TY  - JOUR
A1  - Buder, Kristina
A1  - Lapa, Constantin
A1  - Kreissl, Michael C.
A1  - Schirbel, Andreas
A1  - Herrmann, Ken
A1  - Schnack, Alexander
A1  - Bröcker, Eva-Bettina
A1  - Goebeler, Matthias
A1  - Buck, Andreas K.
A1  - Becker, Jürgen C.
T1  - "Somatostatin receptor  expression in Merkel cell carcinoma as target for molecular imaging"
N2  - Background

Merkel cell carcinoma (MCC) is a rare cutaneous neoplasm with increasing incidence, aggressive behavior and poor prognosis. Somatostatin receptors (SSTR) are expressed in MCC and represent a potential target for both imaging and treatment.

Methods

To non-invasively assess SSTR expression in MCC using PET and the radiotracers [68Ga]DOTA-D-Phe1-Tyr3-octreotide (DOTATOC) or -octreotate (DOTATATE) as surrogate for tumor burden. In 24 patients with histologically proven MCC SSTR-PET was performed and compared to results of computed tomography (CT).

Results

SSTR-PET detected primary and metastatic MCC lesions. On a patient-based analysis, sensitivity of SSTR-PET was 73% for nodal metastases, 100% for bone, and 67% for soft-tissue metastases, respectively. Notably, brain metastases were initially detected by SSTR-PET in 2 patients, whereas liver and lung metastases were diagnosed exclusively by CT. SSTR-PET showed concordance to CT results in 20 out of 24 patients. Four patients (17%) were up-staged due to SSTR-PET and patient management was changed in 3 patients (13%).

Conclusion

SSTR-PET showed high sensitivity for imaging bone, soft tissue and brain metastases, and particularly in combination with CT had a significant impact on clinical stage and patient management.
KW  - Merkel cell carcinoma
KW  - Molecular imaging
KW  - Somatostatin receptor expression
KW  - Positron emission tomography
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-110326
ER  - 
TY  - JOUR
A1  - Bluemel, Christina
A1  - Linke, Fraenze
A1  - Herrmann, Ken
A1  - Simunovic, Iva
A1  - Eiber, Matthias
A1  - Kestler, Christian
A1  - Buck, Andreas K.
A1  - Schirbel, Andreas
A1  - Bley, Thorsten A.
A1  - Wester, Hans-Juergen
A1  - Vergho, Daniel
A1  - Becker, Axel
T1  - Impact of \(^{68}\)Ga-PSMA PET/CT on salvage radiotherapy planning in patients with prostate cancer and persisting PSA values or biochemical relapse after prostatectomy
JF  - EJNMMI Research
N2  - Background

Salvage radiotherapy (SRT) is clinically established in prostate cancer (PC) patients with PSA persistence or biochemical relapse (BCR) after prior radical surgery. PET/CT imaging prior to SRT may be performed to localize disease recurrence. The recently introduced \(^{68}\)Ga-PSMA outperforms other PET tracers for detection of recurrence and is therefore expected also to impact radiation planning.

Forty-five patients with PSA persistence (16 pts) or BCR (29 pts) after prior prostatectomy, scheduled to undergo SRT of the prostate bed, underwent \(^{68}\)Ga-PSMA PET/CT. The median PSA level was 0.67 ng/ml. The impact of \(^{68}\)Ga-PSMA PET/CT on the treatment decision was assessed. Patients with oligometastatic (≤5 lesions) PC underwent radiotherapy (RT), with the extent of the RT area and dose escalation being based on PET positivity.

Results

Suspicious lesions were detected in 24/45 (53.3 %) patients. In 62.5 % of patients, lesions were only detected by 68Ga-PSMA PET. Treatment was changed in 19/45 (42.2 %) patients, e.g., extending SRT to metastases (9/19), administering dose escalation in patients with morphological local recurrence (6/19), or replacing SRT by systemic therapy (2/19). 38/45 (84.4 %) followed the treatment recommendation, with data on clinical follow-up being available in 21 patients treated with SRT. All but one showed biochemical response (mean PSA decline 78 ± 19 %) within a mean follow-up of 8.12 ± 5.23 months.

Conclusions

\(^{68}\)Ga-PSMA PET/CT impacts treatment planning in more than 40 % of patients scheduled to undergo SRT. Future prospective studies are needed to confirm this significant therapeutic impact on patients prior to SRT.
KW  - prostate cancer
KW  - salvage radiotherapy
KW  - PSMA
KW  - PET/CT
KW  - recurrence
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-147798
VL  - 6
IS  - 78
ER  -