Somatom sensation open ct simulator

Patients having metallic implants in the femur were simulated on a Somatom Sensation Open CT simulator (Siemens Healthineer, Germany) (maximum HU = 3000) using 5 mm slice thickness in head first supine position. All 16 patients (right hip implant = 9, left hip implant = 5, and bilateral hip implant = 2) suffering from carcinoma of cervix. The material used for was “titanium”(composition: titanium 88.5%–91.0%; aluminum 5.6%–6.5%, vanadium 3.5%–4.5%, iron 0.25%, oxygen 0.13% and carbon 0.08%, average ED 3.74 relative to water; diameter of femoral heads of prosthesis ranging from 40 to 54 mm.[20 (link)] The thermoplastic cast was made for every patient. The acquired images were transferred to Varian Soma vision contouring stations. The contouring was done using EMBRACE II Guideline.[21 (link)] The PTV, clinical target volume, bladder, rectum, and bowel structures were drawn. Implanted material was also contoured to mark the avoidance zones.

Forty prostate IMRT patients treated before 2013 and fifty VMAT patients treated afterward in the Grand River Hospital were used in this study. This study received institutional ethics approval. All patients were scanned by the Siemens SOMATOM Sensation Open CT-simulator using the same protocol. The CT-simulations were done with patients in supine position and full bladder. The planning target volume (PTV) was in the range of 77.8 cm³ –335 cm³ for IMRT and 120–351 cm³ for VMAT patients. The PTV, clinical target volume (CTV), rectum, bladder, and femoral heads of all patients were contoured. The gross target volume (GTV) was equal to the CTV (prostate volume), and PTV was created by expansion of the CTV with 1 cm around, except 0.7 cm posteriorly. Dosimetric verifications of VMAT for patients were carried out using the ArcCHECK cylindrical detector array.[30 (link)]