This study investigated the surgical benefits of using protoporphyrin IX (PpIX) fluorescence to detect meningioma tissue in 204 patients. The study found that PpIX fluorescence enabled visualization of most meningiomas and identification of residual tumor tissue. However, the study had limitations including its single center design and lack of histopathological correlation or analysis of recurrence rates. While the results suggest PpIX fluorescence may help reduce recurrence risks, more research is needed to determine its true benefits versus potential harms for changing clinical practice.

1. Journal Club
Ahmad M. Badran
23 February 2017
1

2. Matthias Millesi, MD,1,2 Barbara Kiesel, MD,1,2 Mario
Mischkulnig,1 Mauricio Martínez-Moreno, MD,1 adelheid
wöhrer, MD, PhD,2,3 Stefan wolfsberger, MD,1,2 engelbert
Knosp, MD,1,2 and georg widhalm, MD, PhD1,
Analysis of the surgical benefits
of 5-ALA induced fluorescence
in intracranial meningiomas
experience in 204 meningiomas

3. 3
Department of Neurosurgery, 2Comprehensive Cancer Center–Central
Nervous System Tumors Unit, and 3Institute of Neurology, Medical
University of Vienna, Austria
Matthias Millesi, MD,1,2 Barbara Kiesel, MD,1,2 Mario Mischkulnig,1
Mauricio Martínez-Moreno, MD,1 adelheid wöhrer, MD, PhD,2,3 Stefan
wolfsberger, MD,1,2 engelbert Knosp, MD,1,2 and georg widhalm, MD,
PhD1,2
J Neurosurg Volume 125 • December 2016
Institution metrics/ Authors/ Journal

4. 4
This paper is relevant but not original.
This study investigated the possible surgical benefits of
Protoporphyrin IX (PpIX) fluorescence for detection of
meningioma tissue.
Study Relevance and Originality

5. 5
Research hypothesis
Protoporphyrin IX (PpIX) fluorescence enables intraoperatively visualization of
most intracranial meningiomas and allows identification of residual tumour
tissue at specific sites.
Intraoperative detection of residual meningioma tissue by PpIX fluorescence
might reduce the risk of recurrence.

6. 6
Study design
• Cohort study.
• Database (2009-2013).
• Single Centre.
• 190 consecutive patients who were treated for 204 intracranial meningiomas.
• Systematically analyzed the PpIX fluorescence status, fluorescence quality,
and intratumoral fluorescence homogeneity as well as the value of PpIX
fluorescence for detection of residual tumour tissue that might have remained
at specific intraoperative sites.

7. 7
Internal Validity
Single centre analysis and thereby reflects the treatment bias of the
institution and referral patterns.
The number of patients and longitudinal nature of follow-up was good
compared to other reports in the literature.
Statistical analysis was reasonable; For qualitative variables, a chi-square
test was performed. A p value < 0.05 was considered statistically
significant.

8. 8
External validity
Inclusion / exclusion criteria were not clear.
Oral solutions of 5-ALA (20 mg/kg body weight) were administered in all
patients approximately 3 hours before induction of anesthesia. During
resection, each meningioma was checked repeatedly for potential PpIX
fluorescence using a modified neurosurgical microscope (NC4 or Pentero, Carl
Zeiss Surgical GmbH) with the ability to switch to violet-blue excitation light.
To detect new postoperative deficits, a neurological assessment was performed
in each patient prior to surgery as well as before discharge and during the first
follow-up visit approximately 3 months after surgery. A new deficit was
considered permanent if it was still present at the first follow-up visit.
Histopathological diagnosis was established according to the current WHO
criteria and the extent of resections according to Simpson Grading.

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Results

10. 10
Results

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Results

12. 12
Results

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Results

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Results

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Results

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Results

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Discussion
Were all clinically important outcomes considered?
1) did not analyze the presence of tumor cells within the dural tail or the
adjacent cortex.
2) did not perform a systematic histopathological correlation of tissue samples
derived from intratumoral areas with different PpIX fluorescence qualities
(strong, vague, or no fluorescence).
3) the only bone flaps that we analyzed for PpIX fluorescence were those from
cases in which preoperative imaging had shown evidence of tumor
infiltration.
4) the intraoperative semiquantitative classification of PpIX fluorescence as
strong, vague, or none is subject to the neurosurgeon’s perception.
5) did not perform a follow-up analysis of the meningioma cases to investigate
the rate of tumor recurrence.

18. 18
Discussion
The number of patients and longitudinal nature of follow-up relative to other
reports in the literature has justified the conclusion.
Are the likely treatment benefits worth the potential harms and costs?
The author didn’t declare any conflicts of interest.

19. 19
Presentation and style
The paper was clear and organized.
The number of words were acceptable.
The tables and the figures were good.

20. 20
Conclusion
Summary of key strengths and weaknesses (take away message)
Is the study believable (internally valid)?
Is the study relevant (externally valid)?
Will the study change my practice?

21. The End
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