Unveiling the Efficacy of Gamma Knife Radiosurgery for Tectal Plate Gliomas.

BACKGROUND AND OBJECTIVES: Tectal plate gliomas (TPGs) are midbrain tumors that grow slowly and have a benign clinical course. Most TPGs are low-grade astrocytomas, but they can encompass various histological tumor types. Gamma Knife radiosurgery (GKRS) is being explored as a potentially safe and effective treatment option for TPGs, although research in this area is limited. This study aims to evaluate GKRS's efficacy and safety in patients with TPG and provide a comprehensive review of existing literature on the topic. METHODS: This retrospective, single-center study included 48 patients with consecutive TPG who underwent GKRS between September 2005 and June 2022. Patients diagnosed with TPGs based on radiological or tissue-based criteria and who had a minimum follow-up period of 12 months were eligible for inclusion. The primary end points were local control and the absence of GKRS-associated or tumor-associated mortality and morbidity. RESULTS: During a median follow-up of 28.5 months (range, 12-128), the radiological assessment showed tumor control in all cases, with 16.7% achieving a complete response and 68.8% achieving a partial response. Pseudoprogression occurred in 6.2% of cases, with onset ranging from 3 to 8 months. Clinical outcomes revealed no permanent neurological deterioration, with symptoms improving in 14.6% of patients and remaining stable in the others. One patient in the pseudoprogression group experienced transient Parinaud syndrome. One patient died during follow-up because of unrelated causes. The mean survival time after GKRS was 123.7 months. None of the clinical, radiological, or radiosurgical variables showed a correlation with partial/complete response, clinical improvement, or overall survival. CONCLUSION: There is limited research available on the management of TPGs, and this study presents the largest patient cohort treated with GKRS, along with a substantial follow-up duration. Despite its limitations, this study demonstrates the efficacy and low-risk profile of GKRS for TPGs.

Double isocenter optimization with HD-MLC linear accelerator to treat extended fields in patients with head and neck cancers.

PURPOSE: For departments with a congested patient burden or with a limited number of eligible LINACs, we investigated whether LINACS dedicated for SRS-SBRT with limited field high-definition (HD) multi-leaf collimator (MLC) could help to carry this load, and utilized a double-isocenter (DI) optimization with a limited field size of HD-MLC to defeat the craniocaudal field size restriction to match treated plans in a wide-field MLC LINAC for head and neck cancer patients. METHODS: Fourteen patients with locally advanced head and neck cancers were included, previously treated with simultaneous integrated boost volumetric modulated arc treatment (VMAT) in 33 fractions of clinical target volumes (CTV) of 70Gy, 63Gy, and 57Gy, via single isocenter (SI) plans in Millennium MLC-120 of Varian Trilogy. The DI plans were generated on Pinnacle TPS to be delivered in HD 120 leaves MLC on Varian Truebeam. The organs at risk (OAR) doses and the prescription volume parameters were compared. RESULTS: The DI plans in HD-MLC LINACs were successfully matching the previously treated plans for OAR and CTV constraints. The CI (1.18 versus 1.26; p=0.004) and HI (0.23 versus 0.29; p<0.001) were significantly improved with DI, while the MUs (1321.5 versus 800.3; p<0.001) and the treatment delivery times (6.1 versus 3.7 min; p<0.001) per fraction increased modestly with DI compared to SI, respectively. CONCLUSIONS: We revealed that DI optimization plans prepared for HD-MLC could effectively accomplish our goal dosimetrically in locoregionally advanced head and neck cases, despite a modest increase in the MU and treatment delivery times per fraction. This technique may provide an alternative in case of downtimes of standard MLC systems or a standalone treatment machine in case of high volumes requiring extended-field IMRT procedures, or possibly shorten the lengthy waiting times in facilities with limited SRS or SBRT patients.

The Prognostic Significance of Novel Pancreas Cancer Prognostic Index in Unresectable Locally Advanced Pancreas Cancers Treated with Definitive Concurrent Chemoradiotherapy.

PURPOSE: We evaluated the prognostic quality of the novel pancreas cancer prognostic index (PCPI), a combination of CA 19-9 and systemic inflammation response index (SIRI), on the outcomes of locally advanced pancreas adenocarcinoma (LAPAC) patients who received concurrent chemoradiotherapy (C-CRT). METHODS: This retrospective analysis covered 152 unresectable LAPAC patients treated from 2007 to 2019. Receiver operating characteristic (ROC) curve analysis was used to define ideal cutoff thresholds for the pretreatment CA 19-9 and SIRI measurements, individually. The associations between the PCPI groups and progression-free- (PFS) and overall survival (OS) comprised the respective primary and secondary endpoints. RESULTS: The ROC curve analysis distinguished the respective rounded optimal cutoffs at 91 U/m/L (< versus ≥90) and 1.8 (< versus ≥1.8) for CA 19-9 and SIRI, arranging the study cohort into two significantly different survival groups for each, with resultant four likely groups: Group-1: CA 19-9<90 U/m/L and SIRI<1.8, Group-2: CA 19-9<90 U/m/L but SIRI≥1.8, Group-3: CA 19-9≥90 U/m/L but SIRI<1.8, and Group-4: CA 19-9≥90 U/m/L and SIRI≥1.8. Since the PFS (P=0.79) and OS (P=0.86) estimates of the groups 2 and 3 were statistically indistinct, we merged them as one group and created the novel three-tiered PCPI: PCPI-1: CA 19-9<90 U/m/L and SIRI<1.8, PCPI-2: CA 19-9<90 U/m/L but SIRI≥1.8 or CA 19-9≥90 U/m/L but SIRI<1.8, and PCPI-3: CA 19-9≥90 U/m/L and SIRI≥1.8, respectively. Comparative analyses unveiled that the PCPI-1 and PCPI-3 groups had the respective best and worst PFS (17.0 versus 7.5 versus 4.4 months; P<0.001) and OS (26.1 versus 15.1 versus 7.4 months; P<0.001) outcomes, while the PCPI-2 group posed in between. The multivariate analysis outcomes confirmed the novel three tired PCPI's independent prognostic significance on either of the PFS [HR: 5.38 (95% confidence interval (CI): 4.96-5.80); P<0.001)] and OS [HR: 5.67 (95% CI: 5.19-6.15); P<0.001] endpoints, separately. CONCLUSION: The new PCPI introduced here can be used as an independent and reliable prognostic indicator to divide LAPAC patients into three subgroups with discrete survival results.

Low Advanced Lung Cancer Inflammation Index Predicts Poor Prognosis in Locally Advanced Nasopharyngeal Carcinoma Patients Treated with Definitive Concurrent Chemoradiotherapy.

PURPOSE: We aimed to retrospectively investigate the prognostic worth of pretreatment advanced lung cancer inflammation index (ALI) in locally advanced nasopharyngeal carcinoma (LA-NPC) patients treated with concurrent chemoradiotherapy (C-CRT). Patients and Methods. A total of 164 LA-NPC patients treated with cisplatinum-based definitive C-CRT were included in this retrospective cohort analysis. The convenience of ideal pre-C-CRT ALI cut-offs affecting survival results was searched by employing the receiver operating characteristic (ROC) curve analyses. The primary endpoint was the link between the ALI groups and overall survival (OS), while cancer-specific survival (CSS), locoregional progression-free survival [LR(PFS)], distant metastasis-free survival (DMFS), and PFS comprised the secondary endpoints. RESULTS: The ROC curve analyses distinguished a rounded ALI cut-off score of 24.2 that arranged the patients into two cohorts [ALI ≥ 24.2 (N = 94) versus < 24.2 (N = 70)] with significantly distinct CSS, OS, DMFS, and PFS outcomes, except for the LRPFS. At a median follow-up time of 79.2 months (range: 6-141), the comparative analyses showed that ALI < 24.2 cohort had significantly shorter median CSS, OS, DMFS, and PFS time than the ALI ≥ 24.2 cohort (P < 0.001for each), which retained significance at 5- (P < 0.001) and 10-year (P < 0.001) time points. In multivariate analyses, ALI < 24.2 was asserted to be an independent predictor of the worse prognosis for each endpoint (P < 0.001for each) in addition to the tumor stage (T-stage) (P < 0.05 for all endpoints) and nodal stage (N-stage) (P < 0.05 for all endpoints). CONCLUSION: As a novel prognostic index, the pretreatment ALI < 24.2 appeared to be strongly associated with significantly diminished survival outcomes in LA-NPC patients treated with C-CRT independent of the universally recognized T- and N-stages.