الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Renal cell carcinoma (RCC) accounts for approximately 3% of adult malignancies and 90-95% of neoplasms arising from the kidney. This disease is characterized by a lack of early warning signs, diverse clinical manifestations, and resistance to radiation and chemotherapy.
The current classification of RCC describes four major types, namely: clear cell, chromophil (papillary), chromophobe and collecting duct type, with the clear cell RCC being by far the most common type. Pre-operative staging is accurately performed with contrast enhanced CT.
The aim of this work was to study the role of PET/CT in screening metastasis of renal cell carcinoma.
Our study conducted on twenty patients with pathologically proven renal cell carcinoma. 15 males (75%) and 5 females (25%) with higher incidence in the males. Their ages ranged between 46 to 84years old with a mean age of 60.45 ± 10.71 years old. 15 out of 20 patients (75%) were clear cell carcinoma which is the most common type in renal cell carcinoma, 3 patients (15%) were papillary carcinoma &2 patients (10%) were chromophobe carcinoma. Eleven patients (55%) had right nephrectomy &9 patients (45%) had left nephrectomy. 19 patients (95%) underwent radical nephrectomy which considered as a corner stone surgery in renal cell carcinoma and only 1 patient (5%) underwent partial nephrectomy. Among 20 patients 14 patients (70%) recurred with metastasis after two years, 5patients (25%) recurred after five years &1 patient (5%) recurred after 10 years.
15 out of 20 patients (75%) were asymptomatic &5 patients (25%) came with presentation distributed as follow;3 patients (15%) complaining of flank pain ,2 patients complaining of generalized bone aches &1 patient complaining of Weight loss. Seven out of the 20 studied patients had local tumor recurrence with a mean SUV max of 10.50 ± 6.63.in all these patients the mass was detected at the ipsilateral side of the radical nephrectomy. Among 20 studied patients, 8 patients (40%) had regional lymphadenopathy with a mean SUVmax8.98 ± 6.20 with involved either para aortic, porta hepatis, celiac, mesenteric, aortocaval, pre caval or retro caval lymph nodes.
Among 20 studied patients, there were different sites of distant metastasis of renal cell carcinoma distributed as follow ; lung in 8 patients (40% with Suv max10.50 ± 6.63), bone:7 patients (35%) with Suvmax 5.45± 3.51,distant L.N: 6patients(30%) with Suvmax5.83 ± 2.79, liver: 4patients(20%) with Suv max 5.43 ±3.24 ,adrenal gland 4 patients(2%)with Suvmax6.25 ± 2.64 .Among 8 patients (40%) with lung metastasis, 5patients 55%) less than 60 years old& 3 patients (27.3%) more than 60 years old. Overall patients of the youngest age Stratum with lung or bone metastases had a higher rate of harboring multiple concomitant Metastatic sites. In contrast, the effect of age failed to reach statistical significance in patients with lymph node, Adrenal and liver metastases. Among 7 patients (35%) with bone metastasis, PET CT detected all patients while CECT detected only 5 patients (25%) &missed 2 patients (10%). No differences between CECT and PET/CT in detecting metastasis to lung, distant L.N, adrenal or liver.
In our study 2 patients (10%) with wide spread bone metastasis that missed on CECT; PET CT had the role to modify their therapeutic strategy from curative to palliative chemotherapy. PET-CT provides the needed information about both the metabolic activity as well as the anatomical location of the neoplasm combining the advantages of both conventional methods CT and PET.
PET used in the assessment of renal masses and primary staging of RCC. Overall, FDG PET has not greatly improved the detection and management of primary renal cancer because the sensitivity and specificity of this technique seem to be less effective than CT. This is partly because of the excretion of FDG via the urinary tract as well as the significant variability in the uptake of FDG by RCC.
However, it can be useful in restaging and detection of metastatic disease of RCC. In particular, PET/CT is useful for lymph node metastases which can often be falsely negative using the CT size criteria. 18FDG PET/CT has been shown to be as good as conventional methods, with 85.7% accuracy in detecting recurrence or metastases. In addition, it is possible to examine all organ systems in one procedure with no need for contrast agents, which can be detrimental to renal function. A positive PET scan should be considered strongly suspicious for local recurrence or metastasis of renal cell carcinoma, because of the high specificity and PPV of this test. However, because of the limited anatomic Information, PET cannot replace the need for CT in the follow-up of RCC patients.
The use of standard uptake value (SUV) proved to be more efficient in follow up studies after chemotherapy being more related to the functional activity of the residual tumor cells rather than to the size of the tumor itself.