Prof. Zafar Sajjad highlights indications and justification for use of PET CT

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 PET scan seminar at JPMC

Prof. Zafar Sajjad highlights indications
and justification for use of PET CT

RSP should have its own Guidelines for use of PET CT
as health economics are different in different countries

KARACHI: Prof. Zafar Sajjad Professor of Radiology at Aga Khan University was the first speaker at the PET CT seminar organized by JPMC Dept. of Radiology on February 24, 2017. The topic of his presentation was Indications and Justification for PET CT. This session was chaired by Prof.Farhat Abbas along with Brig. Mohammad Ilyas and Prof.Amjad Siraj Memon.  To begin with he appreciated the efforts being made by JPMC in the development of human capacity at this institution. He then discussed in detail the broad indications for the use of PET CT, the appropriate criteria and its limitations.  Speaking about its applications Prof. Zafar Sajjad mentioned 90% in the body, 5% in brain, and 5% in heart. It is useful for tumours, infection, bone, in epilepsy tumors and dementia.  Almost 1.5 million procedures are performed annually as regards application of PET CT.


Prof. Farhat Abbas presenting Memento to Prof. Zafar Sajjad and
Dr. Rizwan Syed at the PET CT seminar held at JPMC on February 24, 2017.

He also referred to the false negative particularly in the brain which uses glucose. In oncology PET CT is used for diagnosis, staging of the tumours, evaluation of response, re-staging tumours, to look at suspected recurrences, for follow up besides radiotherapy planning. However, he made it clear that just because something is indicated, there is no justification for its use.  He then referred to its uses and first mentioned solitary pulmonary nodules for lesion characterization and it was a justified indication for diagnosis.  Its use is also justified for staging of some cancers if you are going to do surgical resection for example in lung cancer. Enhanced detection was just another justified indication. PET CT can also be useful in detecting unknown primary, in recurrent diseases particularly in Head and Neck reconstructive surgery besides monitoring response.


Prof. Zafar Sajjad then referred to the NCCN Practice Guidelines   in oncology for cervical cancer, melanoma, soft tissue sarcoma, bone and joint cancers etc. There is evidence for its appropriate use as it improves diagnosis, performance providing useful information in clinical practice and it has impact on treatment. IAEA, he said, has also issued indications for the use of PET CT. Royal College of Surgeons of Ireland has come up with its own guidelines and the Royal College of Physicians has also published guidelines regarding indications for its use.  Just because PET CT detected something does not justify its use. Indications are considered inappropriate if in malignant tumours there is no impact on patient’s health outcome. He also talked about the use of PET CT vs. CT and Ultrasound in painless swelling of neck. Prof. Zafar Sajjad was of the view that we need to evaluate our patients as in some cases ultrasound is the most reliable and useful for diagnosis.  It is also useful in diverticulitis, infections, granulomatous disease.  His conclusions were that all that glitter is not cancer and used appropriately PET CT is a professional tool in imaging cancer.

During the discussion triage for PET CT was also discussed. It was pointed out that we need to educate the physician and use triage in clinical practice.  It was also suggested that Radiological Society of Pakistan should come up with its own Guidelines for the use of PET CT as local guidelines will be more useful which are prepared keeping in view the local conditions and circumstances. We need to work on what is the cost of care in Pakistan. Health economics are different in different countries. While in US people have prepaid health insurance, in some countries healthcare delivery is absolutely free but in Pakistan most of the health expenditures are out of pocket by the patients. That is why the formulation of local Guidelines is important.


On extreme left Prof. S.H. Manzoor Zaidi along with Dr. Munira and Dr. Farhat Nasim and Dr. Zia Salman Farooqui 
chairing the Second scientific session while Dr. Humayun Bashir from SKMT and Dr. Naveed 
are speaking at the seminar on PET CT held at JPMC on February 24, 2017.

Dr. Rizwan Syed was the next speaker whose presentation was on PET CT variants and artifact. He pointed out that as nuclear physician and radiotherapists, we need to interpret what hot spots are. He then talked about benign and malignant diseases, technical artifacts, sequelae of intervention, FDG physiological uptake, its use in brain, heart, urinary tract, bowel, myocardium, unexpected bowel cancer, skeletal muscle, brown adipose tissue, lymphoid tissue, ovaries, uterus, and arteries. History of the patient is important to find out if they had any surgery. He then showed a number of slides of PET CT images. Brown adipose tissue, he said, can be seen in young females. It is also useful in soft palate, palliative tonsils, post nasal space, lingual tonsils. Similarly it can be used in children, young adults and old adults for urinary tract infections.  One can also look at the morphology of Thymus. It can detect inflammation, infections, abscess, and granulations which is difficult to differentiate. Similarly it is useful in bacterial infections, dental Carrie, esophageal cancer, gastritis. He also referred to pitfalls in assessment of stomach. Its usefulness in benign bone joint lesions, Paget’s disease, osteoarthritis, Rheumatoid Arthritis, various other malignant diseases was also highlighted. In order to avoid any pitfalls it is important to take good history, ensure that the patient has empty bladder and do not move arm during PET CT.


During the discussion it was stated that tumours can hide under most images. It is not enough to know what is normal before one starts reporting abnormal. It was also emphasized that the team should first assess the suitability of the patient and only eligible patient should get PET CT to ensure that this facility available free of cost at JPMC is not misused. Prof. Tariq Mahmood pointed out that patients referred by qualified oncologist and surgical oncologists will be entertained and patients will be taken on merit for this test. It was also pointed out that if access to patient records is not available, it may be difficult to make a decision. The referring physician must be aware of the Guidelines and also know that PET CT will make an impact on treatment. Prof.Zafar Sajjad emphasized the importance of reliable history. Many patients do not know what treatment they had. It was also important to know the environment in which we are working. Brig. Ilyas opined that we do not have guidelines and suggested that a panel of radiologists should be constituted to prepare the guidelines. Oncologists were the first to practice these guidelines. However, moderator of the session Dr. Zia Salman Farooqui pointed out that guidelines are just academic and they do not tell you the whole story. They have to be followed as filter. One should follow guidelines but there are always some exceptions. Prof. Zafar Sajjad said that one should trust the reader and give them feedback and patient should not be denied treatment. There should be some mechanism in place. I cannot tell that it is cancer but it may be malignant as I am not a histopathologists Dr. Rizwan remarked. It was also pointed out that fresh medical graduates should know how to use these services and they should be taught about it.


 Mr. Mushtaq Chhapra Chairman Patients Aid Foundation presenting mementoes to Prof. Amjad Siraj Memon, 
Prof. Farhat Abbas and Brig. Ilyas during the seminar on PET CT held at JPMC on February 24, 2017.

The second session was chaired by Prof. S.H.M. Zaidi along with Dr. Munira and Dr. Farhat Nasim. Dr. Maseehuz Zaman from AKU was the first speaker who discussed the metabolic response criteria. He first talked about physiological examination, anatomical examination and Evaluation of imaging response. The WHO 1971 criteria by Miller mentions complete disappearance of the disease in four weeks as complete response, partial response if there is 50% disease and no response if there is a progressive disease. There are certain limitations like number of lesions measured and small measurable lesions.  RECIST criteria, Dr. Maseehuz Zaman said was revised in 2000. Its limitations include reliability of size measurement, non-measurable diseases, cytostatic therapy and tumour shrinkage, residual mass, metabolic response assessment etc.  He also talked about EORTC criteria for research and treatment of cancer. PERSCIST criteria 2009 by Wahl Richard also have its limitations. It mentions complete metabolic response after two cycles. Response Evaluation in lymphoma was also discussed. He also talked about anatomical changes, metabolic changes in early phase of treatment, high negative predictive value, intensity of uptake. Standardization of PET CT in imaging protocol, he opined, is the key to its success.


During the discussion it was pointed out that one must apply the guidelines in correlation with clinical conditions of the patient. CT images help what nodes look like. One should prepare history of the patient and discuss the clinical condition with the radiologist. Prof. Zafar Sajjad said that one should treat the patient and not the images. Sometimes there is over reliance on radiology. Standardization of PET CT done by various institutions is very important. Scanners are also important and different Scans may have different results.

Dr. Humayun Bashir from SKMCH Research Center Lahore discussed FDG PET in carcinoma of unknown primary. He pointed out that 20-27% primary sites are recognized. Speaking about clinical presentation he mentioned pain, palpable mass. Imaging work up includes Chest X-ray, CT. He also referred to major histologies in CUP, step wise approach to immunochemistry, impact of Position Emission Tomography and intended management which was discussed in detail. He also talked about nuclear imaging of Neuro endocrine tumours with unknown primary, cancer of unknown primary site. Its use in D & M and CUP has established but will continue to change.


 Prof. S.H. Manzoor Zaidi presenting mementoes to Dr. Maseehuz Zaman, Dr. Naveed and Prof. Shabbir Naeem 
during the seminar on PET CT held at JPMC on February 24, 2017.

Dr. Naveed Ahmad from JPMC was the last speaker whose presentation was on Use of PET CT in treatment planning. He discussed in detail indications, dose escalation, PET CT planning in lung tumour, Radiotherapy, planning for abdomen, GIT. Use of PET CT is indicated in planning treatment for cervical cancer patient. It is not recommended for routine diagnosis in Head and Neck though it is useful in Head and Neck cancer.  In brain tumours, it is helpful in planning for lymphoma. PET CT is also useful in planning for radiotherapy. Talking about comparison of CT and PET, Dr. Naveed said that when we looked at the CT again, we had missed some lesions which were visible. It can be utilized for guided biopsies. He laid emphasis that we must spend some time on counseling the patient. At times some lesions are not visible on CT, hence in those situations, PET CT will be helpful.


In his concluding remarks Prof. S.H.M. Zaidi commended the speakers for their informative presentations. It was a very education sessions and satisfying for old-timers like me. Availability of PET CT at JPMC is a big step forward which will help patients visiting JPMC. It will be extremely useful for assessment of cancer patients. He also called upon the Government of Sindh to make available radiotherapy facilities in the province as at present patients have to wait for too long. PET CT is a very useful and better facility but importance of basic radiotherapy treatment facilities cannot be over emphasized. He also commended the forward looking leadership of Patients Aid Foundation for initiating numerous development projects at JPMC.

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