Technology-driven research for radiotherapy innovation

Abstract

Technology has a pivotal role in the continuous development of radiotherapy. The long road toward modern 'high-tech' radiation oncology has been studded with discoveries and technological innovations that resulted from the interaction of various disciplines. In the last decades, a dramatic technology-driven revolution has hugely improved the capability of accurately and safely delivering complex-shaped dose distributions. This has contributed to many clinical improvements, such as the successful management of lung cancer and oligometastatic disease through stereotactic body radiotherapy. Technology-driven research is an active and lively field with promising potential in several domains, including image guidance, adaptive radiotherapy, integration of artificial intelligence, heavy-particle therapy, and 'flash' ultra-high dose-rate radiotherapy. The evolution toward personalized Oncology will deeply influence technology-driven research, aiming to integrate predictive models and omics analyses into fast and efficient solutions to deliver the best treatment for each single patient. Personalized radiation oncology will need affordable technological solutions for middle-/low-income countries, as these are expected to experience the highest increase of cancer incidence and mortality. Moreover, technology solutions for automation of commissioning, quality assurance, safety tests, image segmentation, and plan optimization will be required. Although a large fraction of cancer patients receive radiotherapy, this is certainly not reflected in the worldwide budget for radiotherapy research. Differently from the pharmaceutical companies-driven research, resources for research in radiotherapy are highly limited to equipment vendors, who can, in turn, initiate a limited number of collaborations with academic research centers. Thus, enhancement of investments in technology-driven radiotherapy research via public funds, national governments, and the European Union would have a crucial societal impact. It would allow for radiotherapy to further strengthen its role as a highly effective and cost-efficient cancer treatment modality, and it could facilitate a rapid and equalitarian large-scale transfer of technology to clinic, with direct impact on patient care.

Keywords: Radiation Oncology; adaptive radiotherapy; innovation; personalized medicine; radiotherapy; research; technology.

Fig. 1

Schematic plot of the impact of technology in the last decades in delivering dose distributions more tailored to GTV/CTV in a typical case of tumor next to an organ at risk: At each step, the high‐dose region corresponding to the previous technologies is overlaid to better appreciate the net benefit. Nowadays, image‐guided intensity‐modulated radiotherapy (using multifields or arc, IMRT, and VMAT, respectively) may strictly tailor the prescribed dose distribution to the tumor, using reduced margins thanks to the high precision of the delivery permitted by IGRT.

Fig. 2

Examples of available ‘High‐Tech image‐guided Linacs’: (A) Conventional Linacs equipped with cone‐beam CT [Zurich UH (left) and NKI‐AvL, Amsterdam (right)]: The kV imaging system is perpendicular to the beam axis and CT images are obtained by rotating the gantry; (B) Helical delivery system (OSR, Milano): The Linac is integrated into a CT ring: Megavoltage images are obtained by using the same treatment fan beam paired to a detector array, delivered in a helicoidal way by moving the couch; (C) Robotic system (Erasmus, Rotterdam): Dose delivery is generated by a large number of small noncoplanar beams delivered by the robotic arms, while image guidance (including tracking during delivery) is driven by a perpendicular pair of flat panel on the floor (in the right corner of the picture) paired to two kV X‐rays tubes positioned on the room ceiling; (D) Hybrid MRI‐Linac machines [Zurich UH (left) and NKI‐AvL, Amsterdam (right)]: The Linac is integrated into an MRI. MRI images can be obtained before and during the treatment delivery. (E) Proton system (Protontherapy, Trento): The gantry (left of the picture) is paired to a robotic couch and a diagnostic CT in the room to setup the patient before treatment delivery

Fig. 3

(A) Seventy years, female patient with a diagnosis of synchronous oligometastatic NSCLC: cT2 cN1 cM1b (adrenal), adenocarcinoma, EGFR WT, ALK negative. (B) Status after induction/first‐line chemotherapy. (C) Radical radiotherapy in conventional fractionation for the locoregional primary tumor (C1) and SBRT for the adrenal metastasis (C2). (D) Complete metabolic response 3 months after completion of radiotherapy