Key words DeGIR registry data - interventional radiology - interventional oncology - quality
assurance
Introduction
Over the past 30–40 years, numerous innovative developments and improvements in interventional
oncology have led to significant progress in tumor therapy. In the meantime numerous
studies have shown the high effectiveness of interventional oncological procedures.
This now concerns a wide range of techniques and their application in various tumor
diseases and in different organs, such as the liver, kidney, lung or bone [1 ]
[2 ]
[3 ]. Thus, interventional oncological tumor therapy has been added to numerous current
tumor therapy guidelines in addition to “classic” oncological therapy approaches such
as surgery, chemotherapy and radiation therapy [4 ]
[5 ]. Interventional tumor therapy uses local as well as locoregional methods based on
image guidance utilizing embolization materials, chemotherapeutic agents, radionuclides
or thermal energy applied via a transarterial or transcutaneous approach, among others.
However, due to the very low systemic side effects after oncological interventions,
in many cases these are not only used as competitive therapy methods, but can be combined
with existing therapies [6 ]. For numerous indications, the utilization of interventional oncological procedures
has evolved from a “salvage” option to the method of first choice. Especially for
elderly, multimorbid patients for whom neither surgical nor systemic therapy is an
option due to their general condition, interventional oncology opens up new opportunities
for prolongation and improvement of quality of life, as in the past, only the “best
supportive care” was available for these patients [7 ]
[8 ].
However, in addition to the high effectiveness and acceptance of interventional oncological
procedures, the availability of the procedure and the quality of its implementation
also play a decisive role in practical patient care. In order to record these central
elements in radiological interventions, the German Society for Interventional Radiology
and Minimally Invasive Therapy (DeGIR) transformed its decentralized data management,
in existence since 1987, into a central registry for quality assurance in 2005, which
has been supplemented by the entries of the German Society of Neuroradiology (DGNR)
since 2012. Here, vascular and non-vascular interventions are divided into different
modules: Module A (vasodilator and vascular reconstructive procedures); Module B (vaso-occlusive
procedures); Module C (diagnostic punctures, drains, PTCD, TIPSS); Module D (oncological
procedures including TACE or other tumor-specific embolizations, ablations, percutaneous
tumor therapies); Module E (vascular neuro-interventions), and Module F (neurovascular
embolization treatments). Certification opportunities were created in the respective
modules to document personal expertise. In addition, radiology departments can become
certified as training centers.
The data collected from 2018 and 2019 of Module D (oncological procedures) will be
used to show the extent to which interventional oncological tumor therapy is generally
available in Germany and whether the average number of interventions performed per
center indicates sufficient practical experience.
Materials and Methods
Data Collection
Browser-based software from samedi (samedi GmBH, Berlin, Germany) was used to gather
data from the DeGIR registry for the years 2018–2019. All data on hospitals participating
in the registry were blinded except for location. Based on the collected data, the
number of interventional oncological tumor therapies grouped under Module D was used.
In addition, the number of procedures performed per year was employed to verify which
center could meet or already meets the DeGIR requirement to be a certified training
center. The requirements for DeGIR certification of the center in Module D include
the performance and documentation of at least 20 interventional oncological procedures
per year and the presence of an interventional radiologist with DeGIR Level 2 certification
in Module D [9 ]. Centers with particularly high numbers of procedures (at least 100 procedures per
year) were characterized as “high volume”.
Analysis of Coverage
The participating centers were initially classified according to federal state. A
further subdivision was made into 40 smaller regions in order to obtain a more detailed
overview of the distribution of the individual centers. For regional distribution,
the federal states were again divided into existing government districts as well as
former government districts. States that were never subdivided into government districts
were still included as federal states. Consequently the following breakdown resulted:
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.
The German Federal Statistical Office provided the data regarding the number of hospitals
available at the federal and state levels in 2018 and 2019, as well as population
data [10 ]. The oncological centers were recorded and their breakdown by federal state was
based on the annual reports of the certified oncological centers of the German Cancer
Society from 2018 and 2019 [11 ].
In order to obtain an impression of the discrepancies between interventional oncological
tumor therapies actually performed in Germany and the interventions voluntarily recorded
in the DEGIR registry, the number of ablations performed in 2019 as recorded in the
DeGIR registry was compared with the number documented in the German hospital directory
using the corresponding operation and procedure code (OPS) for ablations (liver, kidney,
lung as well as bone) [12 ].
Statistics and Creation of Graphics
Descriptive statistics were developed using R Statistics (R version 3.5.3 – “Great
Truth”). Calculation of the correlation coefficient was performed using PPMCC. The
graphics were created using the following software: Creative Commons Attribution 3.0
License (www.geonames.org ), Geojson Germany (https://github.com/isellsoap/deutschlandGeoJSON ). Participating centers were grouped at the municipal level in the graphs, so one
point may correspond to multiple centers in some cases.
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), Folium/Geopandas/Shapely/Python
(map creation).
Results
In 2018, 187 hospitals reported oncological interventions in Module D of the DeGIR
registry on a voluntary basis. The number of participating hospitals increased to
216 in 2019. With a total number of 1925 (2018) as well as 1914 (2019) hospitals in
Germany, oncological interventions can thus be documented at 9.7 % (2018) as well
as 11.2 % (2019) of hospitals. Compared to the oncology centers certified by the German
Cancer Society (118 hospitals in 2018 and 120 hospitals in 2019), oncological interventions
were documented in significantly more hospitals. A total of 11,653 oncological interventions
were recorded in 2018 and 12,323 oncological interventions were documented in 2019,
an increase of 6 %. At the same time, however, the average number of oncological interventions
per hospital decreased by 8 %, from 62.3 in 2018 to 57.1 in 2019 ([Fig. 1a, b ]). Regarding the comparability between the interventions surveyed in the DGIR registry
and the interventions actually performed in Germany, the number of surveyed ablations
in the DeGIR registry for 2019 was 2250 and 2388 performed ablations in the German
hospital registry, which corresponds to a difference of 5.8 %.
Fig. 1 a Map with absolute figures per federal state in 2018; b Map with absolute figures per federal state in 2019; c Summarized absolute figures from 2018 and 2019 for administrative districts; d Relative changes between 2018 and 2019 shown in blue with white areas for minor changes
or negative development. © Statistical Federal Republic and State Offices, Germany,
2021. This work is licensed under the data license Germany - Version 2.0 (www.govdata.de/dl-de/by-2–0)
A sufficient number of oncological interventions to achieve certification as a DeGIR
training center in Module D was achieved by 116 clinics in 2018 and 129 clinics in
2019. The number of high-volume centers rose from 31 hospitals in 2018 to 36 in 2019.
Care Situation
Interventional oncological tumor therapies from Module D were performed in all states
as well as separately listed regions. However, there were some significant regional
differences in the recording of the interventions performed. The mean value of documented
oncological interventions from 2018 to 2019 per region was 599 interventions (standard
deviation 414). The lowest number of oncologic interventions was documented in the
Bremen region (n = 17), and the highest number was documented in the Rheinhessen-Pfalz
region (n = 1499) ([Fig. 1c, d ]).
On average, 291 oncological interventions per million population were performed in
Germany in 2018 and 2019 (SD 184), with a median of 269, a minimum of 25 in Bremen,
and a maximum of 773 in Saarland ([Fig. 2 ], [3 ]). A correlation between the number of oncological interventions and the number of
oncological clinics (oncological centers) certified by the German Cancer Society per state
could not be demonstrated (correlation coefficient r = –0.001). There was also no
correlation of oncological interventions with the 17 Comprehensive Cancer Centers
(organ cancer centers of university hospitals) recognized by the German Cancer Aid
(DKH) (correlation coefficient r = 0.049).
Fig. 2 Number of interventions from 2018 and 2019 standardized to one million inhabitants.
The red line shows the standardized value of the Federal Republic from 2018 and 2019.
Fig. 3 Summarized figures from 2018 and 2019 per federal state per one million inhabitants.
© Statistical Federal Republic and State Offices, Germany, 2021. This work is licensed
under the data license Germany - Version 2.0 (www.govdata.de/dl-de/by-2–0)
Discussion
The COVID pandemic has once again demonstrated the importance of comprehensive coverage.
In addition to the necessary provision of sufficient vaccination capacity by private
practice physicians, it is also essential to provide comprehensive coverage in the
oncological field, since these diseases do not allow any postponement of therapy.
Minimally invasive interventional oncological procedures have increasingly become
common alongside the standard therapeutic procedures of surgery, oncology and radiotherapy
[13 ]
[14 ]
[15 ]. In patients in a general state of health suitable for therapy, they represent a
complementary, although in some cases also competitive, therapeutic approach and,
particularly in multimorbid patients, are often one of the last options before the
decision is made to provide best supportive care [13 ]
[16 ]
[17 ]. In practical patient care, however, in addition to the evidence-based therapy recommendation,
the availability of the intended procedure is often a decisive criterion for optimal
therapy tailored to the patient. Here, especially with regard to the increasing number
of guidelines recommending interventional oncological tumor therapy depending on the
tumor entity and stage, it becomes apparent that there is a need for an assessment
regarding the presence of universal coverage of oncological interventions [18 ]. This is all the more true as oncological therapies are increasingly performed on
an outpatient basis, which optimally requires care close to home. In addition to the
widespread availability of evidence-based therapeutic methods, the recording and monitoring
of the quality of a therapeutic procedure is becoming increasingly important. For
example, the German Cancer Society requires an established quality management system
as part of its certification as an oncology center [19 ]. In interventional radiology, quality assurance in Germany is carried out by the
DeGIR quality registry as well as by a modular training program with different certification
levels. Here, a distinction is made between certification for individuals and centers.
Two levels of certification are offered to individuals: DeGIR Level 1, which certifies
a basic qualification in interventional radiology, and DeGIR Level 2, which demonstrates
specialization in interventional radiology/neuroradiology and is divided into modules
from the DeGIR registry. These modular certificates for DeGIR Level 2 could be earned
by 2020 by meeting the minimum numbers for interventions (100 interventions performed
in the desired module) and at least 30 CME points after passing a combined DeGIR written
and oral specialty examination. Since 2021, DeGIR has cooperated with the Cardiovascular
and Interventional Radiological Society of Europe (CIRSE) and conducts a separate
specialty examination according to UEMS standards together with CIRSE. As a result,
all examinees automatically also acquire a European Intervention Certificate with
international UEMS recognition [9 ]. Furthermore, clinics can be certified as a DeGIR center or DeGIR training center
in the various modules, depending on the prerequisites. The results of the analysis
of Module D oncological interventions from the 2018 and 2019 DeGIR Quality Assurance
Registry suggest geographic variation in the provision of interventional oncological
tumor therapies. These are carried out both at the state and regional level throughout
Germany, although there are some significant differences among the individual regions.
The low percentage of 9.7 % and 11.2 %, respectively, of hospitals performing oncological
interventions compared to the total number of hospitals in Germany shows that the
necessary expertise required for such procedures remains an obstacle to implementing
them in hospitals without a designated oncology focus. Making the issue more difficult,
in many smaller hospitals, radiology departments have been replaced by collaboration
with radiology practices that do not offer interventional therapies. Another reason
for the rather low percentage of hospitals with interventional oncological tumor therapies
is the small patient population. With respect to the total number of tumor patients,
only a few are eligible to benefit from oncological interventions, as these interventions
are mostly used in patients with oligometastasis or less common primary tumors, such
as hepatocellular carcinoma (HCC). However, when comparing the number of hospitals
performing oncological interventions with the number of certified oncology centers,
it is seen that significantly more hospitals (58.4 % and 80 %, respectively) can offer
oncological interventions. The strict requirements for certification primarily forms
the basis for the low number of certified oncology centers compared to hospitals with
oncological interventions. Among other things, the requirements of the German Cancer
Society for certification as an oncology center include the following in many areas,
such as for certification as a visceral oncology center and the presence of an interventional
radiology department. Explicitly required here is at least one specialist in radiology
with proof of DeGIR/DGNR Level 2 certification [19 ]. This requirement, along with the increasing number of oncological interventions
from 2018 to 2019 (6 %), again highlights the importance of interventional radiology
in modern tumor therapy. Analogous to the German Cancer Society, certification for
quality assurance is also carried out by DeGIR/DGNR. In 2018 and 2019, more than half
of the hospitals (62 % and 59.7 %, respectively) met the requirement of at least 20
oncological interventions performed per year. As high-volume centers, 16.5 % and 16.6 %
of the hospitals performed more than 100 oncological interventions. This high percentage
of certified or certifiable hospitals suggests a high quality standard of interventions
performed and which could support high-quality training of radiologists in interventional
oncological procedures [20 ]. In particular, the training of board-certified interventional radiologists may
promote the further dissemination of interventional oncological tumor therapies in
the future, since this is still necessary due to geographical differences in availability
described above, which in some cases show a significant drop in such services in structurally
poorer regions. This is also shown by the absolute distribution of oncological interventions
performed in 2018 and 2019, as the mean value of documented interventions per admionistrative
district was 599. Individual districts (Bremen (17), Dessau (38), Halle (28) as well
as Magdeburg (43)) were more than one standard deviation (414) below the mean. To
avoid bias in results due to regions with different population densities, oncological
interventions in 2018 and 2019 were standardized to one million population at the
state level. Here, too, Brandenburg (85), Bremen (25) and Saxony-Anhalt (49) deviated
by more than one standard deviation (184) from the mean value of 291. Similar regional
variations could already be found in the study on vaso-occlusive measures, which was
also based on the DeGIR quality registry data [21 ]. An acceptable correlation that the increased incidence of certified oncology centers
leads to an increase in oncological interventions could not be demonstrated. Likewise,
the converse assumption that the increase in other treatment options in designated
oncology centers could primarily result in fewer oncological interventions could not
be demonstrated in the absence of a correlation between interventions per state and
the presence of comprehensive cancer centers. The reasons for these sometimes considerable
variances remain unclear. The main cause of uncertainty in the interpretation of the
data is means of collection. The recording of performance figures based on the DeGIR
quality registry is carried out on a voluntary basis or as part of the certification
process. For example, it is conceivable that clinics with low intervention numbers
and no prospect of certification may decline to enter their interventions in the quality
registry because of the lack of incentive and increased time required. In particular,
the similar distribution of regional differences with respect to the provision of
interventional procedures in the current study and the DeGIR study on vaso-occlusive
procedures suggests a systemic error [21 ]. With regard to the similar distribution of regional differences in the two studies,
it would also be conceivable that individual high-volume centers do not participate
in data collection and that this leads to significant distortions of the collected
data in structurally poor regions with low hospital density. Due to the anonymity
of the data collected, this could unfortunately not be investigated in greater detail.
However, this distribution phenomenon could also be explained by general regional
differences in terms of hospital density, geographic location, and different care
structures [21 ]. However, the fact that the data collected provide a reliable overview of the current
supply situation with oncological interventions shows that the difference between
the ablations recorded in the DeGIR registry and the ablations performed according
to the German hospital registry – 5.8 % – is rather small.
Conclusions
A Germany-wide provision of interventional oncological tumor therapies could be demonstrated
based on the data of the DeGIR quality registry. However, there are significant geographical
differences in this care, so that it can be assumed that the need for interventional
oncological procedures is not yet adequately met in individual regions. Therefore,
the training of interventional radiologists working in oncology should be further
advanced, and interventional radiologists should be supported or further trained to
be able to offer oncological procedures. In order to be able to assess the availability
situation regarding interventional procedures even more precisely in the future, all
interventions performed should be recorded in the DeGIR quality registry, if possible.
