Patient Characteristics
Prospective study For 46 patients with histologically proven osteosarcoma who were under treatment and regular follow up at the Children Cancer Hospital,
Egypt,
(CCHE) during the period from Oct,
2014 to Oct,
2016.
The age of patients encountered in the study ranged from five to seventeen years with a median of 13 years,
mean of 12.28 +/-0.49.
They included 26 males (56.5%) and twenty females (43.5%) (Fig.
12).
On the basis of histo-pathology,
All patients had high grade osteosarcomas except one patient.
Twenty nine patients proved to be of osteoblastic type (62.2%),
seven patients of chondroblastic type (15.2%),
five patients of focal telangiectatic variant (10.9%), two patients of MFH (malignant fibrous histiocytoma) like tumor (4.3%),
one patient of chondromyxiod variant (rare subtype of low-grade osteosarcoma) (2.2%),
one patient of osteoblastic/chondroblastic variant (2.2%) and one patient of fibroblastic variant (2.2%) (Fig.
13).
According to the site of the primary lesion.
32 patients had their primary tumor at distal femur (69.6%),
ten patients at proximal tibia (21.8%),
one at proximal fibula (2.2%).
i.e.
43 patient around knees (93.6%),
one patient at distal tibia (2.2%),
one patient at left iliac bone (2.2%) and one patient at proximal humerus (2.2%) (Fig.
1).
18 patients presented with (PET/CT detected) metastatic deposits (39.1%) while the rest of the patients (28 patients,
60.9%) did not show any metastatic lesions.
Seven patients presented with lung metastases alone (38.9%),
six patients presented with nodal lesions alone (33.3%),
two patients only presented with bone metastases alone (11.1%),
two patients presented with both lung and nodal lesions (11.1%) and one patient presented with lung,
bone and nodal lesions (5.5%) (fig.2).
Four patients presented with skipped lesions (8.7%).
We noticed that the higher SUVmax1 was recorded by osteoblastic OS while the lower SUVmax1 was recorded by chondroblastic OS.
We tested the correlation between the different pathological types and the SUVmax1,
no statistical significant difference between pathological types regarding SUVmax1 was noted by one-way ANOVA test (p = 0.611).
The change in MRTV calculated for patients who underwent three MRI studies (31 patients) and patients underwent two studies only (1st and 2nd OR 1st and 3rd MRI) (14 patients).
Considering patients with three MRIs,
there were significant increase of MRTV3 at poor responders group only.
(p= 0.024)
Considering patients for whom only two MRIs were available there were significant decrease of MRTV3 at good responders group only (p=0.016).
Changes in PET/CT parameters according to the pathologic response:
SUVmax and TLR are tested,
considering patients for whom three PET/CTs were available (32 patients),
the SUVmax2 showed significant decrease in comparison to baseline study for good responders group (p=0.003).
The SUVmax3 also showed significant decrease for good responders group (p=0.003)
Considering patients for whom only two PET/CTs were available (eight patients had 1st and 2nd studies and six patients had 1st and 3rd studies),
the SUVmax2 showed significant changes in comparison with baseline study for good responders and bad responders groups (p=0.003 and 0.006 respectively),
The SUVmax3 showed significant changes in comparison with base line study for good responders and poor responders groups (both groups had p=0.001).
Considering patients for whom three PET/CTs were available,
the TLR2 showed significant decrease in comparison with base line study for good responders group (p=0.003),
also The TLR3 showed significant decrease change for good responders group (p=0.001).
Considering patients for whom only two PET/CTs were available,
the TLR2 showed significant decrease in comparison with base line study for good responders group (p=0.001),
also TLR3 showed significant decrease for good responders group (p=0.002).