腎細胞癌骨転移例に対する放射線治療の局所効果に関する検討

Abstract

放射線治療を行った骨転移を有する腎細胞癌22例(男18例, 女4例, 平均年齢61歳)を脊椎骨転移群と骨盤骨・長管骨転移群の2群に分類し, 再石灰化率, 再石灰化出現までの期間, 疼痛緩和効果, 効果持続期間について比較検討した。3～51ヵ月の経過観察期間で, 再石灰化率と再石灰化出現までの期間は両群で同等であったが, 骨盤骨・長管骨転移群の約60%で疼痛が完全消失したのに対し, 脊椎骨転移群で疼痛が完全消失したのは1例のみであった。また, 疼痛緩和持続時間は両群とも2～3ヵ月で差を認めなかったが, 治療線量による比較では35Gy以上照射した(10例)方がそれ未満(12例)より2倍以上長い効果持続期間であった。腫瘍縮小は3例に認め, 骨破壊の進行抑制も含めると奏功率は48%であった。骨転移の早期発見および放射線治療により疼痛管理を含めたQOL改善が示唆された。

If bone metastasis of renal cell carcinoma is neglected, pain, paralysis, and pathologic fracture develope; consequently, the patient's quality of life is significantly lowered. We investigated the local effect of the radiation therapy to the patients with metastasis. The investigation targeted 22 cases (27 parts) of renal cell carcinoma with bone metastasis that were treated with radiation therapy in our hospital during the last 6 years. We analyzed cell type, presence or absence of organ metastasis, irradiated site, therapeutic dose, treatment period, and combination therapy. The object was classified into 2 groups by metastatic site: the group with metastasis in the vertebra, and the group of metastasis in the pelvis or long bones. We examined re-calcification rate, length of time to recalcification emergence, pain relief and duration of effect as therapeutic effects. The irradiated site was vertebra in 14, pelvis in 7, and long bone in 6 patients. The therapeutic dose was 15 to 50 Gy, and the average was 35.7 Gy. No difference was found in the re-calcification rate and length of time to recalcification according to the metastatic site. The pain relief effect was significant in the pelvis and long bone group compared to the vertebra group. The effect lasted longer when the radiation dose was 35 Gy or more, compared with a lower dose. The radiation therapy for renal cell carcinoma with bone metastasis was effective to relieve pain and improve the patients' quality of life. The results showed that early detection and recognition of bone metastasis provide local control.