Increased evidence for the prognostic value of FDG uptake on late-treatment PET in non-tumour-affected oesophagus in irradiated patients with oesophageal carcinoma

Purpose

¹⁸F-FDG uptake in irradiated non-tumour-affected oesophagus (NTO) on restaging PET is a potential surrogate for the measurement of radiation-induced inflammation. Radiation-induced inflammation itself has been shown to be of high prognostic relevance in patients undergoing preoperative radiochemotherapy (RCT) for locally advanced oesophageal cancer. We assessed the prognostic relevance of FDG uptake in the NTO in an independent cohort of patients treated with definitive RCT.

Methods

This retrospective evaluation included 72 patients with oesophageal squamous cell carcinoma treated with definitive RCT with curative intent. All patients underwent pretreatment and restaging FDG PET after receiving a radiation dose of 40–50 Gy. Standardized uptake values (SUV_max/SUV_mean), metabolic tumour volume (MTV) and relative changes from pretreatment to restaging PET (?SUV_max/?SUV_mean) were determined within the tumour and NTO. Univariate Cox regression with respect to overall survival (OS), local control (LC), distant metastases (DM) and treatment failure (TF) was performed. Independence of parameters was tested by multivariate Cox regression.

Results

?SUV_max NTO and MTV were prognostic factors for all investigated clinical endpoints (OS, LC, DM, TF). Inclusion of clinical and PET tumour parameters in multivariate analysis showed that ?SUV_max NTO was an independent prognostic factor. Furthermore, multivariate analysis of ?SUV_max NTO using previously published cut-off values from preoperatively treated patients revealed that ?SUV_max NTO was independent prognostic factor for OS (HR?=?1.88, p =?0.038), TF (HR?=?2.11, p =?0.048) and DM (HR?=?3.02, p =?0.047).

Conclusion

NTO-related tracer uptake during the course of treatment in patients with oesophageal carcinoma was shown to be of high prognostic relevance. Thus, metabolically activity of NTO measured in terms of ?SUV_max NTO is a potential candidate for future treatment individualization (i.e. organ preservation).

     

Asphericity of pretherapeutic tumour FDG uptake provides independent prognostic value in head-and-neck cancer

Objective

To propose a novel measure, namely the ‘asphericity’ (ASP), of spatial irregularity of FDG uptake in the primary tumour as a prognostic marker in head-and-neck cancer.

Methods

PET/CT was performed in 52 patients (first presentation, n?=?36; recurrence, n?=?16). The primary tumour was segmented based on thresholding at the volume-reproducible intensity threshold after subtraction of the local background. ASP was used to characterise the deviation of the tumour’s shape from sphere symmetry. Tumour stage, tumour localisation, lymph node metastases, distant metastases, SUV_max, SUV_mean, metabolic tumour volume (MTV) and total lesion glycolysis (TLG) were also considered. The association of overall (OAS) and progression-free survival (PFS) with these parameters was analysed.

Results

Cox regression revealed high SUV_max [hazard ratio (HR)?=?4.4/7.4], MTV (HR?=?4.6/5.7), TLG (HR?=?4.8/8.9) and ASP (HR?=?7.8/7.4) as significant predictors with respect to PFS/OAS in case of first tumour manifestation. The combination of high MTV and ASP showed very high HRs of 22.7 for PFS and 13.2 for OAS. In case of recurrence, MTV (HR?=?3.7) and the combination of MTV/ASP (HR?=?4.2) were significant predictors of PFS.

Conclusions

ASP of pretherapeutic FDG uptake in the primary tumour improves the prediction of tumour progression in head-and-neck cancer at first tumour presentation.

Key Points

?Asphericity (ASP) characterises the spatial heterogeneity of FDG uptake in tumours ? ASP is a promising prognostic parameter in head-and-neck cancer ? ASP is useful for identification of high-risk patients with head-and-neck cancer     

FDG PET as a procedure for detecting simultaneous tumours in head and neck cancer patients

AIM: The presence of simultaneous primary tumours in other regions affects the prognosis and management decisions of head and neck cancer patients. Therefore, early detection of these tumours is necessary. Recent improvements in positron emission tomography (PET) have made it possible to examine the patient's whole body. The present study was undertaken to evaluate the clinical contribution of whole-body PET using fluorodeoxyglucose (FDG) for head and neck cancer patients. METHODS: Fifty-three consecutive patients with previously untreated head and neck cancer were examined. Whole-body FDG PET imaging was performed at 1 h after injection of (18)F-FDG. A 3-D acquisition was undertaken and iterative reconstruction was performed. The final diagnosis of simultaneous primary tumour was established by histological findings or clinical follow-up. RESULTS: Of 53 patients, six (11%) had evidence of simultaneous primary tumour. In five of these six patients, simultaneous primary tumours (two gastric cancer; one colon cancer; one pancreatic cancer; one thyroid cancer) were found by FDG PET. One more patient was found to have prostate cancer on the basis of blood test but this was not detected by FDG PET. In none of the remaining 47 patients, were additional simultaneous primary tumours found by FDG PET or any of the other routine examinations or during follow-up. CONCLUSIONS: The results of this study show a high rate of simultaneous primary tumour in patients with primary head and neck cancer. FDG PET appears to be a promising imaging modality for the detection of simultaneous tumours in head and neck cancer patients.     

FDG PET/MR for lymph node staging in head and neck cancer

Objective

To assess the diagnostic value of PET/MR (positron emission tomography/magnetic resonance imaging) with FDG (18F-fluorodeoxyglucose) for lymph node staging in head and neck cancer.

Materials and methods

This prospective study was approved by the local ethics committee; all patients signed informed consent. Thirty-eight patients with squamous cell carcinoma of the head and neck region underwent a PET scan on a conventional scanner and a subsequent PET/MR on a whole-body hybrid system after a single intravenous injection of FDG. The accuracy of PET, MR and PET/MR for lymph node metastases were compared using receiver operating characteristic (ROC) analysis. Histology served as the reference standard.

Results

Metastatic disease was confirmed in 16 (42.1%) of 38 patients and 38 (9.7%) of 391 dissected lymph node levels. There were no significant differences between PET/MR, MR and PET and MR (p > 0.05) regarding accuracy for cervical metastatic disease. Based on lymph node levels, sensitivity and specificity for metastatic involvement were 65.8% and 97.2% for MR, 86.8% and 97.0% for PET and 89.5% and 95.2% for PET/MR.

Conclusions

In head and neck cancer, FDG PET/MR does not significantly improve accuracy for cervical lymph node metastases in comparison to MR or PET.     

18F-FDG PET在头颈部癌治疗后复发中的应用

目的 探讨＾１８Ｆ－脱氧葡萄糖（ＦＤＧ）ＰＥＴ显像用于头颈部癌治疗后复发的价值。方法 ３８例头颈部癌患者,放疗或手术３个月－３ａ,临床怀疑复发。均行＾１８Ｆ－ＦＤＧＰＥＴ显像,其中２８例行ＣＴ检查,ＰＥＴ图像分析采用目测法与半定量分析法,将肿瘤区＾１８Ｆ－ＦＤＧ摄取分为４级,０级;无摄取;Ｉ级,轻度摄取,Ⅱ级：中度摄取,Ⅲ级;重度摄取。最后诊断依靠病理检查及临床随访,结果 以肿瘤区＾１８Ｆ－ＦＤＧ     

FDG PET in patients with cancer of an unknown primary

BACKGROUND: This prospective study was undertaken to address the capacity of positron emission tomography (PET) with 2-[18F]fluoro-2-deoxy-D-glucose (18F-FDG) to determine the primary tumour site of carcinomas with unknown primary site. PATIENTS AND METHODS: Twenty-five patients with metastases from adenocarcinoma or undifferentiated carcinoma of unknown primary site (CUP) were included prospectively. For all patients, extensive imaging was unsuccessful in localizing the primary site. Patients received 370 MBq of 18F-FDG intravenously, and whole-body images were acquired 60 min after injection. All hot spots that could not be attributed to a metastatic site were considered as the primary tumour. The evaluation of FDG PET data was based on clinical and radiological outcome or surgery if indicated. RESULTS: Twenty-four patients were eligible for analysis. All known metastases were visualized. In six patients, FDG PET showed a primary tumour site which was confirmed by follow-up or surgery. In five patients, the primary tumour site was suggested by FDG PET but not confirmed by clinical outcome. No primary tumour was found in the other patients, with a mean follow-up of 15 months. CONCLUSION: In our series, FDG PET allowed the identification of primary tumour site in one quarter of patients with CUP (6/24). We conclude that FDG PET has a place in the initial staging of these patients.     

Early FDG PET at 10 or 20 Gy under chemoradiotherapy is prognostic for locoregional control and overall survival in patients with head and neck cancer

Purpose  

Our study aimed to explore the optimal timing as well as the most appropriate prognostic parameter of ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG PET) during chemoradiotherapy (CRT) for an early prediction of outcome for patients with head and neck squamous cell carcinoma (HNSCC).     

FDG PET／CT代谢体积对食管癌术后预后的预测价值

目的研究食管癌患者^18F-FDG PET／CTMTV与预后的关系。方法回顾性分析2004年3月至2008年3月行^18F—FDG PET／CT检查的49例Ⅰ—Ⅳa期的食管癌患者,均经病理检查证实,随访资料完整。患者均行食管癌切除术,随访截止至2009年11月,中位随访时间为29（8～57）个月。应用Kaplan—Meier法及Cox比例风险模型分析年龄、性别、肿瘤位置、肿瘤组织分化程度、PET／CT示肿瘤长径、美国肿瘤联合会（AJCC）分期、转移淋巴结个数、原发灶SUVmax及MTV与预后的关系。结果在单因素分析中,仅AJCC分期[χ^2=16．206,危险比（HR）=1．177,P〈0．001）,淋巴结分期（N）（χ^2=9．536,HR=10．833,P=0．002）,浸润深度（T）（χ^2=5．810,FIR=2．397,P=0．016）,淋巴结转移个数（χ^2=11．423,HR=1．567,P=0．001）、MTV（χ^2=3．872,HR=2．433,P=0．049）对预后存在预测作用。对以上变量行多因素分析,仅AJCC分期及MTV是独立的预后因子（r=4．525,HR=1．170,P=0．033;χ^2=4．875,HR=3．071,P=0．027）。Kaplan-Meier生存分析显示术前低MTV组比高MTV组的生存率高（Log—rank检验,χ^2=4．186,P=0．041）。结论MTV与食管癌术后患者的预后密切相关。对于高MTV患者,术后可能需要接受更加积极的治疗。     

Diagnostic performance of post-treatment FDG PET or FDG PET/CT imaging in head and neck cancer: a systematic review and meta-analysis

Purpose

Our objective was to conduct a systematic review and meta-analysis of studies assessing the diagnostic performance of ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG PET) with or without computed tomography (CT) in post-treatment response assessment and/or surveillance imaging of head and neck squamous cell carcinoma (HNSCC).

Methods

A systematic search of the indexed medical literature was done using appropriate keywords to identify relevant studies. Metrics of diagnostic test accuracy, viz. sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were extracted from individual studies and combined using a random effects model to yield weighted mean pooled estimates with 95% confidence intervals (95% CI). The impact of timing of post-treatment scan, study quality and advancements in PET technology was explored through meta-regression.

Results

A total of 51 studies involving 2,335 patients were included in the meta-analysis. The weighted mean (95% CI) pooled sensitivity, specificity, PPV and NPV of post-treatment FDG PET(CT) for the primary site was 79.9% (73.7?C85.2%), 87.5% (85.2?C89.5%), 58.6% (52.6?C64.5%) and 95.1% (93.5?C96.5%), respectively. Similar estimates for the neck were 72.7% (66.6?C78.2%), 87.6% (85.7?C89.3%), 52.1% (46.6?C57.6%) and 94.5% (93.1?C95.7%), respectively. Scans done ??12?weeks after completion of definitive therapy had moderately higher diagnostic accuracy on meta-regression analysis using time as a covariate.

Conclusion

The overall diagnostic performance of post-treatment FDG PET(CT) for response assessment and surveillance imaging of HNSCC is good, but its PPV is somewhat suboptimal. Its NPV remains exceptionally high and a negative post-treatment scan is highly suggestive of absence of viable disease that can guide therapeutic decision-making. Timing of post-treatment imaging has a significant, though moderate impact on diagnostic accuracy.     

F-18 FDG PET/CT following dental extraction in a patient with head and neck cancer

A 48-year-old man with squamous-cell carcinoma of the left tonsillar fossa and cervical lymph node metastases was being staged before radiation and chemotherapy. The patient had periodontal disease, and extraction of 2 teeth was performed before therapy. A staging PET/CT was performed 1 week after extraction. This case demonstrates increased FDG uptake at the extraction sites, which could be potentially mistaken for metastatic lesions, especially without the fused PET/CT images.     

Diagnostic and prognostic correlates of preoperative FDG PET for breast cancer

Purpose

To explore the preoperative utility of FDG PET for the diagnosis and prognosis in a retrospective breast cancer case series.

Methods

In this retrospective study, 104 patients who had undergone a preoperative FDG PET scan for primary breast cancer at the UZ Brussel during the period 2002–2008 were identified. Selection criteria were: histological confirmation, FDG PET performed prior to therapy, and breast surgery integrated into the primary therapy plan. Patterns of increased metabolism were recorded according to the involved locations: breast, ipsilateral axillary region, internal mammary chain, or distant organs. The end-point for the survival analysis using Cox proportional hazards was disease-free survival. The contribution of prognostic factors was evaluated using the Akaike information criterion and the Nagelkerke index.

Results

PET positivity was associated with age, gender, tumour location, tumour size >2 cm, lymphovascular invasion, oestrogen and progesterone receptor status. Among 63 patients with a negative axillary PET status, 56 (88.9?%) had three or fewer involved nodes, whereas among 41 patients with a positive axillary PET status, 25 (61.0?%) had more than three positive nodes (P?Conclusion Preoperative PET axillary node positivity identified patients with a higher burden of nodal involvement, which might be important for treatment decisions in breast cancer patients.     

Second primary malignancies in head and neck cancer patients

Background and purpose

Patients treated for squamous cell carcinoma of the head and neck (HNSCC) carry a high risk of second primary malignancies (SPM). Recently, computed tomography (CT) of the chest was shown to significantly decrease the risk of death due to bronchial carcinoma (BC) in a cohort of smokers whose risk of BC is increased but might be lower than that of patients previously treated for HNSCC. Thus, the present study evaluated the potential benefit of CT and other examinations in the detection of SPM in HNSCC patients.

Patients and methods

Between July 2008 and November 2011, 118 participants underwent a prospective, systematic examination for SPM (13 women, 105 men, median age 62 years). All patients had been previously treated for HNSCC and showed no recurrence or distant metastases at the time of the study start. CT scans, ear–nose–throat endoscopy, and endoscopy of the esophagus and stomach were performed.

Results

Overall, 33 suspicious findings were clarified by additional investigations. In all, 26 SPM were confirmed in 21 of 118 patients (18?%; 10 lung, 7 HNSCC, 3 gastrointestinal, 1 renal). Eighteen of these 21 patients (86?%) underwent therapy with curative intent.

Conclusion

The examinations revealed a high prevalence of curable stage SPM in HNSCC patients. Adapting a surveillance scheme including a chest CT is recommended.     

Increased FDG uptake in breast cancer is associated with prognostic factors

Purpose

To evaluate the relationship between FDG uptake and prognostic factors of breast cancer such as hormone receptors (estrogen and progesterone), expression of c-erbB-2, axillary lymph node status, tumor histology, grade and size.

Materials and methods

Between May 2009 and February 2011; 79 patients (mean age?±?SD: 52.9?±?13.9?years) with biopsy proven breast cancer underwent F-18 FDG PET/CT scanning for staging. Patients with excisional biopsy or neoadjuvant chemotherapy were excluded from the study. Histological types included were invasive ductal carcinoma (n?=?68), invasive lobular carcinoma (n?=?2), and invasive ductal plus lobular mixed carcinoma (n?=?9). Maximum standardized uptake values (SUVmax) were compared with estrogen (ER) and progesterone receptors (PR), expression of c-erbB-2, as well as tumor grade and tumor size. For the evaluation of relationship between tumor SUVmax values and prognosticators such as hormone receptors, tumor histologic grade, and tumor size, statistical analyses were performed using Student t test, Mann?CWhitney U Test and Pearson correlation coefficient and p values of less than 0.05 were considered to indicate statistically significant differences.

Results

All primary breast neoplasms were detected by PET/CT scanner. The mean SUVmax values and breast cancer tumor sizes ranged from 2.09 to 39.0 and 0.7 to 10?cm, respectively. Tumors with negative ER [(n?=?19); SUVmax median (min?Cmax): 15 (2.09?C39.0)] were associated with higher SUVmax values (p?=?0.01). Tumors with overexpression of C-erbB-2 [(n?=?28); SUVmax median (min?Cmax): 16.0 (5.0-39.0)]; tumor grade 3 [(n?=?25); SUVmax median (min?Cmax): 15 (6.43?C39)]; axillary lymph node involvement [(n?=?60); SUVmax median (min?Cmax): 13.61 (4.0?C39.0)]; tumor histopathology and increased tumor size were associated with higher maximum standardized uptake values. However, PR did not show any relationship with SUVmax values.

Conclusion

In the present report, strong relationships were detected between the negativity of ER, overexpression of c-erbB-2, tumor grade, tumor size, histopathology, axillary lymph node involvement and SUVmax values. Accordingly, we believe that SUVmax values obtained with ¹⁸F-FDG PET/CT may provide some information about tumor biology of breast cancer.     

18F-FET PET compared with 18F-FDG PET and CT in patients with head and neck cancer.

Recent studies suggest a somewhat selective uptake of O-(2-[18F]fluoroethyl)-L-tyrosine (FET) in cerebral gliomas and in squamous cell carcinoma (SCC) and a good distinction between tumor and inflammation. The aim of this study was to investigate the diagnostic potential of 18F-FET PET in patients with SCC of the head and neck region by comparing that tracer with 18F-FDG PET and CT. METHODS: Twenty-one patients with suspected head and neck tumors underwent 18F-FET PET, 18F-FDG PET, and CT within 1 wk before operation. After coregistration, the images were evaluated by 3 independent observers and an ROC analysis was performed, with the histopathologic result used as a reference. Furthermore, the maximum standardized uptake values (SUVs) in the lesions were determined. RESULTS: In 18 of 21 patients, histologic examination revealed SCC, and in 2 of these patients, a second SCC tumor was found at a different anatomic site. In 3 of 21 patients, inflammatory tissue and no tumor were identified. Eighteen of 20 SCC tumors were positive for both 18F-FDG uptake and 18F-FET uptake, one 0.3-cm SCC tumor was detected neither with 18F-FDG PET nor with 18F-FET PET, and one 0.7-cm SCC tumor in a 4.3-cm ulcer was overestimated as a 4-cm tumor on 18F-FDG PET and missed on 18F-FET PET. Inflammatory tissue was positive for 18F-FDG uptake (SUV, 3.7-4.7) but negative for 18F-FET uptake (SUV, 1.3-1.6). The SUVs of 18F-FDG in SCC were significantly higher (13.0 +/- 9.3) than those of 18F-FET (4.4 +/- 2.2). The ROC analysis showed significantly superior detection of SCC with (18)F-FET PET or 18F-FDG PET than with CT. No significant difference (P = 0.71) was found between 18F-FDG PET and 18F-FET PET. The sensitivity of 18F-FDG PET was 93%, specificity was 79%, and accuracy was 83%. 18F-FET PET yielded a lower sensitivity of 75% but a substantially higher specificity of 95% (accuracy, 90%). CONCLUSION: 18F-FET may not replace 18F-FDG in the PET diagnostics of head and neck cancer but may be a helpful additional tool in selected patients, because 18F-FET PET might better differentiate tumor tissue from inflammatory tissue. The sensitivity of 18F-FET PET in SCC, however, was inferior to that of 18F-FDG PET because of lower SUVs.     

PET/MRI and PET/CT in follow-up of head and neck cancer patients

Purpose

Positron emission tomography (PET)/MRI combines the functional ability of PET and the high soft tissue contrast of MRI. The aim of this study was to assess contrast-enhanced (ce)PET/MRI compared to cePET/CT in patients with suspected recurrence of head and neck cancer (HNC).

Methods

Eighty-seven patients underwent sequential cePET/CT and cePET/MRI using a trimodality PET/CT-MRI set-up. Diagnostic accuracy for the detection of recurrent HNC was evaluated using cePET/CT and cePET/MRI. Furthermore, image quality, presence of unclear ¹⁸F-fluorodeoxy-D-glucose (FDG) findings of uncertain significance and the diagnostic advantages of use of gadolinium contrast enhancement were analysed.

Results

cePET/MRI showed no statistically significant difference in diagnostic accuracy compared to cePET/CT (91.5 vs 90.6 %). Artefacts’ grade was similar in both methods, but their location was different. cePET/CT artefacts were primarily located in the suprahyoid area, while on cePET/MRI, artefacts were more equally distributed among the supra and infrahyoid neck regions. cePET/MRI and cePET/CT showed 34 unclear FDG findings; of those 11 could be solved by cePET/MRI and 5 by cePET/CT. The use of gadolinium in PET/MRI did not yield higher diagnostic accuracy, but helped to better define tumour margins in 6.9 % of patients.

Conclusion

Our data suggest that cePET/MRI may be superior compared to cePET/CT to specify unclear FDG uptake related to possible tumour recurrence in follow-up of patients after HNC. It seems to be the modality of choice for the evaluation of the oropharynx and the oral cavity because of a higher incidence of artefacts in cePET/CT in this area mainly due to dental implants. However, overall there is no statistically significant difference.     

FDG PET对肿瘤的评估价值

正电子发射体层(PET)是一种能够识别肿瘤内生化、生理变化的诊断影像技术，FDGPET可明显提高肿瘤诊断的准确性。肿瘤的FDG摄入量是与其内对葡萄糖需求量增加的有增殖能力的肿瘤细胞的代谢率呈正比的。FDG PET在肿瘤应用方面，对肿瘤的分期、分型，复发、转移的早期诊断，坏死与存活组织的鉴别，肿瘤生物特征的预测，及治疗反应的监测作用都得到了广泛承认。