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67, 95% CI 0.52-0.85, P=0.001) and patients with hypopharyngeal-laryngeal carcinoma (HR 0.81, 95% CI 0.69-0.94, P=0.005). A trend towards significant interaction was found in favor of oral cavity-oropharyngeal carcinoma (P=0.161). Comparable results were observed in the pre-specified subgroup analyses. Meta-regression analyses suggested that the primary site appeared to be a predictor of survival benefits in HNSCC patients who received treatment with EGFR inhibitors over those who did not.

Our meta-analysis suggests that the survival benefits of EGFR inhibitors might depend on primary sites in HNSCC. Further studies are needed to confirm this finding.

Our meta-analysis suggests that the survival benefits of EGFR inhibitors might depend on primary sites in HNSCC. Further studies are needed to confirm this finding.

Prophylactic cranial irradiation (PCI) was compared to observation in several randomized trials (RCTs), and a reduction greater than 50% was shown regarding the incidence of brain metastases (BM). However, none of these studies showed an improvement of overall survival (OS), possibly related to relatively small sample sizes and short follow-up. The aim of this meta-analysis was therefore to assess the impact of PCI on long term OS for stage III non-small cell lung cancer (NSCLC) compared to observation based on the pooled updated individual patient RCT data.

Seven RCTs were eligible, and data from the four most recent trials (924 patients) could be retrieved. The log-rank observed minus expected number of events and its variance were used to calculate individual and overall pooled hazard ratios (HRs) and 95% confidence intervals (95% CIs) with a fixed effects model. Inter-trial heterogeneity was studied using the I

test. In addition, the 5-year absolute survival difference between arms was calculated for all endpoints. The pre-specified toxicities were reported descriptively.

The median follow-up was 97months (74-108). Compared to observation, no statistically significant impact of PCI on OS was observed (HR 0.90 [0.76-1.07] p=0.23, 5-year absolute difference 1.8% [-5.2-8.8]). PCI significantly prolonged progression-free survival (HR 0.77 [0.66-0.91] p=0.002) and BM-free survival (HR 0.82 [0.69-0.97] p=0.02). The number of patients with high-grade (≥3) toxicity was 6.4% (21/330) for PCI.

No OS benefit by PCI was observed, but PCI prolonged the progression-free survival and BM-free survival at an increased risk of late memory impairment and fatigue.

No OS benefit by PCI was observed, but PCI prolonged the progression-free survival and BM-free survival at an increased risk of late memory impairment and fatigue.

Consensus for defining gross tumor volume (GTV) and clinical target volume (CTV) for limited-field radiation therapy (LFRT) of GBM are not well established. We leveraged a department MRI simulator to image patients before and during LFRT to address these questions.

Supratentorial GBM patients receiving LFRT (46Gy+boost to 60Gy) underwent baseline MRI (MRI1) and interim MRI during RT (MRI2). GTV1 was defined as T1 enhancement+surgical cavity on MRI1 without routine inclusion of T2 abnormality (unless tumor did not enhance). The initial CTV margin was 15mm from GTV1, and the boost CTV margin was 5-7mm. The GTV1 characteristics were categorized into three groups identical T1 and T2 abnormality (Group A), T1 only with larger T2 abnormality not included (Group B), and T2 abnormality when tumor lacked enhancement (Group C). GTV2 was contoured on MRI2 and compared with GTV1 plus 5-15mm expansions.

Among 120 patients treated from 2014-2019, 29 patients (24%) underwent replanning based on MRI2. On MRI2, 84% of GTV2 were covered by GTV1+5mm, 93% by GTV1+7mm, and 98% by GTV1+15mm. On MRI1, 43% of GTV1 could be categorized into Group A, 39% Group B, and 18% Group C. Group B’s patterns of failure, local control, or progression-free survival were similar to Group A/C.

Initial CTV margin of 15mm followed by a boost CTV margin of 7mm is a reasonable approach for LFRT of GBM. Omitting routine inclusion of T2 abnormality from GTV delineation may not jeopardize disease control.

Initial CTV margin of 15 mm followed by a boost CTV margin of 7 mm is a reasonable approach for LFRT of GBM. read more Omitting routine inclusion of T2 abnormality from GTV delineation may not jeopardize disease control.

To quantify the fractionation dependence of carbon (

C) ions and photons in three rat prostate carcinomas differing in growth rate, differentiation and hypoxia.

Three sublines (AT1, HI, H) of syngeneic rat prostate tumors (R3327) were treated with six fractions of either

C-ions or 6 MV photons. Dose-response curves were determined for the endpoint local tumor control within 300days. The doses at 50% control probability (TCD

) and the relative biological effectiveness (RBE) of

C-ions were calculated and compared with the values from single and split dose studies.

Experimental findings for the three tumor sublines revealed (i) a comparably increased RBE (2.47-2.67), (ii) a much smaller variation of the radiation response for

C-ions (TCD

35.8-43.7Gy) than for photons (TCD

91.3-116.6Gy), (iii) similarly steep (AT1) or steeper (HI, H) dose-response curves for

C-ions than for photons, (iv) a larger fractionation effect for photons than for

C-ions, and (v) a steeper increase of the RBE with decreasing fractional dose for the well-differentiated H- than for the less-differentiated HI- and AT1-tumors, reflected by (vi) the smallest α/β-value for H-tumors after photon irradiation.

C-ions reduce the radiation response heterogeneity between the three tumor sublines as well as within each subline relative to photon treatments, independently of fractionation. The dose dependence of the RBE varies between tumors of different histology. The results support the use of hypofractionated carbon ion treatments in radioresistant tumors.

12C-ions reduce the radiation response heterogeneity between the three tumor sublines as well as within each subline relative to photon treatments, independently of fractionation. The dose dependence of the RBE varies between tumors of different histology. The results support the use of hypofractionated carbon ion treatments in radioresistant tumors.