Once daily versus twice-daily radiotherapy in the management of limited disease small cell lung cancer - Decision criteria in routine practise.

BACKGROUND: In limited disease small cell lung cancer (LD-SCLC), the CONVERT trial has not demonstrated superiority of once-daily (QD) radiotherapy (66 Gy) over twice-daily (BID) radiotherapy (45 Gy). We explored the factors influencing the selection between QD and BID regimens. METHODS: Thirteen experienced European thoracic radiation oncologists as selected by the European Society for Therapeutic Radiation Oncology (ESTRO) were asked to describe their strategies in the management of LD-SCLC. Treatment strategies were subsequently converted into decision trees and analysed for agreement and discrepancies. RESULTS: Logistic reasons, patients' performance status and radiotherapy dose constraints were the three major decision criteria used by most experts in decision making. The use of QD and BID regimens was balanced among European experts, but there was a trend towards the BID regimen for fit patients able to travel twice a day to the radiotherapy site. CONCLUSION: BID and QD radiotherapy are both accepted regimens among experts and the decision is influenced by pragmatic factors such as availability of transportation.

A patient with Rothmund-Thomson syndrome and tongue cancer--experience of radiation toxicity.

We describe a male patient with Rothmund-Thomson syndrome (RTS) given postoperative radiotherapy for squamous carcinoma of the tongue. This was well tolerated. This is only the second reported case of oral cancer and radiotherapy in RTS.

Defining target volumes for stereotactic ablative radiotherapy of early-stage lung tumours: a comparison of three-dimensional 18F-fluorodeoxyglucose positron emission tomography and four-dimensional computed tomography.

AIMS: High local control rates are achieved in stage I lung cancer using stereotactic ablative radiotherapy. Target delineation is commonly based on four-dimensional computed tomography (CT) scans. Target volumes defined by positron emission tomography/computed tomography (PET/CT) are compared with those defined by four-dimensional CT and conventional ('three-dimensional') (18)F-fluorodeoxyglucose ((18)F-FDG) PET/CT. MATERIALS AND METHODS: For 16 stage I non-small cell lung cancer tumours, six approaches for deriving PET target volumes were evaluated: manual contouring, standardised uptake value (SUV) absolute threshold of 2.5, 35% of maximum SUV (35%SUV(MAX)), 41% of SUV(MAX) (41%SUV(MAX)) and two different source to background ratio techniques (SBR-1 and SBR-2). PET-derived target volumes were compared with the internal target volume (ITV) from the modified maximum intensity projection (MIP(MOD) ITV). Volumetric and positional correlation was assessed using the Dice similarity coefficient (DSC). RESULTS: PET-based target volumes did not correspond to four-dimensional CT-based target volumes. The mean DSC relative to MIP(MOD) ITV were: PET manual = 0.64, SUV2.5 = 0.64, 35%SUV(MAX) = 0.63, 41%SUV(MAX) = 0.57. SBR-1 = 0.52, SBR-2 = 0.49. PET-based target volumes were smaller than corresponding MIP ITVs. CONCLUSIONS: Conventional three-dimensional (18)F-FDG PET-derived target volumes for lung stereotactic ablative radiotherapy did not correspond well with those derived from four-dimensional CT, including those in routine clinical use (MIP(MOD) ITV). Caution is required in using three-dimensional PET for motion encompassing target volume delineation.