Variable and fixed costs in NHS radiotherapy; consequences for increasing hypo fractionation.

BACKGROUND/PURPOSE: The increased use of hypofractionated radiotherapy changes department activity. While expected to be cost-effective, departments' fixed costs may impede savings. Understanding radiotherapy's cost-drivers, to what extent these are fixed and consequences of reducing activity can help to inform reimbursement strategies. MATERIAL/METHODS: We estimate the cost of radiotherapy provision, using time-driven activity-based costing, for five bone metastases treatment strategies, in a large NHS provider. We compare these estimations to reimbursement tariff and assess their breakdown by cost types: fixed (buildings), semi-fixed (staff, linear accelerators) and variable (materials) costs. Sensitivity analyses assess the cost-drivers and impact of reducing departmental activity on the costs of remaining treatments, with varying disinvestment assumptions. RESULTS: The estimated radiotherapy cost for bone metastases ranges from 430.95€ (single fraction) to 4240.76€ (45 Gy in 25#). Provider costs align closely with NHS reimbursement, except for the stereotactic ablative body radiotherapy (SABR) strategy (tariff exceeding by 15.3%). Semi-fixed staff costs account for 28.1-39.7% and fixed/semi-fixed equipment/space costs 38.5-54.8% of provider costs. Departmental activity is the biggest cost-driver; reduction in activity increasing cost, predominantly in fractionated treatments. Decommissioning linear accelerators ameliorates this, although can only be realised at equipment capacity thresholds. CONCLUSION: Hypofractionation is less burdensome to patients and long-term offers a cost-efficient mechanism to treat an increasing number of patients within existing capacity. As a large majority of treatment costs are fixed/semi-fixed, disinvestment is complex, within the life expectancy of a linac, imbalances between demand and capacity will result in higher treatment costs. With a per-fraction reimbursement, this may disincentivise delivery of hypofractionated treatments.

Axillary radiotherapy for nodal lymphoma: What CTV expansion is required to account for absence of pre-chemotherapy treatment position FDG PET-CT?

Involved site lymphoma radiotherapy clinical target volumes (CTV) require expansion in the absence of treatment-position pre-chemotherapy PET-CT. This prospective imaging study evaluates CTV contouring for axillary lymphoma using diagnostic imaging compared with co-registered treatment-position PET-CT. Generous expansion axially and cranio-caudally is required to encompass pre-chemotherapy disease without treatment-position pre-chemotherapy PET-CT.

Evaluation of clinical target volume expansion required for involved site neck radiotherapy for lymphoma to account for the absence of a pre-chemotherapy PET-CT in the radiotherapy treatment position.

BACKGROUND AND PURPOSE: Involved site radiotherapy clinical target volume (CTV) for lymphoma requires an expansion to account for the absence of radiotherapy treatment-position pre-chemotherapy imaging, which is not widely implemented. This prospective imaging study aims to quantify CTV expansion required for neck radiotherapy. MATERIALS AND METHODS: 10 patients from a prospective single centre imaging study underwent a pre-chemotherapy FDG-PET-CT in both the diagnostic and radiotherapy treatment position, and subsequently received neck radiotherapy post-chemotherapy. CTVINRT and CTVdiagPET were delineated on the planning CT, following co-registration of the radiotherapy position PET-CT and side-by-side assessment of diagnostic PET-CT respectively. RESULTS: Intra-observer variability was limited, with delineation of CTVINRT highly reproducible and slightly lower for CTVdiagPET (mean DICE 0.88 and 0.8 respectively). Superiorly, CTVdiagPET varied by -10 to +15mm from CTVINRT. Inferiorly, CTVdiagPET varied by -18 to +6mm from CTVINRT. Comparing CTVINRT and CTVdiagPET in the axial plane, the mean DICE was 0.74. Mean sensitivity index was 0.75 (range 0.59-0.91), showing that on average 75% of the CTVINRT was encompassed by the CTVdiagPET. CONCLUSIONS: In the absence of treatment-position PET-CT, CTV expansion cranially and caudally by 10mm and 18mm respectively, along with generous contouring in the axial plane, was required to encompass pre-chemotherapy disease.