Animesh Saha

In developed nations, 4D-computed tomography (4D-CT)-based image-guided radiotherapy (IGRT) has become the standard for treating lung carcinoma patients, with the primary goal of achieving disease cure. However, its usage in India remains limited. Here, we compared target volume delineation for radical radiation planning in patients with locally advanced lung carcinoma using helical free-breathing CT (FBCT) and 4D-CT. In addition, we assessed the adequacy of a 5-mm planning target volume (PTV) margin with 4D-CT planning. Fifty patients with locally advanced lung cancer were enrolled in the study. Each patient underwent contouring based on 4D-CT to generate an internal target volume, and a 5-mm PTV margin (PTV_4D) was added for radical radiation. Subsequently, each patient underwent two intensity-modulated radiation therapy (IMRT) plans with comparable planning and optimization parameters. One plan was based on the FBCT-based volume (PTV_3D), while the other was based on the 4D-CT-based volume (PTV_4D). PTV, organ at risk (OAR) dose, and PTV coverage by 95% of the prescribed dose (PTVD 95_3D vs. PTVD 95_4D) were compared between the two schemes. Results revealed that 4D-CT-based planning reduced PTV (mean PTV volume: 539 cc vs. 782 cc) and lowered OAR doses (mean lung dose: 13 Gy vs. 15 Gy; mean esophagus dose: 18.5 Gy vs. 21.15 Gy; mean spinal cord max dose: 35.59 Gy vs. 37.39 Gy). At 3 months after treatment imaging, 40% of the patients showed a complete response, 48% showed a partial response, 4% showed stable disease, and 8% showed progressive disease. In conclusion, 4D-CT-based radiation planning for locally advanced lung carcinoma with a reduced PTV margin of 5 mm can dramatically decrease the PTV and OAR doses without sacrificing PTV coverage compared to FBCT-based planning. However, daily online image guidance or at least a well-defined offline image guidance protocol is recommended when employing such a small PTV margin.

Objectives: The role of concomitant chemoradiotherapy or radiotherapy (RT) after induction chemotherapy (IC) in borderline resectable and locally advanced pancreatic ductal adenocarcinoma is debatable. This systematic review aimed to explore this. Methods: We searched PubMed, MEDLINE, EMBASE, and Cochrane database. Studies were selected reporting outcomes on resection rate, R0 resection, pathological response, radiological response, progression-free survival, overall survival, local control, morbidity, and mortality. Results: The search resulted in 6635 articles. After 2 rounds of screening, 34 publications were selected. We found 3 randomized controlled studies and 1 prospective cohort study, and the rest were retrospective studies. There is consistent evidence that addition of concomitant chemoradiotherapy or RT after IC improves pathological response and local control. There are conflicting results in terms of other outcomes. Conclusions: Concomitant chemoradiotherapy or RT after IC improves local control and pathological response in borderline resectable and locally advanced pancreatic ductal adenocarcinoma. The role of modern RT in improving other outcome requires further research.

A recent study has shown that tight conformity of lung Stereotactic Ablative Radiotherapy (SABR) plans might worsen loco-regional control and can predict distant metastases. The study aims to repor...

Context: Stereotactic body radiotherapy (SBRT) is increasingly being used for early-stage lung cancer and lung oligometastases. Aims: To report our experience of setting up lung SBRT and early clinical outcomes. Settings and Design: This was a retrospective, interventional, cohort study. Subjects and Methods: Patients were identified from multidisciplinary tumor board meetings. They underwent four-dimensional computed tomography-based planning. The ROSEL trial protocol, the Radiation Therapy Oncology Group (RTOG) 0236, and the UK-Stereotactic Ablative Body Radiotherapy Consortium guidelines were used for target volume and organs-at-risks (OARs) delineation, dosimetry, and plan quality assessment. Each SBRT plan underwent patient-specific quality assurance (QA). Daily online image guidance using KVCT or MVCT was done to ensure accurate treatment delivery. Statistical Analysis Used: Microsoft Excel 2010 was used for data analysis. Results: Fifteen patients were treated to one or more lung tumors. One patient received helical tomotherapy in view of bilateral lung oligometastases at similar axial levels. All the remaining patients received volumetric modulated arc therapy (VMAT)-based treatment. The prescription dose varied from 40 to 60 Gy in 5–8 fractions with alternate-day treatment. The mean and median lung V20 was 5.24% and 5.16%, respectively (range, 1.66%–9.10%). The mean and median conformity indexes were 1.02 and 1.06, respectively (range, 0.70–1.18). After a median follow-up of 17 months, the locoregional control rate was 93.3%. Conclusions: SBRT was implemented using careful evaluation of OAR dose constraints, dosimetric accuracy and plan quality, patient-specific QA, and online image guidance for accurate treatment delivery. It was safe and effective for early-stage nonsmall cell lung cancer and lung metastases. Prospective data were collected to audit our outcomes.

Context: Brain metastases are the most common type of intracranial neoplasm, with the total number outnumbering primary brain tumors by a ratio of 10:1 and occur in about 25% of cancer patients. However, controversies exist regarding demographic and clinical profile of brain metastases. Aims: The purpose of this study was to analyze retrospectively the demographic and clinical profile of patients with brain metastases. Settings and Design: Retrospective, single institutional study. Materials and Methods: A retrospective study of 72 patients with brain metastasis was carried out from November 2010 to October 2012. The data pertaining to these patients was entered in a standardized case record form. These include History; clinical examination and other investigations including computed tomography/magnetic resonance imaging scan of the brain. Statistical Analysis: A statistical analysis was performed on the data collected using the MedCalc version 11. Results: Brain metastases were more common in male and occur in 6 ^th decade of life mostly. There was no relationship of occupation or socio-economic status with the incidence of brain metastases. Carcinoma lung was the most common primary giving rise to brain metastases followed by breast. Adenocarcinoma accounts for most common histology of the primary that give rise to metastases. Multiple metastases were more common than the single group. Supratentorial lesions were more common than infratentorial lesions. Among them, parietal lobe was the most common site of involvement. Conclusions: The present study highlights that the incidence of brain metastasis is common in elderly population and mostly due to primary lung. Adenocarcinoma was the most common histology of primary. Majority of lesions has been observed at parietal lobe.