To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
To report a single-institution experience of intensity-modulated radiotherapy (IMRT) and RapidArc treatment plans for the patients treated with low grade mucoepidermoid carcinoma (MEC) of the salivary gland while sparing the organs at risk (OARs) within tolerance limits.
Material and Methods:
Twenty-five patients with MEC were selected to develop and analyse the treatment plans using both of the techniques. Dose distributions were calculated using Eclipse treatment planning system (Varian Medical Systems, Palo Alto, CA). Plans were generated to deliver the dose of 6000 cGy in 30 fractions. For IMRT, seven angle plans were used and for RapidArc, two half arcs were used with the same 6 MV photon beam. Quality of treatment plans was evaluated by using parameters such as, coverage, conformity index (CI), homogeneity index (HI), gradient index (GI), unified dosimetry index (UDI), dose volume histogram, delivery time and OARs sparing for IMRT and RapidArc plans.
The analysis revealed that IMRT and RapidArc coverages are 0·90 and 0·94, respectively; CIs are 1·15 and 1·10, respectively; HIs are 1·12 and 1·07, respectively; GIs are 0·94 and 0·98, respectively. Average UDI values for RapidArc and IMRT are 1·09 and 1·11, respectively. Integral dose comparison shows better OAR sparing for RapidArc. RapidArc plans have the shorter beam on time (45%) in comparison with IMRT plans.
Planning constraints were achieved in both techniques. However, RapidArc showed better quality treatment plan, OARs sparing and shorter delivery time as compared to IMRT.
The main objective of this study is to assure the quality of cervical cancer treatment plans using an electronic portal imaging device (EPID) in RapidArc techniques.
Materials and Methods:
Fifteen cases of cervical cancer patients undergoing RapidArc technique were selected to evaluate the quality assurance (QA) of their treatment. The computed tomography (CT) of each patient was obtained with 3-mm-slice thickness and transferred to the Eclipse treatment planning system. The prescribed dose (PD) of 50·4 Gy with 1·8 Gy per fraction to planning target volume (PTV) was used for each patient. The aim of treatment planning was to achieve 95% of PD to cover 97%, and dose to the PTV should not receive 105% of the PD. All RapidArc plans were created using the AAA algorithm and treated on Varian DHX using 6 MV photon beam, with two full arcs. Gamma analysis was used to evaluate the quality of the treatment plans with accepting criteria of 95% at 3%/3 mm.
In this study, maximum and average gamma values were 2·53 ± 0·409 and 0·195 ± 0·059 showing very small deviation and indicating the smaller difference between both predicted and portal doses. Gamma Area changes from > 0·8 to > 1·2. SD increased to 5·4% and mean standard error increased to 4·67%.
On the basis of these outcomes, we can summarise that the EPID is a useful tool for QA in standardising and evaluating RapidArc treatment plans of cervical cancer in routine clinical practice.
Email your librarian or administrator to recommend adding this to your organisation's collection.