Prognostic value of maximum standardized uptake value measured by pretreatment 18F-FDG PET/CT in locally advanced head and neck squamous cell carcinoma.

PURPOSE/OBJECTIVES: To evaluate the prognostic impact of maximum standardized uptake value (SUVmax) in patients with locally advanced head and neck squamous cell carcinoma (HNSCC) undergoing pretreatment [F-18] fluoro-D-glucose-positron emission tomography/computed tomography (FDG PET/CT) imaging. MATERIALS/METHODS: Fifty-eight patients undergoing FDG PET/CT before radical treatment with definitive radiotherapy (±concomitant chemotherapy) or surgery + postoperative (chemo)radiation were analyzed. The effects of clinicopathological factors (age, gender, tumor location, stage, Karnofsky Performance Status (KPS), and treatment strategy) including primary tumor SUVmax and nodal SUVmax on overall survival (OS), disease-free survival (DFS), locoregional control (LRC), and distant metastasis-free survival (DMFS) were evaluated. Kaplan-Meier survival curves were generated and compared with the log-rank test. RESULTS: Median follow-up for the whole population was 31 months (range 2.3-53.5). Two-year OS, LRC, DFS and DMFS, for the entire cohort were 62.1, 78.3, 55.2 and 67.2%, respectively. Median pretreatment SUVmax for the primary tumor and lymph nodes was 11.85 and 5.4, respectively. According to univariate analysis, patients with KPS < 80% (p < 0.001), AJCC stage IVa or IVb vs III (p = 0.037) and patients undergoing radiotherapy vs surgery (p = 0.042) were significantly associated with worse OS. Patients with KPS < 80% (p = 0.003) or age ≥65 years (p = 0.007) had worse LRC. The KPS < 80% was the only factor associated with decreased DFS (p = 0.001). SUVmax of the primary tumor or the lymph nodes were not associated with OS, DFS or LRC. The KPS < 80% (p = 0.002), tumor location (p = 0.047) and AJCC stage (p = 0.025) were associated with worse cancer-specific survival (CSS). According to Cox regression analysis, on multivariate analysis KPS < 80% was the only independent parameter determining worse OS, DFS, CSS. Regarding LRC only patients with IK < 80% (p = 0.01) and ≥65 years (p = 0.01) remained statistically significant. Nodal SUVmax was the only factor associated with decreased DMFS. Patients with a nodal SUVmax > 5.4 presented an increased risk for distant metastases (HR, 3.3; 95% CI 1.17-9.25; p = 0.023). CONCLUSIONS: The pretreatment nodal SUVmax in patients with locally advanced HNSCC is prognostic for DMFS. However, according to our results primary tumor SUVmax and nodal SUVmax were not significantly related to OS, DFS or LRC. Patients presenting KPS < 80% had worse OS, DFS, CSS and LRC.

A prospective analysis of inter- and intrafractional errors to calculate CTV to PTV margins in head and neck patients.

PURPOSE: To evaluate an institute-specific CTV-PTV margin for head and neck (HN) patients according to a 3-mm action level protocol. METHODS/PATIENTS: Twenty-three HN patients were prospectively analysed. Patients were immobilized with a thermoplastic mask. Inter- and intrafractional set-up errors (in the three dimensions) were assessed from portal images (PI) registration. Digitally reconstructed radiographs (DRRs) were compared with two orthogonal PI by matching bone anatomy landmarks. The isocenter was verified during the first five consecutive days of treatment: if the mean error detected was greater than 2 mm the isocenter position was corrected for the rest of the treatment. Isocenter was checked weekly thereafter. Set-up images were obtained before and after treatment administration on 10, 20 and 30 fractions to quantify the intrafractional displacement. For the set-up errors, systematic (Σ), random (σ), overall standard deviations, and the overall mean displacement (M), were determined. CTV to PTV margin was calculated considering both inter- and intrafractional errors. RESULTS: A total of 396 portal images was analysed in 23 patients. Systematic interfractional (Σ(inter)) set-up errors ranged between 0.77 and 1.42 mm in the three directions, whereas the random (σ (inter)) errors were around 1-1.31 mm. Systematic intrafractional (Σ(intra)) errors ranged between 0.65 and 1.11 mm, whereas the random (σ (intra)) errors were around 1.13-1.16 mm. CONCLUSIONS: A verification protocol (3-mm action level) provided by EPIDs improves the set-up accuracy. Intrafractional error is not negligible and contributes to create a larger CTV-PTV margin. The appropriate CTV-PTV margin for our institute is between 3 and 4.5 mm considering both inter- and intrafractional errors.

Definitive radiotherapy for T1 glottic squamous cell carcinoma: a 15-year Cruces University Hospital experience.

PURPOSE: To evaluate the treatment outcomes for T1 N0 glottic carcinoma after definitive radiotherapy. METHODS: One hundred and seventeen patients treated with radical radiotherapy from 1990 to 2006 were retrospectively reviewed. The median follow-up duration for the entire group was 92 months (range 4-227). A median dose of 70 Gy (range 63-70 Gy) was administered. We determined the rates of local control (LC), regional control, overall survival (OS) and cause-specific survival (CSS) at 5, 10 and 15 years by Kaplan-Meier product-limit method. The Cox regression analysis was performed to identify significant prognostic factors for LC and survival. The incidence of secondary malignancies is also reported. RESULTS: The 5-, 10- and 15-year LC rates for the whole group were 84, 80.2 and 80.2 %, respectively. There were 20 local recurrences, of which 19 were salvaged with laryngectomy, giving an ultimate control rate of 90.6 %. The 5-/10-/15-year OS and CSS rates were 81.2 %/66.1 %/48.3 % and 90.6 %/90.6 %/90.6 %, respectively. None of the parameters analyzed exhibited a statistically significant relationship with LC. The age ≥65 years had a statistically significant effect on OS (but not in CSS), with a hazard ratio of 2.45 (95 % confidence interval 1.29-4.66; p = 0.006). During follow-up, 26 patients (22 %) developed a secondary malignancy. Only two patients (1.7 %) presented with severe toxicity (edema and mucositis). CONCLUSIONS: Radiotherapy alone offers a high likelihood of LC and an excellent CSS rate. In addition, the surgical approach for the salvage is a successful option.