BACKGROUND: This study focuses on quantitative reconstruction of dynamic cardiac SPECT. MATERIAL AND METHODS: The Karhunen-Loeve (KL) transform is first applied to gated frames or sinogram data to de-correlate the dynamic information along the time direction. Then the Poisson noise is treated by a penalized weighted least-squares minimization, followed by an analytical inversion of the treated...

abstractobjective: to investigate the impact of respiratory motion on localization, and quantification lung lesions for the gross tumour volume utilizing an in-house developed auto3dreg programme and dynamic nurbs-based cardiac-torso digitised phantom (ncat). methods: respiratory motion may result in more than 30% underestimation of the suv values of lung, liver and kidney tumour lesions. the m...

At our institution the standard delivery quality assurance (DQA) procedure for tomotherapy plans is accomplished with a water equivalent phantom, EDR2 film, and ion chamber point-dose measurements. Most plans deliver at most 5 Gy to the dose plane; however, recently a stereotactic body radiotherapy (SBRT) protocol has produced plans delivering upwards of 12 Gy to the film plane. EDR2 film satur...

Our institution delivers TBI using a modified Theratron 780 60Co unit. Due to limitations of our treatment planning system in calculating dose for this treatment, we have developed a fast Monte Carlo code to calculate dose distributions within the patient. The algorithm is written in C and uses voxel density information from CT images to calculate dose in heterogeneous media. To test the algori...

introduction dosimetric accuracy is a major issue in the quality assurance (qa) program for treatment planning systems (tps). an important contribution to this process has been a proper dosimetry method to guarantee the accuracy of delivered dose to the tumor. in brachytherapy (bt) of gynecological (gyn) cancer it is usual to insert a combination of tandem and ovoid applicators with a complicat...

We studied the feasibility of evaluating tumor control probability (TCP) reductions for tumor motion beyond planned gated radiotherapy margins. Tumor motion was determined from cone-beam CT projections acquired for patient setup, intrafraction respiratory traces, and 4D CTs for five non-small cell lung cancer (NSCLC) patients treated with gated radiotherapy. Tumors were subdivided into 1 mm sec...

(18)F-fluoro-deoxy-glucose ((18)F-FDG) positron emission tomography (PET) is one of the most sensitive and specific imaging modalities for the diagnosis of non-small cell lung cancer. A drawback of PET is that it requires several minutes of acquisition per bed position, which results in images being affected by respiratory blur. Respiratory gating techniques have been developed to deal with res...

Introduction: Siliconeprosthetic implants are commonlyutilizedfor tissue replacement and breast augmentation after mastectomy. On the other hand, some patients require adjuvant radiotherapy in order to preventlocal-regional recurrence and increment ofthe overall survival. In case of recurrence, the radiation oncologist might have to irradiate the prosthesis.The aim of this study was to evaluate...