Cancer centers worldwide show huge variation in breast radiation therapy planning
A 25-center international study found that radiation doses for breast cancer patients with lymph node involvement vary by as much as 100% across institutions—raising questions about treatment consistency and patient outcomes. The findings suggest that standardized planning protocols could improve care quality and reduce unnecessary radiation exposure to healthy tissue.
Originaltitel: Multi-institutional international investigation of VMAT treatment planning techniques for breast cancer with regional lymph nodes
VMAT-planering för bröstcancer med lymfkörtelbehandling saknar standardiserad strategi — ett problem som kan förlänga utvecklingstiden för nya doseringsprotokoll och skapa leverantörsberoende. En europeisk arbetsgrupp analyserade 22 behandlingsplaner från 25 institutioner och identifierade fem effektiva planeringsmetoder för komplex lymfkörtelomfattning. Resultaten visar stor variation: hjärtdoser spände från 1,5 till 9,5 Gy, ipsilateral lungdos från 12,0 till 17,3 Gy. Målvolymerna fick mellan 49,7–52,1 Gy (lymfkörtel) respektive 51,9–54,1 Gy (bröst), med simultanintegrerad boost på 61,5–66,5 Gy. Universitetet i Hamburg ledde studien tillsammans med sex europeiska centrum. Resultaten är relevanta för radiologikliniker som söker optimeringsvägar, för systemleverantörer som utvecklar planeringsalgoritmer och för kliniker som utvärderar kostnadseffektivitet när olika institutioner använder divergerande metoder.
BACKGROUND: Despite constant developments in radiotherapy, optimizing Volumetric Modulated Arc Therapy (VMAT) dose distributions for whole breast with extensive lymph node involvement remains a challenge. The aim of this study was to gain insights into clinical practices and to identify effective planning strategies. METHODS: The participants of the European Federation of Organisations for Medical Physics VMAT Breast Working Group answered a survey regarding treatment planning routines for breast cancer irradiation and generated a treatment plan for a challenging patient case. The dose prescription was 50.4 Gy in 28 fractions for breast and lymph node volumes, and a simultaneous integrated boost (SIB) of 63 Gy. RESULTS: The survey was completed by 25 participants and covered a wide spectrum of topics of VMAT treatment planning, including beam geometry and organs at risk (OAR) dose constraints. In addition, 22 plans were submitted for comparison. The mean doses ranged between: PTV breast 51.9---54.1 Gy, PTV lymph nodes 49.7---52.1 Gy, SIB 61.5---66.5 Gy, heart 1.5---9.5 Gy, ipsilateral lung 12.0---17.3 Gy, contralateral lung 1.2---6.5 Gy and contralateral breast 1.6---8.9 Gy. Five treatment planning strategies, with high target coverage and the lowest doses to organs at risk, are presented. CONCLUSION: There is a wide variation in VMAT breast planning approaches, planning goals and prioritisation of PTVs and OARs across institutions. Descriptions of effective planning strategies for a challenging breast case are presented.