The Long-Term Outcome of CyberKnife-Based Stereotactic Radiotherapy for Intra/ Extracranial Non-Vestibular Schwannomas: A Single-Center Experience

The long-term outcomes of CyberKnife-based hypofractionated stereotactic radiotherapy (SRT) for intra/ extracranial non-vestibular schwannomas (nVS) need to be accumulated. Patients who received SRT by CyberKnife for nVS from 2010 to 2019 were retrospectively reviewed. A total of 45 patients with nVS were identified. The mean age was 53 (± 18) years old, and 23 patients (51%) were female. Twenty-nine patients (64%) had previous procedures. As for the tumor extension, 22 (49%) nVS were classified as primary intracranial, five (11%) were classified as intra/ extracranial (dumbbell shape), and 18 (40%) were classified as primary extracranial. The median prescribed dose, covering 95% of the planning target volume, was 21 (IQR 21 – 25) Gy, and the median target volume was 7 (IQR 3.6-13.1) cm3. The local control rate of nVS for patients without neurofibromatosis type 2 (NF2) was 100%. Old age (OR 0.92, p-value 0.03) and previous surgery (OR 0.02, p-value 0.02) were significant risk factors for no symptomatic improvement. The progression-free survival was 74 (±33) months clinically and 69 (IQR 36 – 94) months radiologically. During follow-up, two cases (4%) with NF2 resulted in treatment failure, 13 cases (41%) resulted in transient tumor expansion (TTE), 10 (22%) suffered from transient adverse radiation effect (ARE), and two (4%) resulted in permanent ARE. Hypofractionated SRT by CyberKnife for head, neck, and spine nVS was an effective treatment regardless of tumor extension relative to the cranium. Although the risk of permanent ARE was low, some patients experienced transient clinical worsening due to TTE.

Iodine-125 brachytherapy and robotic stereotactic radiotherapy — treatment options for patients with localized prostate cancer

Introduction. Modern radiological treatment options for patients with localized prostate cancer (PCa) have several advantages and allow achieving high rates of biochemical control.Purpose of the study. To compare immediate, proximate, and long-term results of low-dose Iodine-125 brachytherapy (I-125 BT) and robotic stereotactic radiotherapy (SBRT) in patients with localized low- and intermediate-risk PCa.Materials and methods. The study included 296 patients with localized low- and intermediate-risk PCa. I-125 BT and SBRT were performed in 208 and 88 patients, respectively. All patients with an intermediate-risk PCa were prescribed neoadjuvant androgen-deprivation therapy (NADT) with luteinizing hormone-releasing hormone analogues (LHRH) for 4-6 months. Only radiation treatment was used for low-risk PCa. As a result, two groups and four subgroups of patients were formed depending on the treatment method. The immediate, proximate, and long-term results of radiation treatment methods were studied in groups and subgroups.Results. No complications were recorded during brachytherapy I-125. Radiation cystitis grade 1 and radiation rectitis grade 1 were diagnosed after SBRT in 16.6% and 4.0% of cases, respectively. In the only I-125 BT subgroup, the PSA level during the year decreased from 8.3 to 1.1 ng/ml, in the SBRT subgroup — from 7.5 to 0.8 ng/ml. In the case of combined treatment, PSA decreased from 1.2 to 0.93 ng/ml and from 4.5 to 0.5 ng/ml, respectively. Changes in prostate volume, residual volume, and urinary quality (I-PSS) were comparable in all subgroups. Five-year cancer-specific survival and overall survival in the group of patients after SBRT was 100%, after I-125 BT — more than 90%.Conclusion. Radiation treatment options for patients with localized PCa are safe. Conducting NADT does not significantly reduce the prostate volume and does not affect the indicators of urodynamics. High rates of cancer-specific five-year survival rate testify to the effectiveness of the evaluated treatment options.