Targeted Intervention to Improve the Quality of Head and Neck Radiation Therapy Treatment Planning in the Netherlands: Short and Long-Term Impact.

Purpose: To benchmark and improve, through means of a targeted intervention, the quality of intensity modulated radiation therapy treatment planning for locally advanced head and neck cancer (HNC) in the Netherlands. The short and long-term impact of this intervention was assessed.

Methods And Materials: A delineated computed tomography-scan of an oropharynx HNC case was sent to all 15 Dutch radiation therapy centers treating HNC.

The sensitivity of dose distributions for organ motion and set-up uncertainties in prostate IMRT.

Background And Purpose: To determine the effect of organ motion and set-up uncertainties on IMRT dose distributions for prostate.

Methods: For five patients, IMRT techniques were designed to irradiate the CTV (prostate plus seminal vesicles). Technique I delivered 78 Gy to PTV1 (CTV+10 mm margin).

Comparison between manual and automatic segment generation in step-and-shoot IMRT of prostate cancer.

Purpose: To compare two methods to generate treatment plans for intensity-modulated radiotherapy (IMRT) of prostate cancer, delivered in a step-and-shoot mode. The first method uses fluence optimization (inverse planning) followed by conversion of the fluence weight map into a limited number of segments. In the second method, segments are manually assigned using a class solution (forward planning), followed by computer optimization of the segment weights.

Importance of accurate dose calculations outside segment edges in intensity modulated radiotherapy treatment planning.

Background And Purpose: To assess the effect of differences in the calculation of the dose outside segment edges on the overall dose distribution and the optimisation process of intensity modulated radiation therapy (IMRT) treatment plans.

Patients And Methods: Accuracy of dose calculations of two treatment planning systems (TPS1 and TPS2) was assessed, to ensure that they are both suitable for IMRT treatment planning according to published guidelines. Successively, 10 treatment plans for patients with prostate and head and neck tumours were calculated in both systems.

A comparison of forward and inverse treatment planning for intensity-modulated radiotherapy of head and neck cancer.

Background And Purpose: To compare intensity-modulated treatment plans of patients with head and neck cancer generated by forward and inverse planning.

Materials And Methods: Ten intensity-modulated treatment plans, planned and treated with a step&shoot technique using a forward planning approach, were retrospectively re-planned with an inverse planning algorithm. For this purpose, two strategies were applied.

Interinstitutional variations of sensitometric curves of radiographic dosimetric films.

Depth and field size dependence of the sensitometric curves of radiographic films have been studied by various groups. Limited information is, however, available on the magnitude of the variations in sensitometric curves applied in clinical practice in different institutions. In this study we assessed in a systematic way the effect of the various parameters influencing the shape of the sensitometric curve: batch composition, irradiation conditions, film processing, and film scanning.

Reduction of rectal dose by integration of the boost in the large-field treatment plan for prostate irradiation.

Purpose: To reduce the dose in the rectal wall from prostate irradiation at high dose levels.

Methods And Materials: Treatment plans in which the boost fields were integrated into the large fields (simultaneous integrated boost [SIB]) were compared with plans in which the large fields and boost fields were planned individually and applied in a sequential manner (sequential boost). Two target volumes were delineated: PTV1, the target volume of the large fields that is irradiated to 68 Gy, and PTV2, the target volume of the boost fields that is irradiated to 10 Gy.