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SP-0011 IS DOSE ESCALATION APPROPRIATE?
S4
metastases. Although linear accelerator-based spinal SRS was described >15 years ago, reports on SRS and (fractionated) stereotactic body radiation therapy (SBRT) for spinal and paraspinal metastases are still uncommon. The most common indication for spinal or paraspinal SRS/SBRT is painful vertebral metastasis. Patients who are considered particularly suitable for SRS and SBRT include patients with solitary or oligometastatic disease, involvement of 1-2 consecutive or non-contiguous spinal segments, recurrent lesions >3 months following RT, less radiosensitive tumors, R2resection, no indication for surgery, survival prognosis >6 months, and KPS >40-50. Patients with significant or progressive neurologic deficits, epidural spinal cord compression or cauda equina syndrome, and patients who are clear candidates for surgery are not optimal candidates for SRS/SBRT. In accordance with the recommendations for SRS/FSRT of brain metastases, the safety margin around the metastatic lesions should not exceed 2mm. Even small positioning errors may result in a significantly higher dose to the spinal cord. Thus, patient positioning must be very precise and reproducible. This can be achieved with special immobilization devices, cone-beam CT, and tracking systems. Treatment planning must include CT (to identify osteoblastic and osteolytic components) and MRI (to identify spinal cord involvement and extension to soft tissues). Critical structures include spinal cord, cauda equina, and thecal sac. Dose constraints are not yet clear. For SRS, 10 Gy to up to 10% of the spinal cord within 5-6mm of the treated lesions was suggested. The RT regimens used have been heterogeneous. Single-fraction SRS have ranged from 16 to 24 Gy. The most common SBRT regimens were 30-35 Gy in 5 fractions and 24-27 Gy in 3 fractions. No particular regimen has proved to be the best. Pain relief was achieved in 85100% of untreated patients and 43-100% of re-irradiated patients. In a series of 26 patients receiving 18 Gy of SRS after kyphoplasty, pain relief occurred in 92% of patients. Even patients with bone metastasis from less radiosensitive tumors have response rates of 89-96%. For single-fraction RT, the tolerance dose of the spinal cord is not known but estimated to be 8-10 Gy. However, one should be conservative regarding this dose, as many patients received or will receive potentially neurotoxic chemotherapy or novel targeted therapies. Dosimetric studies suggested that a single fraction of 10 Gy to the spinal cord is safe. A maximum dose to spinal cord of 13 Gy in 1 fraction or 20 Gy in 3 fractions is associated with a risk of myelopathy of <1%. However, sufficient long-term data are currently lacking. Vertebral compression fractures have been reported after singlefraction SRS in 39% of treated vertebrae. Osteolytic lesions, metastasis below T9, and involvement of >40% of the vertebral body were identified at risk factors for subsequent fracture. In summary, SRS and SBRT are reasonable options for spinal and paraspinal metastases, in particular for recurrent and less radiosensitive lesions. However, the possibility of late morbidity such as myelopathy and vertebral compression fractures should be considered when selecting patients for SRS or SBRT.
JOINT SYMPOSIUM: ESTRO-EAU: THE CHALLENGE OF TREATING EARLY INTERMEDIATE RISK PROSTATE CANCER SP-0011 IS DOSE ESCALATION APPROPRIATE? D. Dearnaley1 1 The Royal Marsden NHS Foundation Trust, Academic Radiotherapy, Sutton, United Kingdom Several international phase III multicentre trials have now reported long term results of radiotherapy for prostate cancer using dose escalation. All studies show improved outcome in terms of biochemical (PSA) disease control, with some evidence for a delay in the need for salvage (hormonal) treatment. So far, improvements in metastasis free, cause related and overall survival remain elusive. Dose escalation comes at the cost of increased rectal but perhaps not urinary side effects. Improvements in radiotherapy technique using conformal and now intensity modulated (IMRT) and image guided (IGRT) techniques can substantially reduce rectal side effects. The use of normal tissue dose constraints have become standard practice and dose/volume/complication relationships are better understood. Functional imaging is now showing considerable promise enabling the localisation of “dominant” intraprostatic nodules and it is possible to plan suitable focal radiotherapy boosts. Clinical assessment is underway using IGRT/IMRT techniques which may translate into
ESTRO 31
clinical benefit both increasing cancer control and reducing side effects. Evidence suggests that dose escalation and combined modality treatment with androgen suppression are complementary particularly in patients with adverse risk factors, but we do not yet know the optimal combination for patients with intermediate risk disease. The radiobiology of prostate cancer suggests a high fraction sensitivity and large phase III studies of modest or extreme hypofractionation are completing recruitment. Early results suggest favourable side effect profiles. If the alpha beta ratio using external beam radiotherapy is proven to be low then this will have a very significant impact on the fractionation schedules that are used in every day practice and on resource utilisation. Translational studies assessing the predictive value of molecular markers for dose, fractionation and hormonal treatment sensitivity, as well as radiogenomics brings the promise of personalised treatments and schedules in the future. SP-0012 THE ROLE OF ROBOTIC ASSISTED LAPARASCOPY IN THE EARLY TREATMENT OF PROSTATE CANCER C. Abbou1 1 Abbou, Department of Urology, Creteil, France Robotic assistance is now is in teenage period which mind that many questions are still unanswered = EBM is still absent because of the lack of RCS. In the other side, several progresses has been made: the device has evolved thanks to the image technologies (high definition), the ergonomy of the robot and the quality of the news instruments including, clips, clamps, harmonics, florescence, single port etc…. The surgical techniques has also evolved thanks to a better anatomy understanding and also more clear surgical strategies: intrafacial, interfacial and extrafacial. Evaluation of the results is much precise: validated questioners and better criteria: trifeca, quadrifeca, pentafeca (oncologic results, continence, potency, complications….) The rapid return to normal activity is wished by the patients. Conclusion: even is EBM is not yet clearly determined, the robotic assistance become a routine of care if not yet “the standard”. The cost should decrease with the time as well as any routinely used system. SP-0013 INNOVATIVE SURGERY:† OPPORTUNITIES AND CONSTRAINTS - ROBOTIC J.F. Suarez Novo1 1 Hospital de Belvitge Princeps d’Espana, Barcelona, Spain Abstract not received SP-0014 THE ROLE OF ANDROGEN BLOCKADE COMBINED WITH RADIOTHERAPY F. Lohr1 1 University Medical Center Mannheim Abstract not received
SYMPOSIUM: ADAPTIVE RADIOTHERAPY: OPPORTUNITIES AND PITFALLS SP-0015 RULES FOR RE-PLANNING IN ADAPTIVE RADIOTHERAPY L.A. Dawson1 1 Princess Margaret Hospital, Department of Radiotherapy, Toronto, Canada Image guided radiation therapy (IGRT) has permitted the collection of a plethora of geometric data about variability in patient positioning during a course of radiation therapy. Setup error and internal target variations can largely be corrected for using daily IGRT and couch translations. However, IGRT cannot correct for systemic residual rotations and deformations due to tumor shrinkage, tumor growth or adjacent normal tissue change (e.g. head and neck weight loss, bowel filling, lung ateletasis, liver edema). Despite the use of daily IGRT, such changes may lead to clinically meaningful differences in the delivered doses compared to the planned doses. Thus, adaptive radiation therapy has been proposed as a means to correct for such changes. Adaptive radiotherapy refers to the process of
metastases. Although linear accelerator-based spinal SRS was described >15 years ago, reports on SRS and (fractionated) stereotactic body radiation therapy (SBRT) for spinal and paraspinal metastases are still uncommon. The most common indication for spinal or paraspinal SRS/SBRT is painful vertebral metastasis. Patients who are considered particularly suitable for SRS and SBRT include patients with solitary or oligometastatic disease, involvement of 1-2 consecutive or non-contiguous spinal segments, recurrent lesions >3 months following RT, less radiosensitive tumors, R2resection, no indication for surgery, survival prognosis >6 months, and KPS >40-50. Patients with significant or progressive neurologic deficits, epidural spinal cord compression or cauda equina syndrome, and patients who are clear candidates for surgery are not optimal candidates for SRS/SBRT. In accordance with the recommendations for SRS/FSRT of brain metastases, the safety margin around the metastatic lesions should not exceed 2mm. Even small positioning errors may result in a significantly higher dose to the spinal cord. Thus, patient positioning must be very precise and reproducible. This can be achieved with special immobilization devices, cone-beam CT, and tracking systems. Treatment planning must include CT (to identify osteoblastic and osteolytic components) and MRI (to identify spinal cord involvement and extension to soft tissues). Critical structures include spinal cord, cauda equina, and thecal sac. Dose constraints are not yet clear. For SRS, 10 Gy to up to 10% of the spinal cord within 5-6mm of the treated lesions was suggested. The RT regimens used have been heterogeneous. Single-fraction SRS have ranged from 16 to 24 Gy. The most common SBRT regimens were 30-35 Gy in 5 fractions and 24-27 Gy in 3 fractions. No particular regimen has proved to be the best. Pain relief was achieved in 85100% of untreated patients and 43-100% of re-irradiated patients. In a series of 26 patients receiving 18 Gy of SRS after kyphoplasty, pain relief occurred in 92% of patients. Even patients with bone metastasis from less radiosensitive tumors have response rates of 89-96%. For single-fraction RT, the tolerance dose of the spinal cord is not known but estimated to be 8-10 Gy. However, one should be conservative regarding this dose, as many patients received or will receive potentially neurotoxic chemotherapy or novel targeted therapies. Dosimetric studies suggested that a single fraction of 10 Gy to the spinal cord is safe. A maximum dose to spinal cord of 13 Gy in 1 fraction or 20 Gy in 3 fractions is associated with a risk of myelopathy of <1%. However, sufficient long-term data are currently lacking. Vertebral compression fractures have been reported after singlefraction SRS in 39% of treated vertebrae. Osteolytic lesions, metastasis below T9, and involvement of >40% of the vertebral body were identified at risk factors for subsequent fracture. In summary, SRS and SBRT are reasonable options for spinal and paraspinal metastases, in particular for recurrent and less radiosensitive lesions. However, the possibility of late morbidity such as myelopathy and vertebral compression fractures should be considered when selecting patients for SRS or SBRT.
JOINT SYMPOSIUM: ESTRO-EAU: THE CHALLENGE OF TREATING EARLY INTERMEDIATE RISK PROSTATE CANCER SP-0011 IS DOSE ESCALATION APPROPRIATE? D. Dearnaley1 1 The Royal Marsden NHS Foundation Trust, Academic Radiotherapy, Sutton, United Kingdom Several international phase III multicentre trials have now reported long term results of radiotherapy for prostate cancer using dose escalation. All studies show improved outcome in terms of biochemical (PSA) disease control, with some evidence for a delay in the need for salvage (hormonal) treatment. So far, improvements in metastasis free, cause related and overall survival remain elusive. Dose escalation comes at the cost of increased rectal but perhaps not urinary side effects. Improvements in radiotherapy technique using conformal and now intensity modulated (IMRT) and image guided (IGRT) techniques can substantially reduce rectal side effects. The use of normal tissue dose constraints have become standard practice and dose/volume/complication relationships are better understood. Functional imaging is now showing considerable promise enabling the localisation of “dominant” intraprostatic nodules and it is possible to plan suitable focal radiotherapy boosts. Clinical assessment is underway using IGRT/IMRT techniques which may translate into
ESTRO 31
clinical benefit both increasing cancer control and reducing side effects. Evidence suggests that dose escalation and combined modality treatment with androgen suppression are complementary particularly in patients with adverse risk factors, but we do not yet know the optimal combination for patients with intermediate risk disease. The radiobiology of prostate cancer suggests a high fraction sensitivity and large phase III studies of modest or extreme hypofractionation are completing recruitment. Early results suggest favourable side effect profiles. If the alpha beta ratio using external beam radiotherapy is proven to be low then this will have a very significant impact on the fractionation schedules that are used in every day practice and on resource utilisation. Translational studies assessing the predictive value of molecular markers for dose, fractionation and hormonal treatment sensitivity, as well as radiogenomics brings the promise of personalised treatments and schedules in the future. SP-0012 THE ROLE OF ROBOTIC ASSISTED LAPARASCOPY IN THE EARLY TREATMENT OF PROSTATE CANCER C. Abbou1 1 Abbou, Department of Urology, Creteil, France Robotic assistance is now is in teenage period which mind that many questions are still unanswered = EBM is still absent because of the lack of RCS. In the other side, several progresses has been made: the device has evolved thanks to the image technologies (high definition), the ergonomy of the robot and the quality of the news instruments including, clips, clamps, harmonics, florescence, single port etc…. The surgical techniques has also evolved thanks to a better anatomy understanding and also more clear surgical strategies: intrafacial, interfacial and extrafacial. Evaluation of the results is much precise: validated questioners and better criteria: trifeca, quadrifeca, pentafeca (oncologic results, continence, potency, complications….) The rapid return to normal activity is wished by the patients. Conclusion: even is EBM is not yet clearly determined, the robotic assistance become a routine of care if not yet “the standard”. The cost should decrease with the time as well as any routinely used system. SP-0013 INNOVATIVE SURGERY:† OPPORTUNITIES AND CONSTRAINTS - ROBOTIC J.F. Suarez Novo1 1 Hospital de Belvitge Princeps d’Espana, Barcelona, Spain Abstract not received SP-0014 THE ROLE OF ANDROGEN BLOCKADE COMBINED WITH RADIOTHERAPY F. Lohr1 1 University Medical Center Mannheim Abstract not received
SYMPOSIUM: ADAPTIVE RADIOTHERAPY: OPPORTUNITIES AND PITFALLS SP-0015 RULES FOR RE-PLANNING IN ADAPTIVE RADIOTHERAPY L.A. Dawson1 1 Princess Margaret Hospital, Department of Radiotherapy, Toronto, Canada Image guided radiation therapy (IGRT) has permitted the collection of a plethora of geometric data about variability in patient positioning during a course of radiation therapy. Setup error and internal target variations can largely be corrected for using daily IGRT and couch translations. However, IGRT cannot correct for systemic residual rotations and deformations due to tumor shrinkage, tumor growth or adjacent normal tissue change (e.g. head and neck weight loss, bowel filling, lung ateletasis, liver edema). Despite the use of daily IGRT, such changes may lead to clinically meaningful differences in the delivered doses compared to the planned doses. Thus, adaptive radiation therapy has been proposed as a means to correct for such changes. Adaptive radiotherapy refers to the process of