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

Abstract

Background It was reported that reduced radiotherapy is feasible for children with nasopharyngeal carcinoma (NPC) and papilloma virus‐positive oropharyngeal cancer. Therefore, we performed this study to explore the prognosis of reduced‐dose radiation in adult with NPC. Methods Between 2004 and 2013, we retrospectively analyzed 19 patients histologically diagnosed with NPC, who received <66 Gy radiation therapy. Ten patients receiving <54 Gy to the primary site were group A. Nine patients receiving ≥54 Gy were group B. Results Thirteen patients received induction chemotherapy (IC) for two or three cycles. In group A, the 5‐year overall survival (OS) was 50.0%. For group B, the 5‐year OS, locoregional relapse‐free survival, progression‐free survival, and distant metastasis‐free survival were 88.9%, 100.0%, 88.9%, and 88.9%. Group B had a better prognosis than group A on OS (88.9% vs 50.0%, P = .03). Conclusion Patients receiving ≥54 Gy but <66 Gy with IC achieved good local control and long‐term survival.

Effect of Body Size Change on Off-Center Cervical Point and Face Doses in Patients Undergoing Nasopharyngeal Carcinoma Radiotherapy

“…Studies have pointed out that IMRT has significant advantages in improving the tumor control effect and reducing the risk of metastasis and recurrence. Moreover, it can reduce the irradiation dose to peripheral normal tissue to effectively protect the organs, thus minimizing the harmful side effects of radiotherapy and ensuring beneficial treatment effect for improving the quality of life and survival rate [ 14 , 15 ]. However, IMRT still has some limitations such as its precise dose distribution of target region sketch has strict requirements.…”

Volumetric modulated arc therapy versus tomotherapy for late T-stage nasopharyngeal carcinoma

“…One possible explanation for the insignificant advantages in survival outcomes is that patients in the VMAT group were more likely to receive adjuvant chemotherapy because of the higher residual disease rates after radiotherapy, which may counteract the potential advantages of radiotherapy modality (25)(26)(27). Another possible explanation is that the inferiority in dose coverage of the PTVs in the VMAT group may not affect survival outcomes, as several studies have indicated that dose and target volume reduction did not affect the survival outcomes for NPC patients who received induction chemotherapy (28)(29)(30).…”

Quality of Life, Toxicity and Unmet Needs in Nasopharyngeal Cancer Survivors

“…Furthermore, radiation dose was not a significant variable in a univariate analysis of prognostic factors for LRFS. A smaller series (n=19) by Lu et al concluded that patients who received a minimum of 54 Gy had a 5-years LRFS of 100% (70). However, this was a subset of only nine patients, and further details reported that there were no local or regional relapses in the 5-years follow up period when a minimum dose of 60 Gy was given.…”