Correlation between fluorodeoxyglucose hotspots on preradiotherapy PET/CT and areas of cancer local relapse: Systematic review of literature

• Published in: Cancer radiothérapie 2020-08, Vol.24 (5), p.444-452
• Main Authors: Abgral, R., Bourhis, D., Calais, J., Lucia, F., Leclère, J.-C., Salaün, P.-Y., Vera, P., Schick, U.
• Format: Article
• Language: English
• Subjects: FDG hotspots; FDG « hotspots; Life Sciences; Literature review; Local relapse; PET/CT; Radiotherapy; Radiothérapie; Rechute locale; Revue de littérature; TEP-TDM
• ISSN: 1278-3218; 1769-6658
• DOI: 10.1016/j.canrad.2020.04.010

The aim of the present paper is to systematically review all available literature on preradiotherapy high uptake areas (hotspots) as a potential target for dose escalation in different tumour sites, and to understand the potential role and limitations of fluorodeoxyglucose (FDG)-positron-emission tomography (PET)/computed tomography (CT) in this context. An electronic database (Medline) search was conducted to identify articles reporting on a correlation between high tracer uptake on pretreatment PET and preferential sites of local recurrence after radiotherapy. Search was limited to English language. No date range limitation was applied. Among 45 studies initially identified, nine series matching with inclusion criteria have finally been retained from the literature after reviewing (5 retrospective and 4 prospective). Primary tumour locations were head-neck (n=2), lung (n=4), oesophageal (n=2) and rectal (n=1) areas. Overlaps between FDG hotspot on preradiotherapy PET/CT and site of local recurrence on post-treatment scan showed good to excellent agreement. Only studies on head-neck cancer reported moderate agreement probably explained by the lack of reproducibility of the patients positioning between pre- and post-treatment FDG-PET/CT; and by the rigid registration process of images limited by post-therapeutic changes that highly affect anatomical landmarks. FDG hotspot-guided radiotherapy may allow dose escalation in respecting a robust methodology (treatment position, co-registration method, four-dimensional PET). L’objectif de cet article est de faire une revue systématique de toute la littérature disponible pour comprendre le rôle potentiel et les limites selon les localisations tumorales de la tomographie par émission de positons (TEP)-tomodensitométrie (TDM) au fluorodésoxyglucose (FDG) pour l’escalade de dose sur les zones de forte captation du traceur (points chauds ou « hotspots ») avant radiothérapie. Une recherche dans la base de données électronique (Medline) a été menée pour identifier les articles rapportant une corrélation entre les zones de forte captation du traceur à la TEP préthérapeutique et les sites préférentiels de récidive locale après radiothérapie. La recherche était limitée aux articles anglophones. Aucune limite de date de publication n’a été appliquée. Parmi les 45 études initialement identifiées, neuf séries correspondant aux critères d’inclusion ont finalement été retenues après lecture (cinq rétrospectives et quatre prospe