to determine the addition of value of neoadjuvant, concurrent and adjuvant chemotherapy to radiation in the treatment of nasopharyngeal carcinoma with regard to the overall survival (os) and disease free survival (dfs) within a six year period in tehran cancer institute. files of all patients with nasopharyngeal carcinoma treated by radiotherapy with or without concurrent chemotherapy in a cura...

background: keloids are benign fibrous dermal tumors originating from skin injury after surgery, piercing or others wounds. materials and methods: sixty-two patients with keloids were treated postoperatively using orthovoltage irradiation. the total dose delivered was 12 gy in three consecutive days, 4gy per fraction. treatment started 24 h after surgery. the median follow-up was 44.5 months. r...

leiomyosarcoma is a rare entity in prostate but it is the most common type of prostate sarcomas in adult patients. in most reported series the prognosis is poor and the median survival is about 15-18 months. hereby we present a 72 years old man who received combined modality treatment including radical surgery followed by adjuvant chemotherapy and radiotherapy. he has been well for 14 months, b...

Quantification of the setup errors is vital to define appropriate setup margins preventing geographical misses. The no-action-level (NAL) correction protocol reduces the systematic setup errors and, hence, the setup margins. The manual entry of the setup corrections in the record-and-verify software, however, increases the susceptibility of the NAL protocol to human errors. Moreover, the impact...

BACKGROUND To analyze the feasibility of active breath control (ABC), the lung tumor reproducibility and the rationale for single-breath-hold cone beam CT (CBCT)-guided hypofraction radiotherapy. METHODS Single-breath-hold CBCT images were acquired using ABC in a cohort of 83 lung cancer patients (95 tumors) treated with hypofraction radiotherapy. For all alignments between the reference CT a...

BACKGROUND This study used the receiver operating characteristic curve (ROC) to analyze Surveillance, Epidemiology and End RESULTS (SEER) bronchioaveolar carcinoma data to identify predictive models and potential disparity in outcomes. MATERIALS AND METHODS Socio-economic, staging and treatment factors were assessed. For the risk modeling, each factor was fitted by a Generalized Linear Model ...

Margins are used in radiotherapy to assist in the calculation of planning target volumes. These margins can be determined by analysing the geometric uncertainties inherent to the radiotherapy planning and delivery process. An important part of this process is the study of electronic portal images collected throughout the course of treatment. Set-up uncertainties were determined for prostate rad...

PURPOSE To improve patient safety and treatment quality, verification of dose delivery in radiotherapy is desirable. We present a simple, easy-to-implement, open-source method for in vivo planar dosimetry of conformal radiotherapy by electronic portal imaging device (EPID). METHODS Correlation ratios, which relate dose in the mid-depth of slab phantoms to transit EPID signal, were determined ...

The accurate and quantitative determination of three-dimensional patient setup errors in conformal radiotherapy, including setup errors due to out-of-plane rotations, requires methods for registering pre-treatment, three-dimensional planning CT images with intra-treatment, two-dimensional portal images. We have developed a method for performing such a registration based on structural models tha...

The Vero4DRT (MHI-TM2000) is capable of performing X-ray image-based tracking (X-ray Tracking) that directly tracks the target or fiducial markers under continuous kV X-ray imaging. Previously, we have shown that irregular respiratory patterns increased X-ray Tracking errors. Thus, we assumed that audio instruction, which generally improves the periodicity of respiration, should reduce tracking...