Temporal Lobe Reactions After Radiotherapy With Carbon Ions: Incidence and Estimation of the Relative Biological Effectiveness by the Local Effect Model

• Published in: International journal of radiation oncology, biology, physics Vol. 80; no. 3; pp. 815 - 823
• Main Authors: Schlampp, Ingmar, Karger, Christian P., Ph.D, Jäkel, Oliver, Ph.D, Scholz, Michael, Ph.D, Didinger, Bernd, M.D, Nikoghosyan, Anna, M.D, Hoess, Angelika, M.Sc, Krämer, Michael, Ph.D, Edler, Lutz, Ph.D, Debus, Jürgen, M.D., Ph.D, Schulz-Ertner, Daniela, M.D
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.07.2011; Elsevier
• Subjects: Adolescent; Adult; Age; Age Factors; Aged; Biological and medical sciences; BODY; Carbon; Carbon ion radiation therapy; CARBON IONS; Carbon Radioisotopes - therapeutic use; CENTRAL NERVOUS SYSTEM; CHARGED PARTICLES; Chondrosarcoma; Chondrosarcoma - radiotherapy; Chordoma; Chordoma - radiotherapy; CONTRAST MEDIA; Data processing; DIAGNOSTIC TECHNIQUES; DISEASES; Diseases of the osteoarticular system; DOSES; Female; Germany; Hematology, Oncology and Palliative Medicine; Humans; IONS; IRRADIATION; Local effect model (LEM); Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Male; Medical sciences; MEDICINE; Middle Aged; Models, Biological; NEOPLASMS; NERVOUS SYSTEM; NMR IMAGING; NUCLEAR MEDICINE; ORGANS; Photons; Protons; Radiation; RADIATION DOSES; Radiation Injuries - diagnosis; Radiation Tolerance; RADIOLOGY; RADIOLOGY AND NUCLEAR MEDICINE; RADIOTHERAPY; Radiotherapy Dosage; Relative Biological Effectiveness; Retrospective Studies; SARCOMAS; SKELETAL DISEASES; SKELETON; SKULL; Skull Base Neoplasms - radiotherapy; Temporal lobe; Temporal Lobe - radiation effects; THERAPY; TOXICITY; Tumors; Tumors of striated muscle and skeleton; Young Adult; Germany; Chordoma; Carbon ion radiation therapy; Chondrosarcoma; Local effect model (LEM); Toxicity; Temporal lobe; Sarcoma; Diseases of the osteoarticular system; Relative biological effectiveness; Malignant tumor; Radiotherapy; Carbon; Incidence; Osteoarticular system; Heavy-ion therapy; Cartilage; Treatment; Models; Bone; Cancer
• ISSN: 0360-3016; 1879-355X
• DOI: 10.1016/j.ijrobp.2010.03.001

Purpose To identify predictors for the development of temporal lobe reactions (TLR) after carbon ion radiation therapy (RT) for radiation-resistant tumors in the central nervous system and to evaluate the predictions of the local effect model (LEM) used for calculation of the biologically effective dose. Methods and Materials This retrospective study reports the TLR rates in patients with skull base chordomas and chondrosarcomas irradiated with carbon ions at GSI, Darmstadt, Germany, in the years 2002 and 2003. Calculation of the relative biological effectiveness and dose optimization of treatment plans were performed on the basis of the LEM. Clinical examinations and magnetic resonance imaging (MRI) were performed at 3, 6, and 12 months after RT and annually thereafter. Local contrast medium enhancement in temporal lobes, as detected on MRI, was regarded as radiation-induced TLR. Dose-volume histograms of 118 temporal lobes in 59 patients were analyzed, and 16 therapy-associated and 2 patient-associated factors were statistically evaluated for their predictive value for the occurrence of TLR. Results Median follow-up was 2.5 years (range, 0.3--6.6 years). Age and maximum dose applied to at least 1 cm3 of the temporal lobe ( D max, V − 1 cm 3, maximum dose in the remaining temporal lobe volume, excluding the volume 1 cm3 with the highest dose) were found to be the most important predictors for TLR. Dose response curves of D max, V − 1 cm 3 were calculated. The biologically equivalent tolerance doses for the 5% and 50% probabilities to develop TLR were 68.8 ± 3.3 Gy equivalents (GyE) and 87.3 ± 2.8 GyE, respectively. Conclusions D max, V − 1 cm 3 is predictive for radiation-induced TLR. The tolerance doses obtained seem to be consistent with published data for highly conformal photon and proton irradiations. We could not detect any clinically relevant deviations between clinical findings and expectations based on predictions of the LEM.