PET-Bildgebung für die Protonen- und Schwerionentherapie: Hintergrund, Entwicklungen und klinische Implementierung

Zusammenfassung

In der modernen Strahlentherapie hat sich die bildgestützte Strahlentherapie (Image Guided Radiotherapy, IGRT) zunehmend etabliert. Bei der Partikeltherapie ergibt sich neben der reinen Positionsverifikation auch die zusätzliche Möglichkeit, durch die Ionenstrahlen entstehende Aktivierung durch nukleare Interaktionen zwischen Ionen und dem bestrahlten Gewebe mittels PET-Scannern zu messen. Hierbei kann eine Korrelation mit der geplanten und applizierten Dosisverteilung durchgeführt werden, und somit ein nicht-invasives Dosismonitoring erfolgen. Präklinische und klinische Vorarbeiten wurden hierzu bereits durchgeführt und haben überzeugende Ergebnisse geliefert, eine exakte Validierung in der klinischen Routine wird derzeit durchgeführt. Zu diesem Zweck sind die meisten Anlagen zur Partikeltherapie mit PET-CT-Scannern bestückt, die zur Bestrahlungsplanung, Patientenlagerung sowie zum In-vivo-Monitoring der applizierten Dosis herangezogen werden können. Im Vorliegenden Artikel werden die Grundlagen der PET-Bildung zum In-vivo-Dosismonitoring sowie klinische Ergebnisse und Applikationsmöglichkeiten dargestellt.

Abstract

Image-guided radiation therapy (IGRT) has been established within clinical routine for photon treatments. In particle therapy, position verification is also of high importance, but also verification of applied dose by PET-measurements of activity active target fragments formed all along the primary and secondary radiation path can be performed as in-vivo dose monitoring. Preclinical and clinical analyses have shown feasibility and promising results, however, full clinical workup is currently in progress. Therefore, most particle therapy centers are equipped with PET-CT-Scanners, which can be used for treatment planning, position verification and in-vivo dose monitoring.

The present article presents and overview of the physical background of PET-monitoring for ion beam therapy for in-vivo dose monitoring as well as clinical data and different strategies to implement PET-CT-Scanners within particle facilities.

Schlüsselwörter

PET-CT - Aktivierungsmessung - Dose-Guided-Radiotherapie (DGRT) - Image-Guided-Radiotherapie (IGRT)

Key words

PET-CT - actvity monitoring - Dose Guided Radiotherapy (DGRT) - Image Guided Radiotherapy (IGRT)

• Literatur

• 1 Bauer J, Unholtz D, Sommerer F et al. Paving the way towards clinical PET-based in-vivo treatment verification at HIT. PTCOG 50 2011; Philadelphia:May 8-14
• 2 Bednarz B, Daartz J, Paganetti H. Dosimetric accuracy of planning and delivering small proton therapy fields. Phys Med Biol 2010; 55: 7425-7438
• 3 Bennett GW. Visualization and transport of positron emission from proton activation in vivo. Sci 200 1978; 1151-1153
• 4 Combs SE, Jakel O, Haberer T et al. Particle therapy at the Heidelberg Ion Therapy Center (HIT) – Integrated research-driven university-hospital-based radiation oncology service in Heidelberg, Germany. Radiother Oncol 2010; 95: 41-44
• 5 Combs SE, Kieser M, Rieken S et al. Randomized phase II study evaluating a carbon ion boost applied after combined radiochemotherapy with temozolomide versus a proton boost after radiochemotherapy with temozolomide in patients with primary glioblastoma: the CLEOPATRA trial. BMC Cancer 2010; 10: 478
• 6 Enghardt W, Crespo P, Fiedler F et al. Charged hadron tumour therapy monitoring by means of PET. Nucl Instrum Methods 2004; A 525: 284-288
• 7 Enghardt W, Parodi K, Crespo P et al. Dose quantification from in-beam positron emission tomography. Radiother Oncol 2004; 73 (Suppl. 02) S96-S98
• 8 Fiedler F, Priegnitz M, Julich R et al. In-beam PET measurements of biological half-lives of 12C irradiation induced beta+-activity. Acta Oncol 2008; 47: 1077-1086
• 9 Fiedler F, Shakirin G, Skowron J et al. On the effectiveness of ion range determination from in-beam PET data. Phys Med Biol 2010; 55: 1989-1998
• 10 Iseki Y, Kanai T, Kanazawa M et al. Range verification system using positron emitting beams for heavy-ion radiotherapy. Phys Med Biol 2004; 49: 3179-3195
• 11 Knopf AC, Parodi K, Paganetti H et al. Accuracy of proton beam range verification using post-treatment positron emission tomography/computed tomography as function of treatment site. Int J Radiat Oncol Biol Phys 2011; 79: 297-304
• 12 Korreman S, Rasch C, McNair H et al. The European Society of Therapeutic Radiology and Oncology–European Institute of Radiotherapy (ESTRO-EIR) report on 3D CT-based in-room image guidance systems: a practical and technical review and guide. Radiother Oncol 2010; 94: 129-144
• 13 Llacer J. Positron emission medical measurements with accelerated radioactive beams. Nucl Sci Appl 3 1988; 111-131
• 14 Llacer J, Chatterjee A, Alpen EL et al. Imaging by injection of accelerated radioactive particle beams. IEEE Trans Med Imag 3 1984; 80-90
• 15 Moteabbed M, Espana S, Paganetti H. Monte Carlo patient study on the comparison of prompt gamma and PET imaging for range verification in proton therapy. Phys Med Biol 2011; 56: 1063-1082
• 16 Nishio T, Miyatake A, Ogino T et al. The development and clinical use of a beam ON-LINE PET system mounted on a rotating gantry port in proton therapy. Int J Radiat Oncol Biol Phys 2010; 76: 277-286
• 17 Parodi K, Crespo H, Eickhoff H et al. Random coincidences during in-beam PET measurements at microbunched therapeutic ion beams. Instrum Methods Phys Res 2005; A 545: 446-458
• 18 Parodi K, Bortfeld T, Haberer T. Comparison between in-beam and offline positron emission tomography imaging of proton and carbon ion therapeutic irradiation at synchrotron- and cyclotron-based facilities. Int J Radiat Oncol Biol Phys 2008; 71: 945-956
• 19 Parodi K, Ferrari A, Sommerer F et al. Clinical CT-based calculations of dose and positron emitter distributions in proton therapy using the FLUKA Monte Carlo code. Phys Med Biol 2007; 52: 3369-3387
• 20 Parodi K, Paganetti H, Cascio E et al. PET/CT imaging for treatment verification after proton therapy: a study with plastic phantoms and metallic implants. Med Phys 2007; 34: 419-435
• 21 Parodi K, Paganetti H, Shih HA et al. Patient study of in vivo verification of beam delivery and range, using positron emission tomography and computed tomography imaging after proton therapy. Int J Radiat Oncol Biol Phys 2007; 68: 920-934
• 22 Parodi K, Saito N, Chaudhri N et al. 4D in-beam positron emission tomography for verification of motion-compensated ion beam therapy. Med Phys 2009; 36: 4230-4243
• 23 Ponisch F, Parodi K, Hasch BG et al. The modelling of positron emitter production and PET imaging during carbon ion therapy. Phys Med Biol 2004; 49: 5217-5232
• 24 Priegnitz M, Mockel D, Parodi K et al. In-beam PET measurement of 7Li3+ irradiation induced beta+-activity. Phys Med Biol 2008; 53: 4443-4453
• 25 Scholz M, Jakob B, Taucher-Scholz G. Direct evidence for the spatial correlation between individual particle traversals and localized CDKN1A (p21) response induced by high-LET radiation. Radiat Res 2001; 156: 558-563
• 26 Schulz-Ertner D, Tsujii H. Particle radiation therapy using proton and heavier ion beams. J Clin Oncol 2007; 25: 953-964
• 27 Shakirin G, Braess H, Fiedler F et al. Implementation and workflow for PET monitoring of therapeutic ion irradiation: a comparison of in-beam, in-room, and off-line techniques. Phys Med Biol 2011; 56: 1281-1298
• 28 Tomitani T, Kanazawa M, Yoshikawa K et al. Effect of target fragmentations on the imaging of autoactivation of heavy ions. Radiol Oncol 1997; 9 (S2) 79-82
• 29 Unholtz D, Sommerer F, Haberer T et al. Quantitativer Vergleich gemessener und simulierter strahleninduzierter Positronenaktivität nach Protonentherapie. 44. Annual Meeting of the German Society of Biomedical Technique (DGBMT) 2010 2010; October 5–8, 2010
• 30 Vynckier S, Derreumaux S, Richard F et al. Is it possible to verify directly a proton-treatment plan using positron emission tomography?. Radiother Oncol 1993; 26: 275-277