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prostate cancer after primary therapy. All men had suspicion of
at least one lymph node metastasis. Exclusion criteria were
bone or visceral metastases and ongoing androgen deprivation
therapy. The median prostate-specific antigen at the time of
surgery was 1.7 ng/ml. In the main-region analysis, PSMA
imaging had a positive predictive value of 100% and a negative
predictive value of 89%. For anatomic subregions, the accuracy
remained high at 94.1%. The majority of false-negative sub-
regions were adjacent to true-positive subregions. According to
in-depth histopathologic analyses, tumor deposits of 4.5 mm
are needed to reach PSMA-PET detection rates of 90%.
Experts’ comments:
PSMA PET tracers such as
68
Ga-PSMA-11 have clearly improved
the diagnostic pathways in prostate cancer
[1]. PSMA-PET/CT
provides excellent specificity and must be considered the new
gold standard for imaging of men with biochemical recurrence.
In the context of salvage lymphadenectomy, PSMA tracers
were superior to choline in a recent retrospective multi-
institutional analysis
[2]. In primary staging for high-risk dis-
ease, the value of PSMA-PET-imaging is promising, but this will
remain unconfirmed until prospective studies are reported.
A general challenge for PSMA imaging is prostate cancers
with little or no PSMA expression; fortunately, these are
rare. Ligand-specific challenges for
68
Ga-PSMA-11 are
evaluation of tumor foci in close proximity to the bladder
because of urinary excretion of PSMA-11 and the availabili-
ty of the radionuclide, which is limited by generator
capacity and the short half-life of
68
Ga, prohibiting delivery
to distant PET centers. In the future,
18
F-labeled PSMA
tracers such as PSMA-1007 may improve availability, since
they can be produced in cyclotrons in large amounts and
transferred to satellite institutions
[3]. Favorably, PSMA-
1007 also exhibits better image resolution and non-urinary
excretion. Besides, PSMA-PET/magnetic resonance imaging
seems to be of promising value
[4].
If salvage therapy based on PSMA imaging is initiated in
carefully selected patients, there is controversy with regard
to the extent of treatment. In our opinion, the data available
today suggest that bilateral template-based surgery should
be performed to overcome the limitations of PSMA imaging
in detecting micrometastases
[5]. Similarly, radiotherapy
targeting of PET-avid metastases should include some
form of treatment of the pelvic lymph nodes, optimally as
whole-pelvis radiotherapy or at least covering neighboring
subregions. It is still unknown which treatment modalities
provide the most patient benefit, but the first studies testing
multimodal therapy are under way and retrospective data
support combined treatment for optimal local control and
improved next-relapse–free survival
[6].
Conflicts of interest:
The authors have nothing to disclose.
References
[1]
Perera M, Papa N, Christidis D, et al. Sensitivity, specificity, and predictors of positive 68 Ga-prostate-specific membrane antigen positron emission tomography in advanced prostate cancer: a systematic review and meta-analysis. Eur Urol 2016;70:926–37.
[2]
Suardi N, Briganti A, Fossati N, et al. Identifying the optimal candi- date for salvage lymph node dissection for nodal recurrence of prostate cancer: results from a large, multi-institutional analysis. Eur Urol Suppl 2017;16:e1660.[3]
Giesel FL, Hadaschik B, Cardinale J, et al. F-18 labelled PSMA-1007: biodistribution, radiation dosimetry and histopathological valida- tion of tumor lesions in prostate cancer patients. Eur J Nucl Med Mol Imaging 2017;44:678–88.
[4]
Freitag MT, Radtke JP, Afshar-Oromieh A, et al. Local recurrence of prostate cancer after radical prostatectomy is at risk to be missed in 68 G a-PSMA-11-PET of PET/CT and PET/MRI: comparison with mpMRI integrated in simultaneous PET/MRI. Eur J Nucl Med Mol Imaging 2017;44:776–87.
[5]
Maurer T, Gschwend JE, Rauscher I, et al. Diagnostic efficacy of 68 G a-PSMA positron emission tomography compared to conven- tional imaging for lymph node staging of 130 consecutive patients with intermediate to high risk prostate cancer. J Urol 2016;195: 1436–43.
[6]
Rischke HC, Schultze-Seemann W, Wieser G, et al. Adjuvant radio- therapy after salvage lymph node dissection because of nodal relapse of prostate cancer versus salvage lymph node dissection only. Strahlenther Onkol 2015;191:310–20.Boris Hadaschi
k * , Ken Herrmann
Department of Urology and Department of Nuclear Medicine,
University Hospital Essen, Essen, Germany
*Corresponding author. Department of Urology, University Hospital
Essen, Hufelandstrasse 55, 45147 Essen, Germany.
E-mail address:
boris.hadaschik@uk-essen.de(B. Hadaschik).
http://dx.doi.org/10.1016/j.eururo.2017.05.007#
2017 European Association of Urology.
Published by Elsevier B.V. All rights reserved.
Re: Radiation with or Without Antiandrogen Therapy in
Recurrent Prostate Cancer
Shipley WU, Seiferheld W, Lukka HR, et al
N Engl J Med 2017;367:417–28
Experts’ summary:
This prospective, double-blind, controlled study investigated
the effect of combining antiandrogen therapy with salvage
radiation therapy (sRT) for biochemical recurrence (prostate-
specific antigen [PSA] between 0.2 and 4.0 ng/ml) on overall
survival (OS). A total 760 eligible patients who were previ-
ously treated with radical prostatectomy (RP) and pelvic
lymphadenectomy for localized prostate cancer were includ-
ed. Median PSA at inclusion was 0.6 ng/ml. Patients were
treated between 1998 and 2003 with 68.8 Gy on the prostate
bed plus 150 mg of bicalutamide or placebo for 2 yr.
The treatment arm showed a significant increase in 12-yr
OS compared to the placebo arm (76.3% vs 71.3%; hazard
ratio [HR] 0.77;
p
= 0.04; number needed to treat [NNT] 20).
Moreover, at 12 yr the rated of death from prostate cancer
(5.8% vs 13.4%, HR 0.49;
p
<
0.001; NNT 13), occurrence of
metastasis (14.5% vs 23%, HR 0.48;
p
<
0.001; NNT 5) and
second biochemical failure (44% vs 67.9%, HR 0.48;
p
<
0.001; NNT 4.2) were all lower in the bicalutamide
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