Herein, we investigate the long-term clinical outcomes for cervical cancer patients
treated with in-room computed tomography–based brachytherapy. Eighty patients with Stage
IB1–IVA cervical cancer, who had undergone treatment with combined 3D high-dose rate
brachytherapy and conformal radiotherapy between October 2008 and May 2011, were
retrospectively analyzed. External beam radiotherapy (50 Gy) with central shielding after
20–40 Gy was performed for each patient. Cisplatin-based chemotherapy was administered
concurrently to advanced-stage patients aged ≤75 years. Brachytherapy was delivered in
four fractions of 6 Gy per week. In-room computed tomography imaging with applicator
insertion was performed for treatment planning. Information from physical examinations at
diagnosis, and brachytherapy and magnetic resonance imaging at diagnosis and just before
the first brachytherapy session, were referred to for contouring of the high-risk clinical
target volume. The median follow-up duration was 60 months. The 5-year local control,
pelvic progression-free survival and overall survival rates were 94%, 90% and 86%,
respectively. No significant differences in 5-year local control rates were observed
between Stage I, Stage II and Stage III–IVA patients. Conversely, a significant difference
in the 5-year overall survival rate was observed between Stage II and III–IVA patients
(97% vs 72%; P = 0.006). One patient developed Grade 3
late bladder toxicity. No other Grade 3 or higher late toxicities were reported in the
rectum or bladder. In conclusion, excellent local control rates were achieved with minimal
late toxicities in the rectum or bladder, irrespective of clinical stage.
BackgroundThe purpose of this study was to compare carbon ion radiotherapy (C-ion RT) and stereotactic radiotherapy (SBRT) with photon beams for the treatment of hepatocellular carcinoma (HCC), specifically with regard to the dose volume parameters for target coverage and normal tissue sparing.MethodsData of 10 patients who were treated using C-ion RT with a total dose of 60 Gy(RBE) in four fractions were used. The virtual plan of SBRT was simulated on the treatment planning computed tomography images of C-ion RT. Dose volume parameters such as minimum dose covering 90 % of the planning target volume (PTV D90), homogeneity index (HI), conformity index (CI), mean liver dose (MLD), volume of the liver receiving 5 to 60 Gy (V5-60), and max point dose (Dmax) of gastrointestinal (GI) tract were calculated from both treatment plans.ResultsThe PTV D90 was 59.6 ± 0.2 Gy(RBE) in C-ion RT, as compared to 56.6 ± 0.3 Gy in SBRT (p < 0.05). HI and CI were 1.19 ± 0.03 and 0.79 ± 0.06, respectively in C-ion RT, as compared to 1.21 ± 0.01 and 0.37 ± 0.02, respectively in SBRT. Only CI showed a significant difference between two modalities. Mean liver dose was 8.1 ± 1.4 Gy(RBE) in C-ion RT, as compared to 16.1 ± 2.5 Gy in SBRT (p < 0.05). V5 to V50 of liver were higher in SBRT than C-ion RT and significant differences were observed for V5, V10 and V20. Dmax of the GI tract was higher in SBRT than C-ion RT, but did not show a significantly difference.ConclusionsC-ion RT provides an advantage in both target conformity and normal liver sparing compared with SBRT.
The efficacy and toxicity of five-fraction CyberKnife radiotherapy were evaluated in patients with large brain metastases in critical areas. A total of 85 metastases in 78 patients, including tumors >30 cm3 (4 cm in diameter) were treated with five-fraction CyberKnife radiotherapy with a median marginal dose of 31 Gy at a median prescribed isodose of 58%. Changes in the neurological manifestations, local tumor control, and adverse effects were investigated after treatment. The surrounding brain volumes circumscribed with 28.8 Gy (single dose equivalent to 14 Gy: V14) were measured to evaluate the risk of radiation necrosis. Neurological manifestations, such as motor weakness, visual disturbances and aphasia improved in 28 of 55 patients (50.9%). Local tumor control was obtained in 79 of 85 metastases (92.9%) during a median follow-up of eight months. Symptomatic edema occurred in 10 patients, and two of them (2.6%) required surgical resection because of radiation necrosis. The V14 of these patients was 3.0–19.7 cm3. There were 16 lesions with a V14 of ≥7.0 cm3, and two of these lesions developed extensive brain edema due to radiation necrosis. None of the patients with a V14 of <7.0 cm3 exhibited edema requiring surgical intervention. We therefore conclude that a high rate of local tumor control and low rates of complications can be obtained after five-fraction CyberKnife radiotherapy for large metastases in critical areas. The V14 of the surrounding brain is therefore a useful indicator for the risk of radiation necrosis in patients with large metastases.
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