Lung Optimized Treatment with the CyberKnife® Robotic Radiosurgery System

Lung Optimized Treatment with the CyberKnife® Robotic Radiosurgery System
Worldwide, lung cancer is the most common cancer in terms of both incidence and mortality, with 1.61 million new cases and 1.38million deaths in 2008.1 An ever growing number of patients with early stage disease are categorized as poor surgical candidatesdue to co-morbidities such as advanced lung and heart disease. For decades these patients were left with few treatment options and were most often treated with external beam radiation therapy (EBRT). EBRT has limited efficacy due to the inclusion of large volumes of normal tissue within the treatment field, limiting the ability to deliver the high doses needed for tumor control.2 Stereotactic body radiation therapy (SBRT) for the lung directly addresses the dose limitations of EBRT. SBRT allows clinicians to deliver much higher
biologically equivalent doses in one to five fractions. Clinical evidence and publications over the last several years have demonstratedsuperior local control results for SBRT as compared to EBRT3-5, and SBRT has become a standard for the treatment of medically inoperable early stage lung cancer.6

Delivering high doses of radiation in five or fewer fractions to lung tumors demands a high degree of precision and accuracy. The Synchrony® Respiratory Tracking Systemis the only available system that provides real-time tracking for tumors that move with respiration.7 Accurate alignment of each treatment beam with the moving target is
maintained by moving the beam dynamically during treatment.

One challenge to offering CyberKnife® SBRT treatments to lung cancer patients has been the system’s reliance on implanted fiducial markers for tracking.8 Developmentsover the past several years, specifically the advent of the Xsight® Lung Tracking System technology9, allow clinicians to offer fiducial-less treatments to a subset of these
patients (typically peripherally located tumors with a minimum dimension of 15 mm). Using the Synchrony System, with or without fiducial markers, CyberKnife SBRT lung cases have been treated with a total GTV-to-CTV expansion of 3 mm and a CTV-to-PTV expansion of 2 mm.10-12

Now, with the introduction of Lung Optimized Treatment, clinicians can offer the option of fiducial-less treatments to all CyberKnife lung patients, regardless of the location
of the tumor. Lung Optimized Treatment includes the current Xsight Lung Tracking System and provides two new tracking modes: 1-View Tracking and 0-View Tracking.

1-View Tracking is designed for cases in which the treatment target is clearly visible and therefore can be tracked in only one of two the X-ray projections. With 1-View Tracking, motion in the non-tracked plane is accounted for using an Internal Target Volume (ITV) expansion in one direction (along the source-detector imager axis of the
visible view). The ITV expansion needed for 1-View Tracking is expected to be slightly larger than the CTV-to-PTV expansion used with the Xsight Lung Tracking System.
0-View Tracking is designed for cases in which the treatment target is not clearly visible in either of the two X-ray projections. In this case, ITV expansion is used in all directions.

The CyberKnife System tracking technology for treatment of lung tumors includes:
1. The Synchrony Respiratory Tracking System, which provides real-time tracking for tumors that move with respiration
2. The Xsight Lung Tracking System and the Fiducial Tracking System, which allow the target to be treated with no ITV expansion
3. The new 1-View Tracking mode, which requires ITV expansion only along the axis normal to the tracking plane
4. The new 0-View Tracking mode, which requires ITV expansion in all directions

Source: www.accuray.com

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HEPATOCELLULAR CARCINOMA - CK TREATMENT FOR PATIENT FROM MIZORAM

This 46 years old gentleman plumber from Mizoram, who was infected with HIV infection (also has the habit of alcohol & smoking) was diagnosed to have hepatocellular carcinoma Right lobe of liver in January 2010. He underwent chemotherapy treatment & TACE treatment else where, still the disease persisted he came for cyberknife radio surgery in June 2010.
After assessing him with PET CT and other investigations, we decided to take him up for cyberknife radio surgery.

With help of our interventional radiologist. Patient underwent gold fiducial insertion into his lesion under image guidance, after 1 week, he was taken up for treatment planning and verification.

He was treated between 28/6/2010 to 3/7/2010 with five fractions of cyberknife radio surgery, he tolerated the treatment very well.
The whole procedure was done as out patient basis.
Patient came for his 1st follow up in October 2010, he was absolutely feeling better after the treatment with steady improvement in his health.


PET CT in October 2010 showed complete resolution of lesion.
Both patient and we (doctors) are very happy to see the good result.

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organ preserving treatment for small localized choroid melanoma

Title: Radiosurgery with CyberKnife as an organ preserving treatment for small localized choroid melanoma
Authors: KR Prasanna Kumar*, MBBS; Debnarayan Dutta*, MD; Prativa Mishra^, MS; Raghunandhan* MD; P Mahadev * MD, DNB; AN Vaidhyswaran* MD; Sanjay Chandrasekhar* MD; Janos Stumpf *MD, PhD; Rathnadevi* DMRT; V Murali# PhD; PG Kurup# PhD;
*Department of Radiation Oncology, #Medical Physics, Apollo Speciality Hospital, Chennai
^Department of Opthalmology, Apollo Speciality Hospital, Chennai


Abstract



Aim: To evaluate robotic radiosurgery as an organ preserving treatment for localized choroid melanoma of the eye.
Case report: Thirty six year old female patient had complaint of progressive dimness of vision of right eye for six months. Fundoscopy examination showed small lesion (2.5 x 2.5 mm) in macular region. 320 slices CT scan showed organ confined 2.5 x 2.5 mm nodular lesion in the macular region (3 mm superior and 2.5 mm temporal to the origin of optic nerve at fovea) of right eye and was diagnosed with localized choroid melanoma of right eye (visual acuity 6/18 ). Metastatic workup was normal. She was planned for SRS (CyberKnife) as an organ preserving approach. Planning CT scan and CyberKnife treatment (dose 18 Gy single fraction, prescription isodose 85%; treatment time 22 min, GTV 111.6 mm3, 2mm PTV margin, PTV 403 mm3) were done with retro-bulbar anesthesia. Mean dose to right eye, left eye, right eye lens and pituitary gland was 4.9, 0.4, 0.4 and 1 Gy respectively. Maximum dose to optic chiasm, brainstem, right (2% vol) and left optic nerve were 1.4, 2.1, 15 and 0.4 Gy respectively. Skull tracking method was used as tumour tracking method. She completed treatment without any acute complication and visual acuity was preserved.
Conclusion: Robotic radiosurgery is a feasible, acceptable and an appropriate treatment modality as organ preserving approach in small choroid melanomas.

Keywords: Choroid melanoma, Robotic radiosurgery, Organ preserving approach

Rectal Carcinoma with Lung Metastasis

Rectal Carcinoma with Lung Metastasis

Case History
A 77-year-old male was presented to Apollo Speciality Cancer Hospital reporting rectal carcinoma that was diagnosed in the year 2006. The patient was then undergone surgery (anterio perineal resection), radiation therapy and chemotherapy. The patient was clinically stable until the year 2009. In the year 2009, he developed repeated episodes of cough and pain on the right side of the chest. Owing to these complaints, the patient was evaluated by performing whole body PET scan. The scan revealed increased metabolic activity in lower lobe of the right lung and posterior basal segment pleural base mass. No other sight in the body showed activity (disease) in the PET scan. Biopsy from the lung mass was suggestive of metastatic adenocarcinoma.

The patient was diagnosed with solitary lung metastasis with controlled primary site disease and was planned to treat with radical intent using CyberKnife®. He was treated with 45Gy in five fractions in 1 week through CyberKnife® radiosurgery. The patient tolerated the radiosurgery well.

A follow-up CT scan was performed at 6-month post-CyberKnife®. The scan revealed a significant reduction in the lung mass.

Discussion
Generally, patients having solitary (single) or ‘oligo metastasis’ (<3 metastasis) with otherwise good general health and controlled primary disease are treated with curative intent. Surgery (metastectomy) is the preferred treatment. However, surgery may not be possible in a large
number of patients because of their medical condition or age. Therefore, these patients can be treated with radiosurgery using CyberKnife®

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Cholangiocarcinoma treated with CyberKnife

Cholangiocarcinoma treated with CyberKnife

Introduction: Cholangiocarcinoma is a relatively rare disease, however has poor prognosis. Liver resection or transplantation is only curative treatment (1). Unfortunately, majority of the patients present with locally advanced, unresectable disease with extensive tumor spread (2). The treatment is not yet standardized. They are treated with either chemotherapy or radiotherapy or in combination (2-6). CyberKnife is recent advancement in radiation therapy delivery system which has high accuracy and flexibility in targeting the tumor through image-guided stereotactic body radiotherapy (SBRT) system (7).

Case history: Forty eight year old gentleman from Uttar Pradesh, India was diagnosed with inoperable cholangiocarcinoma eight months back. He was treated with chemotherapy for four months. However, post-chemotherapy imaging evaluation did not show any significant response. He was diagnosed as chemo-resistant inoperable cholangiocarcinoma. His liver function was maintained and general condition was good. As he was suffering from inoperable, chemotherapy resistant cholangiocarcinoma, he was referred for radiation therapy and was evaluated for robotic radiosurgery (CyberKnife) treatment. After appropriate evaluation, imaging (PET scan), fiducial placement and planning he was treated with CyberKnife. He received 30 Gy in 5 fractions in one week. Dose to the target was adequate and to adjacent normal structures were within normal limits. He completed treatment without any severe toxicity and is on regular follow up.

Discussion: In early operable choloangiocarcinoma, 3-year overall survival rate after curative surgery is only 40-60% (1-2). Advanced unresectable cholangiocarcinoma patients have poorer prognosis as well as severe complications due to biliary stasis (3,4). They are mainly treated with supportive or palliative care. Main aims of treatment in these patients are to preserve quality of life and improve survival rate. Palliative therapy options in these patients are chemotherapy, radiotherapy, photodynamic therapy and biliary drainage procedures (5). Median survival with palliative chemotherapy and external beam radiation therapy are 5 to 9 and 9 to 12 months respectively (2-6). Inoperable, advanced cholangiocarcinomas remain localized and distant metastasis is not common (1). Hence, these tumours may be treated with localized treatment options with maximum effect. However, cholangiocarcinomas are relatively resistant to both radiation and chemotherapy. Hence, high dose radiation therapy is required to have desired loco-regional control (7). CyberKnife radiosurgery is a SBRT using real time respiratory-motion tracking system, and is known to exert minimal normal tissue injury. High dose of radiation treatment in few fractions are possible with CyberKnife which increases tumour control probability without increasing toxicity (7). High dose radiation therapy with proton beam therapy also has shown promising loco-regional control without additional severe toxicity (2). We suggest that CyberKnife might be a safe and useful treatment option in advanced, unresectible cholangiocarcinoma.

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