Impact of Reirradiation Utilizing Fractionated Stereotactic Radiotherapy for Recurrent Glioblastoma.

BACKGROUND: Patients with recurrent glioblastoma (GBM) have limited treatment options. This study determined whether patients with recurrent GBM treated with initial radiation/temozolomide (TMZ) and reirradiation using fractionated stereotactic radiotherapy (FSRT) had improved outcomes. MATERIALS AND METHODS: We identified 95 patients with recurrent GBM, 50 of whom underwent FSRT at recurrence and 45 who had systemic treatment only (control). The median total FSRT dose at the time of GBM recurrence was 30 Gy in five fractions of the gadolinium-enhanced tumor only. RESULTS: With a median follow-up of 18 months, the progression-free survival (PFS) and overall survival (OS) following initial GBM diagnosis were longer in the reirradiation group compared to the control group (13.5 vs. 7.5 months [p=0.001] and 24.6 vs. 12.6 months [p<0.001], respectively). For patients who underwent reirradiation, the median time interval between the end of the initial radiation and reirradiation was 15.2 months. The median OS after GBM recurrence was longer in the reirradiation group versus the control group (9.9 vs. 3.5 months [p<0.001]), with a one-year OS survival rate of 22%. The hazard ratio for death of patients in the reirradiation group was 0.31 [0.19-0.50]. The reirradiation group had a higher percentage of patients who received bevacizumab (BEV, 62.0% vs. 28.9%, p=0.002) and a lower percentage of patients whose TMZ was discontinued due to toxicity (8.0% vs. 28.9%, p=0.017) compared to the control group. CONCLUSIONS: Reirradiation utilizing FSRT was associated with improved PFS and OS after GBM recurrence compared to the control group who did not receive additional irradiation.

Long-term outcomes after surgical or nonsurgical initial therapy for patients with T4 squamous cell carcinoma of the larynx: A 3-decade survey.

BACKGROUND: The current study was conducted to evaluate long-term disease control, survival, and functional outcomes after surgical and nonsurgical initial treatment for patients with T4 larynx cancer. METHODS: Demographics, disease stage, and treatment characteristics were reviewed for 221 sequential patients treated for T4 laryngeal squamous cell cancer at a single institution between 1983 and 2011. Survival and disease control outcomes were calculated. RESULTS: The median follow-up time was 47 months (71 months for patients still alive at the time of analysis). The overall 5-year and 10-year overall survival rates were 52% and 29%, respectively, and the corresponding disease-free survival rates were 57% and 48%, respectively. Overall 5-year and 10-year locoregional control rates were 78% and 67%, respectively, and the corresponding rates for freedom from distant metastasis were 76% and 74%, respectively. On both univariate and multivariate analyses, lymph node-positive disease at the time of presentation was associated with overall mortality (P<.0001). Patients treated with laryngectomy followed by postlaryngectomy radiotherapy (161 patients) achieved better initial locoregional control than patients treated with a laryngeal preservation (LP) approach (60 patients) throughout the follow-up period (log-rank P<.007) yet the median overall survival times were equal for both groups (64 months; 95% confidence interval 47-87 months and 38-87 months, respectively [P =.7]). Patients treated with an LP approach had a tracheostomy rate of 45% and an any-event aspiration rate of 23%. Rates of high-grade dysphagia at the time of last follow-up were worse for patients treated with an LP approach (P<.01). CONCLUSIONS: Surgery and postoperative radiotherapy can produce substantial long-term cancer control and survival rates for patients with T4 larynx cancer. Caution should be taken when selecting patients for initial nonsurgical treatment because of significant rates of functional impairment despite survival equivalence.

Estimation of daily interfractional larynx residual setup error after isocentric alignment for head and neck radiotherapy: quality assurance implications for target volume and organs-at-risk margination using daily CT on- rails imaging.

Larynx may alternatively serve as a target or organs at risk (OAR) in head and neck cancer (HNC) image-guided radiotherapy (IGRT). The objective of this study was to estimate IGRT parameters required for larynx positional error independent of isocentric alignment and suggest population-based compensatory margins. Ten HNC patients receiving radiotherapy (RT) with daily CT on-rails imaging were assessed. Seven landmark points were placed on each daily scan. Taking the most superior-anterior point of the C5 vertebra as a reference isocenter for each scan, residual displacement vectors to the other six points were calculated postisocentric alignment. Subsequently, using the first scan as a reference, the magnitude of vector differences for all six points for all scans over the course of treatment was calculated. Residual systematic and random error and the necessary compensatory CTV-to-PTV and OAR-to-PRV margins were calculated, using both observational cohort data and a bootstrap-resampled population estimator. The grand mean displacements for all anatomical points was 5.07 mm, with mean systematic error of 1.1 mm and mean random setup error of 2.63 mm, while bootstrapped POIs grand mean displacement was 5.09 mm, with mean systematic error of 1.23 mm and mean random setup error of 2.61 mm. Required margin for CTV-PTV expansion was 4.6 mm for all cohort points, while the bootstrap estimator of the equivalent margin was 4.9 mm. The calculated OAR-to-PRV expansion for the observed residual setup error was 2.7 mm and bootstrap estimated expansion of 2.9 mm. We conclude that the interfractional larynx setup error is a significant source of RT setup/delivery error in HNC, both when the larynx is considered as a CTV or OAR. We estimate the need for a uniform expansion of 5 mm to compensate for setup error if the larynx is a target, or 3 mm if the larynx is an OAR, when using a nonlaryngeal bony isocenter.