The dosimetric impact of the prescription isodose line (IDL) on the quality of robotic stereotactic radiosurgery (SRS) plans

2017 ◽  
Vol 44 (12) ◽  
pp. 6159-6165 ◽  
Author(s):  
Qianyi Xu ◽  
Jiajin Fan ◽  
Jimm Grimm ◽  
Tamara LaCouture ◽  
Sucha Asbell ◽  
...  
Keyword(s):  
Stereotactic Radiosurgery ◽  
Prescription Isodose

Long-Term Quality of Life Following Stereotactic Radiosurgery for Vestibular Schwannoma

2012 ◽  
Vol 73 (S 02) ◽  
Author(s):  
J. Thom ◽  
M. Carlson ◽  
J. Jacob ◽  
C. Driscoll ◽  
B. Neff ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Stereotactic Radiosurgery ◽  
Vestibular Schwannoma

scholarly journals Quality of Automated Stereotactic Radiosurgery Plans in Patients with 4 to 10 Brain Metastases

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3458
Author(s):  
Anna Petoukhova ◽  
Roland Snijder ◽  
Rudolf Wiggenraad ◽  
Linda de Boer-de Wit ◽  
Ivonne Mudde-van der Wouden ◽  
...  
Keyword(s):  
Brain Metastases ◽  
Stereotactic Radiosurgery ◽  
Irradiation Time ◽  
Intensity Modulated Radiotherapy ◽  
Pass Rate ◽  
Conformity Index ◽  
Index Gradient ◽  
Single Isocenter ◽  
Volumetric Modulated Arc Radiotherapy

The purpose was to compare linac-based stereotactic radiosurgery and hypofractionated radiotherapy plan quality of automated planning, intensity modulated radiotherapy (IMRT) and manual dynamic conformal arc (DCA) plans as well as single- and multiple-isocenter techniques for multiple brain metastases (BM). For twelve patients with four to ten BM, seven non-coplanar linac-based plans were created: a manually planned DCA plan with a separate isocenter for each metastasis, a single-isocenter dynamic IMRT plan, an automatically generated single-isocenter volumetric modulated arc radiotherapy (VMAT) plan, four automatically generated single-isocenter DCA plans with three or five couch angles, with high or low sparing of normal tissue. Paddick conformity index, gradient index (GI), mean dose, total V12Gy and V5Gy of uninvolved brain, number of monitor units (MUs), irradiation time and pass rate were compared. The GI was significantly higher for VMAT than for separate-isocenter, IMRT, and all automatically generated plans. The number of MUs was lowest for VMAT, followed by automatically generated DCA and IMRT plans and highest for manual DCA plans. Irradiation time was the shortest for automatically planned DCA plans. Automatically generated linac-based single-isocenter plans for multiple BM reduce the number of MUs and irradiation time with at least comparable GI and V5Gy relative to the reference separate-isocenter DCA plans.

TREATMENT OF SPINAL TUMORS USING CYBERKNIFE FRACTIONATED STEREOTACTIC RADIOSURGERY

Neurosurgery ◽  
2009 ◽  
Vol 64 (2) ◽  
pp. 297-307 ◽  
Author(s):  
Gregory J. Gagnon ◽  
Nadim M. Nasr ◽  
Jay J. Liao ◽  
Inge Molzahn ◽  
David Marsh ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Stereotactic Radiosurgery ◽  
University Hospital ◽  
Postoperative Treatment ◽  
Spinal Tumors ◽  
Radiation Toxicity ◽  
Pain Scores ◽  
Component Scores

Abstract OBJECTIVE Benign and malignant tumors of the spine significantly impair the function and quality of life of many patients. Standard treatment options, including conventional radiotherapy and surgery, are often limited by anatomic constraints and previous treatment. Image-guided stereotactic radiosurgery using the CyberKnife system (Accuray, Inc., Sunnyvale, CA) is a novel approach in the multidisciplinary management of spinal tumors. The aim of this study was to evaluate the effects of CyberKnife stereotactic radiosurgery on pain and quality-of-life outcomes of patients with spinal tumors. METHODS We conducted a prospective study of 200 patients with benign or malignant spinal tumors treated at Georgetown University Hospital between March 2002 and September 2006. Patients were treated by means of multisession stereotactic radiosurgery using the CyberKnife as initial treatment, postoperative treatment, or retreatment. Pain scores were assessed by the Visual Analog Scale, quality of life was assessed by the SF-12 survey, and neurological examinations were conducted after treatment. RESULTS Mean pain scores decreased significantly from 40.1 to 28.6 after treatment (P < 0.001) and continued to decrease over the entire 4-year follow-up period (P < 0.05). SF-12 Physical Component scores demonstrated no significant change throughout the follow-up period. Mental Component scores were significantly higher after treatment (P < 0.01), representing a quality-of-life improvement. Early side effects of radiosurgery were mild and self-limited, and no late radiation toxicity was observed. CONCLUSION CyberKnife stereotactic radiosurgery is a safe and effective modality in the treatment of patients with spinal tumors. CyberKnife offers durable pain relief and maintenance of quality of life with a very favorable side effect profile.

A simple dose gradient measurement tool to complement the conformity index

2006 ◽  
Vol 105 (Supplement) ◽  
pp. 194-201 ◽  
Author(s):  
Ian Paddick ◽  
Bodo Lippitz
Keyword(s):  
Low Dose ◽  
Target Volume ◽  
Mean Value ◽  
Treatment Modalities ◽  
Measurement Tool ◽  
Conformity Index ◽  
Treatment Plans ◽  
Prescription Isodose ◽  
Gradient Measurement

✓A dose gradient index (GI) is proposed that can be used to compare treatment plans of equal conformity. The steep dose gradient outside the radiosurgical target is one of the factors that makes radiosurgery possible. It therefore makes sense to measure this variable and to use it to compare rival plans, explore optimal prescription isodoses, or compare treatment modalities.The GI is defined as the ratio of the volume of half the prescription isodose to the volume of the prescription isodose. For a plan normalized to the 50% isodose line, it is the ratio of the 25% isodose volume to that of the 50% isodose volume.The GI will differentiate between plans of similar conformity, but with different dose gradients, for example, where isocenters have been inappropriately centered on the edge of the target volume.In a retrospective series of 50 dose plans for the treatment of vestibular schwannoma, the optimal prescription isodose was assessed. A mean value of 40% (median 38%, range 30–61%) was calculated, not 50% as might be anticipated. The GI can show which of these prescription isodoses will give the steepest dose falloff outside the target.When planning a multiisocenter treatment, there may be a temptation to place some isocenters on the edge of the target. This has the apparent advantage of producing a plan of good conformity and a predictable prescription isodose; however, it risks creating a plan that has a low dose gradient outside the target. The quality of this dose gradient is quantified by the GI.

scholarly journals Quality of Life Outcomes Following Spine Stereotactic Radiosurgery

2016 ◽  
Vol 96 (2) ◽  
pp. S197 ◽  
Author(s):  
J.A. Miller ◽  
E.H. Balagamwala ◽  
L. Angelov ◽  
J.H. Suh ◽  
M.B. Tariq ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Stereotactic Radiosurgery ◽  
Life Outcomes ◽  
Quality Of Life Outcomes

scholarly journals Long-term quality of life in patients with vestibular schwannoma: an international multicenter cross-sectional study comparing microsurgery, stereotactic radiosurgery, observation, and nontumor controls

2015 ◽  
Vol 122 (4) ◽  
pp. 833-842 ◽  
Author(s):  
Matthew L. Carlson ◽  
Oystein Vesterli Tveiten ◽  
Colin L. Driscoll ◽  
Frederik K. Goplen ◽  
Brian A. Neff ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Stereotactic Radiosurgery ◽  
Short Form ◽  
Individual Treatment ◽  
Control Group ◽  
Treatment Groups ◽  
Sf 36 ◽  
Disease Specific

OBJECT The optimal treatment for sporadic vestibular schwannoma (VS) is highly controversial. To date, the majority of studies comparing treatment modalities have focused on a narrow scope of technical outcomes including facial function, hearing status, and tumor control. Very few publications have investigated health-related quality of life (HRQOL) differences between individual treatment groups, and none have used a disease-specific HRQOL instrument. METHODS All patients with sporadic small- to medium-sized VSs who underwent primary microsurgery, stereotactic radiosurgery (SRS), or observation between 1998 and 2008 were identified. Subjects were surveyed via postal questionnaire using the 36-Item Short Form Health Survey (SF-36), the 10-item Patient-Reported Outcomes Measurement Information System short form (PROMIS-10), the Glasgow Benefit Inventory (GBI), and the Penn Acoustic Neuroma Quality-of-Life (PANQOL) scale. Additionally, a pool of general population adults was surveyed, providing a nontumor control group for comparison. RESULTS A total of 642 respondents were analyzed. The overall response rate for patients with VS was 79%, and the mean time interval between treatment and survey was 7.7 years. Using multivariate regression, there were no statistically significant differences between management groups with respect to the PROMIS-10 physical or mental health dimensions, the SF-36 Physical or Mental Component Summary scores, or the PANQOL general, anxiety, hearing, or energy subdomains. Patients who underwent SRS or observation reported a better total PANQOL score and higher PANQOL facial, balance, and pain subdomain scores than the microsurgical cohort (p < 0.02). The differences in scores between the nontumor control group and patients with VS were greater than differences observed between individual treatment groups for the majority of measures. CONCLUSIONS The differences in HRQOL outcomes following SRS, observation, and microsurgery for VS are small. Notably, the diagnosis of VS rather than treatment strategy most significantly impacts quality of life. Understanding that a large number of VSs do not grow following discovery, and that intervention does not confer a long-term HRQOL advantage, small- and medium-sized VS should be initially observed, while intervention should be reserved for patients with unequivocal tumor growth or intractable symptoms that are amenable to treatment. Future studies assessing HRQOL in VS patients should prioritize use of validated disease-specific measures, such as the PANQOL, given the significant limitations of generic instruments in distinguishing between treatment groups and tumor versus nontumor subjects.

scholarly journals Benefit of dosimetry distribution for patients with brain metastases from non-small cell lung cancer by Cyberknife Stereotactic radiosurgery (SRS) system

2020 ◽  
Author(s):  
Xuyao YU ◽  
Yuwen Wang ◽  
Zhiyong Yuan ◽  
Hui Yu ◽  
Yongchun Song ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Brain Metastases ◽  
Small Cell Lung Cancer ◽  
Stereotactic Radiosurgery ◽  
Cell Lung Cancer ◽  
Treatment Time ◽  
Small Cell ◽  
Small Cell Lung ◽  
Multiple Lesions ◽  
Prescription Isodose

Abstract BackgroundTo pursue high precision in tumor and steeper dose fall-off in healthy tissues of brain metastases stereotactic radiosurgery (SRS), this study investigated an opitimized planning by comparison only one multiple-lesions-plan (MLP) and multiple single-lesion-plans (SLP) in the treatment of brain metastases using Cyberknife (CK) Robotic Radiosurgery System. MethodsFifty non-small cell lung cancer (NSCLC) patients (28 males and 22 females) with 2-4 multiple brain metastases were retrospectively replanned with 12 to 32 Gy prescription dose in 1 to 3 fractions. Two different clinical SRS plans (SLP and MLP) for the same patients were generated, under the same collimator and prescription isodose line (62-68%) by CK Multiplan System. Both the SLP and MLP were able to get ＞95% PTV volume covered prescription isodose and meet the Timmerman 2011 OAR (brainstem, optic nerve and pituitary) constraints.ResultsCompared with the SLP, the maximum dose (Dmax) and mean dose (Dmean) of brainstem in the MLP decreased 0.22-3.13% (2.62%) and 2.71-12.56% (5.57%), over all P＜0.05. While the volumes of whole brain minus the tumors received a single dose equivalence of 8-16Gy (V8Gy-V16Gy) could effectively reduce in the MLP. And the treatment time parameters (the total number of beams and monitor units (MU)) of the MLP declined 3.31% and 1.47% (P＜0.05) respectively. Although there were a few differences of conformity index (CI) and homogeneity index (HI) between two treatment plans, it was no statistical significance (P = 2.94 and 1.08＞ 0.05). ConclusionOne multiple-lesions-plan for brain metastases could achieve higher precision in target and lower dose in healthy tissue, while shorten the treatment time and improve the treatment efficiency.

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