E.P. Xanthopoulos

Stage migration in planning PET/CT scans in patients due to receive radiotherapy for non-small-cell lung cancer.

INTRODUCTION This study examined rates of tumor progression in treatment-naive patients with non-small-cell lung cancer (NSCLC) as determined by repeat treatment-planning fluorine-18 ((18)F) fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT). METHODS AND MATERIALS This study assessed patients who underwent PET/CT simulation for NSCLC stage II/III, radiation-naive, nonmetastatic NSCLC. It compared planning PET/CT with previous PET/CT images. Patients were analyzed for change in stage, treatment intent, or both. Progression was defined as a change in TNM status leading to upstaging, and standardized uptake value (SUV) velocity was defined as [(SUVscan2 - SUVscan1)/interscan interval in days]. RESULTS Of 149 consecutive patients examined between April 2009 and April 2011, 47 had prior PET/CT scans and were included. The median age was 68 years. New nodal disease or metastatic disease was identified in 24 (51%) of 47 patients. Fourteen (30%) had evidence of extrathoracic metastatic disease; the remaining 10 (21%) had new nodal disease that required substantial alteration of treatment fields. At a scan interval of 20 days, the rate of upstaging was 17%. SUV velocity was analyzed in the subset of patients who had their studies on the identical PET/CT scanner (n = 14). Nonupstaged patients had a mean SUV velocity of 0.074 units per day, compared with 0.11 units per day in patients that were upstaged by their second PET/CT scan (P = .020). CONCLUSION Radiation treatment planning with hybrid PET/CT scans repeated within 120 days of an initial staging PET/CT scan identified significant upstaging in more than half of patients. For a subset of patients who underwent both scans on the same instrument, SUV velocity predicts upstaging, and the difference between those upstaged and those not was statistically significant.

Impact of PET staging in limited-stage small-cell lung cancer

Introduction: Although positron emission tomography computed tomography (PET-CT) has been widely used for small-cell lung cancer (SCLC) staging, no study has examined the clinical impact of PET staging in limited-stage (LS) SCLC. Methods: We identified patients with LS-SCLC treated definitively with concurrent chemoradiation. Outcomes were assessed using the Kaplan–Meier approach, Cox regression, and competing risks method. Results: We treated 54 consecutive LS-SCLC patients with concurrent chemoradiation from January 2002 to August 2010. Forty underwent PET, 14 did not, and all underwent thoracoabdominopelvic CT and magnetic resonance imaging neuroimaging. Most patient characteristics were balanced between the comparison groups, including age, race, sex, bone scanning, median dosage, and performance status. More number of PET-staged patients presented with nodal metastases (p = 0.05). Median follow-up was similar for PET-staged and non–PET-staged patients (p = 0.59). Median overall survival from diagnosis in PET-staged patients was 32 versus 17 months in patients staged without PET (p = 0.03), and 3-year survival was 47% versus 19%. Median time-to-distant failure was 29 versus 12 months (p = 0.04); median time-to-local failure was not reached versus 16 months (p = 0.04). On multivariable analysis, PET staging (odds ratio [OR] = 0.24; p = 0.04), performance status (OR = 1.89; p = 0.05), and N-stage (OR = 4.94; p < 0.01) were associated with survival. Conclusion: LS-SCLC patients staged with PET exhibited improved disease control and survival when compared with non–PET-staged LS-SCLC patients. Improved staging accuracy and better identification of intrathoracic disease may explain these findings, underscoring the value of PET-CT in these patients.

Brachial plexopathy in apical non-small cell lung cancer treated with definitive radiation: Dosimetric analysis and clinical implications

PURPOSE Data are limited on the clinical significance of brachial plexopathy in patients with apical non-small cell lung cancers (NSCLC) treated with definitive radiation therapy. We report the rates of radiation-induced brachial plexopathy (RIBP) and tumor-related brachial plexopathy (TRBP) and associated dosimetric parameters in apical NSCLC patients. METHODS AND MATERIALS Charts of NSCLC patients with primary upper lobe or superiorly located nodal disease who received ≥50 Gy of definitive conventionally fractionated radiation or chemoradiation were retrospectively reviewed for evidence of brachial plexopathy and categorized as RIBP, TRBP, or trauma-related. Dosimetric data were gathered on ipsilateral brachial plexuses (IBP) contoured according to Radiation Therapy Oncology Group atlas guidelines. RESULTS Eighty patients were identified with a median follow-up and survival time of 17.2 and 17.7 months, respectively. The median prescribed dose was 66.6 Gy (range, 50.4-84.0), and 71% of patients received concurrent chemotherapy. RIBP occurred in 5 patients with an estimated 3-year rate of 12% when accounting for competing risk of death. Seven patients developed TRBP (estimated 3-year rate of 13%), comprising 24% of patients who developed locoregional failures. Grade 3 brachial plexopathy was more common in patients who experienced TRBP than RIBP (57% vs 20%). No patient who received ≤78 Gy to the IBP developed RIBP. On multivariable competing risk analysis, IBP V76 receiving ≥1 cc, and primary tumor failure had the highest hazard ratios for developing RIBP and TRBP, respectively. CONCLUSIONS RIBP is a relatively uncommon complication in patients with apical NSCLC tumors receiving definitive doses of radiation, while patients who develop primary tumor failures are at high risk for developing morbid TRBP. These findings suggest that the importance of primary tumor control with adequate doses of radiation outweigh the risk of RIBP in this population of patients.

Prognostic value of primary tumor FDG uptake for occult mediastinal lymph node involvement in clinically N2/N3 node-negative non-small cell lung cancer

Objectives:The objective of this study was to identify predictive factors of occult mediastinal nodal involvement on staging positron emission tomography with 18F-fluorodeoxyglucose in patients with non–small cell lung cancer. Methods:We performed a retrospective review of 665 patients with suspected non–small cell lung cancer who underwent staging positron emission tomography with 18F-fluorodeoxyglucose from January 1, 2000 through August 31, 2010 at the Hospital of the University of Pennsylvania with clinical stage I or II disease and no evidence of N2 or N3 involvement on staging positron emission tomography (PET). A total of 201 of these patients underwent invasive pathologic staging of the mediastinum at the Hospital of the University of Pennsylvania with pathology reports available at the time of review. Results:A total of 63 of the 201 patients were found to have N2 disease at the time of pathologic staging. The mean standardized uptake value (SUV) of the primary tumor for patients with occult N2 metastases was significantly higher than the node-negative patients (SUV 9.31 vs. 7.24, P=0.04). Histology, tumor location (central vs. peripheral), sex, and age were not predictive for occult N2 disease. A multivariate analysis was performed and identified primary tumor SUV>6 was the only significant predictor (P=0.02). An analysis by quartile identified a primary tumor SUV>10 to have an odds ratio of 1.72 compared with an SUV<4 of occult N2 involvement. Conclusions:Increased primary tumor SUV predicted for increased risk of mediastinal nodal disease. Tumor location was not predictive of PET-occult mediastinal nodal involvement, in contrast to previous publications. Pathologic staging of the mediastinum should be strongly considered in these patients even with a negative mediastinum on PET.

Definitive dose thoracic radiation therapy in oligometastatic non-small cell lung cancer: A hypothesis-generating study

PURPOSE A subset of patients with minimal extrathoracic disease may benefit from aggressive primary tumor treatment. We report comparative outcomes in oligometastatic non-small cell lung cancer (NSCLC) treated with and without definitive, conventionally fractionated thoracic radiation therapy. METHODS AND MATERIALS We identified consecutive patients with stage IV NSCLC who had an Eastern Cooperative Oncology Group performance status ≤2 and ≤4 total sites of metastatic disease and who had been prescribed ≥50 Gy of thoracic radiation. RESULTS Twenty-nine patients with oligometastatic NSCLC were identified between January 2004 and August 2010. Median survival was 22 months from diagnosis. Four patients (14%) experienced pneumonitis greater than or equal to grade 3; 6 (21%) had esophagitis greater than or equal to grade 3. Local control was associated with improved survival (P = .02). In matched subset analysis, median survival was 9 months (P < .01) in patients who received chemotherapy alone. Median time to local failure was 18 versus 6 months (P = .01). On multivariable analysis, radiation (P < .01; odds ratio [OR], 0.33), fewer metastases (P < .01; OR, 2.14), and female sex (P < .01; OR, 0.41) were associated with improved survival. CONCLUSIONS Definitive dose radiation therapy may improve survival in a select subset of patients with minimal extrathoracic disease in whom local progression is of primary concern. Prospective trials are needed to further evaluate the role of local control in oligometastatic NSCLC.

Analysis of the Relationship Between Response to Chemotherapy and Response to Radiation Therapy in Patients With Non–Small Cell Lung Cancer Receiving Sequential Treatment

Objectives: We examine whether induction chemotherapy response predicts thoracic radiotherapy response in locally advanced or oligometastatic non–small cell lung cancer. Materials and Methods: Between January 2001 to August 2010, 25 consecutive patients were identified who received systemic dose chemotherapy followed by definitive thoracic radiotherapy alone. All patients had measurable disease after chemotherapy that was evaluable for response to radiotherapy. Response to each modality was scored by RECIST as stable disease (SD), progressive disease (PD), partial response (PR), or complete response (CR). Results: Patients had adenocarcinoma (n=13), squamous cell carcinoma (n=8), or other histologies (n=4). They had stage IIIA (n=6), IIIB (n=14), and IV (n=5) disease. Patients received 2 to 6 cycles (median 4) of platinum-based chemotherapy followed by radiotherapy (median 66.6/1.8 Gy [range 50 to 84 Gy]). Median time between chemotherapy end and radiotherapy start was 6.7 weeks (range, 1.6 to 53.4 wk). Twelve patients responded to chemotherapy (all were PRs) and 13 did not (SD+PD). Fifteen patients responded to radiotherapy (7 CR, 8 PR) and 10 did not (SD+PD). Of the 12 patients who responded to chemotherapy, 8 also responded to radiotherapy (4 CR, 4 PR). Of the 13 chemotherapy nonresponders, 7 responded to radiotherapy (3 CR, 4 PR). &khgr;2 analysis did not find any association between chemotherapy and radiotherapy response (P=0.513). Regression analysis also failed to identify any correlation between chemotherapy and radiotherapy response (r2=0.008). Conclusions: This study suggests that response to chemotherapy does not predict response to radiotherapy in locally advanced or oligometastatic non–small cell lung cancer. Lack of response to chemotherapy, therefore, should not preclude treatment with definitive radiotherapy.

Five-year Long-term Outcomes of Stereotactic Body Radiation Therapy for Operable Versus Medically Inoperable Stage I Non–small-cell Lung Cancer: Analysis by Operability, Fractionation Regimen, Tumor Size, and Tumor Location

Background: Stereotactic body radiation therapy (SBRT) is standard for medically inoperable stage I non–small‐cell lung cancer (NSCLC) and is emerging as a surgical alternative in operable patients. However, limited long‐term outcomes data exist, particularly according to operability. We hypothesized long‐term local control (LC) and cancer‐specific survival (CSS) would not differ by fractionation schedule, tumor size or location, or operability status, but overall survival (OS) would be higher for operable patients. Patients and Methods: All consecutive patients with stage I (cT1‐2aN0M0) NSCLC treated with SBRT from June 2009 to July 2013 were assessed. Thoracic surgeon evaluation determined operability. Local failure was defined as growth following initial tumor shrinkage or progression on consecutive scans. LC, CSS, and OS were calculated using Cox proportional hazards regression. Results: A total of 186 patients (204 lesions) were analyzed. Most patients were inoperable (82%) with Eastern Cooperative Oncology Group performance status of 1 (59%) or 2 (26%). All lesions received biological effective doses ≥ 100 Gy most commonly (94%) in 3 to 5 fractions. The median follow‐up was 4.0 years. LC at 2 and 5 years were 95.6% (95% confidence interval, 92%‐99%) and 93.7% (95% confidence interval, 90%‐98%), respectively. Compared with operable patients, inoperable patients did not have significant differences in 5‐year LC (93.1% vs. 96.7%; P = .49), nodal failure (31.4% vs. 11.0%; P = .12), distant failure (12.2% vs. 10.4%; P = .98), or CSS (80.6% vs. 91.0%; P = .45) but trended towards worse OS (34.2% vs. 45.3%; P = .068). Tumor size, location, and fractionation did not significantly influence outcomes. Conclusions: SBRT has excellent, durable LC and CSS rates for early‐stage NSCLC, although inoperable patients had somewhat lower OS than operable patients, likely owing to greater comorbidities.

Rectal balloon use limits vaginal displacement, rectal dose, and rectal toxicity in patients receiving IMRT for postoperative gynecological malignancies

Pelvic radiotherapy for gynecologic malignancies traditionally used a 4-field box technique. Later trials have shown the feasibility of using intensity-modulated radiotherapy (IMRT) instead. But vaginal movement between fractions is concerning when using IMRT due to greater conformality of the isodose curves to the target and the resulting possibility of missing the target while the vagina is displaced. In this study, we showed that the use of a rectal balloon during treatment can decrease vaginal displacement, limit rectal dose, and limit acute and late toxicities. Little is known regarding the use of a rectal balloon (RB) in treating patients with IMRT in the posthysterectomy setting. We hypothesize that the use of an RB during treatment can limit rectal dose and acute and long-term toxicities, as well as decrease vaginal cuff displacement between fractions. We performed a retrospective review of patients with gynecological malignancies who received postoperative IMRT with the use of an RB from January 1, 2012 to January 1, 2015. Rectal dose constraint was examined as per Radiation Therapy Oncology Group (RTOG) 1203 and 0418. Daily cone beam computed tomography (CT) was performed, and the average (avg) displacement, avg magnitude, and avg magnitude of vector were calculated. Toxicity was reported according to RTOG acute radiation morbidity scoring criteria. Acute toxicity was defined as less than 90 days from the end of radiation treatment. Late toxicity was defined as at least 90 days after completing radiation. Twenty-eight patients with postoperative IMRT with the use of an RB were examined and 23 treatment plans were reviewed. The avg rectal V40 was 39.3% ± 9.0%. V30 was65.1% ± 10.0%. V50 was 0%. Separate cone beam computed tomography (CBCT) images (n = 663) were reviewed. The avg displacement was as follows: superior 0.4 + 2.99 mm, left 0.23 ± 4.97 mm, and anterior 0.16 ± 5.18 mm. The avg magnitude of displacement was superior/inferior 2.22 ± 2.04 mm, laterally 3.41 ± 3.62 mm, and anterior/posterior 3.86 ± 3.45 mm. The avg vector magnitude was 6.60 ± 4.14 mm. For acute gastrointestinal (GI) toxicities, 50% experienced grade 1 toxicities and 18% grade 2 GI toxicities. For acute genitourinary (GU) toxicities, 21% had grade 1 and 18% had grade 2 toxicities. For late GU toxicities, 7% had grade 1 and 4% had grade 2 toxicities. RB for gynecological patients receiving IMRT in the postoperative setting can limit V40 rectal dose and vaginal displacement. Although V30 constraints were not met, patients had limited acute and late toxicities. Further studies are needed to validate these findings.

The Role of Advanced Imaging in Assessing Response to Definitive Chemoradiation Before Prophylactic Cranial Irradiation in Limited-Stage Small-Cell Lung Cancer

Micro‐Abstract We examined the responses to chemoradiation according to imaging modality in limited‐stage small‐cell lung cancer (SCLC). Provided patients achieved at least a partial response, advanced imaging response neither affected survival nor added information to the decision to offer prophylactic cranial irradiation (PCI), suggesting that limited‐stage SCLC patients with partial response using any imaging modality should not be denied PCI. Introduction: Prophylactic cranial irradiation (PCI) improves survival for small‐cell lung cancer (SCLC). Evidence for PCI in limited‐stage SCLC largely derives from studies requiring only chest x‐ray (CXR) to determine remission status. We analyzed thoracic chemoradiation therapy (TCRT) outcomes according to imaging modality to determine which patients benefitted most from PCI. Patients and Methods: All limited‐stage SCLC patients who received TCRT as well as PCI at our institution were reviewed. Imaging between TCRT end and PCI start was characterized as complete (CR), partial (PR), or other response. Results: Thirty‐eight consecutive patients were assessed for TCRT response before PCI with CXR (n = 21), chest computed tomography (CT; n = 27), and/or positron emission tomography (PET)/CT (n = 11). CR was identified on 71% of CXRs, 41% of CT scans, and 18% of PET/CT scans. Median survival was 28.3 months for the entire cohort and did not differ for patients who had CXR alone versus CT and/or PET/CT for restaging (P = .78) or those with PR using any modality versus CR using all modalities (22.6 months vs. 45.5 months; P = .22). CT CR patients had numerical but not statistically significant improved 2‐year (P = .18) and 3‐year (P = .13) survival compared with CT PR. Conclusion: CXR remains an appropriate modality to assess TCRT response before PCI in limited‐stage SCLC. Advanced imaging did not inform the decision to offer PCI in this study. Because of similar excellent survival profiles independent of imaging modality and TCRT response, this analysis suggests limited‐stage SCLC patients with PR using any modality should not be denied PCI, akin to standards for extensive‐stage SCLC.

Predicting axillary lymph node metastasis from kinetic statistics of DCE-MRI breast images.

The presence of axillary lymph node metastases is the most important prognostic factor in breast cancer and can influence the selection of adjuvant therapy, both chemotherapy and radiotherapy. In this work we present a set of kinetic statistics derived from DCE-MRI for predicting axillary node status. Breast DCE-MRI images from 69 women with known nodal status were analyzed retrospectively under HIPAA and IRB approval. Axillary lymph nodes were positive in 12 patients while 57 patients had no axillary lymph node involvement. Kinetic curves for each pixel were computed and a pixel-wise map of time-to-peak (TTP) was obtained. Pixels were first partitioned according to the similarity of their kinetic behavior, based on TTP values. For every kinetic curve, the following pixel-wise features were computed: peak enhancement (PE), wash-in-slope (WIS), wash-out-slope (WOS). Partition-wise statistics for every feature map were calculated, resulting in a total of 21 kinetic statistic features. ANOVA analysis was done to select features that differ significantly between node positive and node negative women. Using the computed kinetic statistic features a leave-one-out SVM classifier was learned that performs with AUC=0.77 under the ROC curve, outperforming the conventional kinetic measures, including maximum peak enhancement (MPE) and signal enhancement ratio (SER), (AUCs of 0.61 and 0.57 respectively). These findings suggest that our DCE-MRI kinetic statistic features can be used to improve the prediction of axillary node status in breast cancer patients. Such features could ultimately be used as imaging biomarkers to guide personalized treatment choices for women diagnosed with breast cancer.