title: Feasibility of stereotactic body radiation therapy with volumetric modulated arc therapy and high intensity photon beams for hepatocellular carcinoma patients.
abstract: BACKGROUND
  To report technical features, early outcome and toxicity of stereotactic body radiation therapy (SBRT) treatments with volumetric modulated arc therapy (RapidArc) for patients with hepatocellular carcinoma (HCC).
  
  
  METHODS
  Twenty patients (22 lesions) were prospectively enrolled in a feasibility study. Dose prescription was 50 Gy in 10 fractions. Seven patients (35%) were classified as AJCC stage I-II while 13 (65%) were stages III-IV. Eighteen patients (90%) were Child-Pugh stage A, the remaining were stage B. All patients were treated with RapidArc technique with flattening filter free (FFF) photon beams of 10 MV from a TrueBeam linear accelerator. Technical, dosimetric and early clinical assessment was performed to characterize treatment and its potential outcome.
  
  
  RESULTS
  Median age was 68 years, median initial tumor volume was 124 cm3 (range: 6-848). Median follow-up time was 7.4 months (range: 3-13). All patients completed treatment without interruption. Mean actuarial overall survival was of 9.6 ± 0.9 months (95%C.L. 7.8-11.4), median survival was not reached; complete response was observed in 8/22 (36.4%) lesions; partial response in 7/22 (31.8%), stable disease in 6/22 (27.3%), 1/22 (4.4%) showed progression. Toxicity was mild with only 1 case of grade 3 RILD and all other types were not greater than grade 2. Concerning dosimetric data, Paddick conformity index was 0.98 ± 0.02; gradient index was 3.82 ± 0.93; V95% to the clinical target volume was 93.6 ± 7.7%. Mean dose to kidneys resulted lower than 3.0 Gy; mean dose to stomach 4.5 ± 3.0 Gy; D(3) 1(cm) to spinal cord was 8.2 ± 4.5 Gy; D1% to the esophagus was 10.2 ± 9.7 Gy. Average beam on time resulted 0.7 ± 0.2 minutes (range: 0.4-1.4) with the delivery of an average of 4.4 partial arcs (range: 3-6) of those 86% non-coplanar.
  
  
  CONCLUSIONS
  Clinical results could suggest to introduce VMAT-RapidArc as an appropriate SBRT technique for patients with HCC in view of a prospective dose escalation trial.
authors.forename: Po-Ming
authors.initials: PM
authors.lastname: Wang
authors.forename: Wei-Chung
authors.initials: WC
authors.lastname: Hsu
authors.forename: Na-Na
authors.initials: NN
authors.lastname: Chung
authors.forename: Feng-Ling
authors.initials: FL
authors.lastname: Chang
authors.forename: Chin-Jyh
authors.initials: CJ
authors.lastname: Jang
authors.forename: Antonella
authors.initials: A
authors.lastname: Fogliata
authors.forename: Marta
authors.initials: M
authors.lastname: Scorsetti
authors.affiliation: Oncology Institute of Southern Switzerland, Bellinzona, Switzerland. lucozzi@iosi.ch.
authors.forename: Luca
authors.initials: L
authors.lastname: Cozzi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D015331:Cohort Studies; D003131:Combined Modality Therapy; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D058958:Organs at Risk / Q000473:pathology / Q000528:radiation effects; D017785:Photons / Q000009:adverse effects / Q000627:therapeutic use*; D016634:Radiosurgery / Q000009:adverse effects; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects / Q000379:methods*