Prospective assessment of patterns of failure after high-precision definitive (chemo)radiation in head-and-neck squamous cell carcinoma.
OBJECTIVE
To prospectively analyze patterns of failure in patients with head-and-neck squamous cell carcinoma treated with definitive high-precision radiotherapy with a focus on location of failure relative to target volume coverage.


METHODS
Sixty patients treated with three-dimensional conformal radiotherapy or intensity-modulated radiation therapy were included. Locoregional failure volume was defined on the planning data set at relapse, and dose received was analyzed by use of dose-volume histograms.


RESULTS
Thirteen patients were deemed to have had locoregional failures, of which two did not have any viable tumor on salvage neck dissection, leaving eleven patients with proven persistent or recurrent locoregional disease. Of these, 9 patients had in-field failure, 1 marginal failure, and 1 both in-field and marginal failures. Overall, only 2 of 11 patients (18%) with relapse had any marginal failure. Of the 20 sites of locoregional failure, 15 (75%) were in-field and 5 (25%) marginal. Distant metastases were detected in 3 patients, whereas a second new primary developed in 3 others. With a median follow-up of 26 months (interquartile range, 18-31 months) for surviving patients, the 3-year local control, locoregional control, disease-free survival, and overall survival rates were 75.3%, 74%, 67.2%, and 60.5%, respectively.


CONCLUSIONS
Locoregional relapse remains the predominant pattern of failure in head-and-neck squamous cell carcinoma treated with high-precision definitive radiotherapy with the majority of failures occurring "in-field" within the high-dose volume. Marginal failures can occur, particularly in the vicinity of the spared parotid gland. The therapeutic index of high-precision conformal radiotherapy is largely dependent on adequate selection and delineation of target volumes and organs at risk.
Gupta
Tejpal
T
Department of Radiation Oncology, Advanced Centre for Treatment Research & Education in Cancer/Tata Memorial Hospital, Tata Memorial Centre, Mumbai, India. tejpalgupta@rediffmail.com
Jain
Sandeep
S
Agarwal
Jai Prakash
JP
Ghosh-Laskar
Sarbani
S
Phurailatpam
Reena
R
Pai-Shetty
Rajershi
R
Dinshaw
Ketayun A
KA
D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D004359:Drug Therapy, Combination / Q000379:methods; D005260:Female; D006801:Humans; D007012:Hypopharyngeal Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D007822:Laryngeal Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009959:Oropharyngeal Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D010610:Pharyngeal Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D011446:Prospective Studies; D020266:Radiotherapy, Conformal / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods; D016879:Salvage Therapy / Q000379:methods; D017211:Treatment Failure