Keywords
gamma knife - awareness - radiosurgery - neurosurgery - clinical rotations
Introduction
Since its introduction to medicine in the 1960s, gamma knife radiosurgery (GKRS) has
become a vital component of neurosurgery due to its ability to target specific head
and spine conditions with extremely precise gamma ray beams while minimizing damage
to surrounding normal tissue.[1] In order to relieve symptoms with a low incidence of problems, high rates of effectiveness,
and high levels of patient satisfaction, GKRS aims to kill or disable the targeted
tissues. However, despite its significant promise, the optimal use of GKRS, particularly
in terms of patient selection and treatment protocols, remains uncertain. This has
led to a more limited application of GKRS to certain medical conditions.
GKRS has been clinically applied to treat various intracranial disorders, including
meningiomas, acoustic neuromas, metastatic brain tumors, and cerebral arteriovenous
malformations (AVMs).[2] Among its many indications, the most commonly treated functional disorder is trigeminal
neuralgia, with studies showing pain relief in 69 to 85% of patients after 1 year,
59% after 2 years, and 38 to 52% after 5 years.[2]
[3] Overall, the incidence of complications following GKRS is low, with hypesthesia
being the most frequently reported side effect, typically occurring between 6 and
36 days after treatment.[3]
Given the lack of previous research on awareness of GKRS among medical professionals,
our study aims to assess and increase understanding and awareness of GKRS within the
medical field in The University of Jordan. Our goal is to provide valuable insights
into the importance and potential benefits and clinical applications of GKRS as a
treatment option.
Materials and Methods
A cross-sectional quantitative study was conducted in the Jordan University Hospital
(JUH), in Amman/Jordan, to explore the level of awareness among medical students in
their clinical years (fourth, fifth, and sixth medical students), interns, residents,
and specialists about GKRS.
Instrument
An online questionnaire with two components that was created by a neurosurgeon with
experience using GKRS served as the primary data collection tool.
The first step was to collect data on the participants' year of medical school, whether
they were interns, residents, or specialists, their source of neurosurgery experience,
if any, and whether or not they had heard of GKRS. The second section of the study,
which established information about gamma knife specifically, was only open to those
who had heard about GKRS. This included information on indications (such as Parkinson's,
obsessive compulsive disorder [OCD], dystonia, depression, and brain metastases, vestibular
schwannoma, meningioma, glioblastoma WHO grade 4, spinal tumor, brain AVM, brain aneurysm,
brain cavernoma, migraine, trigeminal neuralgia, arterial hypertension, or diabetes
mellitus) are possible indications or not; side effects (i.e., whether infection,
intracranial hemorrhage, psychiatric changes, permanent neurological deficit, seizures,
dizziness, or radiation necrosis) are common, rare, or not a complication; availability
of the procedure in Jordan; cost (<10,000, 10,000–30,000, 30,000–60,000, >60,000 Jordanian
Dinar [JD]); and whether they believe it is covered by public health insurance or
not.
The survey was created with Google Forms and distributed to our sample population
via a secure link. The participants completed it on their own, and they were all given
our contact information in case they had any questions or required more details about
the study or the questionnaire. The complete survey questionnaire is provided in [Appendix A1] (available in the online version).
Data Analysis
After 451 completed questionnaires, the study was concluded. Our team's researchers
entered the gathered data and used Google Forms and Excel for analysis. Following
a descriptive analysis, percentages and frequencies were used to describe the findings.
Ethical Consideration
The participants gave their written agreement in order to access the questionnaire;
they were all guaranteed the privacy of the information gathered about them and were
not asked for any personal information. They were made aware that participation was
entirely voluntary and that stopping at any time would not have any negative effects.
Results
Among 451 respondents, 119 (26.4%) were fourth-year medical students, 170 (37.7%)
were fifth-year medical students, 85 (18.8%) were sixth-year medical students, 25
(5.5%) were interns, 44 (9.8%) were residents, and 8 (1.8%) were specialists. A total
of 65.19% (294) have had neurosurgery experience, while 34.81% (157) have not. Among
those who have had neurosurgery experience, 280/294 gained it only from medical school
rotation, 8/294 gained it from both medical school rotation and internship, and 6/294
gained it from both medical school rotation and a neurosurgery residency program ([Table 1]).
Table 1
Demographics of respondents
|
Possible responses
|
Responses count (n = 451)
|
Percentage
|
|
Year of medical school/experience
|
4
|
119
|
26.4%
|
|
5
|
170
|
37.7%
|
|
6
|
85
|
18.8%
|
|
Internship
|
25
|
5.5%
|
|
Residency
|
44
|
9.8%
|
|
Medical specialty
|
8
|
1.8%
|
|
Neurosurgery experience
|
Who has had neurosurgery experience
|
294
|
65.19%
|
|
From medical school rotation only
|
280
|
95.24%
|
|
From medical school rotation and internship
|
8
|
2.72%
|
|
From medical school rotation, internship and residency program
|
6
|
2.04%
|
|
Heard about gamma knife radiosurgery
|
Yes
|
286
|
63.4%
|
|
No
|
165
|
36.6%
|
When asked if they have heard of GKRS, 63.4% (286/451) answered yes, and 36.6% (165/451)
answered no ([Table 1]).
Although 34.81% (157/451) have not had neurosurgery experience, 37.85% (59/157) of
them have heard about GKRS, while 62.42% (98/157) have not. Among those who have had
neurosurgery experience (65.19%, 294/451), 77.21% (227/294) have heard about GKRS,
while 22.79% (67/294) have not ([Table 2]).
Table 2
Number of respondents who have/have not had neurosurgery experience and have/have
not heard about gamma knife radiosurgery
|
Number of respondents
who have had neurosurgery experience
|
Number of respondents
who have not had neurosurgery experience
|
|
Number of respondents who have heard about gamma knife radiosurgery
|
227
|
59
|
|
Number of respondents who have not heard about gamma knife radiosurgery
|
67
|
98
|
Only those who had heard about GKRS were asked additional questions about its indications,
side effects, expected time for clinical outcomes, availability in Jordan, cost, and
coverage by public health insurance.
When asked about possible indications for GKRS, the most commonly agreed-upon indications
were vestibular schwannoma (222/286), meningioma (217/286), brain metastases (210/286),
and brain cavernoma (176/286). On the other hand, diabetes (267/286), arterial hypertension
(259/286), migraine (228/286), and depression (214/286) were the most common diseases
that were not believed to be possible indications. Regarding dystonia, nearly half
of the respondents considered it a possible indication. Other indications mentioned
in the questionnaire are demonstrated in [Fig. 1].
Fig. 1 Perceived indications for Gamma Knife Radiosurgery (GKRS) among respondents. AVM,
arteriovenous malformation; OCD, obsessive compulsive disorder.
Regarding side effects of GKRS, they were asked to classify whether the side effect
is common, rare, or not a complication, including infections, intracranial hemorrhages,
psychiatric changes, permanent neurological deficits due to gamma knife radiation,
seizures, dizziness, and radiation necrosis. Most respondents (67%) agreed that dizziness
is a common complication, while 27% and 6% said it is rare and not a complication,
respectively. Permanent neurological deficit such as ataxia, facial neuropathy, vertigo,
trigeminal neuropathy, due to gamma knife radiation was the most common side effect
believed to be rare (58%, 166/286), followed by intracranial hemorrhages and seizures
(53%, 152/286 for both), then radiation necrosis and psychiatric changes, respectively.
Regarding infection, 44% (127/286) of respondents agreed that it is not a complication,
while 16% (47/286) agreed that it is a common side effect ([Fig. 2]).
Fig. 2 Respondents' classification of GKRS-related complications.
To investigate how awareness levels regarding the indications and side effects differ
across medical school years, data from sixth-year medical students who have completed
their neurosurgery rotations were compared to data from fourth-year medical students
who have not yet completed their neurosurgery rotations.
Regarding indications, vestibular schwannoma was identified as an indication by 79%
of sixth-year students and 70% of fourth-year students. Awareness of brain metastases
as an indication was similar between groups, with 77% of both fourth- and sixth-year
students identifying it.
Regarding side effects, dizziness was chosen as a common symptom by 74% of sixth-year
students and 61% of fourth-year students. Seizure was identified as a rare symptom
by 61% of sixth-year students and 45% of fourth-year students.
Diverse responses were detected when we asked about the expected time for improvements
and achieving the required clinical outcomes: 26.9% expected it in 6 months, 24.1%
in 1 week, 23.1% in 1 month, 16.8% immediately, and 9.1% in 1 year.
Almost all respondents (97.9%) believed that GKRS is available in Jordan. A total
of 44.8% believed that it costs less than 10,000 JD, 43.7% ranged the cost between
10,000 and 30,000 JD, 8.7% between 30,000 and 60,000 JD, and 2.8% more than 60,000
JD.
About public health insurance coverage, 53.1% thought that GKRS is covered by it,
whereas 46.9% did not.
Discussion
GKRS delivers an intensive dose of precision beams to treat a region of disease while
conserving normal tissue. It is a minimally invasive, painless, safe, and effective
treatment for a wide range of intracranial conditions. In 1996, Jordan became the
first nation in the Middle East and the 14th nation worldwide to use GKRS.[4] The JUH Gamma Knife Unit was established in 2021, and as of right now, 100 patients
have had treatment there.
Regretfully, no prior research of this kind has been conducted, either domestically
or internationally, to determine medical field personnel's and students' awareness
of GKRS. Since medical students will likely be the future interns, residents, and
referring physicians in many neurosurgical cases, it is crucial to raise awareness
of GKRS as a potential course of treatment.
Since the neurosurgery rotation is only a 2-week course offered in the fifth year
of medical school at the University of Jordan, about one-third of the respondents
had not encountered it during their clinical training. Furthermore, our study included
fourth- and fifth-year medical students who had not yet completed their neurosurgery
rotations. Approximately one-third of the respondents have not yet completed their
neurosurgery rotation, which explains why 36.6% of them have never heard of GKRS.
Despite completing the rotation, the remaining one-third of students were unaware
of GKRS because few had the opportunity to view the Gamma Knife Unit and get that
clinical exposure, as there were few neurosurgeons with expertise in this technique,
and GKRS is not included in the neurosurgery curriculum.
We found that there was no significant difference in awareness level between sixth-year
students who had finished their neurosurgery rotation and fourth-year students who
had not, indicating that the neurosurgery rotation did not have a significant impact
on increasing the level of awareness. This can be attributed to the same factors mentioned
previously.
To participate in the second part of the study, which develops particular information
regarding GKRS, participants had to have heard about the procedure.
Meningioma, brain metastases, vestibular schwannoma, and brain cavernoma were the
most frequently properly believed indications by the respondents in our survey. Correctly,
59%, 57%, and 40% of respondents thought that glioblastoma multiforme, brain AVM,
and brain aneurysm were indications for GKRS.
Even though spinal tumors and spinal AVMs are not indications for GKRS, a larger percentage
of respondents—56% and 44%, respectively—than anticipated think they are. This is
untrue because the second cervical spine is the lower limit for GKRS.[5] Furthermore, this illustrates a lack of knowledge regarding the gamma knife's site
of action.
Remarkably, 57% of participants concurred that trigeminal neuralgia is not an indication,
despite the fact that GKRS is thought to be a very successful treatment method. A
total of 91.75% of 497 individuals with medically refractory classical trigeminal
neuralgia were found to be pain-free after a median of 10 days and to have been pain-free
for over 10 years without the need for medication.[6]
Despite several studies demonstrating their efficacy in treating movement disorders,
including Parkinson's and dystonia, 40% and 51%, respectively, agreed that these conditions
are not appropriate candidates for gamma knife intervention.
Although gamma knife intervention may be the only option for treating some severe
and intractable cases of OCD and depression, only 37% and 25%, respectively, of respondents
identified these conditions as such.[7] The majority of respondents held the opposite opinion, the erroneous notion that
GKRS is not used for psychiatric conditions is the cause of this outcome.
Migraine, diabetes, and arterial hypertension were chosen incorrectly as indications
by 20%, 7%, and 9% of the participants, respectively.
Permanent neurological impairments and dizziness are common side effects of GKRS.
In a prior study, individuals with vestibular schwannomas treated with GKRS had the
following outcomes: 18% experienced new ataxia, 5% had permanent facial neuropathy,
4% experienced vertigo, and 1% complained of trigeminal neuropathy.[8] In our study, 67% of participants correctly identified dizziness as a typical side
effect, but only 36% properly identified lasting neurological damage.
One uncommon side effect of GKRS that has been documented is seizures. Merely 0.3%
of the 835 individuals who underwent GKRS reported having new-onset seizures.[9] Due to high levels of uncertainty, about half of the respondents thought it was
an uncommon side effect, and the other half thought it was common.
Cerebral bleeding, infections, radiation necrosis, or psychological abnormalities
are not potential adverse effects of GKRS. Due to the minimally invasive nature of
GKRS, a study found that the danger of cerebral hemorrhage and infection appears to
go unnoticed.[10] Another study found that there was no radiation necrosis during long-term follow-up.[11] Furthermore, a study revealed that there was no difference in the patients' psychiatric
baselines before and after GKRS and that it might even improve the patients' mental
health.[12]
According to our findings, a small percentage of respondents accurately classified
radiation necrosis, psychological abnormalities, and cerebral bleeding as non-complications
following GKRS.
However, a larger portion (44%) accurately believed that infections were not a side
effect.
It is evident that answers to most of the adverse effects alternate between classifying
them as common and uncommon. This illustrates the respondents' ambiguity and ignorance
about those side effects. It should be highlighted, nonetheless, that there is broad
agreement among the respondents that infection is not a side effect, while dizziness
is, indicating some degree of consensus regarding these particular side effects.
Based on several research studies, improvements usually show up 6 months after starting
GKRS. The results of the study, however, show that respondents' expectations varied
widely, with similar percentages anticipating improvement in 1, 2, or 3 months. The
majority of respondents were unable to provide a more specific expectation and may
have been choosing from the first three possibilities at random, as just a tiny percentage
of respondents—16.8% and 9.1%, respectively—expected improvement immediately or within
a year.
Ninety-seven percent of the respondents knew that GKRS was available in Jordan. The
fact that JUH, the research site, has a Gamma Knife unit may be the reason for this
high degree of awareness. There is some disagreement, though, about how much the surgery
would cost. Of the respondents, 44.8% think it will cost less than 10,000 JD, 43.7%
think it will cost between 10,000 and 30,000 JD, and a minority think it will cost
more than 60,000 JD. It should be mentioned that GKRS actually costs about 8,000 JD
on average in Jordan.
Nearly half of the respondents think that GKRS is not covered by public health insurance
when it comes to GKRS insurance coverage. It is crucial to remember that GKRS is covered
by Jordan's national health insurance. This level of awareness emphasizes the importance
of awareness campaigns.
This study's sample size, selection bias, and generalizability are its shortcomings.
The small sample size, the focus on medical service providers at JUH solely, and the
fact that only eight of the survey responses came from specialists while the majority
came from fourth and fifth-year medical students may limit the ability to generalize
the findings to the whole of Jordan's medical professional population. Future studies
to incorporate a broader range of Jordanian health institutions would be needed.
Furthermore, the study's location at JUH, which houses the Gamma Knife Unit, might
have had an impact on participants' awareness.
In conclusion, the low level of awareness among respondents regarding GKRS can be
attributed to several factors, including limited exposure to these units and reliance
on anecdotal knowledge, an underestimation of the potential benefits, and the fact
that this is a relatively new technology in the neurosurgical area. This shortage
of knowledge prompts us to focus our efforts on dispelling misconceptions about gamma
knife indications and raising awareness. We can accomplish this by introducing the
Gamma Knife Unit to interns and students more often during clinical rotations, changing
the curriculum to include lectures on the subject, and advocating in-person training,
extracurricular activities, workshops, and journal club discussions with students
from various specialties and levels regarding recent research.
