Postural instability (PI) is common in idiopathic Parkinson's disease (IPD). We measured sensory and motor contributions to PI in 50 patients with advanced IPD, off and on medication and in a subset pre- and 3, 6 and 12 months post-unilateral pallidotomy, using computerized dynamic posturography [specifically, the Sensory Organization Test (SOT) and the Unified Parkinson's Disease Rating Scale (UPDRS) subscale PIGD (Postural Instability and Gait Disorder)]. Off medication, all patients had abnormal PIGD scores. The group could be separated into those with normal SOT equilibrium scores (SOTN) and those, the majority, with abnormal postural control when sensory feedback was limited (SOTABN). Medication improved the PIGD scores but worsened the SOT scores in the majority of patients. Increases in spontaneous sway in some patients contributed to the negative effect of medication on SOT scores. However, this could not explain the detrimental effect of medication on SOT scores in at least 40% of patients. On the other hand, pallidotomy improved both PIGD and SOT scores in both groups. A predictor of good outcome from pallidotomy concerning PI was the degree of worsening of the effect that medication had on SOT5 scores. PI in IPD appears to be multifactorial. We propose that the PIGD score reflects sensory and motor aspects of postural control, with normal sensory feedback, while the SOT equilibrium scores measure the sensory organizational process of postural control in the presence of altered sensory inputs. There is a dissociation between the effects of medication and pallidotomy on motor and sensory components of postural control, which may reflect the underlying pathophysiological mechanism responsible for these different components of PI. We suggest that patients with advanced IPD and PI on medication should consider adjuvant surgical treatment for better postural control.

BACKGROUND:The current study was performed to compare the clinical outcomes and toxicity in patients treated with postoperative chemoradiotherapy for gastric cancer using intensity-modulated radiotherapy (IMRT) versus 3-dimensional conformal radiotherapy (3D CRT). METHODS: Fifty-seven patients with gastric or gastroesophageal junction cancer were treated postoperatively: 26 with 3D CRT and 31 with IMRT. Concurrent chemotherapy was capecitabine (n ¼ 31), 5-fluorouracil (5-FU) (n ¼ 25), or none (n ¼ 1). The median radiation dose was 45 Gy. Dose volume histogram parameters for kidney and liver were compared between treatment groups. RESULTS: The 2-year overall survival rates for 3D CRT versus IMRT were 51% and 65%, respectively (P ¼ .5). Four locoregional failures occurred each in the 3D CRT (15%) and the IMRT (13%) patients. Grade 2 acute gastrointestinal toxicity was found to be similar between the 3D CRT and IMRT patients (61.5% vs 61.2%, respectively) but more treatment breaks were needed (3 vs 0, respectively). The median serum creatinine from before radiotherapy to most recent creatinine was unchanged in the IMRT group (0.80 mg/dL) but increased in the 3D CRT group from 0.80 mg/dL to 1.0 mg/dL (P ¼ .02). The median kidney mean dose was higher in the IMRT versus the 3D CRT group (13.9 Gy vs 11.1 Gy; P ¼ .05). The median kidney V20 was lower for the IMRT versus the 3D CRT group (17.5% vs 22%; P ¼ .17). The median liver mean dose for IMRT and 3D CRT was 13.6 Gy and 18.6 Gy, respectively (P ¼ .19). The median liver V30 was 16.1% and 28%, respectively (P < .001). CONCLUSIONS: Adjuvant chemoradiotherapy was well tolerated. IMRT was found to provide sparing to the liver and possibly renal function. Cancer 2010;116:3943-52.

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Purpose:To quantify pancreas tumor motion on both a planning 4D-CT and during a single fraction treatment using the CyberKnife linear accelerator and Synchrony respiratory tracking software, and to investigate whether a single 4D-CT study is reliable for determining radiation treatment margins for patients with locally advanced pancreas cancer. Methods and Materials: Twenty patients underwent fiducial placement, biphasic pancreatic protocol CT scan and 4D-CT scan in the treatment position while free-breathing. Patients were then treated with a single 25 Gy fraction of stereotactic body radiotherapy. Predicted pancreas motion in the superior-inferior (SI), left-right (LR), and anterior-posterior (AP) directions was calculated from the maximum inspiration and maximum expiration 4D-CT scan. For CyberKnife treatments, mean respiratory cycle motion and maximum respiratory cycle motion was determined in the SI, LR, and AP directions. Results: The range of centroid movement based on 4D-CT in the SI, LR, and AP directions were 0.9 to 28.8 mm, 0.1 to 13.7 mm, and 0.2 to 7.6 mm, respectively. During CyberKnife treatment, in the SI direction, the mean motion of the centroid ranged from 0.5 to 12.7 mm. In the LR direction, the mean motion range was 0.4 to 9.4 mm. In the AP direction, the mean motion range was 0.6 to 5.5 mm. The maximum range of movement (mean) during CyberKnife treatment in the SI, LR, and AP directions were 4.5 to 48.8 mm (mean 20.8 mm), 1.5 to 41.3 mm (mean 11.3 mm), and 1.6 to 68.1 mm (mean 13.4 mm), respectively. Neither the maximum or mean motion correlated with the 4D-CT movement. Conclusions: There is substantial respiratory associated motion of pancreatic tumors. The 4D-CT planning scans cannot accurately predict the movement of pancreatic tumors during actual treatment on CyberKnife.

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