Preliminary Results of Intensity Modulated Radiation Therapy Alone for 122 Patients with Untreated Nasopharyngeal Carcinoma

Definitive intensity-modulated radiation therapy for nasopharyngeal carcinoma: long-term outcome of a multicenter prospective study

PURPOSE

To evaluate long-term outcome in nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiation therapy.

METHODS

Between January 2006 and August 2008, 300 patients with histologically proven NPC were enrolled in this multicenter prospective study. All patients received definitive IMRT. Cisplatin-based concurrent chemotherapy was given to patients with stages III-IVb disease.

RESULTS

Median follow-up time was 47.1 months (range 11-68 months). Median survival time was not reached. For all patients, the 4-year local control (LC), regional control (RC), distant metastasis-free survival (DMFS), and overall survival (OS) were 94.0, 95.1, 85.0, and 86.1 %, respectively. Thirty-five patients experienced locoregional failures: 18 were local only, 15 were regional only, and 2 were both local and regional. Forty-two patients developed distant metastasis. Of these, 32 patients had single organ metastasis, and 10 patients had multiple organ metastasis. The most common acute toxicities were mucositis, dermatitis, and xerostomia. Grade 0-2 mucositis, dermatitis, and xerostomia occurred in 200 patients (66.7 %), 288 patients (96.0 %), and 286 patients (95.3 %), respectively. Grade 3 mucositis, dermatitis, and xerostomia were seen in 100 patients (33.3 %), 12 patients (4.0 %), and 14 patients (4.7 %), respectively. No Grade 4 acute toxicities were observed. The most common late toxicity for 284 patients who survived for more than 2 years was xerostomia. At 3 months after treatment, 16.2 % of patients had Grade 1, 73.6 % had Grade 2, and 10.2 % had Grade 3 xerostomia. However, the severity of xerostomia decreased over time. At 24 months, only 12.3 % of patients had Grade 2 xerostomia, and none had Grade 3 or 4 xerostomia.

CONCLUSIONS

IMRT for NPC patients achieved excellent long-term locoregional control (LRC) and OS, with acceptable acute and late toxicities. After the treatment, xerostomia was improved over time. Distant metastasis remained the main cause of failure. More effective systemic therapy is demanding for reducing the risk of distant metastasis.

IMRT and IGRT in head and neck cancer: Have we delivered what we promised?

Intensity-modulated radiation therapy (IMRT) is a revolutionary new paradigm that aims at improving the therapeutic ratio by increasing the dosegradient between target tissues and surrounding normal structures thereby offering probability of better loco-regional control with decreased risk of complications. IMRT is relatively intolerant to set-up uncertainties, warranting periodic image-guidance, making Image-Guided Radiation Therapy (IGRT) a natural corollary to IMRT. There are several challenges associated with the planning, delivery, and quality assurance of the IMRT and IGRT processes that must be addressed to realize the full potential of such exciting and promising technology. Given the complexities involved, it is quite intuitive to understand that IMRT and IGRT are resource-intensive, demanding increased labor, rigour, and expenses too. Other disadvantages associated with high-precision techniques include potentially increased risk of marginal failures, decreased dose homogeneity, and an increase in total body dose with increased risk of secondary carcinogenesis. The aim of this review is to define the role of IMRT and IGRT in contemporary head and neck oncologic practice through a critical appraisal of pertinent literature. Despite relatively short follow-up and limited clinical outcomes data, the weight of evidence suggests that loco-regional control is not inferior (either comparable or even better) and toxicity lesser with IMRT resulting in potentially improved quality-of-life, prompting the widespread adoption of such technology in community practice. Ongoing clinical trials in head and neck IMRT are currently addressing issues to optimize the IMRT process, adopting functional imaging for dose-painting, and incorporating adaptive re-planning strategies to further improve outcomes.

Further improvement in outcomes of nasopharyngeal carcinoma with optimized radiotherapy and induction plus concomitant chemotherapy: an update of the Milan experience

PURPOSE

To report the outcome of a consecutive series of patients with nonmetastatic nasopharyngeal carcinoma (NPC), focusing on the impact of treatment-related factors.

METHODS AND MATERIALS

Between 2000 and 2006, 87 patients with NPC were treated with either conventional (two- or three-dimensional) radiotherapy (RT) or with intensity-modulated RT (IMRT). Of these patients, 81 (93%) received either concomitant CHT (24%) or both induction and concomitant chemotherapy (CHT) (69%). Stage was III in 36% and IV in 39% of patients. Outcomes in this study population were compared with those in the previous series of 171 patients treated during 1990 to 1999.

RESULTS

With a median follow-up of 46 months, actuarial rates at 3 years were the following: local control, 96%; local-regional control, 93%; distant control (DC), 90%; disease-free survival (DFS), 82%; overall survival, 90%. In Stage III to IV patients, distant control at 3 years was 56% in patients treated with concomitant CHT only and 92% in patients treated with both induction and concomitant CHT (p = 0.014). At multivariate analysis, histology, N-stage, RT technique, and total RT dose had the strongest independent impact on DFS (p < 0.05). Induction CHT had a borderline effect on DC (p = 0.07). Most dosimetric statistics were improved in the group of patients treated with IMRT compared with conventional 3D technique. All outcome endpoints were substantially better in the study population compared with those in the previous series.

CONCLUSIONS

Outcome of NPC has further improved in the study period compared with the previous decade, with a significant effect of RT technique optimization. The impact of induction CHT remains to be demonstrated in controlled trials.

Treatment outcomes after radiotherapy alone for patients with early-stage nasopharyngeal carcinoma

PURPOSE

To analyze the treatment outcomes of patients with early-stage nasopharyngeal carcinoma after radiotherapy (RT) alone and discuss the effects of different T and N stages on the prognosis.

METHODS AND MATERIALS

The clinical data from 362 early-stage (T1-T2N0-N1M0, 1992 Fuzhou, China staging system) nasopharyngeal carcinoma patients who had undergone RT alone between January 1999 and December 2001 and were hospitalized in the Cancer Center of Sun Yat-Sen University were collected and reviewed.

RESULTS

The median follow-up was 70 months. The 5-year overall survival rate for the whole group was 85%. The 5-year overall survival rate of those with T1N0, T2N0, and T1N1 was 96.6%, 91.3%, and 85.8%, respectively, with no statistically significant difference detected among the three groups (p > .05). However, the 5-year overall survival rate of 73.1% for those with Stage T2N1 was significantly different from that of the former three groups. The 5-year local recurrence-free survival and 5-year regional recurrence-free survival rates among the four groups was not significantly different (p < .05). The 5-year distant metastasis-free survival rate of those with Stage T1N0, T2N0, and T1N1 was 94.9%, 97.5%, and 95.6%, respectively, without any significant differences (p > .05); however, the 81.2% rate for those with Stage T2N1 was significantly different (p < .05).

CONCLUSION

RT alone for Stage T1N0, T2N0, and T1N1 yielded satisfactory results. The outcome for those with T2N1 was obviously poorer than that for the other three groups. The main reason for treatment failure in this group was distant metastasis. Patients who have a high risk of distant metastasis in the T2N1 group may need combined treatment instead of RT alone.

The current status of intensity-modulated radiation therapy in the treatment of nasopharyngeal carcinoma

Radiation therapy is the mainstay of treatment in nasopharyngeal carcinoma, alone or in combination with chemotherapy. In the early stage, it can be managed by radiotherapy alone. For locally advanced-stage disease, several meta-analyses have demonstrated the role of concurrent chemoradiotherapy. Conventional radiation therapy results in significant side effects, particular xerostomia, leading to poor quality of life. With the maturity of intensity-modulated radiation therapy in the recent 10 years, more and more evidences have shown the advantages of intensity-modulated radiation therapy over conventional radiation therapy, regarding the local-regional control, survival rate and quality of life. This article reviews the utilization of intensity-modulated radiation therapy in the management of nasopharyngeal carcinoma with respect to its technical advantages, clinical outcome, critical organ sparing and quality of life, and the dilemma in target delineation. In particular, an issue of treatment-related dysphagia will also be discussed.