title: Locoregional recurrences after post-operative volumetric modulated arc radiotherapy (VMAT) in oral cavity cancers in a resource constrained setting: experience and lessons learned.
abstract: OBJECTIVE
  The conformal nature of dose distribution produced by volumetric modulated arc radiotherapy (VMAT) increases the risk of geographic miss. Data regarding patterns of failure after VMAT in oral cavity cancers in resource-constrained settings are scarce. The aim of the present study was to ascertain the patterns of failure in patients receiving adjuvant VMAT intensity-modulated radiotherapy (IMRT) for oral cavity cancer in Malabar Cancer Center, Kerala, India.
  
  
  METHODS
  Data of patients with oral cavity cancer receiving adjuvant VMAT IMRT between April 2012 and March 2014 were collected. Recurrent volumes were delineated on the treatment planning images and classified as defined by Dawson et al (Dawson LA, Anzai Y, Marsh L, Martel MK, Paulino A, Ship JA, et al. Patterns of local-regional recurrence following parotid-sparing conformal and segmental intensity-modulated radiotherapy for head and neck cancer. Int J Radiat Oncol Biol Phys 2000; 46: 1117-26).
  
  
  RESULTS
  75 patients with a median follow-up of 24 months were analysed. 41 (55%) patients had oral tongue cancers and 52 (69%) of the patients had Stage IVA cancers. The 2-year locoregional recurrence-free survival, disease-free survival and overall survival were 88.9%, 82.1% and 80.5%, respectively. With a median time to failure of 6.5 months, five infield and three outfield failures were identified.
  
  
  CONCLUSIONS
  A relatively low rate of outfield failure and lack of marginal failure attests to the efficacy of VMAT in such patients. Modifications to our existing target delineation policy have been proposed.
  
  
  CONCLUSIONS
  The use of standardized target delineation methods allows safe use of VMAT IMRT even in resource-constrained settings.
authors: 1 Department of Radiation Oncology, Malabar Cancer Center, Kerala, India.
authors: S
authors: S
authors: Chakraborty
authors: V M
authors: VM
authors: Patil
authors: S
authors: S
authors: Babu
authors: G
authors: G
authors: Muttath
authors: S K
authors: SK
authors: Thiagarajan
mesh_terms: D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D015897:Comorbidity; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007194:India; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D011829:Radiation Dosage; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D018714:Radiotherapy, Adjuvant; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D012307:Risk Factors; D015996:Survival Rate; D014057:Tomography, X-Ray Computed
references: BMC Cancer. 2011;11:37
references: 21269518
references: Am J Clin Oncol. 2010 Dec;33(6):599-603
references: 21063195
references: Int J Radiat Oncol Biol Phys. 2011 Aug 1;80(5):1412-22
references: 20675073
references: Int J Radiat Oncol Biol Phys. 2011 Sep 1;81(1):140-9
references: 20732767
references: Int J Radiat Oncol Biol Phys. 2011 Nov 15;81(4):e215-22
references: 21531515
references: Head Neck. 2012 Jun;34(6):900-6
references: 21284058
references: Radiat Oncol. 2012;7:84
references: 22686297
references: Radiat Oncol. 2012;7:175
references: 23088283
references: Oral Oncol. 2013 Jun;49(6):e19
references: 23490886
references: Asian Pac J Cancer Prev. 2013;14(5):2829-34
references: 23803039
references: Otolaryngol Head Neck Surg. 2014 Jan;150(1):81-6
references: 24145147
references: Int J Oral Maxillofac Surg. 2014 Apr;43(4):387-92
references: 24262611
references: Strahlenther Onkol. 2014 May;190(5):433-43
references: 24595416
references: Head Neck. 2015 Jul;37(7):933-9
references: 24634078
references: Head Neck. 2015 Aug;37(8):1176-80
references: 24798182
references: Int J Radiat Oncol Biol Phys. 2000 Mar 15;46(5):1117-26
references: 10725621
references: Int J Radiat Oncol Biol Phys. 2003 Feb 1;55(2):312-21
references: 12527043
references: J Clin Oncol. 1991 Jan;9(1):191-2
references: 1985169
references: Int J Radiat Oncol Biol Phys. 2005 Oct 1;63(2):410-21
references: 16168834
references: Head Neck. 2005 Oct;27(10):843-50
references: 16161069
references: Radiother Oncol. 2006 Apr;79(1):15-20
references: 16616387
references: Strahlenther Onkol. 2007 Aug;183(8):417-23; discussion 424-5
references: 17680220
references: Int J Radiat Oncol Biol Phys. 2008 Nov 1;72(3):737-46
references: 18486356
references: Int J Radiat Oncol Biol Phys. 2009 Mar 15;73(4):1096-103
references: 18707827
references: Head Neck Oncol. 2009;1:17
references: 19527507
references: J Appl Clin Med Phys. 2009;10(4):3068
references: 19918236
references: Head Neck. 2010 Jun;32(6):714-22
references: 19827119
references: Radiother Oncol. 2011 May;99(2):101-7
references: 21621868