Adaptations in Radiosurgery Practice during COVID Crisis
Correspondence Address: Source of Support: None, Conflict of Interest: None DOI: 10.4103/0028-3886.299161
Source of Support: None, Conflict of Interest: None
Keywords: Corona virus, gamma knife radiosurgery, pandemic, sterilization
The COVID-19 crisis has changed neurosurgical practice significantly. We are now in the aggressive phase of this crisis and we hope to reach a plateau and downfall in cases soon. As radiosurgery is considered to be an elective procedure, the majority of the centers stopped radiosurgery practices, given the safety concerns, to maintain the principles of social distancing, pragmatic use of the resources, and team relocation to emergency services. The definition of an elective radiosurgery procedure remains elusive. Compared to traditional neurosurgical definition of elective and emergent, radiosurgery procedure probably has to wait longer than other neurosurgical counterparts. It is the right time to understand the unique role of radiosurgery during unprecedented challenges posed by the COVID-19 pandemic. The epidemiological data so far has identified at-risk patient populations in the elderly, oncohematological disorders, and comorbidities such as hypertension, diabetes mellitus, etc. Many patients designated for gamma knife radiosurgery (GKRS) may be suffering from these comorbidities and are at a higher risk of complications than younger relatively healthy patient population.
We are still unsure about the epidemiological nature of this disease. India went through the biggest lockdown in history. The second most populous nation of the world was on a standstill for 67 days in a stretch. India has six working GKRS centers that treat around 2000 cases per annum. Though there is no mention of how to triage patients waiting for radiosurgery in any of the neurosurgical guidelines, and some have given explicit guidelines to consider stereotactic radiosurgery SRS) in place of open surgery in cases of brain metastasis whenever possible and have made palliative SRS as a nonpriority.
At present, there are no practice guidelines specific for gamma knife radiosurgery (GKRS) in these situations. There are logistic and operational concerns for the optimal and rational delivery of the radiosurgery for various indications without jeopardizing the safety of the health care providers and patients both. Though elective radiosurgery services cannot be discontinued for long, we need a roadmap in the continuing crisis in the aftermath of this situation. We expect piling up of the pending cases with new patients adding to it and rescheduling of the patients. In the current article, authors have tried to prepare the radiosurgery centers for adjustments in the radiosurgery practices with some troubleshooting details.
Also, due to the high risk of transmission of the virus during neurosurgical procedures, there is a possibility that an unprecedented number of patients may be referred/considered for radiosurgery instead of open neurosurgery. Even patients who were planned for focal radiotherapy (RT) or hypofractionated RT could be redirected to undergo radiosurgery. It is imperative during this period that we have to make careful case selection and be ready to manage patients during this humongous humanitarian crisis.
In this evolving crisis, we are facing newer problems every day; hence the precautions cannot be foolproof and need to be dynamic with the coming evidence in time. With the present evidence so far concerning other streams of medicine, the following adaptations would be of great help in better management of the current scenario:
After a referral for radiosurgery is received, we need to screen the possibilities of COVID suspected patients telephonically. Any patient suffering from cough, fever, loss of smell, or history/contact to the COVID affected area should be asked to first review with the pulmonologist/general medicine, or the COVID helpline. All patients should visit with a negative test report [nucleic acid reverse transcription-polymerase chain reaction (RT PCR)_ from throat swab and negative chest CT scan]. Self-sufficient patients are advised to come alone, and for patients needing help, a single person should be allowed to accompany during the hospital visit. No new patient should be evaluated without prior evaluation by telemedicine.
Once the patient is asked for the radiosurgical treatment, he/she must be proven negative on testing, a day prior to radiosurgery. Radiosurgery is a multidisciplinary team, which involves neurosurgeon, radiation oncologist, medical physicist, nursing staff, and radio technicians. Many centers decide the candidature of tumor board meetings. To minimize the chances of unnecessary exposure, only one team leader should evaluate the patient, and other team members can review the findings on various online platforms.
We need to develop in-hospital definitions and classifications of the emergency and elective indications for GKRS. The risk stratification should only be till the crisis abates, so that the waiting list can be triaged judiciously. A typical radiosurgery center treats nearly two to three patients per day for 5 working days a week. The waiting period for various radio surgical units ranges from 2 to 3 months. Depending upon the geographical location, the indications vary. Most of the patients in India either belong to benign intracranial tumors or vascular pathologies. Metastasis accounts for 5%–10% of the total patient load. Contrary to this, metastasis remains the most common indication in the radiosurgical centers in Japan.
Due to the prolonged lockdown, there may be approximately 600 patients on the waiting list, which would be rescheduled in the country. Among these patients, the triage should be based on the presumed pathology, the natural history of the disease, and the clinical condition of the patient [Table 1]. Any asymptomatic incidentaloma can be kept on watchful waiting. While minimally symptomatic patients such as growing vestibular schwannoma or residual nonfunctional pituitary adenoma should be kept on the elective list. Single or oligometastatic lesions of the brain with favorable outcomes should be prioritized urgently. Metastasis with a chemo-sensitive profile or favorable immunohistochemical markers should be kept on directed chemotherapy in cases where radiosurgery may not affect the overall survival and quality of life to a significant extent. As the intubation and elective ventilation are considered high-risk procedures, concerning coronavirus, we should refrain from pediatric patients and the ones in need of anesthesia during GKRS. [Table 1] details the indications for urgent, semi-urgent, and elective indications. The indications can be dynamic and changed as per the changing patient load and growing evidence.
Social distancing is a proven method to prevent community spread of the coronavirus. We need to adopt measures to maintain proper social distancing both at the e-consultation as well as treatment areas. The patient consultations are to be done maximally on telecommunication (email, WhatsApp, and videoconferencing). At the entrance of the department, the temperature should be screened again, and any patient with temperature >37.5 ˚C should not be allowed and sent to the screening unit. The patient consultation can be done through an intervening glass door to avoid any aerosol contamination. The tumor board meeting should be by video conferencing, minimizing the contact between individual team members. The screenshots are taken separately for the target delineation, planned treatment, radiosurgery indices, and approved plan. These screenshots are to be sent to the radiation oncologist and the neurosurgeon. Among the multiple plans, a plan unanimously selected is approved for the radiation delivery. As the patient does not require any follow-up visit in the coming months, one is encouraged to consult electronically for any query in between. As any radiological effect starts appearing by the end of the first year the six-month MRI should be deferred at present. In the waiting room, the patient and the relatives are asked to stay at 1 m distance from each other. Newspaper stands, magazines, and broachers should be removed to prevent any fomite infection.
Adequate protective equipment, which includes personal protective equipment (PPE) and N95 masks, should be used by staff directly in contact with the patients. We should prefer the frameless stereotactic radiosurgery (e.g., ICON) to frame-based procedures. Consider the frame localizer, frame engaging unit over the gamma couch as infected material and sterilization should be done after every procedure. Most of the gamma knife centers have positive pressure centralized air conditioning that may help in the virus dissipation; hence air conditioning should be avoided at this time. The whole gamma unit can be fumigated at the end of the day.
The radiosurgery has only a few moments when the staff comes in close contact with the patient, i.e., fixation of the frame/thermoplastic mask, bubble measurement, fixation of the head in the gamma gantry, and frame removal. However, we should follow strict adherence to PPE and N95 face mask to safeguard the patient and the caregivers both.
We treat the majority of the patients based on magnetic resonance imaging (MRI). Arteriovenous malformation is the only indication that needs additional digital subtraction imaging (DSA) for the exact nidus definition. If the patient has earlier undergone DSA as a diagnostic procedure, we can omit this step to minimize in-hospital transportation and additional procedure. With a coregistration of earlier performed stereotactic MRI with particular emphasis to time-of-flight (TOF) and TOF contrast, nidus definition can be accurate without compromising on the quality of the treatment.
We should try to minimize the number of fractions as much as possible. This is the time when daycare radiosurgery should be done. For multiple fractions, frameless stereotactic radiosurgery should be used. As metastasis is a relatively urgent indication for radiation treatment, all oligometastatic lesions should be treated with radiosurgery in place of whole-brain radiation treatment.
To provide effective treatment in a shorter period, and better utilization of the resources, radiosurgery can be done in two shifts. One patient should be treated in the morning, followed by an interval for sterilization of the gamma gantry and services followed by another treatment in the evening, and sterilization in the night. It needs a two-team approach for the nursing team and the radio technicians. The planning can be done in the morning only, but there should be an adequately spaced time interval between two treatment sessions.
The medical physicist can do treatment planning, and the same can be checked and approved by radiation oncologists and neurosurgeons. Traditionally every treatment plan should be approved by a medical physicist, neurosurgeon, and radiation oncologist. For the time being, high-quality images should be used for evaluation and treatment planning necessary for radiosurgery and follow-up. The treatment plan can be digitally signed by the team members and should be kept in a secured fashion in an online repository. However, we should be especially sure about the target delineation, coverage, conformity, Paddick index, and the radiation dose for every individual indication. The routine checklist should incorporate certain points with respect to the corona crisis [Table 2].
The staff is encouraged to use no-touch technique and frequent alcohol use for disinfection. All surfaces are repeatedly cleaned with alcohol-based solutions including computer apparatus, keyboards, and mouse. A single operator is asked to handle data entry, image definition, target and organs at risk delineation, treatment planning, and approval. All high touch equipment within the planning station should be covered with a transparent plastic sheet that should be discarded every day. Disposable sheets are utilized for the patient's position on the gamma couch and in the waiting area. Staff members should comply with the institutional guidelines for their safety while dealing with the patients.
Despite the best of our measures, the chances of infection cannot be completely nullified. An additional consent for the corona virus should be taken detailing, the need for rescheduling of the individual case, risk of nosocomial infection, and participation of the case in future research studies.
In a hypothetical situation, a COVID negative patient may turn out to be positive after the completion of GKRS treatment or the tests may be a false negative. While the treatment room can be disinfected, the gamma gantry remains a matter of concern as it opens only at the time of treatment. In case the gamma gantry is infected with the patients' aerosols. There are no specific time frames for which the virus may remain active on any solid surface, and when can we treat the next patient after treatment. In such a situation, the gantry needs separate sterilization. The machine should be kept in the service mode, and the gantry gates should be opened. During this time, the radiation sources and the cobalt collimators are covered with a tungsten block. The gantry should be sterilized with the fumigation system, and the gantry can be wiped with 70% ethanol-based disinfectant. Following this, the gamma machine and the room should be separately sterilized. The human resources for this purpose should comply with the maximum protection, which includes PPE with powered air-purifying respirator (PAPR). The guidelines from the manufacturers ensure permissible radiation safety with the phantom-based studies and thermoluminescence unit recordings in the laboratory-based studies for cleaning the gamma gantry with the cobalt sources in the parked position.
The use of drugs adversely affecting the immune status of the patient should be used for the minimum possible duration. The use of steroids should be dictated by the disease in question in COVID negative patients.
Every patient presenting to GKRS treatment should be considered as a potential asymptomatic COVID carrier. Patients should be categorized based on the priority (urgent, semi-urgent, or elective) on the basis of pathological and clinical status. There is a high risk of aerosol dispersion during gamma radiation delivery in the gamma gantry. The above recommendations can be used to minimize the chances of pathogenic exposure to the patient and caregivers both.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
[Table 1], [Table 2]