A Study of Cases with Rib Metastasis Difficult to Distinguish from Microfractures on Bone Scintigraphy

A retrospective study of about 10,000 cases at Kawasaki Medical School Hospital on whom bone scans were performed over a six year period revealed five cases in which metastasis was mistaken for a benign rib lesion. This mistake occurred because the accumulation pattern of the radionuclide in the rib region on the bone scan indicated a so-called "hot spot" observed with microfractures rather than the rod-like increased accumulation along costal bones that is coincident with the finding of bone metastasis. This experience suggests that solitary hot spots in the rib region on bone scans should be diagnosed carefully, as such an accumulation is most frequently associated with a benign etiology but rarely may be a malignant lesion

自然発生黒色腫担癌豚の選択的熱中性子捕捉療法 : 線量分布と局所反応の検討

前臨床実験として自然発生黒色腫担癌豚に10B-BPA(10B-Para-boronophenylalanine)を用いた選択的熱中性子捕捉療法を施行し,その時の局所,全身の中性子およびγ線の線量分布を調べたので局所反応とともに報告する.熱中性子源として武蔵工業大学原子炉研究所の原子炉を用いた.10B-BPA 15.8g(200mg/kg)を経静脈的に投与し,100kw,210分間の熱中性子照射を行った.腫瘍部以外を遮蔽するために,bismuth面より順にLiFシート,LiFタイル,鉛ブロックを配置した.上記collimation systemにより腫瘍周辺組織の熱中性子線量を腫瘍部の約1/100に減弱させることができ,また全身被曝線量軽減の意味からも効果を認めた.また,局所反応においても,ビラン,潰瘍等を伴わず治療傾向を示した.We carried out pre-clinical experiment for treatment of spontaneously occurring melanoma using 10B-Para-boronophenylalanine (10B-BPA) and also measured actual dose distribution of neutron and γ-ray irradiation on melanoma itself, surrounding normal tissue and distant body surfaces. As the source of the thermal neutron beam, we used Musashi Institute of Technology Reactor for Medical Purposes. An hour prior to thermal neutron irradiation of 100kw for 210 minutes, 15.8g of 10B-BPA (200mg/kg) was administered to the pig then the pig was undertaken general anesthesia which was remotely maintained and set in irradiation in front of the bismuth surface of the reactor. LiF tiles, LiF sheets and lead blocks were arranged as the collimator for shielding the pig skin but for the melanoma lesion. The neutron fluence to tumor surrounding normal skin was about one hundredth of that to melanoma and this collimation system was so effective that further decrease in neutron fluence and γ-ray to distant body surface were attained. As the result of this experiment, the pig melanoma showed complete disappearance and the lesion was covered by normal skin without erosive and ulcerative changes