Regional Failure-free Survival Research Articles

Long-term treatment outcome of nasopharyngeal carcinoma (NPC) using intensity-modulated radiotherapy (IMRT).

5582 Background: A number of centers have reported promising early results of treating NPC patients using IMRT, in terms of locoregional control and parotid sparing. This study evaluated the sustainability of early favorable results, and late events. Methods: 231 consecutive NPC patients were treated with IMRT between 2000 and 2005. The proportion of stage I, IIA, IIB, III, IVA, and IVB disease was 8%, 5%, 14%, 32%, 28%, and 13% respectively. The prescribed dose was 66 Gy over 33 daily fractions to the gross tumor, 60 Gy to the planning target volume, and 54–60 Gy to the clinically negative neck. Majority of T1-2a patients received brachytherapy boost (12 Gy/ 4 fractions), and T2b-T4 patients received conformal or IMRT boost (6-8 Gy/ 3-4 fractions). Stage III–IVB patients also received concurrent chemotherapy, with or without neoadjuvant chemotherapy. Results: The median follow-up period was 59 months. The overall 6-year local failure-free survival (LFFS), regional failure-free survival (RFFS), distant metastasis-free survival (DMFS), and overall survival (OS) was 82%, 91%, 75%, and 66% respectively. Between 3 to 6 years there was a drop in LFFS, RFFS, and OS, while DMFS plateaued. Local failure was dominated by within-field failure (85%). 68% of local failure involved the skull base and intracranial region (rT3/4). Only two patients developed visual impairment despite a proportion of T3/4 patients had received > 54Gy to the optic nerves or chiasm. Radiation-induced malignancy occurred in 3 patients (2 in oral tongue, 1 in nasal cavity). The 5-year cumulative incidence of radiation-induced tongue cancer was 1.43%, higher than that seen after 2-dimensional radiotherapy. Conclusions: Although IMRT at a dose between 66-74 Gy achieves good early response and promising late toxicity profile, further locoregional recurrence can be seen on longer follow-up, especially at or above skull-base region. More vigorous use of adaptive and image-guidance radiotherapy may be needed to overcome potential setup error and volumetric changes during treatment course. The incidence of radiation-induced oral tongue cancer warrants further assessment. No significant financial relationships to disclose.

Whole-Field Simultaneous Integrated-Boost Intensity-Modulated Radiotherapy for Patients With Nasopharyngeal Carcinoma

To retrospectively review the outcomes of our patients with newly diagnosed nondisseminated nasopharyngeal carcinoma treated with intensity-modulated radiotherapy using a whole-field simultaneous integrated-boost technique. A total of 175 patients treated with WF-SIB between mid-2004 and 2005 were eligible for study inclusion. The distribution of disease by stage was Stage IA in 10.9%, Stage IIA in 2.3%, Stage IIB in 21.7%, Stage III in 41.1%, Stage IVA in 14.9%, and Stage IVB in 9.1%. Of the 175 patients, 2 (1.2%), 10 (5.7%), and 163 (93.1%) had World Health Organization type I, II, and III histologic features, respectively. We prescribed 70 Gy, 60 Gy, and 54 Gy delivered in 33 fractions within 6.5 weeks at the periphery of three planning target volumes (PTV; PTV70, PTV60, and PTV54, respectively). Of the 175 patients, 46 with early T-stage disease received a brachytherapy boost, and 127 with advanced local or regional disease received chemotherapy. The median follow-up period was 34 months. The overall 3-year local failure-free survival, regional failure-free survival, distant failure-free survival, and overall survival rate was 93.6%, 93.3%, 86.6%, and 87.2%, respectively. Cox regression analysis showed Stage N2-N3 disease (p = .029) and PTV (p = .024) to be independent factors predicting a greater risk of distant failure and poor overall survival, respectively. Grade 3 acute mucositis/pharyngitis occurred in 23.4% of patients, and Stage T4 disease was the only significant predictor of mucositis/pharyngitis (p = .021). Whole-field simultaneous integrated-boost intensity-modulated radiotherapy with a dose >70 Gy achieved excellent locoregional control, without an excess incidence of severe, acute mucositis/pharyngitis, in the present study. Strategies for using such highly conformal treatment for patients with a large tumor and late N-stage disease are potential areas of investigation for future studies.

P.311 Clinical evaluation of stage I and II tongue cancer

This study was aimed to characterize patterns of lymphatic spread and assess the value of prophylactic elective neck irradiation (ENI) for esthesioneuroblastoma (ENB).A retrospectively analysis of 116 patients with newly diagnosed ENB at our institution over 35-year period was undertaken.32 patients (28%) presented lymph node metastasis at initial diagnosis, the common sites involved were level II, Ib, level III and VIIa. Among 80 N-negative patients staged in Modified Kadish B/C, 50 patients were delivered with ENI, 30 patients were not. The 5-year regional failure-free survival was 98% in patients treated with ENI and 75% in patients without ENI (p = 0.005), regional failure rate decreased significantly from 23% (7/30) to 2% (1/50) after ENI (p = 0.002). Multivariate analysis also suggested that ENI was an independent favorable predictor for regional controlling (HR, 0.102; 95% CI: 0.012–0.848; p = 0.035).This is the largest cohort of ENB so far in a single institute, and also the first detailed description of nodal spread patterns of N-positive ENB. Elective neck irradiation reduced the regional failure significantly and should be recommended as a part of initial treatment strategy for patients staged with Modified Kadish B/C.

Clinical Features and Outcome of the Tall Cell Variant of Papillary Thyroid Carcinoma

To study the clinical features and outcome of the tall cell variant (TCV) of papillary thyroid carcinoma (PTC). A single-institution retrospective analysis was performed to review patients with TCV and the usual type of PTC diagnosed from 1960 to 2000. Fourteen of 1,108 patients (median follow-up, 8.9 yr) diagnosed with PTC had TCV. Ten were female, and four were male, with a mean age of 53.7 (33-81) years. All were ethnic Chinese. Compared with the usual PTC cohort, TCV patients presented at an older age (mean, 53.7 vs. 45.2 yr; P = .015). They had a higher rate of extrathyroidal extension (78.6% vs. 43.4%, P = .009), tracheal invasion (28.6% vs. 9%, P = .034), and carotid vessel invasion (14.3% vs. 1.5%, P = .021). TCV patients had more frequent gross (42.9% vs. 17.2%) and microscopic (14.3% vs. 6%) postoperative locoregional residual disease (P = .008). They also had a higher percentage of stage III and IV disease (American Joint Committee on Cancer, 6th ed) (74.3% vs. 31.3%, P = .009). Ten-year local failure-free, regional failure-free, and metastasis-free survival were worse in the TCV group (78.6% vs. 88.8%. P = .017; 53.0% vs. 85.9%, P < .0001; 35.7% vs. 92.1%, P < .0001, respectively). The 10-year cause-specific survival was also lower in TCV patients (48.2% vs. 93.4%, P < .0001). TCV presents at a higher stage with more advanced local disease. It has a higher risk of locoregional and distant relapse and a worse overall survival rate. Stratification by stage reveals that TCV has significantly higher mortality compared with PTC for stage IV disease. Aggressive treatment and close follow-up of these patients is necessary.

High-Dose-Rate Intracavitary Brachytherapy Boost for Early T Stage Nasopharyngeal Carcinoma{PRIVATE}

To investigate any possible therapeutic gain from dose escalation with brachytherapy for early T stage nasopharyngeal carcinoma (NPC). One hundred forty-five patients with T1-2b N0-3 NPC were boosted with high-dose-rate intracavitary brachytherapy after completion of two-dimensional external radiotherapy (ERT) during the period from 1999 to 2003. To compare the efficacy of brachytherapy boost, another 142 patients with T1-2b N0-3 disease who were treated with ERT alone during 1994 to 1999 were evaluated. All patients were treated with ERT to a total dose of 66 Gy in 6.5 weeks. The brachytherapy boost group was given 10-12 Gy in 2 weekly fractions. Dose escalation beyond 66 Gy with brachytherapy boost was shown to improve local control and survival. The 5-year actuarial local failure-free survival, regional failure-free survival, distant metastasis-free survival, progression-free survival, cancer-specific survival, and overall survival rates for the brachytherapy group and the control group were 95.8% and 88.3% (p = 0.020), 96% and 94.6% (p = 0.40), 95% and 83.2% (p = 0.0045), 89.2% and 74.8% (p = 0.0021), 94.5% and 83.4% (p = 0.0058), and 91.1% and 79.6% (p = 0.0062), respectively. The 5-year major-complication-free survival rate was 89.5% for the brachytherapy group and 85.6% for the control group (p = 0.23). For patients who are treated with two-dimensional treatment techniques, dose escalation with brachytherapy boost improves local control and overall survival of patients with T1-T2a and possibly non-bulky T2b disease.

Treatment results of 1070 patients with nasopharyngeal carcinoma: An analysis of survival and failure patterns

The aim of this analysis was to evaluate the outcomes of patients with nasopharyngeal carcinoma (NPC) treated primarily by external beam irradiation (ERT) and to explore for possible ways to improve the treatment results. One thousand seventy patients with nonmetastatic NPC treated from 1990 to 1998 were retrospectively analyzed. The distribution according to the Union Internationale Contre le Cancer (UICC) (1997 edition) staging system at initial diagnosis was as follows: stage I, n = 113; stage IIA, n = 38; stage IIB, n = 360; stage III, n = 306; stage IVA, n = 136; stage IVB, n = 117; T1, n = 284; T2a, n = 88; T2b, n = 398; T3, n = 149; T4, n = 151; N0, n = 321; N1, n = 393; N2, n = 238; N3a, n = 29; N3b, n = 89. Two hundred eight patients were given neoadjuvant chemotherapy. Ninety-seven patients were diagnosed with locally persistent disease and were salvaged with high dose rate intracavitary brachytherapy. Multivariate analysis was performed with the Cox regression proportional hazards model. The 5-year actuarial local failure-free survival, regional failure-free survival, distant metastasis-free survival, progression-free survival, cancer-specific survival, and overall survival rates were 80.9%, 93.3%, 77.2%, 62.7%, 71.4%, and 66.5%, respectively. Isolated distant metastasis occurred in 191 patients (18%). The distributions were as follow: stage I, 2.1% (two of 95); stage IIA, 5.7% (two of 35); stage IIB, 14.9% (45 of 302); stage III, 26.4% (62 of 235); stage IVA, 40% (40 of 100); stage IVB, 47.1% (40 of 85). Results of the multivariate analysis of various clinical endpoints were discussed. By studying these failure patterns, it is hoped that we could refine future treatments according to the failure patterns of patients with different risks of locoregional and distant failure. The 18% incidence of isolated distant metastasis is too high to be ignored. Maximizing the local control and minimizing the risk of distant metastasis and late complications should be the key objectives in designing future clinical trials.