Head and neck (HN) cancer is an endemic disease in Taiwan, China. Locally recurrent HN cancer after full‐dose irradiation poses a therapeutic challenge, and boron neutron capture therapy (BNCT) may be a solution that could provide durable local control with tolerable toxicity. The Tsing‐Hua Open Pool Reactor (THOR) at National Tsing‐Hua University in Hsin‐Chu, provides a high‐quality epithermal neutron source for basic and clinical BNCT research. Our first clinical trial, entitled “A phase I/II trial of boron neutron capture therapy for recurrent head and neck cancer at THOR”, was carried out between 2010 and 2013. A total of 17 patients with 23 recurrent HN tumors who had received high‐dose photon irradiation were enrolled in the study. The fructose complex of l ‐boronophenylalanine was used as a boron carrier, and a two‐fraction BNCT treatment regimen at 28‐day intervals was used for each patient. Toxicity was acceptable, and although the response rate was high (12/17), re‐recurrence within or near the radiation site was common. To obtain better local control, another clinical trial entitled “A phase I/II trial of boron neutron capture therapy combined with image‐guided intensity‐modulated radiotherapy (IG‐IMRT) for locally recurrent HN cancer” was initiated in 2014. The first administration of BNCT was performed according to our previous protocol, and IG‐IMRT was initiated 28 days after BNCT. As of May 2017, seven patients have been treated with this combination. The treatment‐related toxicity was similar to that previously observed with two BNCT applications. Three patients had a complete response, but locoregional recurrence was the major cause of failure despite initially good responses. Future clinical trials combining BNCT with other local or systemic treatments will be carried out for recurrent HN cancer patients at THOR.

Background: To investigate serum carcinoembryonic antigen (CEA) as a prognostic factor for rectal cancer patients receiving pre-operative chemoradiotherapy (CRT). Methods: Between 2000 and 2009, 138 patients with advanced rectal cancer receiving CRT before surgery at our hospital were retrospectively classified into 3 groups: pre-CRT CEA <6 ng/ml (group L; n = 87); pre-CRT CEA ≥ 6 ng/ml and post-CRT CEA <6 ng/ml (group H-L; n = 32); and both pre- and post-CRT CEA ≥ 6 ng/ml (group H-H; n = 19). CEA ratio (defined as post-CRT CEA divided by pre-CRT CEA), post-CRT CEA level and other factors were reviewed for prediction of pathologic complete response (pCR). Results: Five-year disease-free survival (DFS) was better in groups L (69.0%) and H-L (74.5%) than in group H-H (44.9%) (p = 0.024). Pathologic complete response was observed in 19.5%, 21.9% and 5.3% of groups L, H-L and H-H respectively (p = 0.281). Multivariate analysis showed that ypN stage and pCR were independent prognostic factors for DFS and that post-CRT CEA level was independently predictive of pCR. As a whole, post-CRT CEA <2.61 ng/ml predicted pCR (sensitivity 76.0%; specificity 58.4%). For those with pre-CRT CEA ≥6 ng/ml, post-CRT CEA and CEA ratio both predicted pCR (sensitivity 87.5%, specificity 76.7%). Conclusions: In patients with pre-CRT serum CEA ≥6 ng/ml, those with “normalized” CEA levels after CRT may have similar DFS to those with “normal” (<6 ng/ml) pre-CRT values. Post-CRT CEA level is a predictor for pCR, especially in those with pre-CRT CEA ≥6 ng/ml.

The authors report the long-term treatment results of Gamma Knife surgery (GKS) for patients with low-grade astrocytomas who underwent surgery at a single institution. A series of 21 patients (median age 20 years) with 25 intracranial low-grade astrocytomas (World Health Organization Grades I and II) were treated with GKS between 1993 and 2003. Among them, four underwent GKS as a primary treatment. Two underwent GKS as a treatment boost after radiotherapy. In the other 15 patients, GKS was performed as an adjuvant or salvage treatment for residual/recurrent tumors after the patients had undergone craniotomy. Tumor volumes ranged from 0.2 to 13.3 ml (median 2.4 ml). Prescription margin doses ranged from 8 to 18 Gy (median 14.5 Gy). Radiation volumes were 1.3 to 21.6 ml (median 3.6 ml). Patients underwent regular follow up, with neurological evaluation and magnetic resonance imaging studies obtained at 6-month intervals. One patient was lost to follow-up. The clinical follow-up time was 5 to 144 months (median 67 months). Complete tumor remission was seen in three patients. The 10-year progression-free patient survival rate after GKS was 65%. Tumor progression was found in six patients of whom five received further salvage treatment. All the tumor progression occurred within the GKS-treated volumes. Mild-to-moderate adverse radiation effects (AREs) were found in eight patients. Both of the patients who had undergone GKS as a treatment boost after radiotherapy developed AREs, but with good shrinkage of tumors. Gamma Knife surgery provides durable long-term local tumor control with acceptable toxicity for some patients with highly selected low-grade astrocytomas.