Risk Factors for Radiotherapy Failure in the Treatment of Spinal Metastases.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To build a predictive model for risk factors for failure of radiation therapy, hypothesizing a higher SINS would correlate with failure. METHODS: Patients with spinal metastasis being treated with radiation at a tertiary care academic center between September 2014 and October 2018 were identified. The primary outcome measure was radiation therapy failure as defined by persistent pain, need for re-irradiation, or surgical intervention. Risk factors were primary tumor type, Karnofsky and ECOG scores, time to treatment, biologically effective dose (BED) calculations using α/ß ratio = 10, and radiation modality. A logistic regression was used to construct a prediction model for radiation therapy failure. RESULTS: One hundred and seventy patients were included. Median follow up was 91.5 days. Forty-three patients failed radiation therapy. Of those patients, 10 required repeat radiation and 7 underwent surgery. Thirty-six patients reported no pain relief, including some that required re-irradiation and surgery. Total SINS score for those who failed reduction therapy was <7 for 27 patients (62.8%), between 7-12 for 14 patients (32.6%), and >12 for 2 patients (4.6%). In the final prediction model, BED (OR .451 for BED > 43 compared to BED ≤ 43; P = .174), Karnofksy score (OR .736 for every 10 unit increase in Karnofksy score; P = .008), and gender (OR 2.147 for male compared to female; P = .053) are associated with risk of radiation failure (AUC .695). A statistically significant association between SINS score and radiation therapy failure was not found. CONCLUSIONS: In the multivariable model, BED ≤ 43, lower Karnofksy score, and male gender are predictive for radiotherapy failure. SINS score was among the candidate risk factors included in multivariable model building procedure, but it was not selected in the final model. LEVEL OF EVIDENCE: Prognostic level III.

Percutaneous lumbopelvic fixation for pathologic sacral fractures and spinopelvic dissociation: patient series.

BACKGROUND: Because patients with advanced cancer live longer, the number of patients with the sequelae of metastatic spine disease has increased. Pathologic instability of the mobile spine has been classified, and minimally invasive surgery has been well described. However, pathologic sacral instability is uncommon and often underdiagnosed. Although most sacral fractures are stable, patients with unstable U- or H-type fractures have spinopelvic dissociation and can experience progressive pain, sacral kyphosis, and neurological injury. Open lumbopelvic fusion carries a high perioperative risk for this patient population, which has often been previously radiated and is medically frail. The authors investigated the utility and safety of percutaneous lumbopelvic fixation, as previously described for traumatic spinopelvic dissociation, in the oncological setting. The authors retrospectively reviewed five consecutive patients with unstable pathologic sacral fractures who had undergone percutaneous lumbopelvic fixation after conservative management failed. OBSERVATIONS: Patients experienced significant improvement between pre- and postoperative visual analog scale scores (9.2 and 1.6, respectively) and Eastern Cooperative Oncology Group grades (median 3 and 1, respectively). All patients were independently ambulatory at the final follow-up. Sagittal alignment remained stable in four patients and worsened in one. There were no major medical or surgical complications. LESSONS: Percutaneous lumbopelvic fixation shows promising results for palliation, durability, and safety for pathologic sacropelvic instability.

Image Distortion in Biplanar Slot Scanning: Patient-specific Factors.

BACKGROUND: Error within imaging measurements can be due to processing, magnification, measurement performance, or patient-specific factors. Previous length measurement studies based on radiographs have shown good intraclass correlation coefficients (ICCs) on single images; but have not assessed interimage distortion. In our study, "image distortion in biplanar slot scanning: technology-specific factors" we determined that there is minimal image distortion due to the image acquisition when using biplanar slot scanning. In this study, we aim to determine the role of patient-specific factors in image distortion, specifically evaluating interimage distortion. METHODS: Digital radiographs and biplanar slot scanner images were reviewed in 43 magnetically controlled growing rod (MCGR) patients. Fifty-five postoperative anteroposterior digital radiographs, 184 follow-up biplanar slot-scanner scanner posteroanterior and 76 biplanar slot-scanner scanner laterals were measured by 2 residents and 1 attending. The manufacturer reported average actuator diameter of 9.02 mm was used as our reference width. RESULTS: Overall, within image interobserver ICC were moderate to excellent (0.635 to 0.983), but the interimage ICCs were poor (0.332). Digital radiographs consistently overestimated the MCGR actuator width (mean=9.655) and biplanar slot-scanner scanner images underestimated it (mean=8.935). The measurement range was large with biplanar slot-scanner scanner posteroanterior (up to 15%) and lateral (22%) measurements and with digital radiographs (39%). Patients with abnormal muscle tone had higher degrees of measurement variability. CONCLUSIONS: We found that neither biplanar slot scanning nor digital radiography was precise or accurate. Digital radiographs consistently overestimated MCGR actuator width and biplanar slot scanning underestimated it. The poor ICC's within and between image subtypes and large standard error of measurement reflected a magnitude of distortion that needs to be accounted for when using length measurements clinically. Unlike the clinically insignificant error that we noted in our previous study "image distortion in biplanar slot scanning: technology-specific factors" (0.5% to 1.5% of the measurement), the error noted in this study (0.2% to 38.5% of the measurement) has the potential to be clinically significant. Patients who have abnormal muscle tone had larger measurement errors, likely stemming from motion during the slot scanning process. LEVEL OF EVIDENCE: Level III.

A systematic review on the reporting of outcome data in studies on autologous osteochondral transplantation for the treatment of osteochondral lesions of the talus.

PURPOSE: The purpose of this study was to systematically review studies on autologous osteochondral transplantation (AOT) for osteochondral lesions (OCLs) of the talus and descriptively analyze the outcome data reported to determine whether it is consistent from one study to another and able to be pooled for systematic review. METHODS: A systematic electronic search was performed using the MEDLINE and EMBASE databases. Studies that were published between January 1966 and June 2011 were included in the review. Only studies that reported data specifically on AOT for treatment of OCLs of the talus and written in English were included in this review. A predefined data sheet with 36 variables was created, and it was determined whether or not each of those variables were reported or not reported. The 36 variables were then grouped into 6 categories, and the categorical means were reported. RESULTS: A total of 20 studies were included in this systematic review. The categories of general demographics and study design were generally well reported (each more than 80% of studies). Patient-reported outcomes and clinical variables were reported less in 73% and 67% of studies, respectively. The least-reported categories were patient history (45%) and imaging data (49%). CONCLUSIONS: Inconsistencies and an underreporting of data were apparent between studies, such that pooling was deemed not possible. An effort must be made by investigators to ensure that there is adequate reporting of data in studies of AOT treatment for OCLs of the talus.

Platelet-rich plasma in tendon models: a systematic review of basic science literature.

PURPOSE: To perform a systematic review of the basic science literature on the use of platelet-rich plasma (PRP) in tendon models. METHODS: We searched the PubMed/Medline and Embase databases in June 2012 using the following parameters: ((tenocytes OR tendon OR tendinitis OR tendinosis OR tendinopathy) AND (platelet rich plasma OR PRP OR autologous conditioned plasma OR ACP)). The inclusion criteria for full-text review were in vivo and in vitro studies examining the effects of PRP on tendons and/or tenocytes. Clinical studies were excluded. Only studies published in peer-reviewed journals that compared PRP directly with a control were included. Data were extracted based on a predefined data sheet, which included information on PRP preparation, study methods, and results. Studies were analyzed for trends, comparing and contrasting the reported effects of PRP. RESULTS: The search yielded 31 articles for inclusion in our review. Of the studies, 22 (71%) reported platelet concentrations in the PRP; 6 (19%) reported cytology. Eight in vivo studies found decreased tendon repair time, increased fiber organization, or both with PRP treatment. Eight in vitro studies reported that PRP treatment increased cell proliferation; 7 reported an increase in growth factor expression. Three in vivo studies found increased vascularity, and 4 found increased tensile strength with PRP treatment. CONCLUSIONS: In the basic science studies evaluated, it appears that PRP confers several potential effects on tendon models compared with a control. However, the literature is inconsistent with regard to reporting the methods of preparation of PRP and in reporting platelet concentrations and cytology. CLINICAL RELEVANCE: Establishing proof of concept for PRP may lead to further high-quality clinical studies in which the appropriate indications can be defined.