CyberKnife Radiosurgery in lung cancer

Stereotactic radiosurgery in lung cancer DR.DEBNARAYAN DUTTA, Consultant Radiation Oncologist, Apollo speciality hospital Chennai

Radiosurgery is a non-invasive option in early lung cancer. High dose precise radiosurgery has immense potential. Early data from phase II studies have shown excellent loco-regional control and survival function. CyberKnife Radiosurgery in lung cancer has following advantages: 1.     Cyberknife has the unique technology of ‘see and shoot’. In this technology before each treatment field matching of the target and ‘intra-fraction motion correction’ is done, hence minimal normal lung comes in the radiation field. 2.      Cyberknife has sub-millimeter treatment accuracy. Margin (planning target volume) required (where normal lung comes) is minimal around the target. High dose region volume is minimal with Cyberknife and lung toxicity is expected to be lower compared with conventional treatment. 3.     Cyberknife has the multiple isocentric technique with non-coplanar field arrangement, hence have unmatched conformity index (uniform dose is delivered). Cyberknife use ‘pencil beam’ with multiple small beamlets delivered from various angles (maximum 1200 different position) hence ‘penumbra’ margin is less. 4.     As dosimetry is favorable and total dose delivered with Cyberknife is not higher compared with conventional fraction (usual dose delivered with Cyberknife 60 Gy/3 fr/ 1 week) there is no expected increase in lung toxicity with Cyberknife. Phase II prospective studies with Cyberknife have not shown any increase in radiation induced pneumonitis. 5.     ‘STAR trial’ is a multicentric randomized study initiated by MD Anderson Cancer Centre may provide answer to impact of Cyberknife on lung toxicity. There are other few ongoing clinical studies with hypofractionated radiation therapy on lung cancer that will provide useful information in near future   For more information of successful treatments using cyberknife you may please blog your comments or write to lakshmipriya_b@apollohospitals.com Radiosurgery in brain tumours Short course radiation therapy is the one of the most talked about subject in recent years and also a fascinating research zone. Hypofractionated radiation therapy is an old concept, but only in recent years with tremendous improvement in radiation therapy delivery technologies there is a significant visible surge in it’s applicability in clinical practice. Modern radiation therapy technology is capable of delivering high dose to the target while sparing majority of the adjacent critical structures. Hence, it is possible to deliver short course of treatment regimen with higher dose per fraction without increasing in toxicity. In brain tumours, radiosurgery with gamma-knife is considered standard of care in many of the clinical indications such as small meningiomas, acaustic schwannomas, residual low grade gliomas, AVMs and solitary/ oligo brain metastasis. Gamma-knife radiosurgery is in clinical practice for more than five decades.  There are several prospective and randomized studies (level I evidence) with long-term follow up data supporting the use of radiosurgery in these clinical indications. Other indications of radiosurgery are pituitary tumour, craniopharyngiomas, glomus tumours, chordomas and others. Robotic radiosurgery (CyberKnife®) is precision radiosurgery delivery system and an extension of gamma-knife system. CyberKnife uses the principle of gamma-knife, but with linear accelerator source instead of multiple cobalt sources. CyberKnife is capable to treating all tumours indicated for gamma-knife with similar accuracy. This modern tool has some additional advantages from gamma-knife, such as 1) CyberKnife can use fractionated treatment, hence relatively larger tumours can be treated, 2) require only thermoplastic mask, no need for invasive frame, 3) has inverse planning system, can spare critical structure, 4) there is a ‘intra-fraction’ correction technology with imaging, 5) there is no need to change the source, hence may be more cost effective and 6) can be used to treat extra-cranial tumours also. CyberKnife has a linear accelerator attached with a robot and is capable of treatment from various coplanar and non-coplanar field arrangements. CyberKnife has sub-millimeter accuracy and unmatched dose distribution.  The advanced technology behind CyberKnife uses image guidance technology and computer-controlled robotics to deliver and extremely precise dose of radiation to targets, avoiding the surrounding healthy tissue, and adjusting for patient and tumor movement during treatment. In conclusion, CyberKnife is an extension of gammaknife radiosurgery delivery system. This machine has immense promise to treat with short course regimens with high dose and improve local control without increasing toxicities.

Glomus Jugulare Tumour successfully treated with cyberknife

MEDICAL REPORT

This 41 years old gentleman a case of glomus jugulare tumour was diagnosed in 2005. He underwent embolisation in 15.03.2005 followed by excision of tumour on 18.03.2005 at Kerala.
On follow up in 5.05.2005 MRI showed residual lesion of size 3.4 x2.2 cm. Patient underwent SRS on 26.07.2005 for a dose of 10 Gy to 80% isodose at elsewhere.
On follow up found recurrence in 2007 for which he went to same center where no further treatment was offered.
Then he went to another hospital in Kerala where he was offered 2nd open surgery for which patient was not willing. Then in April 2010 MRI done showed increase in lesion size about 4.3 cm x 4.21 cm x6.0 cm in size.
TREATMENT

Patient came to Apollo speciality bospital for further treatment. Patient was treated with Cyberknife boost and IMRT after discussion through our tumour board
Now follow MRI revealed good regression of size of tumour and volume analysis showed almost close to 40 to 50 % of reduction in tumour volume.

For more information you may blog your comments or write to lakshmipriya_b@apollohospitals.com

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.

For further information ,you may please blog your comments are write to lakshmipriya_b@apollohospitals.com

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

Radiosurgical Treatment of Primary Liver Cancer: Baylor Radiosurgery Center Experience

Radiosurgical Treatment of Primary Liver Cancer: Baylor Radiosurgery Center Experience

John O’Connor, M.D., Medical DirectorBaylor Radiosurgery Center, Dallas, TXRobert Goldstein, M.D., Director, Liver and Pancreas Disease CenterBaylor University Medical Center, Dallas, TX

Hepatocellular carcinoma (HCC) is the fifth most common cancer and third leading cause of cancer death, with 626,000 new cases and 598,000 deaths per year.1 Although it is less common in the United States, its incidence has tripled in the past 30 years principally in relation to the spread of hepatitis C infection.2 Survival for patients with hepatocellular cancer remains poor, about 10% at 5 years.3 HCC is potentially curable with hepatic resection or transplantation, but fewer than 30% of patients are eligible for surgery.4,5 Liver transplantation is the primary treatment for patients with cirrhosis and unresectable HCC, with low rates of recurrence and 5-year survival of about 70%.6,7

Stereotactic body radiotherapy (SBRT) has the ability to deliver high, focused doses while limiting irradiation of normal liver tissue. The use of SBRT for both primary and metastatic liver cancer is increasing worldwide at an impressive rate as clinicians are encouraged by favorable safety and efficacy data.8-11 CyberKnife® researchers have been active in the use of SBRT for liver as well.12-14 At the Baylor Radiosurgery Center we have been treating unresectable HCC since April of 2005. In March 2010 we updated our findings at the CyberKnife Scientific Meeting in Dallas.

We presented outcomes of a retrospective review of 24 patients with 27 tumors. All patients were evaluated by a liver transplant surgeon prior to radiosurgery and were deemed unresectable. The median tumor diameter was 4 cm and we have successfully treated liver tumors as large as 11 cm in diameter. Patients were treated with the CyberKnife System using Synchrony® Respiratory Tracking. The median dose was 42 Gy (range 27 - 54 Gy) to the median 66% isodose line (range 50 - 80%), delivered in 3 daily fractions in 22 patients and 5 fractions in four patients. We followed our patients using MRI obtained at 3-month intervals.

To date our outcomes have been encouraging. Grade 1 or 2 toxicity (based on CTCAE 3.0 guidelines) occurred in four patients (17%); a single Grade 3 toxicity was observed. There were no Grade 4-5 toxicities and no occurrence of radiation-induced liver disease. Overall local tumor control in all patients based on RECIST criteria was 87% at a median follow-up of 12 months. One-year Kaplan-Meier survival was 43%, and median survival was 11 months.

An additional eight patients with HCC (and nine tumors) were treated as a “bridge” to liver transplantation, that is, to control the growth of their tumors so that they may remain on the organ waitlist until a liver is available for transplant. We presented our preliminary findings on these patients at the 2009 meeting of the American Society for Radiation Oncology (ASTRO).15 All of these patients proceeded to transplant in a median of 90 days (range 8 – 209 days) after radiosurgery. We assessed the tissue response in the explanted tissue; three of the lesions responded completely, three were reduced in size, and three were stable.

The CyberKnife System has become a valuable component of our treatment program for unresectable HCC. Its ability to track liver tumors as they move with respiration has allowed us to deliver high doses of radiation accurately to achieve excellent rates of local control.

Source: Accuray Newsletter April 2010

For more information you may please blog your comments or write to lakshmipriya_b@apollohospitals.com

CYBERKNIFE FOR GASTRIC CANCERS

Stereotactic body radiotherapy for isolated para-aortic lymph node recurrence after curative resection in gastric cancer

Metastases from gastric cancer are common and can progress rapidly; even with aggressive treatment 5-year survival rates are low. However, researchers from Korea Institute of Radiological & Medical Sciences hypothesized that there is a certain population of such patients in whom the disease follows a more indolent course, based on studies of patients with
resected liver metastases. This population may benefit from SRS of isolated metastases from
gastric primaries. Thus, they treated 7 such patients with the CyberKnife® System, delivering 45 to 51 Gy (median 48 Gy) in 3 fractions. The patients were followed for 14 to 33 months (median 26 months). Local control was achieved in 6 of 7 patients; 2 patients were disease-free, 3 were alive with disease, and 2 patients died of disease progression. Three-year actuarial overall survival was 43%, and disease-free survival was 29%. The authors conclude that the results support their hypothesis that an indolent subgroup with less aggressive disease progression who could benefit
from the use of local treatments such as CyberKnife Radiosurgery.
 
Source: Accuray's focus newsletter