Key words Oncology - Interventional radiology - DeGIR-registry - nationwide availability - supportive
therapy
Introduction
In addition to vascular image-guided procedures, non-vascular minimally invasive interventional
radiology procedures are an indispensable part of modern medicine. These include image-guided
biopsies and drainage, port catheter implantation, pain management and osteoplastic
procedures. The spectrum of diseases treated is very heterogeneous and includes mainly
malignant diseases but also benign diseases such as osteoporosis or inflammatory bile
duct stenosis. These procedures are classified as Module C by the German Society for
Interventional Radiology and Minimally Invasive Therapy (DeGIR). There are numerous
clinical cooperation partners for this type of surgery, such as visceral surgery,
gastroenterology, gynecology, orthopedics, trauma surgery, neurosurgery, urology and
many others.
Current oncological treatment concepts include not only causal therapy of the underlying
disease, such as chemotherapy, ablation or surgical therapy, but also increasingly
complex supportive measures in order to achieve an optimal outcome and improve the
patientʼs quality of life. Interventional radiology plays an incrementally important
role in these supportive interventions pre-therapeutically, post-therapeutically,
as well as the management of complications, and is therefore represented in various
national (e. g., S3 guidelines) and international guidelines [1 ]
[2 ]
[3 ]
[4 ]
[5 ]. Supportive pre-therapeutic interventions of interventional radiology in the treatment
of tumor diseases include, for example, biopsy of suspicious masses to confirm a diagnosis
or marking of confirmed malignant tumors in preparation for therapy, such as prior
to radiation, ablation or surgical removal. Pretherapeutic, bioptic intervention makes
malignancy diagnosis and the resulting individualized therapy possible in the first
place, as knowledge of tumor biology based on obtained tissue samples is critical.
Benign findings can be detected early on in a minimally invasive and safe manner to
avoid unnecessary treatments or major invasive diagnostic procedures. Bile duct interventions
are another important pillar of supportive, peritherapeutic measures in modern oncology.
For example, stenoses and occlusions of the bile ducts in central liver tumors, bile
duct malignancies, and pancreatic head carcinomas can be treated interventionally.
The lower morbidity and mortality of interventional procedures compared with open
operative procedures is of high importance in mostly palliative situations [6 ]. Likewise, the implantation of port catheters is one of the important supportive
measures in modern tumor therapy [7 ]
[8 ]. Furthermore, pain that is difficult to control with medication can occur in the
course of advanced tumor diseases. This can be successfully and safely treated by
interventional, targeted deactivation of nerves, so that the quality of life of tumor
patients can be enhanced [8 ]. These techniques are also used for pain patients with benign conditions (e. g.,
degenerative spine disease). In addition, osteolysis can occur during tumor diseases
and eventually lead to fractures, which increases the morbidity as well as mortality
of tumor patients. These osteolyses can be stabilized by radiologically-guided osteoplasty
before a fracture occurs to improve patientsʼ quality of life [5 ].
Even in the case of oncologically successful treatment of a tumor, the underlying
tumor tissue can become infected, allowing abscesses to develop, arising not only
in the area of the treated tumor, but may also be triggered by certain therapeutic
approaches, e. g., the risk of an intrahepatic abscess is increased by the placement
of a biliodigestive anastomosis after pancreatic head resection [9 ]
[10 ]
[11 ]. In addition to malignancies, benign diseases also lead to abscesses or other fluid
accumulation, thus interventional drainage techniques are also used in these cases.
Abscesses can be treated minimally invasively by percutaneous drainage with very high
level of patient safety [12 ]. In addition to abscess drainage, percutaneous creation of a nephrostoma as a complement
to endoscopic retrograde procedures is also an important tool of interventional radiology
[13 ]. In addition to the aforementioned techniques and indications, numerous other non-vascular
interventions using similar techniques with image guidance have been established and
often represent individually important clinical solutions for patients. All of the
above procedures can be performed under local sedation and usually do not require
general anesthesia, thus these therapies can be offered to a wide range of patients.
The German Society for Interventional Radiology and Minimally Invasive Therapy (DeGIR)
has been recording vascular and non-vascular interventions for over 25 years as part
of a quality assurance program based on a registry operated jointly with the German
Society for Neuroradiology (DGNR). This Registry comprises the following modules:
Module A (vasodilator and vascular reconstructive procedures); Module B (vaso-occlusive
procedures); Module C (diagnostic punctures, drains, PTCD, TIPS, port implantations,
osteoplasty, pain therapy, etc.). Module D (oncological procedures including primarily
tumor-specific embolizations and ablations); Module E (vascular neuro-interventions),
and Module F (neurovascular embolization treatments) [14 ].
The description of good, nationwide interventional radiological care for cerebral
thrombectomy (Module E), revascularizing interventions (Module A) and emergency care
for acute bleeding utilizing catheter embolization (Module B) has already been published
based on DeGIR quality assurance data [14 ]
[15 ]
[16 ]
[17 ]. This current study presents the interventional supportive procedures of DeGIR Module
C (excluding the placement of a transjugular intrahepatic portosystemic shunt [TIPS]).
The purpose of this study is to investigate whether interventional radiological therapy
in Module C (excluding the installation of a TIPS) is available to patients in Germany
on a nationwide basis. The interventions in DeGIR Module C are particularly challenging,
as many different techniques are required to cover the sometimes very diverse approaches.
Materials and Methods
Data Collection
The study results of the current work are based on DeGIR Registry data from 2018 and
2019. The data was collected using software from Samedi (samedi GmbH). Module C (excluding
the placement of a TIPS) was recorded as a proxy for those supportive interventions
for tumor disease.
The number of centers meeting the criteria for DeGIR certification as a training center
(at least 50 procedures per year) or already certified was recorded. Centers with
more than 500 interventions per year were defined as “high volume”.
Analysis of Coverage
As described in the preliminary work on Modules B and E, the data breakdown was organized
by German federal state. For a more detailed analysis of the area coverage, without
making the data of individual clinics visible, the recorded Module C interventions
were broken down into 40 smaller regions (government districts, former government
districts and federal states [if there was never a division into government districts]:
Arnsberg, Berlin, Brandenburg, Braunschweig, Bremen, Chemnitz, Darmstadt, Dessau,
Detmold, Dresden, Düsseldorf, Freiburg, Gießen, Halle, Hamburg, Hanover, Karlsruhe,
Kassel, Koblenz, Cologne, Leipzig, Lüneburg, Magdeburg, Mecklenburg-Vorpommern, Middle
Franconia, Münster, Lower Bavaria, Upper Bavaria, Upper Franconia, Upper Palatinate,
Rhine-Hesse-Palatinate, Saarland, Schleswig-Holstein, Swabia, Stuttgart, Thuringia,
Trier, Tübingen, Lower Franconia, Weser-Ems) [14 ]
[18 ].
Analysis of selected Quality Parameters
As an example, as proxy parameters for a high quality of results from the register
database, quality parameters for diagnostic puncture, drainage and marking were analyzed,
such as the indication in an interdisciplinary board, technical success and complications
in the first 24 hours.
Statistics
A descriptive statistical analysis employed the R Statistics program (R version 3.5.3
(2019–03–11) – “Great Truth”) [19 ]. The accepted significance level was p = 0.05.
Creation of Graphics
Creation of the graphics was as previously described [14 ].
The following software was employed:
Creative Commons Attribution 3.0 License (http://www.geonames.org ), Geojson Deutschland https://github.com/isellsoap/deutschlandGeoJSON , https://www.destatis.de/DE/Service/Impressum/copyright-genesis-online.html (Statistisches Bundesamt (Destatis), https://krankenhausatlas.statistikportal.de/ ; Data license dl-de/by-2–0, https://www.govdata.de/dl-de/by-2–0.
Technical data:
© German Federal Office of Statistics data according to Section 21 of the Hospital
Remuneration Act, 2016.
© Federal Statistical Offices and state census data: 2011 census
Basic data:
© EuroGeographics (2013) European Boundary Map 2013 at 1:3000 000 scale
© GeoBasis-DE/BKG (2018) Germany administrative boundaries 2017 at 1:250 000 scale
© GeoBasis-DE/BKG (2018) WebAtlasDE
Genesis-Online; Data license dl-de/by-2–0), Openstreetmap (https://www.openstreetmap.org/copyright © OpenStreetMap contributors), Folium/Geopandas/Shapely/Python (map creation).
Results
In 2018 and 2019, a total of 136 328 procedures at 216 centers were recorded in DeGIR
Module C. In 2018, the number of documented procedures was 64 887 at 205 centers;
164 centers met certification requirements; 41 centers were considered high-volume
centers with more than 500 documented procedures per year.
In 2019, the number of documented procedures was 71 441 at 216 centers; 179 centers
met certification requirements; 44 centers identified as high-volume centers with
more than 500 documented procedures per year.
On average, 389 cases were documented per hospital in 2018 and 394 cases in 2019;
the increase per hospital in 2019 is not statistically significant but is relevant
in the aggregate when new participating centers are included, with an overall increase
of 10 % (6554 more cases than the previous year). [Table 1 ] shows a breakdown of the registered services for the years 2018 and 2019. [Table 2 ] shows the anatomical regions of biopsies.
Table 1
Listing of the various services and performance figures of the DeGIR Module C without
TIPS.
Type of intervention
2018
(n = 68 971)
2019
(n = 75 890)
Year-on-year change (n = + 7183)
Biospy
23 116 (34 %)
25 112 (33 %)
1996 (+ 8,6 %)
Drainage
8075 (12 %)
8958 (12 %)
883 (+ 10,9 %)
Marking
3367 (5 %)
4207 (6 %)
840 (+ 24,9 %)
Osteoplasty
874 (1 %)
819 (1 %)
–55 (–6,3 %)
Recanalization/reconstruction non-vascular
1516 (2 %)
1578 (2 %)
62 (+ 4,1 %)
Pain/infiltration treatment/neurolysis
20 866 (30 %)
22 327 (29 %)
1461 (+ 7,0 %)
Other procedures:
Port, PICC
Cava filter
Foreign body removal
Position correction
PRG
11 103 (16 %)
12 889 (17 %)
1996 (+ 18,0 %)
Note: The sum of interventions in this table is larger than the study population for
the geographic region analysis, as it also includes data from interventions without
region assignment.
Table 2
Listing of the anatomical regions including the absolute intervention numbers in DeGIR
Module C in 2018 and 2019.
Anatomical region
2018
%
2019
%
Autonomic nervous system
60
0,3
37
0,1
Gall bladder
12
0,1
18
0,1
Gastrointestinal tract
46
0,2
67
0,3
Heart
6
0,0
1
0,0
Pelvis
1133
4,9
429
1,7
Head/neck
342
1,5
347
1,4
Liver
2743
11,9
3067
12,2
Lung
3938
17,0
4002
15,9
Lymph nodes
1392
6,0
1532
6,1
Mamma
6508
28,2
7148
28,5
Male genitals
426
1,8
596
2,4
Mediastinum
295
1,3
342
1,4
Spleen
43
0,2
46
0,2
Muscle tissue/subcutis
861
3,7
996
4,0
Adrenal gland
139
0,6
165
0,7
Kidney
592
2,6
707
2,8
Ovaries
13
0,1
21
0,1
Pancreas
155
0,7
201
0,8
Peritoneum/mesentery
522
2,3
1204
4,8
Pleura
259
1,1
272
1,1
Retroperitoneum/extraperitoneal space
943
4,1
407
1,6
Thorax/peripheral skeletal system
1460
6,3
2931
11,7
Uterus
5
0,0
7
0,0
Spine/Ilio sacral joint
1207
5,2
569
2,3
Note: The total number of procedures in this table is larger than the study population
for the geographic region analysis, as it also includes data from procedures without
region assignment.
Coverage of Care
Normalized to one million inhabitants, an average of 781 interventions were performed
across Germany in 2018 and 860 in 2019. Based on the calculations of the individual
federal states from 2018 and 2019 together, this results in a mean of 1579 per million
inhabitants (standard deviation = 943). The interquartile range (IRQ) is 1224–1784
interventions per million inhabitants; the minimum value is 7 in Bremen and the maximum
value of 4,062 in Saarland. The median is 1500. [Fig. 1 ] provides an overview of the registered services per million inhabitants for each
federal state.
Fig. 1 Procedure documentation according to states. In [Fig. 1 ] the number of interventions is illustrated by a bar plot for each state in Germany.
The number is a summary of 2018 and 2019 and normalized on one million citizens. The
red line illustrates the median of 1500.
An analysis of the administrative districts or former administrative districts results
in an average of 3408 interventions per year (calculated from 2018 and 2019) in 40
regions; the standard deviation is 2627. The median is 2892 procedures per year. There
were no districts without procedures registered in Module C. [Fig. 2 ] illustrates the absolute number of interventions by federal state and region as
well as the related trend. [Fig. 3 ] shows the combined number from 2018 and 2019 of interventions per million inhabitants
for each federal state.
Fig. 2 Comprehensive distribution and evolution of interventions. In [Fig. 2 ] the numbers of interventions of 2018 and 2019 are illustrated for the states and
regions. In A–C the absolute numbers are encoded in increasing green and the changes from 2018 and
2019 in increasing blue D . In A the absolute numbers of interventions in 2018 are shown for each state and in B those from 2019. C illustrates the summarized region associated numbers from 2018 and 2019. In D percentual changes of interventions between 2018 and 2019 on state level are illustrated;
small changes and negative tendencies were encoded as white areas.
Fig. 3 Procedures in the different states per million inhabitants. Areal coverage of interventional
supportive oncologic therapy (2018 and 2019) on state level per one million citizens
in Germany.
Trend between the Years 2018 and 2019.
There were no statistically significant changes in registered cases between 2018 and
2019, but there was an overall increase of just over 10 %. Similar to Module B, some
significant variations between individual districts and individual states occurred
for Module C as well. [Fig. 2 D ] illustrates the trend between 2018 and 2019 for each state. The increase at the
state level averaged 13 % (IRQ: 0–19 %).
Analysis of selected Quality Parameters
The indication for Module C procedures was generally interdisciplinary. This was the
case for drain placement in 84 %, marking in 75 %, and biopsy in 80 %. The quality
of outcome was very high; for all three procedures; the technical success rate was
99 %, while the complication rate was significantly less than 1 %. [Table 3 ] provides a detailed breakdown of selected quality characteristics.
Table 3
Summary of selected quality parameters for biopsy, drainage and marking.
Type of intervention
2018
%
2019
%
Total
%
Drainage
8075
8958
17 033
Interdisciplinary indication
6388
79,1
7952
88,8
14 340
84,2
Technically successful
(target volume recorded or macroscopically representative or positive microbiology)
7957
98,5
8863
98,9
16 820
98,7
Occurrence of a complication in the first 24 h
21
0,3
16
0,2
37
0,2
Marking
3367
4207
7574
Interdisciplinary indication
1996
59,3
3654
86,9
5650
74,6
Technically successful
(target area successfully marked)
3344
99,3
4188
99,5
7532
99,4
Occurrence of a complication in the first 24 h
0
0,0
0
0,0
0
0,0
Biopsie
23 116
25 112
48 228
Interdisciplinary indication
17 085
73,9
21 242
84,6
38 327
79,5
Technically successful
(target volume recorded or macroscopically representative)
22 837
98,8
24 808
98,8
47 645
98,8
Occurrence of a complication in the first 24 h
29
0,1
24
0,1
53
0,1
Discussion
Analysis from 2018 and 2019 DeGIR Registry data regarding nationwide coverage of interventional
radiological procedures in DeGIR Module C (excluding TIPS) shows suffieicnt availability
exists for these procedures on a state-wide level; in addition, professional qualifications
and experience regarding the required procedures are well distributed across the individual
regions. Regions with comparatively lower numbers of procedures correspond to regions
that have a low density of hospitals, see [Fig. 4 ]. At the district level, there is no region where this type of interventional radiology
procedure is not available. The present results document not only the good availability
of the above-mentioned interventions, but also a very high intervention quality.
Fig. 4 Distribution of hospitals in Germany. Distribution of hospitals throughout Germany.
https://www.destatis.de/DE/Service/Impressum/copyright-genesis-online.html (Statistisches Bundesamt (Destatis), https://krankenhausatlas.statistikportal.de/ ; Datenlizenz dl-de/by-2–0, https://www.govdata.de/dl-de/by-2-0 .
Nonvascular interventional radiological procedures have an assured and increasing
place in modern oncological concepts [20 ]. Interventional radiology performs both pre-therapeutic and post-therapeutic procedures
under imaging guidance less radically than with surgical procedures. These include,
for example, marking or biopsy as the basis for planning tumor therapy. Likewise,
one of the modern pillars of tumor therapy is the placement of port catheters, as
these allow safe administration of chemotherapy and other drugs; these catheters are
also installed using interventional radiology. However, peri- and post-therapeutic
measures are likewise offered, such as drainage placement or interventional pain therapy/neurolysis
for affected nerves.
The above-mentioned procedures can contribute in various ways to enable and facilitate
oncological therapy and to reduce the mortality and morbidity of patients, especially
in palliative situations, and thus improve the overall outcome [21 ].
In addition to the quality and safety of therapies, ubiquitous availability plays
the most important role in practical patient care. Therefore, this study investigated
the availability of different supportive oncology and interventional radiology-guided
nonvascular interventions in Germany.
DeGIR Registry data from 2018 and 2019 demonstrate a high level of nationwide availability
at the state level, similar to the analysis for hemorrhage or stroke care. Numerous
hospitals suitable for DeGIR training center certification or currently with certification
are available in Germany for the training of young radiologists interested in interventional
radiology. Although individual procedures from Module C are also provided by other
disciplines, there is currently no published data on the exact number and area-wide
distribution. Corresponding registry data from other professional societies are not
currently available for these interventions. Due to the specialty definition of radiology
as well as the special expertise in imaging procedures, many diagnostic and therapeutic
measures from DeGIR Module C can only be provided by interventional radiologists,
including, for example, CT-guided biopsy or marking. Of other supportive measures,
only individual types of intervention are also covered by other specialist disciplines,
e. g. ultrasound-guided breast biopsies in gynecology. The costs of an interventional
radiological procedure are often lower with the same effectiveness; port implantation
in the angiography unit, for example, is more cost-effective than surgical implantation
with the same complication rate [22 ]. In addition, the interventional radiologist can be an important clinical partner
in the overall treatment approach.
Interpretation of Registry Data
Similar to prior studies, this analysis selected DeGIR data from Module C as a proxy
for procedure distribution and experience for interventional radiology-guided, nonvascular
procedures with a focus on diagnosis and treatment of tumor disease. Likewise, data
provision was voluntary for the study years 2018 and 2019. There are also great regional
fluctuations for Module C as previously shown in publications regarding the other
individual modules B and E. Similarly, due to the voluntary nature of the registry
documentation, a relevant but ultimately unknown number of missing entries (unreported
numbers) can be assumed. As already discussed in the publications on Modules B and
E, the scope and quality of the reported data are influenced by the motivation and
activity of individuals in the clinics. City-states in particular are more affected
by statistical fluctuations and the above-mentioned influences.
Coverage of Care
The analysis of the DeGIR Module C (excluding TIPS) shows, analogous to the other
modules, overall good nationwide coverage at federal state level with interventional-radiologically
guided, nonvascular interventional measures. The normalized, mean average number of
interventions at the federal state level from 2018 and 2019 corresponds to the value
of the normalized total interventions in relation to the Federal Republic of Germany
(1579 vs. 1641). Nevertheless, the number of interventions in each federal state varies
significantly per million inhabitants (see [Fig. 3 ]). Individual regions such as Saxony-Anhalt, Bremen or Saarland deviate by more than
one standard deviation from the mean. As discussed above and in previous studies,
fluctuations in the scope of the documentation of the register data are responsible
for this.
The above-mentioned favorable training situation in Germany could support the further
training of more interventional radiologists and a more even distribution of these
radiologists to less well-provided regions, thus allowing greater homogeneous area
coverage in Germany in the future.
Overall, the data allow the statement that a comprehensive supply of radiologically-guided
interventional measures for the supportive treatment of tumor diseases is assured
in Germany; in addition, the training situation for prospective interventional radiologists
is favorable.
