Non-operative management involving chemoradiation therapy combined with high-dose-rate brachytherapy for T3 rectal cancer using a vaginal shielded cylindrical applicator: a technical report.

It has been shown that a group of rectal cancer patients will achieve a pathological complete response following preoperative chemoradiotherapy, and non-operative management has recently gained attention. To escalate the tumour dose and increase the likelihood of pathological complete response, brachytherapy can play an important role in safely increasing the total dose. However, at the time this report was published, an applicator dedicated to rectal brachytherapy was unaffordable in Japan. Here, we report two T3 rectal cancer patients who were inoperable or refused surgery and treated by chemoradiotherapy following intracavitary brachytherapy involving a vaginal cylinder applicator with lead shielding.

[A case of effective multidisciplinary treatment for advanced gallbladder carcinoma with distant lymph node metastases].

A 59-year-old woman with upper abdominal pain was diagnosed as having an advanced-stage gallbladder carcinoma with significant metastases in the para-aortic lymph nodes to the more distant right external iliac nodes by imaging studies. These findings suggested that the tumor was unresectable, and therefore, palliative cholecystectomy with lymph node biopsy was performed. Furthermore, we initiated chemoradiotherapy with linac radiotherapy( 50 Gy) and weekly gemcitabine (GEM 300 mg/body) for 6 weeks. Partial response (PR) was achieved after chemoradiotherapy. Subsequently, we initiated chemotherapy with GEM alone (1,000 mg/m2) on days 1, 8, and 15, every 28 days for 15 courses. Following disease progression, we initiated chemotherapy with S-1 alone( 80 mg/m2/day) on days 1-14, every 21 days for 9 courses, as second-line treatment. Two years later, following re-progression of the disease, we performed best supportive care with retrograde ureteral stenting for hydronephrosis and retrograde biliary stenting for obstructive jaundice. The patient survived for 35 months after palliative surgery. Moreover, she remained well and performed normal activities for 34 months. This experience indicates that, in patients with unresectable gallbladder carcinoma, multidisciplinary treatment could extend survival and improve the quality of life.

Relative biological effectiveness of 290 MeV/u carbon ions for the growth delay of a radioresistant murine fibrosarcoma.

The relative biological effectiveness (RBE) for animal tumors treated with fractionated doses of 290 MeV/u carbon ions was studied. The growth delay of NFSa fibrosarcoma in mice was investigated following various daily doses given with carbon ions or those given with cesium gamma-rays, and the RBE was determined. Animal tumors were irradiated with carbon ions of various LET (linear energy transfer) in a 6-cm SOBP (spread-out Bragg peak), and the isoeffect doses; i.e. the dose necessary to induce a tumor growth delay of 15 days were studied. The iso-effect dose for carbon ions of 14 and 20 keV/microm increased with an increase in the number of fractions up to 4 fractions. The increase in the isoeffect dose with the fraction number was small for carbon ions of 44 keV/microm, and was not observed for 74 keV/microm. The alpha and beta values of the linear-quadratic model for the radiation dose-cell survival relationship were calculated by the Fe-plot analysis method. The alpha values increased linearly with an increase in the LET, while the beta values were independent of the LET. The alpha/beta ratio was 129 +/- 10 Gy for gamma-rays, and increased with an increase in the LET, reaching 475 +/- 168 Gy for 74 keV/microm carbon ions. The RBE for carbon ions relative to Cs-137 gamma-rays increased with the LET. The RBE values for 14 and 20 keV/microm carbon ions were 1.4 and independent of the number of fractions, while those for 44 and 74 keV/microm increased from 1.8 to 2.3 and from 2.4 to 3.0, respectively, when the number of fractions increased from 1 to 4. Increasing the number of fractions further from 4 to 6 was not associated with an increase in the RBE. These results together with our earlier study on the skin reaction support the use of an RBE of 3.0 in clinical trials of 80 keV/microm carbon beams. The RBE values for low doses of carbon beams were also considered.