Analysis of late toxicity in nasopharyngeal carcinoma patients treated with intensity modulated radiation therapy

Abstract

PurposeTo observe the late toxicities in nasopharyngeal carcinoma (NPC) patients who achieved long-term survival after intensity modulated radiation therapy (IMRT).Methods208 untreated NPC patients who received IMRT and survived more than five years with locoregional disease control and no metastasis were evaluated in this study. The prescription dose to the gross target volume of nasopharynx (GTVnx), positive neck lymph nodes (GTVnd), clinical target volume 1 (CTV1) and 2 (CTV2) was 68Gy/30f, 60-66Gy/30f, 60 Gy/30f and 54Gy/30f, respectively. The nasopharynx and upper neck targets were irradiated using IMRT, and the lower neck and supraclavicular fossae targets were irradiated using the half-beam technique with conventional irradiation. The late toxicities were evaluated according to the LENT/SOMA criteria of 1995.ResultsThe median follow-up time was 78 months (60–96 months). The occurrence rates of cervical subcutaneous fibrosis, hearing loss, skin dystrophy, xerostomia, trismus, temporal lobe injury, cranial nerve damage, cataract, and brain stem injury induced by radiotherapy were 89.9%, 67.8%, 47.6%, 40.9%, 7.21%, 4.33%, 2.88%, 1.44%, and 0.48%, respectively. No spinal cord injury and mandible damage were found. Grade 3–4 late injuries were observed as follows: 1 (0.48%) skin dystrophy, 4 (1.92%) cervical subcutaneous fibrosis, 2 (0.96%) hearing loss, 2 (0.96%) cranial nerve palsy, and 1 (0.48%) temporal lobe necrosis. No grade 3–4 late injuries occurred in parotid, temporomandibular joints and eyes. Xerostomia decreased gradually over time and then showed only slight changes after 4 years. The change in the incisor distance stabilised by 1 year after RT, however, the incidence of hearing loss, skin dystrophy, subcutaneous fibrosis and nervous system injuries increased over time after RT.ConclusionThe late injuries in most NPC patients who had long-term survivals after IMRT are alleviated. Within the 5 years of follow-up, we found xerostomia decreased gradually; The change in the incisor distance stabilised by 1 year after RT; while hearing loss, nervous system injuries increased over time after RT.

Very late xerostomia, dysphagia, and neck fibrosis after head and neck radiotherapy

“…33,44 Concerning xerostomia and neck fibrosis, our patients did not use medication nor did they receive an intervention. 33,44 Concerning xerostomia and neck fibrosis, our patients did not use medication nor did they receive an intervention.…”

Prognosis of nasopharyngeal carcinoma with insufficient radical dose to the primary site in the intensity‐modulated radiotherapy era

“…In the NPC-2003-GPOH/DCOG trial, 12.2% and 85.4% of the patients received CR and PR, respectively, after three courses of IC with cisplatin, 5-fluorouracil, and folinic acid. 23 A large number of studies have shown that the irradiation dose is closely related to the incidence and severity of complications. 19 These studies showed that the addition of IC to CCRT for locally advanced NPC allowed for the possibility to reduce the radiation dose.…”

Neoadjuvant and Concurrent Chemotherapy Have Varied Impacts on the Prognosis of Patients with the Ascending and Descending Types of Nasopharyngeal Carcinoma Treated with Intensity-Modulated Radiotherapy

“…Radiotherapy: Target volumes were delineated according to our institutional treatment protocol [16], in agreement with International Commission on Radiation Units and Measurements Reports (ICRU) 50 and 62. Planning target volumes (PTVs) for all gross tumour volumes and clinical target volumes (CTVs) were generated automatically after tumour target delineation according to immobilization and localization uncertainties.…”