Implantation of an ICL was effective for the correction of high myopia. Predictability must be improved and the long-term safety of the ICL determined. The main concerns over potential cataract formation, pigmentary dispersion, and angle-closure glaucoma remain.

Object The cumulative experience worldwide indicates complete radiosurgical obliteration rates of brain arteriovenous malformations (AVMs) ranging from 35 to 90%. The purpose of this study was to propose a strategy to increase the obliteration rate for AVMs through the dynamic definition of the key target volume (KTV). Methods A prospective series of patients harboring an AVM was assessed using digital subtraction angiography in which a digital counter was used to measure the several stages of the frame-by-frame circulation time. All the patients were analyzed using dynamic measurement planning to define the KTV, corresponding to the volume of the shunt with the least vascular resistance and the earliest venous drainage. All patients underwent catheter-based angiography, a subgroup was additionally assessed by means of a superselective catheterization, and among these a further subgroup received embolization. The shunts were also categorized according to their angioarchitectural type: fistulous, plexiform, or mixed. The authors applied the radiosurgery-based grading system (RBGS) as well to find a correlation with the obliteration rate. Results This series includes 44 patients treated by radiosurgery; global angiography was performed for all patients, including dynamic measurement planning. Eighty-four percent of them underwent superselective catheterization, and 50% of the total population underwent embolization. In the embolized arm of the study, the pretreatment volume was up to 120 ml. In patients with a single treatment, the mean volume was 8.5 ml, and the median volume was 6.95 ± 4.56 ml (mean ± standard deviation), with a KTV of up to 15 ml. For prospectively staged radiosurgery, the mean KTV was 28 ml. The marginal radiation dose was 18–22 Gy, with a mean of dose 20 Gy. The mean RBGS score was 1.70. The overall obliteration rate was 91%, including the repeated radiosurgery group (4 patients), in which 100% showed complete obliteration. The overall permanent deficit was 2 of 44 patients, 1 in each group. Conclusions Dynamic definition of the KTV might increase the obliteration rate, even in complex AVMs, allowing the treatment of smaller volumes off the recruitment vessels (pseudonidus). By using this technique, the authors avoided double-blind treatment, where the neurosurgeon does not know precisely which type of lesion he or she is irradiating and the interventionalist does not know why and what he or she is embolizing.

The use of stereotactic volume calculation is highly recommended in planning, follow up, and determination of the outcome in patients participating in radiosurgical treatment and should lead to more uniform reports of the response to treatment.

Object. Volume estimation is one of the most important criteria in the evaluation and follow up of radiosurgical treatments and outcomes; however, several limitations are involved in the calculation estimation of target volumes. Methods. Retrospective and prospective studies were conducted to evaluate the efficacy of a new noninvasive stereotactic method when it is compared with geometric volume calculation of intracranial tumors for planning stereotactic radiosurgery treatment as well as for follow up and outcome evaluation. Two equations were created that permit comparison of the calculated and measured volumes. These equations took linear and quadratic forms, respectively. Volume estimation using the stereotactic approach compared with traditional volume calculation gave more accurate results regardless of the shape and size of the lesion. Conclusions. The use of stereotactic volume calculation is highly recommended in planning, follow up, and determination of the outcome in patients participating in radiosurgical treatment and should lead to more uniform reports of the response to treatment.

Entrevista a Felipe Zuleta Lleras Periodista de El Radar de Caracol TV, Columnista de El Espectador, ex-viceministro de comunicaciones y ex consejero presidencial de comunicaciones