A.S. Chiang

Pain Flare Is a Common Adverse Event in Steroid-Naïve Patients After Spine Stereotactic Body Radiation Therapy: A Prospective Clinical Trial

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.

Predictors of Chest Wall Toxicity after Lung Stereotactic Ablative Radiotherapy

AIMS To determine the incidence and predictive factors of rib fracture and chest wall pain after lung stereotactic ablative radiotherapy (SABR). MATERIALS AND METHODS Patients were treated with lung SABR of 48-60 Gy in four to five fractions. The treatment plan and follow-up computed tomography scans of 289 tumours in 239 patients were reviewed. Dose-volume histogram (DVH) metrics and clinical factors were evaluated as potential predictors of chest wall toxicity. RESULTS The median follow-up was 21.0 months (range 6.2-52.1). Seventeen per cent (50/289) developed a rib fracture, 44% (22/50) were symptomatic; the median time to fracture was 16.4 months. On univariate analysis, female gender, osteoporosis, tumours adjacent (within 5 mm) to the chest wall and all of the chest wall DVH metrics predicted for rib fracture, but only tumour location adjacent to the chest wall remained significant on the multivariate model (P < 0.01). The 2 year fracture-free probability for those adjacent to the chest wall was 65.6%. Among those tumours adjacent to the chest wall, only osteoporosis (P = 0.02) predicted for fracture, whereas none of the chest wall DVH metrics were predictive. Eight per cent (24/289) experienced chest wall pain without fracture. CONCLUSIONS None of the chest wall DVH metrics independently predicted for SABR-induced rib fracture when tumour location is taken into account. Patients with tumours adjacent (within 5 mm) to the chest wall are at greater risk of rib fracture after lung SABR, and among these, an additional risk was observed in osteoporotic patients.

A comparison between accelerated hypofractionation and stereotactic ablative radiotherapy (SABR) for early-stage non-small cell lung cancer (NSCLC): Results of a propensity score-matched analysis

BACKGROUND AND PURPOSE Stereotactic ablative radiotherapy (SABR) has become standard for inoperable early-stage non-small cell lung cancer (NSCLC). However, there is no randomized evidence demonstrating benefit over more fractionated radiotherapy. We compared accelerated hypofractionation (AH) and SABR using a propensity score-matched analysis. MATERIALS AND METHODS From 1997-2007, 119 patients (T1-3N0M0 NSCLC) were treated with AH (48-60 Gy, 12-15 fractions). Prior to SABR, this represented our institutional standard. From 2008-2012, 192 patients (T1-3N0M0 NSCLC) were treated with SABR (48-52 Gy, 4-5 fractions). A total of 114 patients (57 per cohort) were matched (1:1 ratio, caliper: 0.10) using propensity scores. RESULTS Median follow-up (range) for the AH cohort was 36.3 (2.5-109.1) months, while that for the SABR group was 32.5 (0.3-62.6)months. Three-year overall survival (OS) and local control (LC) rates were 49.5% vs. 72.4% [p=0.024; hazard ratio (HR): 2.33 (1.28, 4.23), p=0.006] and 71.9% vs. 89.3% [p=0.077; HR: 5.56 (1.53, 20.2), p=0.009], respectively. On multivariable analysis, tumour diameter and PET staging were predictive for OS, while the only predictive factor for LC was treatment cohort. CONCLUSIONS OS and LC were improved with SABR, although OS is more closely related to non-treatment factors. This represents one of the few studies comparing AH to SABR for early-stage lung cancer.