PURPOSE:

To quantitatively evaluate dose distribution characteristics achieved with helical tomotherapy (HT) for whole-brain irradiation (WBRT) with integrated boost (IB) to multiple brain metastases in comparison with alternative techniques.

METHODS AND MATERIALS:

Dose distributions for 23 patients with 81 metastases treated with WBRT (30 Gy/10 fractions) and IB (50 Gy) were analyzed. The median number of metastases per patient (Nmets) was 3 (range, 2-8). Mean values of the composite planning target volume of all metastases per patient (PTVmets) and of the individual metastasis planning target volume (PTVind met) were 8.7 ± 8.9 cm(3) (range, 1.3-35.5 cm(3)) and 2.5 ± 4.5 cm(3) (range, 0.19-24.7 cm(3)), respectively. Dose distributions in PTVmets and PTVind met were evaluated with respect to dose conformity (conformation number [CN], RTOG conformity index [PITV]), target coverage (TC), and homogeneity (homogeneity index [HI], ratio of maximum dose to prescription dose [MDPD]). The dependence of dose conformity on target size and Nmets was investigated. The dose distribution characteristics were benchmarked against alternative irradiation techniques identified in a systematic literature review.

RESULTS:

Mean ± standard deviation of dose distribution characteristics derived for PTVmets amounted to CN = 0.790 ± 0.101, PITV = 1.161 ± 0.154, TC = 0.95 ± 0.01, HI = 0.142 ± 0.022, and MDPD = 1.147 ± 0.029, respectively, demonstrating high dose conformity with acceptable homogeneity. Corresponding numbers for PTVind met were CN = 0.708 ± 0.128, PITV = 1.174 ± 0.237, TC = 0.90 ± 0.10, HI = 0.140 ± 0.027, and MDPD = 1.129 ± 0.030, respectively. The target size had a statistically significant influence on dose conformity to PTVmets (CN = 0.737 for PTVmets ≤4.32 cm(3) vs CN = 0.848 for PTVmets >4.32 cm(3), P=.006), in contrast to Nmets. The achieved dose conformity to PTVmets, assessed by both CN and PITV, was in all investigated volume strata well within the best quartile of the values reported for alternative irradiation techniques.

CONCLUSIONS:

HT is a well-suited technique to deliver WBRT with IB to multiple brain metastases, yielding high-quality dose distributions. A multi-institutional prospective randomized phase 2 clinical trial to exploit efficacy and safety of the treatment concept is currently under way.

PURPOSE:

To test the hypotheses that (1) the increased risk of stroke conferred by childhood cranial radiation therapy (CRT) persists into adulthood; and (2) atherosclerotic risk factors further increase the stroke risk in cancer survivors.

METHODS AND MATERIALS:

The Childhood Cancer Survivor Study is a multi-institutional retrospective cohort study of 14,358 5-year survivors of childhood cancer and 4023 randomly selected sibling controls with longitudinal follow-up. Age-adjusted incidence rates of self-reported late-occurring (≥5 years after diagnosis) first stroke were calculated. Multivariable Cox proportional hazards models were used to identify independent stroke predictors.

RESULTS:

During a mean follow-up of 23.3 years, 292 survivors reported a late-occurring stroke. The age-adjusted stroke rate per 100,000 person-years was 77 (95% confidence interval [CI] 62-96), compared with 9.3 (95% CI 4-23) for siblings. Treatment with CRT increased stroke risk in a dose-dependent manner: hazard ratio 5.9 (95% CI 3.5-9.9) for 30-49 Gy CRT and 11.0 (7.4-17.0) for 50+ Gy CRT. The cumulative stroke incidence in survivors treated with 50+ Gy CRT was 1.1% (95% CI 0.4-1.8%) at 10 years after diagnosis and 12% (95% CI 8.9-15.0%) at 30 years. Hypertension increased stroke hazard by 4-fold (95% CI 2.8-5.5) and in black survivors by 16-fold (95% CI 6.9-36.6).

CONCLUSION:

Young adult pediatric cancer survivors have an increased stroke risk that is associated with CRT in a dose-dependent manner. Atherosclerotic risk factors enhanced this risk and should be treated aggressively.

PURPOSE:

To evaluate the efficacy of irradiation of internal mammary nodes (IMN) on 10-year overall survival in breast cancer patients after mastectomy.

METHODS

AND

PATIENTS:

This multicenter phase 3 study enrolled patients with positive axillary nodes (pN+) or central/medial tumors with or without pN+. Other inclusion criteria were age <75 and a Karnofsky index ≥70. All patients received postoperative irradiation of the chest wall and supraclavicular nodes and were randomly assigned to receive IMN irradiation or not. Randomization was stratified by tumor location (medial/central or lateral), axillary lymph node status, and adjuvant therapy (chemotherapy vs no chemotherapy). The prescribed dose of irradiation to the target volumes was 50 Gy or equivalent. The first 5 intercostal spaces were included in the IMN target volume, and two-thirds of the dose (31.5 Gy) was given by electrons. The primary outcome was overall survival at 10 years. Disease-free survival and toxicity were secondary outcomes.

RESULTS:

T total of 1334 patients were analyzed after a median follow-up of 11.3 years among the survivors. No benefit of IMN irradiation on the overall survival could be demonstrated: the 10-year overall survival was 59.3% in the IMN-nonirradiated group versus 62.6% in the IMN-irradiated group (P=.8). According to stratification factors, we defined 6 subgroups (medial/central or lateral tumor, pN0 [only for medial/central] or pN+, and chemotherapy or not). In all these subgroups, IMN irradiation did not significantly improve overall survival.

CONCLUSIONS:

In patients treated with 2-dimensional techniques, we failed to demonstrate a survival benefit for IMN irradiation. This study cannot rule out a moderate benefit, especially with more modern, conformal techniques applied to a higher risk population.

PURPOSE:

To determine the incidence of pain flare after spine stereotactic body radiation therapy (SBRT) in steroid-naïve patients and identify predictive factors.

METHODS AND MATERIALS:

Forty-one patients were treated with spine SBRT between February 2010 and April 2012. All patients had their pain assessed at baseline, during, and for 10 days after SBRT using the Brief Pain Inventory. All pain medications were recorded daily and narcotics converted to an oral morphine equivalent dose. Pain flare was defined as a 2-point increase in worst pain score as compared with baseline with no decrease in analgesic intake, a 25% increase in analgesic intake as compared with baseline with no decrease in worst pain score, or if corticosteroids were initiated at any point during or after SBRT because of pain.

RESULTS:

The median age and Karnofsky performance status were 57.5 years (range, 27-80 years) and 80 (range, 50-100), respectively. Eighteen patients were treated with 20-24 Gy in a single fraction, whereas 23 patients were treated with 24-35 Gy in 2-5 fractions. Pain flare was observed in 68.3% of patients (28 of 41), most commonly on day 1 after SBRT (29%, 8 of 28). Multivariate analysis identified a higher Karnofsky performance status (P=.02) and cervical (P=.049) or lumbar (P=.02) locations as significant predictors of pain flare. In those rescued with dexamethasone, a significant decrease in pain scores over time was subsequently observed (P<.0001).

CONCLUSIONS:

Pain flare is a common adverse event after spine SBRT and occurs most commonly the day after treatment completion. Patients should be appropriately consented for this adverse event.

PURPOSE:

To validate the prognostic value of interval to biochemical failure (IBF) in patients with high-risk prostate cancer (HiRPCa) treated with combined-modality radiation therapy (CMRT) with or without androgen deprivation therapy (ADT).

METHODS AND MATERIALS:

We conducted a retrospective review of HiRPCa (prostate-specific antigen >20 ng/mL, Gleason score [GS] 8-10, or clinical T stage T3-T4) treated with either dose-escalated external beam radiation therapy (EBRT) or CMRT. Interval to biochemical failure was classified as ≤18 or >18 months from the end of all therapy to the date of biochemical failure (BF). Kaplan-Meier methods and Cox proportional hazards regression were used to evaluate the prognostic value of IBF ≤18 months for distant metastasis (DM) and prostate cancer-specific mortality (PCSM).

RESULTS:

Of 958 patients with a median follow-up of 63.2 months, 175 patients experienced BF. In those with BF, there were no differences in pretreatment clinical characteristics between the EBRT and CMRT groups, except for a higher proportion of patients with GS 8-10 in the CMRT group (70% vs 52%, P=.02). Median IBF after all therapy was 24.0 months (interquartile range 9.6-46.0) in the EBRT group and 18.9 months (interquartile range 9.2-34.5) in the CMRT group (P=.055). On univariate analysis, IBF ≤18 months was associated with increased risk of DM and PCSM in the entire cohort and the individual EBRT and CMRT groups. On multivariate analysis, only GS 9-10 and IBF ≤18 months, but not the radiation therapy regimen or ADT use, predicted DM (hazard ratio [HR] 3.7, P<.01, 95% confidence interval [CI] 1.4-10.3 for GS 9-10; HR 3.9, P<.0001, 95% CI 2.4-6.5 for IBF ≤18 months) and PCSM (HR 14.8, P<.009, 95% CI 2.0-110 for GS 9-10; HR 4.4, P<.0001, 95% CI 2.4-8.1 for IBF ≤18 months).

CONCLUSIONS:

Short IBF was highly prognostic for higher DM and PCSM in patients with HiRPCa. The prognostic value of IBF for DM and PCSM was not affected by the radiation therapy regimen or ADT use.

BACKGROUND:

There are no well-established normal tissue sparing dose-volume histogram (DVH) criteria that limit the risk of urinary toxicity from prostate radiation therapy (RT). The aim of this study was to determine which criteria predict late toxicity among various DVH parameters when contouring the entire solid bladder and its contents versus the bladder wall. The area under the histogram curve (AUHC) was also analyzed.

METHODS AND MATERIALS:

From 1993 to 2000, 503 men with prostate cancer received 3-dimensional conformal RT (median follow-up time, 71 months). The whole bladder and the bladder wall were contoured in all patients. The primary endpoint was grade ≥2 genitourinary (GU) toxicity occurring ≥3 months after completion of RT. Cox regressions of time to grade ≥2 toxicity were estimated separately for the entire bladder and bladder wall. Concordance probability estimates (CPE) assessed model discriminative ability. Before training the models, an external random test group of 100 men was set aside for testing. Separate analyses were performed based on the mean age (≤ 68 vs >68 years).

RESULTS:

Age, pretreatment urinary symptoms, mean dose (entire bladder and bladder wall), and AUHC (entire bladder and bladder wall) were significant (P<.05) in multivariable analysis. Overall, bladder wall CPE values were higher than solid bladder values. The AUHC for bladder wall provided the greatest discrimination for late bladder toxicity when compared with alternative DVH points, with CPE values of 0.68 for age ≤68 years and 0.81 for age >68 years.

CONCLUSION:

The AUHC method based on bladder wall volumes was superior for predicting late GU toxicity. Age >68 years was associated with late grade ≥2 GU toxicity, which suggests that risk-adapted dose constraints based on age should be explored.

BACKGROUND:

To examine whether nuclear NF-κB expression correlates with outcome in patients with head and neck squamous cell carcinoma (HNSCC) treated with primary chemoradiation therapy (CRT).

METHODS AND MATERIALS:

Between 2007 and 2010, 101 patients with locally advanced primary HNSCC were treated with definitive simultaneous CRT. Pretreatment biopsy specimens were analyzed for NF-κB p65 (RelA) nuclear immunoreactivity. A sample was assigned to be positive with more than 5% positive nuclear expression. The predictive relevance of NF-κB and clinicopathologic factors for overall survival (OS), progression-free survival (PFS), local progression-free survival (LPFS), and metastasis-free survival (DMFS) was examined by univariate and multivariate analysis.

RESULTS:

No significant differences between the groups were observed with regard to age, sex, total radiation dose, fractionation mode, total chemotherapy applied, T stage or grading. Patients with p65 nuclear positive biopsy specimens showed significantly a higher rate of lymph node metastasis (cN2c or cN3 status, P=.034). Within a mean follow-up time of 25 months (range, 2.33-62.96 months) OS, PFS, and DMFS were significantly poorer in the p65 nuclear positive group (P=.008, P=.027, and P=.008, respectively). These correlations remained significant in multivariate analysis.

CONCLUSION:

NF-κB/p65 nuclear expression is associated with increased lymphatic and hematogenous tumor dissemination and decreased survival in HNSCC patients treated with primary CRT. Our results may foster further investigation of a predictive relevance of NF-κB/p65 and its role as a suitable target for a molecular-based targeted therapy in HNSCC cancer.