Posts Tagged ‘IMRT’
The first day of AAPM opened Sunday at 1 PM. Elekta, Impac Software and CMS Software are located in the largest booth at the show, which is near the Hall’s front entrance. [ Click here for AAPM Floorplan ]
AAPM is expecting over 2500 people at the show this year slightly less than last year, although physicistsare still registering. The Elekta booth was very busy during the first day with special interest in CMS Software’s treatment planning system, Monaco with VMAT which was just cleared by the FDA on July 17th. The workstations were packed all day with back-to-back demos.
The theme of this year’s show is, “Beyond rapid there is Elekta VMAT” and it is depicted through engaging graphics of young children in red capes, a subtle nod to VMAT as the hero of conformal therapy procedures with its multiple arc capability and high dose conformance, not to mention that the time and total monitor units needed to deliver these treatments can be reduced drastically from standard IMRT protocols.
There has been a lot of buzz about VMAT throughout the technical sessions, which positions Elekta very well in this space.
Three copies of this year’s AAPM summer school physics book, “Clinical Dosimetry Measurements in Radiotherapy” will be raffled off and shipped to AAPM attendees on August 3rd.
- Elekta Booth at AAPM 2009
Click To view more image from AAPM 2009
Potential of volumetric modulated arc therapy (VMAT) for anal cancer –
Anal cancer is primarily treated with radio chemotherapy and represents a complex treatment situation due to the size, shape and position of the pelvic planning treatment volume (PTV). Pelvic radiation therapy may cause significant acute and late toxicity, therefore advanced 3D treatment planning strategies as well as intensity modulated radiotherapy (IMRT) are used to reduce exposure to organs at risk (OAR). Volumetric modulated arc therapy (VMAT) may provide excellent dose distributions with very short treatment times. This case-based planning study explores this potential.
read more about VMAT for Anal Cancer
Institution: The Christie Hospital NHS Trust, Manchester, UK – Wade Centre for Radiotherapy Research
Patient: Female, 37 years
Diagnosis: Left atrium myxoid sarcoma
Plan: Five-field IMRT
Image guidance: Elekta VolumeViewTM on-line correction
Positioning: In-house immobilization
Treatment: 60Gy in 33 fractions , V20 <25%, Spinal cord dose <45Gy
Patient history and diagnosis
A 37 year-old female developed right-sided chest pain which rapidly worsened and lead to the patient’s collapse. A cardio echo scan revealed cardiomegaly with a filling defect in the left atrium extending through to the left ventricle. The patient went on to have open-heart surgery, where a tumor arising in atrial septum was discovered measuring 6cm x 3cm. Histology revealed the tumor to be a pleomorphic high-grade myxoid sarcoma. The initial concern was to gain local control of the disease, and taking into consideration the patient’s age and otherwise excellent physical health, a course of radiation therapy was planned. The intention was to deliver a reasonable dose of radiation to a limited volume of the heart.
Planned Treatment
The clinical target volume (CTV) was identified as the left atrium, and a margin of 2cm was applied in all directions to generate the planning target volume (PTV). The dose limiting regions were the left ventricle and lung. A total dose of 60Gy in 33 fractions was prescribed. The V20 (volume of lung receiving >20Gy) was kept below 25%. The ventricle dose was kept as low as was reasonably practical and the dose to the spinal cord was maintained <45Gy. Due to the high degree of dose conformity required to avoid critical structures while delivering the planned dose, a standard conformal plan was not suitable (an initial standard conformal plan produced a V20> 25% and resulted in a high dose to the ventricles) and a five-field intensity modulated radiation therapy (IMRT) plan had to be employed. Mega-voltage imaging was deemed as unsuitable for verification purposes due to the location of the target volume and Elekta VolumeViewTM 3D imaging was requested as an alternative.
VolumeView™ transverse plane reconstruction
Continue to download the remainder of this Case Study
Read more studies at http://www.elekta.com/proof
Axial dose distribution & Sagittal dose distribution
Deliver a higher dose to the prostate while sparing or minimizing the dose to the rectum, in an effort to reduce or eliminate acute and delayed rectal morbidity. Total session time, including patient positioning, ultrasound-guided targeting, and intensity modulated radiotherapy (IMRT) delivery should not exceed 30 minutes, maintaining the existing patient load. Rationale for IMRT approach Radiotherapy planning with PrecisePLAN® IMRT at United Radiation Oncology (URO) demonstrates a considerable decrease in radiation dose to the rectum.
Patient selection
Patients diagnosed with prostate cancer and referred to URO receive an initial consultation,consisting of history, physical exam, psychosocial assessment and discussion of treatment options. Candidates for IMRT are those patients with adverse prognostic factors, whose outcome may improve in response to dose escalation.Adequate localization of the prostate via ultrasound is critical, therefore the patient must be able to drink sufficient fluid to fill the bladder.
Read more on this Prostate Cancer Case Study
Located in Fuzhou, the capital city of Fujian Province in southeastern China, Fujian Tumor Hospital is a 1,000-bed hospital specializing in cancer treatment, education and research. It treats about 10,000 patients a year. The hospital previously had one Elekta Precise Treatment System™, one Siemens unit and one Theratron cobalt unit. Jianji Pan, M.D., Deputy Director of Fujian Province Tumor Hospital, explains,
“Because we had such a good experience with the Elekta Precise Treatment System and with Elekta services and support, we ordered the Elekta Synergy® system last year. we also ordered the
Elekta Compact
HexaPOD™ evo robotic treatment table and stereotactic accessories for advanced IMRT and IGRT.”
Prof. Pan adds,
“we were treating patients from seven in the morning until 10 at night, and we still had a long patient queue due to the high demand.”
read more about the World’s first Elekta Compact installed in China
Patient history and diagnosis
88-year-old woman with an unresectable pancreatic cancer. The patient complained of generalized weakness, early satiety, decreased appetite and back pain. A CT scan demonstrated a 3.2 x 3.2cm hypodense soft tissue mass causing distortion of the head of the pancreas and the uccinate process. There was marked dilatation of the apancreatic duct. There was 1.9 x 1.7cm low density retroperitoneal lymph node and a second 1.1cm aortocaval lymph nodes. An endoscopic ultrasound with fine needle aspiration confirmed malignant cells consistent with adenocarcinoma of a pancreaticobiliary primary. The patient was treated with a single course of gemcitabine chemotherapy and then concurrent radiotherapy and xeloda.
2D dose distribution for the VMAT plan
The patient had a long standing diagnosis of myelodysplastic syndrome, but had been quite healthy otherwise. Just prior to her diagnosis, the patient was living by herself.
Treatment planning
As a first step in creating the VMAT plan, an IMRT optimization was performed. 18 equispaced beams were used in this optimization. Next, a home-grown arc-sequencing algorithm was used to translate the optimized fluence maps into a deliverable single-arc VMAT plan. A total of 90 control points were used. To ensure the deliverability and accuracy of the VMAT plan, the maximum MLC leaf motion between adjacent control points was set to be 2.5cm per degree of gantry rotation. The resulting VMAT plan was loaded into the Philips Pinnacle3® treatment planning system for a final dose calculation and plan evaluation.
Read more of this VMAT Case Study here
Elekta volumetric modulated arc therapy (VMAT) is a new intensity-modulated radiation therapy (IMRT) treatment technique that combines the market’s only fully digital linear accelerator, 3D volumetric imaging, and advanced treatment planning expertise. This powerful trio delivers a treatment that improves the sparing of critical structures and healthy tissue—in dramatically shorter treatment times—all without comprising target coverage and patient safety.
Conformance. One or multiple arcs for precise dose control resulting in better avoidance of critical structures.
Speed. Dramatically shorter treatment times than current IMRT techniques.
Ultra-low Dose. Allows daily 3D volumetric imaging and fewer MUs.
More info at: http://www.elekta.com/vmat
Image Guided Radiation Therapy (IGRT) – Image guided radiation therapy (IGRT) combines scanning technology, which allows planar or X-ray Volume Imaging (XVI), with IMRT. This enables physicians to adjust the radiation beam based on the position of the target tumor and critical organs, at time of treatment, optimizing the accuracy and precision of the radiotherapy.
Intensity Modulated Radiotherapy (IMRT) - Varying both the delivered dose and shape of the radiation field to match the shape of the tumor.
Intracerebral – Within the cerebrum (the large rounded structure of the brain)
Intracranial – Within the skull or cranium
Intraoperative radiation therapy (IORT) - Special technique whereby a radiation dose is delivered to a surgically exposed organ or tumor bed
Intractable – Does not respond to treatment, e.g., intractable pain
Invasive procedure – Involves invasion of the body by some foreign agent, a knife, a catheter, a cannula.
Invasive tumor – Crosses tissue boundaries into neighboring tissues – classic sign of a malignant tumor.
Inverse Planning – A sophisticated software program that interprets clinical data to determine the best course of radiation therapy treatment.
Treatment of a right upper lobe lung tumor using Active Breathing Coordinator™ in a patient with severe pulmonary insufficiency at Centre Régional, Léon-Bérard, Lyon, France –
A 68-year-old male, former smoker, presented with a long history of severe pulmonary insufficiency, which had been managed for several years with oxygen therapy. More recently, as his pulmonary function improved the oxygen therapy was stopped.
Right upper lobe lung tumor
A recent radiograph showed a 4cm diameter tumor in the right upper lobe. CT-scan confirmed a solid mass 48 x 42mm in right upper lobe, with suspicious infra-cranial nodes (between 15 and 20mm in diameter). A PET scan showed a fixed primary tumor but a mobile mediastinum. Cranial CT and abdominal CT were normal. The tumor was considered as stage T2-3 N0-M0.
Click here for the Full Case Study
For more case studies click here
- Largest Neurosurgical Center in Russia Acquires Elekta’s Leksell Gamma Knife Perfexion February 6, 2012Russia’s first Leksell Gamma Knife® Perfexion™ system has found a home at the renowned N.N. Burdenko Neurosurgical Institute, just a five-minute car ride from Moscow’s Red Square. On June 2, 2011, a 59-year-old woman was the first Perfexion patient, receiving Gamma Knife® radiosurgery to treat tumor tissue that remained following open surgery. Now, eight mon […]
- Largest Neurosurgical Center in Russia Acquires Elekta’s Leksell Gamma Knife Perfexion February 6, 2012N.N. Burdenko Neurosurgical Institute improves treatment of patients with multiple metastasesRead more... […]
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