studies have been done to evaluate diagnostic accuracy, role in pathogenesis, elucidate behaviour and role in treatment protocols. However, variations have been reported in the expression of CK patterns in these odontogenic cysts, which could be due to the lack of standardization of laboratory techniques. The present study has tried to shed light on CK 18 and 19 expression in odontogenic cysts and offer the brief review of previous studies on these CK. AIM: The aim of the present study was to evaluate the intensity and expression patterns of CK 18 and 19 in OKCs, DCs and RCs. MATERIALS AND METHODS: A total of 60 cases, 20 each of OKC, DC and RC were confirmed histologically and evaluated for immunohistochemical expression pattern and intensity of CK 18 and 19. RESULTS: A focal and variable expression of CK 18 was observed in 25% of OKCs, 15% of DCs and 10% of RCs. CK 19 was expressed in 75% of OKCs and 100% in DCs as well as RCs. CONCLUSION: The intensity and expression of Cytokeratin 19 was more in all three cysts compared to Cytokeratin 18.

Survival of Triple Negative versus Triple Positive Breast Cancers: Comparison and Contrast.

BACKGROUND: Triple negative (TN) and triple positive (TP) breast cancers both are aggressive types but TN generally has a shorter survival. OBJECTIVES: To compare the clinical characteristics and treatment outcomes for patients with TN versus TP breast cancer and to assess various prognostic factors affecting overall survival. MATERIALS AND METHODS: A retrospective audit of 85 breast cancer patients was conducted in the Department of Radiation Oncology and Medical Oncology on patients from 2006 to 2013 for whom IHC for ER, PgR and Her-2 neu were available. The patients were strati ed into: ER-, PR- and Her-2 neu- (Arm A, n=47) and ER+, PgR+ and Her-2 neu+ (Arm B, n=38). RESULTS: TN subtype had higher numbers of premenopausal and advanced stage patients as compared to TP subtype. The locoregional recurrence (LRR) and distant metastatic rate was also higher in TN subtype but there was no de nite pattern in both the arms. Among the prognostic factors, patients with premenopausal status and advanced stage in TN breast cancer had inferior survival (P=0.07) whereas for those with postmenopausal status and early stage there was no survival difference between the two arms. CONCLUSIONS: TN subtype tends to be more aggressive in terms of younger age and advanced stage at presentation, higher tumour grade, LRR and metastasis, suggesting need for future research efforts on providing aggressive treatment to these patients. We could attribute better outcome for TP subtype to receptor positivity enabling role of hormonal treatment and targeted therapy, although less number of patients received targeted therapy.

Three Weekly Versus Weekly Cisplatin as Radiosensitizer in Head and Neck Cancer: a Decision Dilemma.

Cisplatin-based concurrent chemoradiation plays an undisputed key role as definitive treatment in unresectable patients with locally advanced squamous cell carcinoma head and neck or as an organ preservation strategy. Treatment with 100 mg/m2 3-weekly cisplatin is considered the standard of care but is often associated with several adverse events. The optimum drug schedule of administration remains to be defined and presently, there is insufficient data limiting conclusions about the relative tolerability of one regimen over the other. This review addresses regarding the optimal dose schedule of cisplatin focusing mainly on three-weekly and weekly dose of cisplatin based concurrent chemoradiotherapy in locally advanced head and neck cancer with an emphasis on mucositis, dermatitis, systemic toxicity, compliance, and treatment interruptions. To derive a definitive conclusion, large prospective randomized trials are needed directly comparing standard 3-weekly cisplatin (100 mg/m2) with weekly schedule (30 - 40 mg/m2) of concurrent cisplatin based chemoradiotherapy in locally advanced squamous cell carcinoma head and neck.

Impact of Adaptive Radiotherapy on Locally Advanced Head and Neck Cancer - A Dosimetric and Volumetric Study.

UNLABELLED: Objective of the study is to evaluate volumetric and dosimetric alterations taking place during radiotherapy for locally advanced head and neck cancer (LAHNC) and to assess benefit of replanning in them. MATERIALS AND METHODS: Thirty patients with LAHNC fulfilling the inclusion and exclusion criteria were enrolled in a prospective study. Planning scans were acquired both pre-treatment and after 20 fractions (mid-course) of radiotherapy. Single plan (OPLAN) based on initial CT scan was generated and executed for entire treatment course. Beam configuration of OPLAN was applied to anatomy of interim scan and a hybrid plan (HPLAN30) was generated. Adaptive replanning (RPLAN30) for remaining fractions was done and dose distribution with and without replanning compared for remaining fractions. RESULTS: Substantial shrinkage of target volume (TV) and parotids after 4 weeks of radiotherapy was reported (p<0.05). No significant difference between planned and delivered doses was seen for remaining fractions. Hybrid plans showed increase in delivered dose to spinal cord and parotids for remaining fractions. Interim replanning improved homogeneity of treatment plan and significantly reduced doses to cord (Dmax, D2% and D1%) and ipsilateral parotid (D33%, D50% and D66%) (p<0.05). CONCLUSIONS: Use of one or two mid-treatment CT scans and replanning provides greater normal tissue sparing alongwith improved TV coverage.