Reappraisal of Target Definition for Sacrococcygeal
Chordoma: Comparative Assessment with Computed
Tomography (CT) and Magnetic Resonance Imaging
(MRI) Volume 55- Issue 1
Murat Beyzadeoglu*, Selcuk Demiral, Ferrat Dincoglan and Omer Sager
Department of Radiation Oncology, University of Health Sciences, Gulhane Medical Faculty, Turkey
Received: February 11, 2024; Published: February 19, 2024
*Corresponding author: Murat Beyzadeoglu, University of Health Sciences, Gulhane Medical Faculty, Department of Radiation Oncology, Gn. Tevfik Saglam Cad. 06018, Etlik, Kecioren, Ankara, Turkey
Objective: Chordomas account for a relatively small proportion of intracranial and primary bone tumors. However, they may cause local bone destruction with a typically aggressive disease course. Chordomas arise from embryonic remnants of the primitive notochord. Common localizations for chordoma include the spheno occipital region, sacrococcygeal region, and vertebral bodies. While distant metastasis is typically rare, chordomas may cause mass effect on the brainstem, cranial nerves and the spinal cord. Also, palpable mass may be a presentation for sacrococcygeal chordomas. While surgery remains to play a major role for successful management of sacrococcygeal chordomas, irradiation may serve as a complementary or alternative therapeutic strategy in certain circumstances. In the current study, we aimed at assessing target definition for sacrococcygeal chordomas with comparative evaluation of Computed Tomography (CT) and Magnetic Resonance Imaging (MRI).
Materials and Methods: Primary objective of the current study was focused on target definition for sacrococcygeal chordomas with comparative evaluation of CT and MRI. All included patients were referred for RT at Department of Radiation Oncology at Gulhane Medical Faculty, University of Health Sciences for sacrococcygeal chordoma. We have performed a comparative analysis of target definition by CT simulation images for radiation treatment planning and with MRI.
Results: As the main result of this study, we have found that CT and MRI defined target definition resulted in differences.
Conclusion: In this study, we have found that CT and MRI defined target definition resulted in differences. Thus, fusion of CT and MRI has been utilized for ground truth target volume determination. Our results may have implications for implementation of multimodality imaging for target definition of sacrococcygeal chordomas despite the need for further supporting evidence.
Abbreviations: CT: Computed Tomography; MRI: Magnetic Resonance Imaging; EBRT: External Beam Radiation Therapy; IMRT: Intensity Modulated Radiation Therapy; ART: Adaptive Radiation Therapy; AAPM: American Association of Physicists in Medicine; ICRU: International Commission on Radiation Units and
Measurements; IGRT: Image Guided Radiotherapy
Chordomas account for a relatively small proportion of intracranial
and primary bone tumors. However, they may cause local bone
destruction with a typically aggressive disease course. Chordomas
arise from embryonic remnants of the primitive notochord. Common
localizations for chordoma include the sphenooccipital region,
sacrococcygeal region, and vertebral bodies. While distant metastasis
is typically rare, chordomas may cause mass effect on the brainstem,
cranial nerves, and the spinal cord. Also, palpable mass may
be a presentation for sacrococcygeal chordomas. Microscopically,
physaliphorous cells can be observed [1,2]. Sacrococcygeal chordomas
may extend to the sacrum and may manifest as painful swelling
within the sacrococcygeal region. Typical findings on Computed Tomography
(CT) include an expansile lesion accompanied by peripheral
calcification. Magnetic Resonance Imaging (MRI) may serve as
an excellent imaging tool for assessment of osseous extent and soft
tissue involvement. Both surgery and irradiation may be utilized for
management of chordomas [3-11]. Irradiation may be used as an adjuvant
or alternative therapeutic approach. External Beam Radiation
Therapy (EBRT), particule therapy, and Stereotactic RT techniques
may be utilized for effective management. While using higher doses
for irradiation may contribute to improved local control outcomes,
toxicity profile of radiation delivery should also be taken into account
to maintain patient’s quality of life.
Several advances have taken place in technology in the millennium
era. Molecular imaging methods, Image Guided RT (IGRT), automatic
segmentation techniques, Intensity Modulated RT (IMRT),
stereotactic RT, and Adaptive RT (ART) have been introduced for optimal
radiotherapeutic management of patients [12-49]. Admittedly,
improved treatment outcomes may solely be achieved through close
collaboration among related disciplines for cancer management. Tumor
boards may significantly contribute to bringing together surgical
oncologists, radiation oncologists, medical oncologists, imaging and
other relevant specialists to discuss about patient, tumor, and treatment
characteristics. While surgery remains to play a major role for
successful management of sacrococcygeal chordomas, irradiation
may serve as a complementary or alternative therapeutic strategy in
certain circumstances. In the current study, we aimed at assessing target
definition for sacrococcygeal chordomas with comparative evaluation
of CT and MRI.
At our Department of Radiation Oncology at Gulhane Medical
Faculty, University of Health Sciences, we have long been treating a
high patient population from several places from Turkey and abroad.
Within this context, several benign and malignant tumors have been
irradiated at our tertiary cancer center for decades. The primary objective
of the current study was focused on target definition for sacrococcygeal
chordomas with comparative evaluation of CT and MRI.
All included patients were referred for RT at Department of Radiation
Oncology at Gulhane Medical Faculty, University of Health Sciences
for sacrococcygeal chordoma. We have performed a comparative
analysis of target definition by CT simulation images for radiation
treatment planning and with MRI. CT simulations of the patients were
performed at CT-simulator (GE Lightspeed RT, GE Healthcare, Chalfont
St. Giles, UK) available at our institution. Also, MRI of patients
have been acquired and used for comparative assessment. A Linear
Accelerator (LINAC) with the capability of contemporary IGRT techniques
has been utilized for irradiation. After rigid patient immobilization,
planning CT images have been acquired at CT simulator for radiation
treatment planning. Thereafter, acquired RT planning images
have been transferred to the contouring workstation via the network.
Treatment volumes and critical organs have been defined on these
images and structure sets have been generated. Also, target definition
has also been performed on MRI for comparison. All patients have
been treated by using state of the art RT techniques at the Department
of Radiation Oncology at Gulhane Medical Faculty, University of
Health Sciences.
This original research article has been designated for reappraisal
of target definition for sacrococcygeal chordomas with comparative
evaluation of CT and MRI. Irradiation procedures have been carried
out at our Radiation Oncology Department of Gulhane Medical Faculty
at University of Health Sciences, Ankara. Prior to treatment, all
included patients have been individually evaluated by a multidisciplinary
team of experts from surgical oncology and radiation oncology.
We considered the reports by American Association of Physicists
in Medicine (AAPM) and International Commission on Radiation
Units and Measurements (ICRU) for accurate radiation treatment
planning. Radiation physicists have generated radiation treatment
plans by taking into account the relevant normal tissue dose limitations
through meticulous consideration of contemporary guidelines
and clinical experience. Tissue heterogeneity, electron density, CT
number and HU values in CT images have also been considered by
radiation physicists for precise radiation treatment planning. Main
endpoint of radiation treatment planning has been to achieve optimal
target coverage without violation of normal tissue dose constraints.
Image Guided Radiotherapy (IGRT) techniques including kilovoltage
cone beam CT and electronic digital portal imaging have been used,
and radiation treatment was performed by Synergy (Elekta, UK) LINAC.
As the main result of this study, we have found that CT and MRI defined
target definition resulted in differences. Thus, fusion of CT and
MRI has been utilized for ground truth target volume determination.
Chordomas comprise a relatively smaller proportion of intracranial
and primary bone tumors. Nevertheless, they may cause local
bone destruction with a typically aggressive disease course. Chordomas
originate from embryonic remnants of the primitive notochord.
Common localizations for chordoma include the sphenooccipital region, sacrococcygeal region, and vertebral bodies. While distant metastasis is typically rare, chordomas may cause mass effects on the
brainstem, cranial nerves, and the spinal cord. Also, palpable mass
may be a presentation for sacrococcygeal chordomas. Microscopically,
physaliphorous cells can be observed [1,2]. Sacrococcygeal chordomas
may extend to the sacrum and may manifest as painful swelling
within the sacrococcygeal region. Typical findings on Computed Tomography
(CT) include an expansile lesion accompanied by peripheral
calcification. Magnetic Resonance Imaging (MRI) may serve as
an excellent imaging tool for assessment of osseous extent and soft
tissue involvement. Both surgery and irradiation may be utilized for
management of chordomas [3-11]. Irradiation may be used as an adjuvant
or alternative therapeutic approach. External Beam Radiation
Therapy (EBRT), particule therapy, and stereotactic RT techniques
may be utilized for effective management. While using higher doses
for irradiation may contribute to improved local control outcomes,
toxicity profile of radiation delivery should also be taken into account
to maintain patient’s quality of life. Several advances have taken place
in technology in the millennium era.
Molecular imaging methods, Image Guided RT (IGRT), automatic
segmentation techniques, Intensity Modulated RT (IMRT), stereotactic
RT, and Adaptive RT (ART) have been introduced for optimal radiotherapeutic
management of patients [12-49]. Admittedly, improved
treatment outcomes may solely be achieved through close collaboration
among related disciplines for cancer management. Tumor boards
may significantly contribute to bringing together surgical oncologists,
radiation oncologists, medical oncologists, imaging and other relevant
specialists to discuss about patient, tumor, and treatment characteristics.
While surgery remains to play a major role for successful
management of sacrococcygeal chordomas, irradiation may serve as a
complementary or alternative therapeutic strategy in certain circumstances.
In the current study, we aimed at assessing target definition
for sacrococcygeal chordomas with comparative evaluation of CT and
MRI. At our Department of Radiation Oncology at Gulhane Medical
Faculty, University of Health Sciences, we have long been treating a
high patient population from several places from Turkey and abroad.
Within this context, several benign and malignant tumors have been
irradiated at our tertiary cancer center for decades. The primary objective
of the current study was focused on target definition for sacrococcygeal
chordomas with comparative evaluation of CT and MRI.
All included patients were referred for RT at Department of Radiation
Oncology at Gulhane Medical Faculty, University of Health Sciences
for sacrococcygeal chordoma.
We have performed a comparative analysis of target definition
by CT simulation images for radiation treatment planning and with
MRI. CT simulations of the patients were performed at CT-simulator
(GE Lightspeed RT, GE Healthcare, Chalfont St. Giles, UK) available at
our institution. Also, MRI of patients have been acquired and used
for comparative assessment. A Linear Accelerator (LINAC) with the
capability of contemporary IGRT techniques has been utilized for
irradiation. After rigid patient immobilization, planning CT images
have been acquired at CT simulator for radiation treatment planning.
Thereafter, acquired RT planning images have been transferred to
the contouring workstation via the network. Treatment volumes and
critical organs have been defined on these images and structure sets
have been generated. Also, target definition has also been performed
on MRI for comparison. All patients have been treated by using state
of the art RT techniques at Department of Radiation Oncology at
Gulhane Medical Faculty, University of Health Sciences. This original
research article has been designated for reappraisal of target definition
for sacrococcygeal chordomas with comparative evaluation of CT
and MRI. Irradiation procedures have been carried out at our Radiation
Oncology Department of Gulhane Medical Faculty at University
of Health Sciences, Ankara. Prior to treatment, all included patients
have been individually evaluated by a multidisciplinary team of experts
from surgical oncology and radiation oncology.
We considered the reports by American Association of Physicists
in Medicine (AAPM) and International Commission on Radiation
Units and Measurements (ICRU) for accurate radiation treatment
planning. Radiation physicists have generated radiation treatment
plans by taking into account the relevant normal tissue dose limitations
through meticulous consideration of contemporary guidelines
and clinical experience. Tissue heterogeneity, electron density, CT
number and HU values in CT images have also been considered by
radiation physicists for precise radiation treatment planning. Main
endpoint of radiation treatment planning has been to achieve optimal
target coverage without violation of normal tissue dose constraints.
Image Guided Radiotherapy (IGRT) techniques including kilovoltage
cone beam CT and electronic digital portal imaging have been used,
and radiation treatment was performed by Synergy (Elekta, UK) LINAC.
As the main result of this study, we have found that CT and MRI defined
target definition resulted in differences. Thus, fusion of CT and
MRI has been utilized for ground truth target volume determination.
In the context of radiation oncology, optimal target definition and critical
organ sparing may be considered among the critical components
of optimal radiotherapeutic management. While definition of larger
treatment volumes could lead to excessive radiation induced toxicity,
definition of smaller treatment volumes may result in treatment
failures. Adaptive RT strategies and multimodality imaging-based target
definition have been suggested for achieving improved outcomes
[50-102]. In this study, we have found that CT and MRI defined target
definition resulted in differences. Thus, fusion of CT and MRI has been
utilized for ground truth target volume determination.
Our results may have implications for implementation of multimodality
imaging for target definition of sacrococcygeal chordomas
despite the need for further supporting evidence.
Beyzadeoglu M, Dincoglan F, Demiral S, Sager O (2023) An Original Article Revisiting the Utility of Multimodality Imagıng For Refıned Target Volume Determinatıon Of Recurrent Kidney Carcinoma. Canc Therapy & Oncol Int J 23(5): 556122.
Demiral S, Dincoglan F, Sager O, Beyzadeoglu M (2023) Reappraisal of Treatment Volume Determination for Parametrial Boosting in Patients with Locally Advanced Cervical Cancer. Canc Therapy & Oncol Int J 24(5): 556148.