The Novel “CLASS” Algorithmic Scale for Patient Selection in Meningioma Surgery

The very basic tenet of medicine is that a treatment is given if the treatment's benefits far outweigh the risks. In the previous chapter, both benefit and risk factors for meningioma surgery were described and reviewed. To briefly reiterate, the risk factors associated with outcome following meningioma surgery include the following: patient's preoperative co-morbidity (C), tumor location (L), patient's age (A), tumor size (S), and the symptoms/signs (S) caused by the tumor. Additionally, a history of prior surgery and radiation were also found to be significant risk factors. The benefit factors, which are largely conceptual and difficult to quantify, include alteration of the natural history, with a chance to cure when Simpson grade 1 resection is performed, and reversal or improvement of neurologic signs and symptoms. Tumor size and neurologic signs/ symptoms, although significant risk factors, simultaneously represent only two benefit factors in meningioma surgery. The larger the tumor, the greater is the potential benefit for the patient following surgery. Similarly, when patients present with neurologic symptoms or deficits, there is potential for reversal, improvement, or stabilization of symptoms following surgery. The more severe or reversible the symptoms or deficits are, the greater the benefit would be for the patient. Based on the previous chapter's data relating to the factors influencing outcome following meningioma surgery, we aimed to develop a novel and simple standardized guideline to help select patients for meningioma surgery. Following the basic principle of medicine described above, this scale simply weighs and assesses the risks and benefits of surgery for an individual patient with meningioma.