High-precision radiation therapy with integrated biological imaging and tumor monitoring: evolution of the Munich concept and future research options.
OBJECTIVE
To describe an emerging concept of high-precision radiotherapy, a modality characterized by adaptation to patient and organ movements, which might occur between fractions or even during radiation delivery.


RESULTS
Today's unprecedented technical capabilities to visualize the target volume and create conformal dose distributions allow for avoidance of critical structures or targeted treatment intensification within a conventionally imaged, anatomically defined tumor. The success of selective dose escalation depends on (1) correct staging and target volume identification, which can be improved by biological imaging, and (2) identification of biologically relevant subvolumes, which determine tumor control. Current efforts are directed at different methods, such as positron emission tomography and magnetic resonance spectroscopy, and integrating them into treatment planning.


CONCLUSIONS
Early clinical trials assessing the safety and efficacy of image- and biology-guided radiotherapy are ongoing. The same modalities might be used to determine the individual tumor response during treatment and to adapt therapy. Temporal changes in tumor biology, which might represent both a challenge and a chance with regard to adaptation of treatment, need to be addressed in greater detail.
Grosu
Anca L
AL
Department of Radiation Oncology, Klinikum rechts der Isar, Technical University of Munich, Germany.
Molls
Michael
M
Zimmermann
Frank B
FB
Geinitz
Hans
H
Nüsslin
Fridtjof
F
Schwaiger
Markus
M
Nieder
Carsten
C
D000818:Animals; D002986:Clinical Trials as Topic; D019583:Dose Fractionation, Radiation; D005858:Germany; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods / Q000639:trends; D009682:Magnetic Resonance Spectroscopy; D009367:Neoplasm Staging; D009369:Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D011379:Prognosis; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods / Q000639:trends; D011881:Radiotherapy, Computer-Assisted / Q000379:methods* / Q000639:trends*; D020266:Radiotherapy, Conformal / Q000379:methods; D016896:Treatment Outcome