CYBERKNIFE IN TREATMENT OF PITUITARY ADENOMAS

CYBERKNIFE IN TREATMENT OF PITUITARY ADENOMAS


In recent years, CyberKnife has emerged as an important treatment modality in the management of pituitary adenomas. Treatment results after performing CyberKnife and the complications of this procedure are reviewed.
Methods
Twenty-six patients with pituitary adenomas received stereotactic radiosurgery with the CyberKnife (CKRS). The follow-up periods ranged from 7 months to 47 months (mean±SD : 30±12.7 months). The patients consisted of 17 with non-functioning adenomas, 3 with prolactinomas and 6 with acromegaly. The change in the tumor volume, visual acuity, hormonal function, and complications by this therapy were analyzed in each case.
Results
The tumor control rate was 92.3%. Hormonal function was improved in all of the 9 (100%) functioning adenomas. Hormonal normalization was observed in 4 of the 9 (44%) patients with a mean duration of 16 months. In two patients (7.6%), visual acuity worsened due to cystic enlargement of the tumor after CKRS. No other complications were observed.
Conclusion
CyberKnife is considered safe and effective in selected patients with pituitary adenomas. However, longer follow-up is required for a more complete assessment of late toxicity and treatment efficacy.

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Rationale and Potential Clinical Applications for CyberKnife Robotic IMRT™

The CyberKnife® System as an Image-guided Intensity Modulated Radiotherapy Device: Rationale and Potential Clinical Applications for CyberKnife Robotic IMRT™

Donald B. Fuller, M.D., Radiation Oncologist Radiosurgery Medical Group (RSMG); CyberKnife Centers of San Diego

In clinical practice, the CyberKnife® Robotic Radiosurgery System has been almost exclusively used as a radiosurgical device, engineered to deliver conformal, ablative radiation treatments in one to five fractions to a wide variety of malignant lesions in the CNS, head and neck, lung, liver, pancreas, prostate and other sites.1-8 Although there is no medical reason why this device has not been used to deliver conventionally fractionated radiotherapy, this function has not previously been described, presumably due to the long treatment times associated with early-generation CyberKnife Systems. Nevertheless, the MultiPlan® Treatment Planning System is capable of computing very elegant intensity modulated radiotherapy (IMRT) dose distributions, and improvements in device efficiency have made the delivery of these IMRT plans feasible in clinical practice, thus leading to new CyberKnife treatment applications that would best be described as “Robotic IMRT™.”

The new CyberKnife VSI™ platform includes a number of enhancements that improve efficiency, including Sequential Optimization treatment planning, the Iris™ Variable Aperture Collimator (which allows for modulation of the beam during treatment9,15), the increased dose rate of a 1,000 MU/min linear accelerator and a 20% increase in robotic traversal speed. In addition, a treatment time reduction tool accessed during plan optimization allows the user to reduce the total number of treatment beams and nodes while still meeting treatment plan objectives.

Collectively, these enhancements create a device that can reduce treatment times by over half compared with predecessor CyberKnife Systems, while maintaining the precision and accuracy of the CyberKnife product.

SOURCE: ACCURAY FOCUS NEWSLETTER JAN, 2010

CYBERKNIFE SUCCESS STORY - TREATMENT OF PROSTATE CANCER

CYBERKNIFE SUCCESS STORY - TREATMENT OF PROSTATE CANCER

DR.MAHADEV Senior Consultant, Radiation Oncology

71 Yrs old Mr.Birendra Singh from Gopalganj, Bihar was devastated when he was diagnosed to have Prostate cancer. He had gone to his urologist for just a routine checkup because he was having difficulty in passing urine for the last couple of months. A routine PSA done was in the range of 15ng/ml. A transrectal biopsy revealed grade 2 adenocarcinoma of the prostate gland with a Gleason’s score of 3+4.

Mr.Singh went to Delhi for an opinion. He consulted various doctors which included several urologists, surgical oncologists and radiation oncologists.The options given to him included wait and watch, bilateral orchidectomy(removal of both testis), Radical prostatectomy, Brachytherapy(seed /HDR implant).The opinions were so varied that the family could not take a decision for 3 months.

Patient also consulted Apollo Hospitals at Ranchi in Jharkhand where he was advised to go to Apollo Speciality Hospital Chennai as all the treatment options were available there and he was also told that a full team of doctors decide on a treatment in the tumor board.

Mr Birendra Singh’s nephew who lives in the United States, meanwhile contacted his uncle from there and told him about a new treatment called the cyberknife which he had read on the internet. His nephew was very impressed by what he had read on the net- outpatient treatment, non-invasive, very precise radiation delivered robotically and just 5 sittings with practically no side effects. He asked his uncle to come to US for treatment as he thought it was unlikely that this treatment option would be available in India.

After going through all the treatment options Mr.Birendra Singh decided he would go in for Cyberknife as he found that to be the best treatment modality in his opinion. He visited Chennai in March 2009 to take a final decision. We had just then started using Cyberknife and we told him that the latest version of Cyberknife is now available here. He was told that the cost of cyberknife would be around 40,000 US dollars in US. We told him that the cost of treatment here would be Rs 400,000.

As we had just started Cyberknife Mr Singh was anxious about our technical capability. But when he came to know that the entire team was trained at the Stanford University, California, where actually the cyberknife was invented, he immediately decided to have the treatment here.

The first step in the treatment process was counselling him about the various treatment aspects.This included explaining to him the various stages of the treatment preparation ,planning and execution.The expected benefits and the various side effects that can be expected was explained to him in detail.The side effects that are normally seen with this treatment can be increased frequeny of micturition and bowel movemens.Very rarely, rectal bleeding can be seen as a late effect of radiotherapy.

The second step was placing 5 gold fiducials into the prostate gland transperinealy under transrectal guidance which took about half an hour. These fiducials are necessary for the machine to track the prostate gland during the entire course of treatment. Normally, we have to wait for a week after placing the fiducials for doing the planning CT scan. This is necessary because in the first couple of days, the seeds can migrate.

The third step in his planning was the making of a special type of bed called Vacloc for immobilization of the patient during treatment. Vacloc is a vacuum bed which takes the shape of the patient so that daily reproducibility of the patient in the same position can be achieved easily. This took about 10 minutes following which a CT scan was done with the patient lying in the vacloc in the treatment position.


Next, the Radiation oncologist contours the prostate gland, bladder and rectum. Then, the medical physicist puts on the treatment beams. The treatment plan was ready the next day and was reviewed by the oncologist and urologist.The treatment plan was finalized and the patient was asked to come for treatment the following day which happened to be a Tuesday. Patient was asked to have a light breakfast before 8 am and report for treatment at 10am.He was also asked to take a laxative the previous night and antacids.This preparation is a very important part of the treatment as improper bowel evacuation and gas in the bowel can interfere with the accuracy of the treatment.As cyberknife can achieve submillimeter target accuracy and continuously tracks the target while treatment ,it is absolutely essential that patients follow this preparatory regimen very carefully.Mr Singh was prescribed 5 treatment sittings on consecutive days.

Each treatment lasted for about 45-50 minutes and Mr.Birendra Singh completed his treatment on schedule on Saturday.He had initially booked his tickets for Sunday but as he did not have any side effects he preponed his journey to Saturday night.He was advised to have a PSA after 3 months which confirmed that the PSA had come down to normal values.

MR. BIRENDRA SINGH AFTER COMPLETING 5 TREATMENT SITTINGS

Mr.Singh Reported back to us in the first week of December. His PSA which was repeated was less that 1ng/ml which shows excellent response to treatment. There were practically no side effects during and after the treatment.



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Cyber Knife Radio surgery in Pediatric Patients

Cyber Knife Radio surgery in Pediatric Patients

Dr.R.Rathna Devi, Sr. Consultant Radiation Oncologist

“One little girl told me “ I want to go to school” she was one of my early pediatric patient with AVM for the new facility, Cyber Knife. That’s what was on her mind. And that’s what she did. She went to school immediately after her treatment. This made a tremendous difference to the family and to the child, and I was very happy to have offered her this”.



Cyber Knife radio surgery has a great advantage in treatment of pediatric intra and extra cranial lesions which includes non – invasive immobilization, low radiotherapy exposure to the developing normal brain other tissues and ability to fractionate the treatment.

Young patients in the past were usually required to wear a of head frame (Gamma Knife, other kind of radiosurgery equipments), and had to remain anesthetized during the entire, often day long procedure.


These procedures uses rigid metal frame attached directly to the patient’s skull to orient the radiation beams, making it difficult to treat young children with small/ fragile heads. Because the frame cannot be removed between the initial imaging and subsequent treatment, doctors also had to work fast with the other types of radio surgery. With the clock ticking, we had to place the frame, perform CT/MRI or other imaging studies; get everyone involved to meet, plan the treatment and then treat the patient, while the patient is intubated and asleep. This is not an optimal situation.

Fortunately now at Apollo Speciality Hospital we can treat young patients (who can hop off the table and go home or to school) after the initial imaging step while we plan the treatment strategy. The non invasive process uses tiny focused beams of radiation to perform radio surgery on a patients head or body. This technique allows us (Doctors) to attack trouble spots deep within the brain while minimizing the dose of radiation to surrounding healthy tissue. This is particularly important in children, whose brain is still developing.

ADVANTAGE - CYBERKNIFE

Cyberknife which was developed by John Adler, uses a mesh mask to stabilize the head. The technology tracks any unintentional movement on the part of the patient and adjusts the radiation path as necessary. Children who can understand the importance of holding still can undergo the treatment while conscious, younger kids can have short term anesthesia for approximately hour – long diagnostic and treatment session. The recovery from anesthesia is usually quicker because they don’t usually have to be intubated.

At Apollo specialty hospital, till date we had the opportunity to treat 11 children with Cyberknife radio surgery. Our first Cyberknife patient was a pediatric patient with cervico medullary haemangioblastoma 15 years male patient from Tripura . He presented with neck pain, poor cough reflex, and difficulty in swallowing and upper limb tingling sensation. Investigations revealed cervico medullary expansile lesion involving medulla to C2 C3 level.

He underwent occipito cervical craniotomy and decompression, because of high vascularity, surgery was abandoned. He underwent Cyberknife radio surgery between 24th to 26th March 2009. In the first follow up after 3 months, his symptoms completely disappeared follow up MRI showed reduction in size of lesion and contrast enhancing portion of the lesion reduced significantly.

This boy really benefited out of Cyberknife radio surgery. Treating only the affected area with out affecting adjacent brain tissue. He is due for his 10th Std board exam now.

Intracranial


We have treated 4 patients with AVM, and other treated indications include :


1 patient with Supracellular Hemartoma


1 patient with pineliocytoma


1 patient with Recurrent Meningioma


1 patient with Brainstem Glioma


1 patient with Pilocytic astrocytoma (residual)


Spine


1 patient with vertebral Haemangioma


To conclude, Cyberknife: represents an entirely new approach to radiosurgery. It is the only system that combines robotics, and advanced image guidance to deliver frameless radio surgery.

Cyberknife features robotic arm and proprietary image guided technology. The robotic arm is computer controlled and has an arm movement precision of 0.5mm.

Greatest advantage is an out patient basis treatment.


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