Julie Lucey

18 FDG uptake during induction chemoradiation for oesophageal cancer fails to predict histomorphological tumour response

To determine whether [18F]-fluorodeoxyglucose-positron emission tomography (FDG-PET) could predict the pathological response in oesophageal cancer after only the first week of neoadjuvant chemoradiation. Thirty-two patients with localised oesophageal cancer had a pretreatment PET scan and a repeat after the first week of chemoradiation. The change in mean maximum standardised uptake value (SUV) and volume of metabolically active tissue (MTV) was compared with the tumour regression grade (TRG) in the final histology. Those who achieved a TRG of 1 and 2 were deemed responders and 3–5 nonresponders. In the responders (28%), the SUV fell from 12.6 (±6.3) to 8.1 (±2.9) after 1 week of chemoradiation (P=0.070). In nonresponders (72%), the results were 9.7 (±5.4) and 7.1 (±3.8), respectively (P=0.003). The MTV in responders fell from 36.6 (±22.7) to 22.3 (±10.4)  cm3 (P=0.180), while in nonresponders, this fell from 35.9 (±36.7) to 31.9 (±52.7) cm3 (P=0.405). There were no significant differences between responders and nonresponders. The hypothesis that early repeat FDG-PET scanning may predict histomorphologic response was not proven. This may reflect an inflammatory effect of radiation that obscures tumour-specific metabolic changes at this time. This assessment may have limited application in predicting response to multimodal regimens for oesophageal cancer.

Clinical implication and prognostic significance of standardised uptake value of primary non-small cell lung cancer on positron emission tomography: analysis of 176 cases

OBJECTIVE We sought to assess the clinical implication and prognostic significance of maximum standardised uptake value (SUV(max)) of primary non-small cell lung cancer (NSCLC) staged by integrated PET-CT. METHODS A retrospective review was carried out on 176 consecutive patients with histologically proven NSCLC who underwent staging with integrated PET-CT prior to curative intent surgical resection. SUV(max) of primary NSCLC were measured and correlated with tumour characteristics, lymph node involvement, surgical stage, type of surgical resection and survival following resection. RESULTS SUV(max) was significantly higher in centrally located tumours, tumours > or =4.0 cm, squamous cell subtype, poorly differentiated tumours, advanced T stage, advanced nodal stage, pleural invasion, and patients requiring complex surgical resection. SUV(max) value of 15 was the best discriminative cut-off value for survival generated by log-rank test. When patients were stratified based on this value, those with SUV(max) >15 were more likely to have centrally located tumours, squamous cell subtype, advanced T stage, advanced nodal stage, advanced American Joint Committee on Cancer (AJCC) stage, larger tumour size and required more advanced surgical resections than a simple lobectomy. Overall survival was significantly longer for patients with SUV(max) < or =15 than those with SUV(max) >15. Furthermore, nodal stage specific survival following resection (i.e. non-N2 and N2) were significantly better in patients with SUV(max) < or =15 than SUV(max) >15. CONCLUSION SUV(max) correlates with tumour characteristics, surgical stage and prognosis following resection. SUV(max) may be a useful preoperative tool, in addition to other known prognostic markers, in allocating patients with potentially poor prognosis preoperatively to neoadjuvant chemotherapy prior to resection in order to improve their overall survival. Prospective and randomised trials are warranted.

Early Repeated 18F-FDG PET Scans During Neoadjuvant Chemoradiation Fail to Predict Histopathologic Response or Survival Benefit in Adenocarcinoma of the Esophagus

This study evaluated the role of 18F-FDG PET as an early predictor of histopathologic response to neoadjuvant chemoradiotherapy and overall survival in patients with adenocarcinoma of the esophagus undergoing multimodal therapy. Methods: Thirty-seven patients with locally advanced adenocarcinoma of the esophagus underwent pretreatment and an intratreatment 18F-FDG PET scan in the second week of a 6-wk regimen of neoadjuvant chemoradiotherapy. Histopathologic response and overall survival were correlated with percentage change in 18F-FDG uptake (%Δmaximum standardized uptake value [%ΔSUVmax]). Results: In 16 patients (43%), treatment induced a histopathologic response (<10% viable tumor cells), which was associated with a significant (P < 0.05) survival benefit. The optimal reduction in 18F-FDG uptake, which separated histopathologic responders and nonresponders, was a −26.4% ΔSUVmax (receiver-operating-characteristic curve analysis). At this separation, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy (area under the receiver operating characteristic curve) were 62.5%, 71.4%, 62.5%, 71.4%, and 67.4%, respectively, for intratreatment 18F-FDG PET scans. Kaplan–Meier survival analysis of 18F-FDG PET responders (>26.4% reduction in SUVmax), compared with 18F-FDG PET nonresponders (<26.4% reduction in SUVmax), revealed no survival benefit for responders (P = 0.6812). Conclusion: The %ΔSUVmax during the second week of induction chemoradiation did not correlate either with histopathologic response or with survival. Our results show that, in contrast to published reports on neoadjuvant chemotherapy, combined chemoradiotherapy in patients with adenocarcinoma of the esophagus lowers the predictive accuracy of early repeated 18F-FDG PET in identifying histopathologic responders and those with chances for increased survival below clinically applicable levels.

Mediastinal Lymph Node Staging by Means of Positron Emission Tomography Is Less Sensitive in Elderly Patients with Non-Small-Cell Lung Cancer

PURPOSE We sought to identify the impact of age on the sensitivity and specificity of integrated positron emission tomography/computed tomography (PET-CT; CT) on mediastinal lymph node staging of patients with non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS We conducted a retrospective review of 206 consecutive patients with histologically proven NSCLC who underwent resection and/or mediastinoscopy in our center between September 2004 and January 2007. All of these patients had preoperative staging with integrated PET-CT as an adjunct to chest CT before resection and/or mediastinoscopy. Diabetic patients and patients who received neoadjuvant chemotherapy were excluded. The pathologic results of all of these cases were reviewed and correlated with those on CT and integrated PET-CT. RESULTS The sensitivity and positive predictive values (PPV) of PET-CT in mediastinal nodal staging were significantly lower in elderly patients (age>or=65 years; sensitivity, 42%; PPV, 66%) than in younger patients (age<65 years; sensitivity, 52%; PPV, 74%). Specificity and negative predictive values were similar in both groups. CONCLUSION PET-CT staging of the mediastinum is less sensitive in elderly patients with NSCLC who have a lower PPV. Positive mediastinal uptake on PET-CT should be verified by mediastinoscopy, irrespective of age. Elderly patients with positive mediastinal uptake should not be refuted a curative intent surgical resection on the basis of positive mediastinal uptake alone.

(18)F-FDG PET-detected synchronous primary neoplasms in the staging of esophageal cancer: incidence, cost, and impact on management.

Purpose 18F-Fluorodeoxyglucose positron emission tomography (18F-FDG PET) imaging is increasingly the standard of care in the staging of esophageal cancer. Synchronous neoplasms may be identified, and this study evaluated the prevalence of such tumors and their impact on management. Methods Five hundred ninety-one (73.6%) of 803 consecutive patients with biopsy-proven esophageal cancer underwent staging 18F-FDG PET or PET/CT scans. 18F–FDG-avid lesions were considered synchronous primary neoplasms if occurring at locations atypical for metastases from the known primary, a marked discordance in the 18F-FDG avidity from that of the primary tumor, and if there was no prior detection on conventional imaging. Additional investigations as appropriate were undertaken, and histopathological verification was obtained where possible to validate the suspected synchronous neoplasm. Results A synchronous neoplasm was suspected in 55 (9.3%) of 591 patients, predominantly at sites in the colon (26) and head and neck (21). Additional investigations in 43 cases revealed malignant neoplasms in 8 (18.6%), premalignant in 9 (20.9%), and benign lesions in 26 (60.5%) cases. The management plan was altered in 8 patients, 1.4% overall. The total cost of added tests was

Pattern and predictors of occult mediastinal lymph node involvement in non-small cell lung cancer patients with negative mediastinal uptake on positron emission tomography

27,482.57 (&OV0556;21,024) with the decision to treat the esophageal cancer deferred by a mean of 10.7 days. Conclusion 18F-FDG uptake concerning for synchronous neoplasms is evident in approximately 1 in 10 cases, and of these a minority will represent a malignant neoplasm that significantly impacts on treatment. The overall added costs per patient are relatively modest and the treatment delay within acceptable limits of clinical practice.