Nancy E. Fitzgerald

18F-FDG PET/CT as an Indicator of Progression-Free and Overall Survival in Osteosarcoma

The aim of our study was to retrospectively evaluate whether maximum standardized uptake value (SUVmax), total lesion gylcolysis (TLG), or change therein using 18F-FDG PET/CT performed before and after initial chemotherapy were indicators of patient outcome. Methods: Thirty-one consecutive patients who underwent 18F-FDG PET/CT before and after chemotherapy, followed by tumor resection, were retrospectively reviewed. Univariate Cox regression was used to analyze for relationships between covariates of interest (SUVmax before and after chemotherapy, change in SUVmax, TLG before and after chemotherapy, change in TLG, and tumor necrosis) and progression-free and overall survival. Logistic regression was used to evaluate tumor necrosis. Results: High SUVmax before and after chemotherapy (P = 0.008 and P = 0.009, respectively) was associated with worse progression-free survival. The cut point for SUVmax before chemotherapy was greater than 15 g/mL* (P = 0.015), and after chemotherapy it was greater than 5 g/mL* (P = 0.006), as measured at our institution and using lean body mass. Increase in TLG after chemotherapy was associated with worse progression-free survival (P = 0.016). High SUVmax after chemotherapy was associated with poor overall survival (P = 0.035). The cut point was above the median of 3.3 g/mL* (P = 0.043). High TLG before chemotherapy was associated with poor overall survival (P = 0.021). Good overall and progression-free survival was associated with a tumor necrosis greater than 90% (P = 0.018 and 0.08, respectively). A tumor necrosis greater than 90% was most strongly associated with a decrease in SUVmax (P = 0.015). Conclusion: 18F-FDG PET/CT can be used as a prognostic indicator for progression-free survival, overall survival, and tumor necrosis in osteosarcoma.

Quality Initiatives: CT Radiation Dose Reduction: How to Implement Change without Sacrificing Diagnostic Quality

The risks and benefits of using computed tomography (CT) as opposed to another imaging modality to accomplish a particular clinical goal should be weighed carefully. To accurately assess radiation risks and keep radiation doses as low as reasonably achievable, radiologists must be knowledgeable about the doses delivered during various types of CT studies performed at their institutions. The authors of this article propose a process improvement approach that includes the estimation of effective radiation dose levels, formulation of dose reduction goals, modification of acquisition protocols, assessment of effects on image quality, and implementation of changes necessary to ensure quality. A first step toward developing informed radiation dose reduction goals is to become familiar with the radiation dose values and radiation-associated health risks reported in the literature. Next, to determine the baseline dose values for a CT study at a particular institution, dose data can be collected from the CT scanners, interpreted, tabulated, and graphed. CT protocols can be modified to reduce overall effective dose by using techniques such as automated exposure control and iterative reconstruction, as well as by decreasing the number of scanning phases, increasing the section thickness, and adjusting the peak voltage (kVp setting), tube current-time product (milliampere-seconds), and pitch. Last, PDSA (plan, do, study, act) cycles can be established to detect and minimize negative effects of dose reduction methods on image quality.

Novel treatment for desmoplastic small round cell tumor: hyperthermic intraperitoneal perfusion

BACKGROUND Less than 200 cases have been reported in the world literature since desmoplastic small round cell tumor (DSRCT) was first described in 1989. To date, chemotherapy, radiation therapy, and surgery have resulted in a poor survival of 30% to 55%. We used hyperthermic intraperitoneal chemotherapy (HIPEC) at the time of complete tumor resection as an adjunct to treatment of pediatric and adolescent patients with DSRCT. PURPOSE The aim of this study was to assess survival as a function of disease burden and response to HIPEC in patients with DSRCT. METHODS Twenty-four patients with DSRCT from 1995 to 2008 were evaluated. Eight patients undergoing cytoreductive surgery and HIPEC were compared with 16 historical controls that had chemotherapy +/- radiation therapy or surgery alone. RESULTS Median age was 12 years in 8 patients who underwent HIPEC. Significant morbidity after HIPEC included renal insufficiency and gastroparesis. There were no operative mortalities. The estimated median overall 3-year survival for patients not undergoing surgery or HIPEC was 26% compared with 71% in patients who underwent HIPEC. Extraabdominal metastasis correlated with poor survival (P = .021). CONCLUSION Hyperthermic intraperitoneal chemotherapy is safe in children with DSRCT. It may prolong disease-free survival in selected cases of DSRCT. It may have a limited role as an adjunct to local control in patients with DSRCT.

Tumor necrosis in osteosarcoma: inclusion of the point of greatest metabolic activity from F-18 FDG PET/CT in the histopathologic analysis

ObjectiveTo determine if the location of the point of maximum standardized uptake value (SUVmax) being included in or not included in the histopathologic slab section corresponded to tumor necrosis or survival.Materials and methodsTwenty-nine osteosarcoma patients underwent post-chemotherapy [fluorine-18]-fluoro-2-deoxy-D-glucose (FDG) positron-emission tomography–computed tomography (PET/CT) prior to resection. PET/CT images were correlated with slab-section location as determined by photographs or knowledge of specimen processing. The location of the point of SUVmax was then assigned as being ‘in’ or ‘out’ of the slab section. Cox’s proportional hazard regression was used to evaluate relationships between the location and value of SUVmax and survival. Logistic regression was employed to evaluate tumor necrosis.ResultsNo correlation was found between the SUVmax location and survival or tumor necrosis. High SUVmax correlated to poor survival.ConclusionHigh SUVmax value correlated to poor survival. Minimal viable tumor (> 10%) following chemotherapy is a known indicator of poor survival. No correlation was found between the location of SUVmax and survival or tumor necrosis. Therefore, the SUVmax value either does not correspond to a sufficient number of tumor cells to influence tumor necrosis measurement or it was included in the out-of-slab samples that were directed to viable-appearing areas of the gross specimen. Since high SUVmax has been previously found to correspond to poor tumor necrosis, and tumor necrosis is simply an estimate of the amount of viable tumor, SUVmax likely represents many viable tumor cells. Therefore, when not in the slab section, SUVmax was likely included in the tumor necrosis measurement through directed sampling, validating our current method of osteosarcoma specimen analysis.

Pediatric sarcomas and related tumors of the head and neck.

Sarcomas of the head and neck region are a rare group of tumors in children and present challenges with regard to evaluation and treatment. Rhabdomyosarcomas are the most common sarcomas of the head and neck in children. Presence of metastases and complete surgical resectability continue to be the most relevant clinical prognostic factors in patients with sarcomas. However, many patients present with unresectable tumors; these require radiation therapy, which is associated with concerns about immediate and long-term side effects. New technologies, including proton beam therapy (PBT), appear very promising in terms of reducing acute and long-term toxic effects. A multi-disciplinary approach is required for best long-term outcomes in children with head and neck sarcomas.

Central Venous Line Placement in the Superior Vena Cava and the Azygos Vein: Differentiation on Posteroanterior Chest Radiographs

OBJECTIVE The purpose of this study was to determine, first, the accuracy with which radiologists reading posteroanterior chest radiographs differentiate whether a central venous line is in the superior vena cava or the azygos vein and, second, the circumstances in which radiologists may omit the lateral view to determine the position of a central venous line. MATERIALS AND METHODS Twenty-four radiologists evaluated 60 posteroanterior chest radiographs to determine the position of a central venous line in the superior vena cava or azygos vein. Investigators evaluated the appearance of the central venous lines to refine rules for determining central venous line position on a frontal radiograph and omitting the lateral view. RESULTS The accuracy of posteroanterior radiography for determining central venous line position was 90% at one study location and 85.5% at the other. No central venous line in the azygos vein extended more than 10.9 mm caudal to the cephalic edge of the right main bronchus. No central venous line in the superior vena cava had a down-the-barrel or curved appearance at the caudal edge. CONCLUSION For central venous lines extending at least 15 mm caudal to the cephalic edge of the right main bronchus and having no down-the-barrel or curved caudal appearance, categorization was nearly 100% accurate. Therefore, if desired to save radiation exposure and cost, it may be feasible to omit lateral views in radiography of patients with central venous lines extending at least 15 mm caudal to the cephalic edge of the right main bronchus in whom the caudal edge does not have a down-the-barrel or curved appearance.

Peritoneal sarcomatosis in pediatric malignancies

Peritoneal sarcomatosis (PSC) is defined as peritoneal involvement of multiple sarcomatous tumors. Desmoplastic small round cell tumors (DSRCT) and rhabdomyosarcomas are the most common pediatric PSC cases. PSC has been treated with chemotherapy and mainly palliative surgery, but long‐term outcome has been poor. New imaging technologies have improved the evaluation of disease extent and patterns of peritoneal dissemination, and cytoreductive surgery followed by hyperthermic intraperitoneal chemotherapy (HIPEC) is being evaluated as a treatment option to prolong remission in pediatric patients. We will review the clinical characteristics, potential biologic mechanisms, radiographic characteristics, and potential therapies for pediatric PSC patients. Pediatr Blood Cancer 2013; 60: 12–17.