Feasibility of radiosurgery for patients with spinal tumors treated in lateral decubitus position: A case series from Memorial Sloan Kettering Cancer Center.

INTRODUCTION: Often in clinical practice radiation oncologists encounter patients who require treatment to the spine commonly in the setting of metastatic disease. These metastases usually cause pain, immobility, or neurologic deficits mandating expedited therapy to alleviate the suffering of our patients. Spine radiosurgery techniques have been used extensively for palliation purposes; however, given the patients' deteriorating condition or pain and inability to tolerate anesthesia the radiation oncologist is often left with the conundrum of how to best set up his or her patient in preparation for radiosurgery if supine is not a viable option. In the Memorial Sloan Kettering Cancer Center several patients have been treated successfully in the lateral decubitus position to overcome this set-up issue. In this report, the feasibility of the lateral decubitus set-up for patients who benefit from radiosurgery to the spine when and if they cannot tolerate standard supine position is explored. OBJECTIVE: To report on a retrospective case series of three patients with a total of four lesions who were treated with radiosurgery for spinal metastases while set up in the lateral decubitus position. METHODS AND MATERIALS: This is a retrospective case series of 3 patients who were treated with radiosurgery to the spine for palliation of painful metastatic foci. Patients were treated in the lateral decubitus position in 1-5 fractions in order to be eligible for this retrospective case series. Their set-up data, and clinical outcomes were then compared with historic controls. RESULTS: Patients who were treated in the lateral decubitus position were set up reliably and reproducibly. Additionally clinical outcomes on routine follow-up and imaging, and toxicity profiles also corroborated the utility of this treatment set-up. CONCLUSIONS: Routinely employing optical surface tracking during patient setup followed by KVCBCT prior to treatment delivery along with intra-fractional monitoring is safe and effective while utilizing the lateral decubitus position for the treatment of spinal metastases for patients who cannot tolerate the supine position. Finally the patient follow-up also corroborated that treatments were successful thus lending credence to the safety, ease, effectiveness, and feasibility of this patient set-up.

Dose-escalated radiation therapy with and without short-course androgen deprivation for intermediate-risk prostate cancer.

AIM: To investigate outcomes in intermediate-risk (IR) prostate cancer patients receiving dose-escalated external beam radiation therapy (RT) with or without short-course androgen deprivation (ADT). PATIENTS AND METHODS: This study comprised of 203 patients with IR prostate cancer who were treated at a single institution to a dose of 7,560 cGy or more between 2003-2010. Of these, 62 (30.5%) patients received ADT. Biochemical recurrence, distant metastatic-free survival, prostate cancer-specific survival, and overall survival were analyzed using the Kaplan-Meier method. RESULTS: The median follow-up was 62 months and the median duration of ADT was 6 months. The 6-year biochemical control was 89.2% for those receiving RT plus ADT versus 76.7% in those receiving RT alone (p=0.02). There were no differences between the two groups regarding distant metastatic-free survival, prostate cancer-specific survival, and overall survival (respective p-values of 0.91, 0.50, 0.67). CONCLUSION: Dose-escalated RT and short-course ADT results in improved biochemical outcomes for IR prostate cancer.

Clinical presentation of retinoblastoma in a middle-income country.

The presenting features of retinoblastoma in developing countries and their correlation with disease stage and patient survival are poorly known and they may be useful as background information for planning early diagnosis initiatives. Therefore, we undertook a retrospective review of 508 patients (467 evaluable, 296 unilateral) treated in Argentina from 1988 to 2008. Patients presented at an older age than reported from high-income countries [mean age 24 mo (range, 0 to 165 mo), 31 mo for unilateral (range, 0 to 165 mo), and 13.3 mo (range, 0 to 62 mo) for bilateral disease]. Leukocoria was the most common presenting sign (n=402, 86%). Strabismus was the only complaint in 25 (5.3%) patients. Forty-two patients (9%) presented with an enlarged eyeball and 37 (7.9%) with a red eye. Retinoblastoma was diagnosed in 22 (4.7%) asymptomatic children. These patients and those with strabismus alone were significantly younger and had a significantly better survival. Children presenting with enlarged eyeballs were significantly older and had significantly lower survival. In multivariable analysis older age and presentation with enlarged eyeballs were independently associated to advanced stage and mortality (P<0.001). Retinoblastoma is diagnosed in later stages in our setting and presentation with eye enlargement and increasing age at diagnosis correlate with worse outcome.

Pharmacokinetic analysis of topotecan after intra-vitreal injection. Implications for retinoblastoma treatment.

Topotecan is a promising drug with activity against retinoblastoma, however, attaining therapeutic concentrations in the vitreous humor is still a challenge for the treatment of vitreous seeds in retinoblastoma. Our aim was to characterize topotecan pharmacokinetics in vitreous and aqueous humor, and to assess the systemic exposure after intra-vitreal injection in rabbits as an alternative route for maximizing local drug exposure. Anesthetized rabbits were administered intra-vitreal injections of 5 microg of topotecan. Vitreous, aqueous, and blood samples were collected at pre-defined time points. A validated high-performance liquid chromatography assay was used to quantitate topotecan (lactone and carboxylate) concentrations. Topotecan pharmacokinetic parameters were determined in vitreous, aqueous and plasma using a compartmental analysis. Topotecan lactone concentrations in the vitreous of the injected eye were about 8 ng/mL 48 h after drug administration. The median maximum vitreous, aqueous and plasma total topotecan concentrations (C(max)) were 5.3, 0.68 and 0.21 microg/mL, respectively. The C(max) vitreous/aqueous of treated eyes and the C(max) vitreous/plasma were approximately 8 and 254, respectively. Total topotecan exposure (AUC) in the vitreous of the injected eye was 50 times greater than the total systemic exposure. These findings suggest that intra-vitreal administration of only 5 microg of topotecan reaches significant local levels over an extended period of time while minimizing systemic exposure in the rabbit. Intra-vitreal topotecan administration offers a promising alternative route for enhanced drug exposure in the vitreous humor with potential application for treatment of vitreal seeds in retinoblastoma while avoiding systemic toxicities.