title: Quantitative echography in primary uveal melanoma treated by proton beam therapy.
abstract: OBJECTIVE
  To describe the dynamics of thickness and internal reflectivity after proton beam therapy (PBT) in uveal melanoma.
  
  
  METHODS
  One hundred and ninety-eight consecutive patients with choroidal or ciliary body melanoma treated by PBT were retrospectively considered.
  
  
  METHODS
  The post-PBT follow-up included ophthalmologic examination, retinography, and B and A modes of standardized echography every 6 months. A total of 1393 examinations were performed. We take into account 4 tumour categories according to the seventh TNM classification.
  
  
  RESULTS
  Before PBT, tumour thickness ranged from 1.5 to 12.5 mm with a mean of 5.9 mm. Its decrease after radiotherapy was best fitted by the sum of a first-order exponential decay and a constant with a decay half-life of 15 months. Based on the fit, tumour thickness stabilized on a constant value representing, on average, 47% of the initial value. Mean internal reflectivity before PBT was 68%. The dynamics of the reflectivity were best fitted by an exponential and a constant, with rise half-life of 11 months, and stability value of 87%.
  
  
  CONCLUSIONS
  We found that ultrasonographic dynamics of uveal melanoma treated by PBT resembles a function composed of the sum of a constant and a first-order exponential, as previously noted in studies on brachytherapy. Interestingly, after PBT, because of its shorter half-life, internal reflectivity has a faster dynamic response than thickness in large tumours, suggesting that increase of internal reflectivity is a more sensitive indicator of early response to therapy in larger tumours.
authors: Galliera Hospital, Ocular Oncology Center, Genoa University, Genoa, Italy. Electronic address: carlo.mosci@galliera.it.
authors: Carlo
authors: C
authors: Mosci
authors: Galliera Hospital, Ocular Oncology Center, Genoa University, Genoa, Italy.
authors: Francesco B
authors: FB
authors: Lanza
authors: Department of Computer and Information Science, Genoa University, Genoa, Italy.
authors: Sofia
authors: S
authors: Mosci
authors: Department of Computer and Information Science, Genoa University, Genoa, Italy.
authors: Annalisa
authors: A
authors: Barla
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008545:Melanoma / Q000145:classification / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D008875:Middle Aged; D061766:Proton Therapy; D012189:Retrospective Studies; D014463:Ultrasonography; D014604:Uveal Neoplasms / Q000145:classification / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D055815:Young Adult; D000098943:Uveal Melanoma