Prognostic impact of primary tumor volume in patients with nasopharyngeal carcinoma treated by definitive radiation therapy.
OBJECTIVE
Tumor burden has been confirmed as one of the important indicators in disease control after treatment for various types of malignancies. This report aims to document the value of the primary tumor volume of nasopharyngeal carcinoma [gross tumor volume of the primary site (GTV-P)] in predicting the treatment outcome after high-dose definitive radiation therapy.


METHODS
A total of 154 patients with nasopharyngeal carcinoma were prospectively treated with accelerated hyperfractionated radiotherapy alone to a total dose of 78 Gy/60 fractions/6 weeks (biological effective dose = 88.2 Gy).


METHODS
Patients were assessed for local control, disease-free survival and distant failure free survival. The GTV-P was calculated by summation of area technique after delineation of the primary tumor contours on computed tomography images.


RESULTS
The median GTV-P was 14.5 mL for T1, 23.3 mL for T2, 35.8 mL for T3, and 50.9 mL for T4 diseases (P < .05). With a median follow-up of 61 months, the 5-year local failure-free rate, disease-free survival and distant failure-free survival rates were 89.4% versus 48.9% (P = .002), 56.6% versus 0% (P = .001), and 66.9% versus 16.5% (P = .0001), respectively, for patients whose GTV-P were < or =60 mL and >60 mL. Multivariate analysis revealed that GTV-P is an independent prognostic factorfor local control (hazard ratio = 3.568, P = .035). There fore, the GTV-P was significantly associated with the treatment outcome after high-dose radiation delivered in accelerated hyperfractionated schedule for nasopharyngeal cancer patients.


CONCLUSIONS
Tumor volume is a reliable indicator for supplementing the T classification of the Tumor, Node, Metastasis staging system for predicting local control after definite radiation therapy.
Shen
Chunying
C
Department of Radiation Oncology, Cancer Hospital of Fudan University, Shanghai, China.
Lu
Jiade Jay
JJ
Gu
Yajia
Y
Zhu
Guopei
G
Hu
Chaosu
C
He
Shaoqin
S
D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000473:pathology* / Q000532:radiotherapy*; D018572:Disease-Free Survival; D019583:Dose Fractionation, Radiation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis / Q000473:pathology / Q000532:radiotherapy; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000401:mortality / Q000473:pathology* / Q000532:radiotherapy*; D009367:Neoplasm Staging; D011379:Prognosis; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed; D047368:Tumor Burden