Pathologica 4-07.pdf - Pacini Editore

PATHOLOGICA 2007;99:255
Correlation between pathologic tumor
response and radiologic tumor response to
preoperative chemo-radiation therapy in 40
cases of localized high-grade soft tissue
sarcoma
P. Collini, M. Barisella, A. Messina * , C. Morosi * , A. Gronchi
** , P.G. Casali *** , S. Stacchiotti *** , S. Pilotti
Anatomic Pathology C Unit, * Radiology Unit, ** Musculoskeletal
Surgery Unit, *** Sarcoma Unit, Cancer Medicine
Department, IRCCS Fondazione Istituto Nazionale Tumori,
Milan, Italy
Introduction. Tumor response to treatment is not always dimensional
(RECIST criteria), but can be a “tissue” response,
as already seen in GISTs. To improve the assessment of ‘tumor
responsé, we tried a) to correlate radiological and pathological
patterns of tumor response to concurrent preoperative
chemotherapy and radiation therapy in localized high-grade
soft tissue sarcomas (STS) and b) to validate these new radiologic,
non-dimensional “tissue response” criteria through
the comparison with the pathological response.
Methods. Between April 2002 and September 2006, 40 consecutive
patients with localized high-grade STS of extremities
or superficial trunk received 3 cycles of neoadjuvant Epirubicin
+ Ifosfamide and concomitant radiotherapy, followed by
surgery, within a prospective Italian Sarcoma Group (ISG) tri-
Patologia iatrogena
al. MRIs were taken before the neoadjuvant treatment and before
surgery. Radiologically, changes in tumor size and tissue
characteristics, along with contrast enhancement variations
were recorded. Histotype and FNCLCC grade were assessed
on pretreatment biopsies. The post-treatment surgical specimens
were oriented with the surgeon and sampled with a mapping
of the lesion (about a sample per cm). Histologically, we
evaluated the percentage of residual tumor (tentatively scored
as 0%, < 50%, > 50%) and the quality and quantity of posttreatment
changes (necrosis, hemorrhage, cysts, fibrohistiocytic
reaction, and sclerohyalinosis). Eventually, we compared
the histologic results with the radiologic assessment.
Results. We recorded a stable, larger or slightly diminished
dimension in 22 cases (55%), in which there were no radiologic
tissue changes. At histology, these cases showed a
residual viable tumour more than 50%. They were considered
“non-responders” both for radiology and pathology. Other 18
cases (45%) showed a stable or larger diameter, and would be
considered “non- responders” by RECIST criteria. Though,
there were radiographic signs of tissue changes and histologically
the residual tumour was less than 50%. Actually, these
cases were considered as “responders”.
Conclusions. Through dimensional RECIST criteria, we
were able to appreciate only a proportion of responsive patients.
In order to predict the actual pathologic tumor response,
some kind of assessment of “tissue responses” on
MRI may usefully integrate the dimensional data.