title: Tumor regrowth between surgery and initiation of adjuvant therapy in patients with newly diagnosed glioblastoma.
abstract: To assess incidence and degree of regrowth in glioblastoma between surgery and radiation therapy (RT) and to correlate regrowth with presurgical imaging and survival, we examined images of 32 patients with newly diagnosed glioblastoma who underwent MR spectroscopic imaging (MRSI), perfusion-weighted imaging (PWI), and diffusion-weighted imaging (DWI) prior to surgery, after surgery, and prior to RT/temozolomide. Contrast enhancement (CE) in the pre-RT MR image was compared with postsurgical DWI to differentiate tumor growth from postsurgical infarct. MRSI and PWI parameters were analyzed prior to surgery and pre-RT. Postsurgical MRI indicated that 18 patients had gross total and 14 subtotal resections. Twenty-one patients showed reduced diffusion, and 25 patients showed new or increased CE. In eight patients (25%), the new CE was confined to areas of postsurgical reduced diffusion. In the other 17 patients (53%), new CE was found to be indicative of tumor growth or a combination of tumor growth and surgical injury. Higher perfusion and creatine within nonenhancing tumor in the presurgery MR were associated with subsequent tumor growth. High levels of choline and reduced diffusion in pre-RT CE suggested active metabolism and tumor cell proliferation. Median survival was 14.6 months in patients with interim tumor growth and 24 months in patients with no growth. Increased volume or new onset of CE between surgery and RT was attributed to tumor growth in 53% of patients and was associated with shorter survival. This suggests that reducing the time between surgery and adjuvant therapy may be important. The acquisition of metabolic and physiologic imaging data prior to adjuvant therapy may also be valuable in assessing regions of new CE and nonenhancing tumor.
authors.affiliation: Department of Radiology and Margaret Hart Surbeck Laboratory of Advanced Imaging, University of California, San Francisco, San Francisco, CA, USA. pirzkall.andrea@gene.com
authors.forename: Andrea
authors.initials: A
authors.lastname: Pirzkall
authors.forename: Colleen
authors.initials: C
authors.lastname: McGue
authors.forename: Suja
authors.initials: S
authors.lastname: Saraswathy
authors.forename: Soonmee
authors.initials: S
authors.lastname: Cha
authors.forename: Raymond
authors.initials: R
authors.lastname: Liu
authors.forename: Scott
authors.initials: S
authors.lastname: Vandenberg
authors.forename: Kathleen R
authors.initials: KR
authors.lastname: Lamborn
authors.forename: Mitchel S
authors.initials: MS
authors.lastname: Berger
authors.forename: Susan M
authors.initials: SM
authors.lastname: Chang
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Nelson
mesh_terms: D000328:Adult; D000368:Aged; D001931:Brain Mapping; D001932:Brain Neoplasms / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging; D005909:Glioblastoma / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007124:Immunoenzyme Techniques; D009682:Magnetic Resonance Spectroscopy; D008875:Middle Aged; D011300:Preoperative Care; D011880:Radiotherapy Planning, Computer-Assisted; D018714:Radiotherapy, Adjuvant; D015996:Survival Rate; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism
chemical_list: D003287:Contrast Media; C513496:MIB1 ligase, human; D044767:Ubiquitin-Protein Ligases