Performance evaluation of gated volumetric modulated arc therapy

Background: Aim of this study is to evaluate the accuracy of the gated volumetric modulated arc therapy [VMAT/RapidArc] using 2D planar dosimetry, DynaLog files and COMPASS 3D dosimetry system. Materials and Methods: Pre-treatment quality assurance of 10 gated VMAT plans was verified using 2D array and COMPASS 3D dosimetry system. Advantage of COMPASS over 2D planar is that it provides the clinical consequence of error in treatment delivery. Measurements were performed for non-gated and different phase gating window level [80%, 50%, 30% and 20%] to know the impact of gating in VMAT dose delivery. Results: In 2D planar dosimetry, gamma agreement index [GAI] for all measurements were more than 95%. DynaLog file analysis shows the average deviations between actual and expected positions of monitor units, gantry and multi-leaf collimator. The STDVs MU and gantry position were less than 0.10 MU and 0.33[degree sign] respectively. Root mean square [RMS] of the deviations of all leaves were less than 0.58 mm. The results from COMPASS show that 3D dose volume parameters for ten patients measured for different phase gating window level were within the tolerance level of +/-5%. Average 3D gamma of PTV and OAR's for different window level was less than 0.6. Conclusion: The results from this study show that gated VMAT delivery provided dose distributions equivalent to non-gated delivery to within clinically acceptable limits and COMPASS along with Matrix[Evolution] can be effectively used for pretreatment verification of gated VMAT plans

Clinicopathologic features of non-small cell lung cancer in India and correlation with epidermal growth factor receptor mutational status.

INTRODUCTION: We performed retrospective analysis of 106 patients with lung cancer for which formalin‑fixed paraffin‑embedded tissues was available. Their epidermal growth factor receptor (EGFR) mutation status and treatment outcomes are described. MATERIALS AND METHODS: All patients with confirmed non–small cell lung cancer (NSCLC) during Jan 2008 to Dec 2010 were included. EGFR sequencing was performed with ABI PRISM 310 genetic analyzer. RESULTS: Forty‑two (39.6%) patients had mutation in one of the four exons characterized. Patients whose EGFR mutational status was not available at presentation before the start of treatment were started on chemotherapy, n = 46 (43.39%). If EGFR mutational analysis was available and mutations were present, the patients were started on either upfront tyrosine kinase inhibitor (TKI), n = 15 (14.15%) or if on chemotherapy arm were allowed to finish six cycles and then start with maintenance TKIs, n = 26 (24.52%). The median progression free survival for patients with and without mutations was 11 months (95% CI,7-14) and 9 months (95% CI,7-10) respectively. A median PFS of 14 months (95%CI, 12-16) was seen in the mutation‑positive group that received both chemotherapy followed by switch maintenance with TKIs versus 8 months (95%CI, 7-8 months) in the group that received only TKI. CONCLUSION: The prevalence of EGFR mutations in this population of NSCLC patients was 39.6% with exon 19 mutation being the most common. The observed benefit of addition of chemotherapy over TKI in EGFR mutation‑positive group raises the question, can we offer the therapy of chemotherapy–TKI combination to EGFR mutation‑positive lung cancer patients as shown in the present study.

Effect of exercise training on functional capacity & quality of life in head & neck cancer patients receiving chemoradiotherapy.

Background & objectives: Patients with head and neck cancer (HNC) undergoing chemoradiotherapy (CRT) suffer from fatigue causing a decrease in functional capacity and quality of life (QoL). Limited research in the field of exercise training among these patients demanded the need for this study to assess the effects of exercise training on functional capacity and quality of life. Methods: A randomized controlled trial was conducted on 48 patients with HNC undergoing CRT. The exercise group received an individually tailored, supervised, exercise programme for six weeks, while the control group did not receive any form of exercise. Functional capacity and QoL were assessed at baseline and at the end of the intervention using the six minute walk distance (6MWD) and medical outcomes survey short form 36 (SF 36). Results: The mean age of patients was 52 yr with 42 males. After six weeks, the 6MWD improved by 42 metres (P<0.05) in the exercise group while the control group showed a decrease by 96 metres (P<0.001). There was an improvement on the mental component score (MCS) of SF36 for the exercise group (4.8; P<0.05) and the physical component score (PCS) remained almost the same, while a decrease in PCS and MCS was seen in the control group (-5.9; P=0.064 and -17.3; P<0.05). When 6MWD and SF36 were compared between the groups, there was a statistically significant difference (P<0.001) seen after six weeks. Interpretation & conclusions: Our results showed that the functional capacity and QoL decreased among those not receiving a supervised exercise program, while exercise training improved functional capacity and QoL in HNC patients undergoing CRT.

Discriminating thyroid cancers from benign lesions based on differential expression of a limited set of miRNA using paraffin embedded tissues.

Background : Micro-RNAs (miRNAs) are expressed in a tissue-specific manner and are known to demonstrate differential expression even among the various subtypes of a given tumor. This differential expression has been harnessed successfully in the development of diagnostic assays for various malignant tumors. These assays have been found to be relevant and of value as additional diagnostic tools even among thyroid tumors, particularly with regard to thyroid carcinomas of follicular morphology. Materials and Methods : A limited set of miRNA have been assessed as part of this study in an effort to use minimal number of miRNA markers (miR-187, miR-221, miR-222, and miR-224) to differentiate the benign from the malignant thyroid tumors using miRNA derived from paraffin embedded material. Results : While miR-221 and miR-222 were found to provide good accuracy as individual markers (86% and 84%), a combination of the two provided slightly better accuracy (91%). Both miR-221 and 222 were able to significantly differentiate malignant tumors from the benign samples (P< 0.001) individually and as a combination of markers. However, inclusion of miR-187 and miR-224 in the panel did not provide any additional benefit. Conclusion : While a combination of miR-221 and 222 when used in a diagnostic panel could provide fairly good accuracy additional markers may need to be investigated to augment their diagnostic utility.