No abstract

We consider a scheduling problem with a single machine and a set of jobs which have to be processed sequentially. While waiting for processing, jobs may deteriorate, causing the processing requirement of each job to grow after a fixed waiting time t 0 . We prove that the problem of minimizing the makespan completion time for all jobs is NP-hard. Next we consider the problem for a natural special case where the job requirement grows linearly at a job-specific rate after t 0 . We develop a fully polynomial time approximation scheme for the problem in this case. We also give further NP-hardness results, and a polynomial time algorithm for the case where the job-specific rate is proportional to the initial processing requirement of each job.1998 Academic Press

IntroductionFrame-based stereotactic biopsy is well-established to play an essential role in neurosurgery. In recent years, different robotic devices have been introduced in neurosurgery centers. This study aimed to compare the SINO surgical robot-assisted frameless brain biopsy with standard frame-based stereotactic biopsy in terms of efficacy, accuracy and complications.MethodsA retrospective analysis was performed on 151 consecutive patients who underwent stereotactic biopsy at Chongqing Sanbo Jiangling Hospital between August 2017 and December 2021. All patients were divided into the frame-based group (n = 47) and the SINO surgical robot-assisted group (n = 104). The data collected included clinical characteristics, diagnostic yield, operation times, accuracy, and postoperative complications.ResultsThere was no significant difference in diagnostic yield between the frame-based group and the SINO surgical robot-assisted group (95.74 vs. 98.08%, p > 0.05). The mean operation time in the SINO surgical robot-assisted group was significantly shorter than in the frame-based group (29.36 ± 13.64 vs. 50.57 ± 41.08 min). The entry point error in the frame-based group was significantly higher than in the robot-assisted group [1.33 ± 0.40 mm (0.47–2.30) vs. 0.92 ± 0.27 mm (0.35–1.65), P < 0.001]. The target point error in the frame-based group was also significantly higher than in the robot-assisted group [1.63 ± 0.41 mm (0.74–2.65) vs. 1.10 ± 0.30 mm (0.69–2.03), P < 0.001]. Finally, there was no significant difference in postoperative complications between the two groups.ConclusionRobot-assisted brain biopsy becomes an increasingly mainstream tool in the neurosurgical procedure. The SINO surgical robot-assisted platform is as efficient, accurate and safe as standard frame-based stereotactic biopsy and provides a reasonable alternative to stereotactic biopsy in neurosurgery.

OBJECTIVE To evaluate the value of the concept of the “Hexahedron” in the supratotal resection (SPTR) of frontal gliomas in both dominant and nondominant hemispheres . METHODS All consecutive patients who underwent SPTR for frontal gliomas under the guidance from the concept of the “Hexahedron” were retrospectively analysed for lesion location, pathology, extent of resection (EOR), and complications from May 2020 to June 2021. Volumetric EOR was measured and classified as SPTR, (in which the volume of the postoperative cavity was larger than the preoperative tumour volume), gross total resection (GTR, > 95% by volume) or subtotal resection (STR, ≤ 95% by volume) after independent radiological review. RESULTS Six men and two women (mean age: 47.13 years; range: 26–69 years) were included. All eight patients underwent frontal craniotomy combined frontotemporal craniotomy for resection of frontal gliomas. Neuropathological examination confirmed a diagnosis of glioblastoma WHO Grade IV in 4 patients, anaplastic oligodendroglioma WHO Grade III in 1, anaplastic astrocytoma WHO Grade III in 2 and diffuse astrocytoma WHO Grade II in 1. SPTR was achieved in six patients and STR was achieved in two. The main postoperative complications were contralateral paresis in 2 patients and memory disturbances in 1 patient. There were no cases of rebleeding or secondary operation during hospitalization. CONCLUSIONS In the presented eight cases the concept of the “Hexahedron” allowed for safe surgical supratotal resection of frontal gliomas.

No abstract