Treatment planning for prostate focal laser ablation in the face of needle placement uncertainty

Abstract

The probability of completely ablating a focal target using FLA is sensitive to the level of needle placement uncertainty, especially as the target length approaches and becomes greater than the diameter of ablated tissue that each individual laser fiber can achieve. The results of this work can be used to help determine individual patient eligibility for prostate FLA, to guide the planning of prostate FLA, and to quantify the clinical benefit of using advanced systems for accurate needle delivery for this treatment modality.

Optimization of laser dosimetry based on patient-specific anatomical models for the ablation of pancreatic ductal adenocarcinoma tumor

“…Since the cancer was spread in a large portion of the pancreatic head in patient #4, the optimal laser setting was not achieved according to the prediction performed within the operating range. Multi-fiber laser ablation or pulled back technique with a single fiber, in which multiple ablations are executed at specified increments in order to cover the whole tumor 45 , 51 , 52 , can be explored as alternatives for the ablation of large tumors such as the one in patient #4.…”

Mechatronic system for in-bore MRI-guided insertion of needles to the prostate: An in vivo needle guidance accuracy study

“…Lesions exceeding a threshold size necessitate insertion of multiple fibers per tumor (14,20,21), for which prediction of the probability of successful ablation requires a more complex analysis. Such an analysis has been recently published under the assumptions of simplified target and ablation region geometries for FLA therapy, and we refer the interested reader to that work (22). Because error in needle placement is of clinical importance, its cause must be discussed.…”

MRI Robot for Prostate Focal Laser Ablation: An Ex Vivo Study in Human Prostate

“…Laser ablation is an inherently MRI-safe technique as it introduces only non-magnetic optical fibers into the tissue. Visualase™ (Medtronic, Dublin, Ireland) laser ablation system ( Figure 1b) is a US Food and Drug Administration (FDA) cleared device for minimally invasive ablation, with applications in neurosurgery and urology, such as deep brain lesioning or prostate focal therapy [3]. The laser machine, navigation system, and cooling pump are placed outside the MRI room and the fiber and cooling tubes are passed through the conduit connecting the MRI room and the control room.…”

“…The abovementioned robots had been designed mainly for prostate biopsy. Cepek et al developed a manually controlled four-degrees of freedom (DoF) transperineal mechanism for needle alignment for FLA under MRI-guidance [3] with a median guidance error of 3.5 mm in 10 patients. This is perhaps the first try to use a mechatronic device to assist physicians during FLA.…”