Clinical evaluation of synthetic computed tomography methods in adaptive proton therapy of lung cancer patients.

Background And Purpose: Efficient workflows for adaptive proton therapy are of high importance. This study evaluated the possibility to replace repeat-CTs (reCTs) with synthetic CTs (sCTs), created based on cone-beam CTs (CBCTs), for flagging the need of plan adaptations in intensity-modulated proton therapy (IMPT) treatment of lung cancer patients.

Materials And Methods: Forty-two IMPT patients were retrospectively included.

Actual target coverage after setup verification using surgical clips compared with external skin markers in postoperative breast cancer radiation therapy.

Purpose: After changing from offline setup verification to online setup verification using external skin markers in breast cancer patients, we noticed an increase in localized acute skin toxicity beneath the markers. Also, in vivo 3-dimensional dose measurements showed deviations between the delivered and the planned dose distributions; therefore, we investigated the accuracy of setup verification using surgical clips in the tumor bed, with a focus on target coverage of whole breast and tumor bed.

Methods And Materials: Orthogonal kilovoltage images were acquired before every fraction in 35 breast cancer patients, deriving an online 3-dimensional setup error by matching on external skin markers.

The PET-boost randomised phase II dose-escalation trial in non-small cell lung cancer.

Purpose: The local site of relapse in non-small cell lung cancer (NSCLC) is primarily located in the high FDG uptake region of the primary tumour prior to treatment. A phase II PET-boost trial (NCT01024829) randomises patients between dose-escalation of the entire primary tumour (arm A) or to the high FDG uptake region inside the primary tumour (>50% SUV(max)) (arm B), whilst giving 66 Gy in 24 fractions to involved lymph nodes. We analysed the planning results of the first 20 patients for which both arms A and B were planned.

Use of skin markers and electronic portal imaging to improve verification of tangential breast irradiation.

We investigated the added value of skin markers in 566 electronic portal images (EPIs) in 48 breast cancer patients treated with tangential fields. EPIs were matched to the corresponding DRRs using skin markers, anatomy, or a combination of both. Skin markers improved determination of setup errors in cranio-caudal direction.