Purpose: To investigate the energy dependence/spectral sensitivity of silicon diodes designed for small-field dosimetry and obtain response factors (RFs) for arbitrary photon spectra using Monte Carlo (MC) simulations.   Methods: The EGSnrc user-code DOSRZnrc was used to calculate the dose deposition in water and in the active volume of a stereotactic diode f...

Compared with adults, the number of children requiring radiotherapy each year is very small (of 3000 new patients treated annually at the Bristol Radiotherapy and Oncology Centre, 50 are children) but the treatment of a child may make greater demands on time and resources than an adult. There are important differences between adults and children that must be considered by the radiotherapist. Th...

In the radiotherapy treatment planning of a lesion located in the head region with small field radiation beams, the heterogeneity corrections play an important role. In this work, we investigated the influence of a bony heterogeneity on dose profile inside a soft tissue phantom containing a bony material. PDD curves were obtained by simulation using the Monte Carlo code EGSnrc and employing Ecl...

max. 2000 char.): A comparison of dosimetry methods at different clinics can be used as a means to uncover systematic uncertainties in radiotherapy. To assess the current status of reference dosimetry and small-field dosimetry in clinical practice, a collaborative comparison study involving several dosimetry methods was performed by DTU Nutech at six Danish clinics. The first part of the interc...

This study compared field-in-field (FIF) radiotherapy with conformal radiotherapy with physical wedges for the treatment of unilateral cervical malignant lymphoma. Two treatment plans, the FIF technique and conformal RT, were generated for each of 32 patients with unilateral cervical malignant lymphoma. To compare the 2 treatment plans, dose-volume histograms of the planning target volume (PTV)...

In small-cell lung cancer, the optimal combination of chemotherapy and radiotherapy is not clearly established. To assess the value of delayed thoracic radiotherapy, we performed a randomized clinical trial in 53 complete responder patients after eight courses of chemotherapy. Twenty-seven patients received a mean of 46.5 Gy-equivalent of radiotherapy and 26 patients received no treatment until...

BACKGROUND Post-radiation sarcoma (PRS) is an uncommon disease manifesting as sarcoma in a previously irradiated field, usually with a latent period of 5 years or more. Literature is limited to small series. Optimal management of this disease is unclear. Positive margins are common following attempted curative surgery and outcomes are poor. Radiotherapy is hardly used and its effect on PRS is n...