子宮頸癌に対するCTに基づく画像誘導小線源治療：線量ー体積パラメータと臨床アウトカ ムの相関

博士(医学)琉球大

Computed tomography–based image-guided brachytherapy for cervical cancer : correlations between dose–volume parameters and clinical outcomes

This study evaluated the oncologic outcomes and complications of cervical cancer patients in terms of CT-based image-guided brachytherapy (IGBT) parameters. Of 68 cervical cancer patients treated with definitive radiotherapy/concurrent chemoradiotherapy, most received whole-pelvis external beam RT (EBRT) of 40 Gy in 20 fractions, pelvic EBRT with central shield of 10 Gy in 5 fractions, and CT-based IGBT of 18 Gy in 3 fractions prescribed to point A. Cumulative EBRT and IGBT doses were calculated as the total equivalent dose in 2 Gy fractions (EQD2). The median follow-up was 31 (3–52) months. The 2-year overall survival, local control, pelvic control, and disease-free survival rates of the 68 patients were 92%, 83%, 82% and 73%, respectively. The HR-CTV D90, length from the tandem axis to left/right margin of the HR-CTV (T-LR), and HR-CTV volume were significant IGBT parameters for predicting local/pelvic control. Patients who received an HR-CTV D90 of >60 Gy, compared with ≤60 Gy, had significantly better local/pelvic control. Furthermore, 70 Gy was a marginally significant HR-CTV D90 cut-off affecting local control. T-LR was an independent IGBT parameter predicting local/pelvic control on multivariate analysis. Three patients developed Grade 3 or higher treatment-related complications. The D2cm3 of organs at risk were not significant predictors of complications. Future challenges for further improving outcomes include additional interstitial needles for irregularly shaped HR-CTVs, and moderate dose escalation, especially for patients with poor tumor responses

Appropriate radiation dose for symptomatic relief and local control in patients with adult T cell leukemia/lymphoma

Adult T-cell leukemia/lymphoma (ATL) is an aggressive peripheral T-cell neoplasm that occurs only in patients with human T-cell leukemia virus type 1. No large study or randomized trial investigating radiotherapy (RT) for ATL has been performed. We retrospectively reviewed 55 courses of RT for 41 consecutive patients with ATL who underwent RT between 2000 and 2016 at our institutions. The results showed that RT for local ATL lesions can achieve symptomatic improvement in 92% of cases. Local remission, either complete remission (CR) or partial response (PR), was achieved in 100% of the patients (CR: 89%, PR: 11%) with ≥40 Gy irradiation. CR or PR was achieved in 71% (CR: 29%, PR: 43%) with 30–39 Gy and in 73% (CR: 6.7%, PR: 67%) with ≤29 Gy irradiation. The mean total radiation dose in the CR and PR groups differed significantly (38 vs 25 Gy, P = 0.0002). The maximum acute toxicity was Grade 0–2 in all patients, except for one patient experienced Grade 3 radiation dermatitis. In-field relapses occurred in 36% of patients, and the frequency of in-field relapses was 11%, 30% and 71% among those who achieved CR, PR and SD, respectively. All 9 patients who received total skin irradiation experienced cutaneous relapses, with a median of 63 days (range, 7–210 days). Almost all (39 of 41) patients with ATL experienced out-of-field progression after RT. In conclusion, RT was confirmed to be effective and safe for palliative treatment of local ATL lesions