Wednesday, October 31, 2012

Radiosurgery in gastro-intestinal malignancies

Radiosurgery in gastro-intestinal malignancies 

DR.DEBNARAYAN DUTTA, Radaitaion oncologist, Apollo speciality Hospital

Common gastro-intestinal (GI) malignancies are colon cancer, carcinoma rectum and anal canal, pancreatic cancer, cholangiocarcinoma, carcinoma stomach, hepatocellular carcinoma (HCC) and liver metastasis. Other uncommon tumours include gastro-intestinal stromal tumour (GIST), klaskin tumour and neuro-endocrine tumour. Surgery is the treatment option in these tumours. Unfortunately, majority of these tumours are inoperable at presentation and treated with supportive/palliative intent. Majority of these tumours are relatively chemotherapy (CT) resistant. Role of conventional radiation therapy (RT) in gastro-intestinal malignancies are also not well defined in many of these tumours.

Response rate with delivered dose is not acceptable, and dose escalation is not possible with conventional RT without compromising in critical structure (small intestine, duodenum) tolerance. With modern stereotactic whole body RT (SBRT) higher dose of radiation can be delivered in shorter duration and normal tissue tolerance is respected. SBRT has evolved in recent years and also have promise to improve local control in these relative resistant tumours. Pre-operative and adjuvant RT is established in carcinoma of rectum.

In recent years, short course RT (hypofractionated RT, 25 Gy/5 Fr) had shown to be equally effective as conventional RT (1.8-2 Gy/Fr) in inoperable rectal cancer. Role of conventional RT in inoperable pancreatic cancer has been argued in the EORTC study. Whereas, short course RT (fractionated radiosurgery) is slowly being accepted as an option to complete RT early, start adjuvant CT at the earliest and also improve quality of life (QOL). In liver metastasis, radiosurgery is a non-invasive alternative to surgery. Higher equivalent radiation dose delivered with radiosurgery there may have comparable survival function in selected patients.

Radiosurgery is an option in liver tumour close to porta, sub-diaphragmatic location (segment VIII), nodal involvement and in medically inoperable patients. In hepatocellular carcinoma (HCC), fractionated radiosurgery is an option as ‘bridge therapy’ for patients waiting for liver transplant, medically inoperable patients, chemotherapy resistant, post TACE residual and in recurrent HCCs. Radiosurgery is also consider as primary treatment in suitable patients. There is an ongoing multicentric randomized trial comparing chemotherapy and radiosurgery in HCCs.

In uncommon slow growing tumours such as cholangiocarcinoma, neuro-endocrine tumour and klaskin tumour fractionated radiosurgery have excellent response rate and improve symptoms. In conclusion, modern fractionated stereotactic radiosurgery is an option in many of the GI malignancies improves response rate and also may improve QOL. In coming years with publication of more matured data from randomized and prospective phase II studies the role of radiosurgery will be established. ours , 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.

Radiosurgery in brain tumours

Radiosurgery in brain tumours

Dr.DEBNARAYAN DUTTA, CONSULTANT RADIATION ONCOLOGIST< APOLLO SPECIALITY HOSPITAL CHENNAI
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.

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

Tuesday, October 30, 2012

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.

Factors influencing quality of life in adult patients with primary brain tumors


Factors influencing quality of life in adult patients with primary brain tumors
Rakesh Jalali and Debnarayan Dutta
NeuroOncology Group, Tata Memorial Hospital, Mumbai, India (R.J.); Apollo Specialty Hospital, Chennai,
India (D.D.)

We performed a literature reviewwith respect to factors influencing health-related quality of life (QOL) in adults with
primary brain tumors. A comprehensive, peer-reviewed literature search was performed including studies examining
QOL in adults with high-grade gliomas and lowgrade gliomas and in routine neuro-oncology practice. The interpretation and implication of QOL domain scores may be different in high-grade, low-grade, and benign brain tumors. Several patient-related, treatment-related, and sociocultural factors influence QOL scores. Pretreatment baseline QOL domain scores have been shown to be a predictive parameter for survival function. Implementation of QOL scores in routine clinical practice is underused. QOL is an important outcome measure in the treatment of patients with brain tumors and should be incorporated as a surrogate end point along with traditional end points, such as disease-free and overall survival in most current trials.

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