gms | German Medical Science

48th Meeting of the Particle Therapy Co-Operative Group

Particle Therapy Co-Operative Group (PTCOG)

28.09. - 03.10.2009, Heidelberg

Protontherapy of ocular tumors for very young children under general anesthesia

Meeting Abstract

  • J. Heufelder - BerlinProtonen am Helmholtz Zentrum Berlin, Charité – Universitätsmedizin Berlin, Berlin
  • A. Weber - BerlinProtonen am Helmholtz Zentrum Berlin, Charité – Universitätsmedizin Berlin, Berlin
  • L. Moser - Klinik für Radioonkologie und Strahlentherapie, Campus Benjamin Franklin, Charité – Universitätsmedizin Berlin, Berlin
  • G. Willerding - Augenklinik, Campus Benjamin Franklin, Charité – Universitätsmedizin Berlin, Berlin
  • B. Brunne - Klinik für Anästesiologie und operative Intensivmedizin, Campus Benjamin Franklin, Charité – Universitätsmedizin Berlin, Berlin
  • D. Cordini - BerlinProtonen am Helmholtz Zentrum Berlin, Charité – Universitätsmedizin Berlin, Berlin
  • R. Stark - BerlinProtonen am Helmholtz Zentrum Berlin, Charité – Universitätsmedizin Berlin, Berlin
  • W. Hinkelbein - Klinik für Radioonkologie und Strahlentherapie, Campus Benjamin Franklin, Charité – Universitätsmedizin Berlin, Berlin
  • M. H. Foerster - Augenklinik, Campus Benjamin Franklin, Charité – Universitätsmedizin Berlin, Berlin

PTCOG 48. Meeting of the Particle Therapy Co-Operative Group. Heidelberg, 28.09.-03.10.2009. Düsseldorf: German Medical Science GMS Publishing House; 2009. Doc09ptcog089

DOI: 10.3205/09ptcog089, URN: urn:nbn:de:0183-09ptcog0891

Published: September 24, 2009

© 2009 Heufelder et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en). You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.


Outline

Text

Background: With its high local control rates of about 95% and high dose conformation proton therapy is a very powerful tool in the treatment of ocular tumors. Generally to achieve these results the cooperation of the patient is absolutely necessary. Small children are unable to cooperate in the appropriate way; therefore they must be treated under general anesthesia. Here we present an approach of an anesthetized child's treatment at a horizontal eye beam line.

Material and methods: To prepare the treatment room of the Charité's proton therapy unit BerlinProtonen at the Helmholtz Institute Berlin (HZB, former HMI) for the treatment of anesthetized children a mobile anesthesia workstation was installed. Car seats, for different body sizes, were modified to fit to the treatment chair.

The anesthesia procedure takes place on a separate couch for anesthesia in the treatment room. Under general anesthesia the child is transferred into one of the modified car seats. Within the seat the child is still in a lying position, the body is fixed by seat belts. A thermoplastic mask fixed at the car seat immobilizes the head. The car seat with the child is then mounted at the treatment chair and moved into a nearly sitting position. In treatment position the eyelids are moved out of the irradiation field by lid retractors. A suction cup is attached to the cornea to adjust the gazing angle of the eye for treatment. After verification of the localization the irradiation takes place. The position of the eye and the vital signs are continuously monitored in the treatment and in the control room.

Following treatment the child is transferred to the couch for recovery from anesthesia. As soon as the child can breathe by itself and has protective reflexes, it is transferred to a recovery room for observation until an ambulance transports the patient back to the eye hospital.

Results: Prior to the treatment course a simulation session with the child under general anesthesia is necessary to fit the immobilization mask and test the feasibility of the treatment plan. The treatment procedure itself takes about 2 hours: one hour for anesthesia and positioning, one minute irradiation, few minutes dismounting and roughly 45 minutes for recovery from anesthesia. Simulating an emergency situation we are able to dismount the child in less than a minute, so that the anesthesiologist has full access to the child for emergency procedures.

With this set up we treated three children (10 months, 5 years, and 7 months). Treatment was tolerated well. With the frontal irradiation approach we can use the benefits of a dedicated eye beam line: sharp lateral penumbra and sharp distal fall off, enabling us to spare the bones of the skull completely.

Conclusions: Proton therapy of ocular tumors for very young children under general anesthesia on a horizontal eye beam line is feasible. The neighboring bones of orbit and skull are kept free of irradiation.