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Ovarian Radiation Dose During Heterotopic Ossification Radiation Prophylaxis
I. J. Radiation Oncology d Biology d Physics
S640
Volume 81, Number 2, Supplement, 2011
hormone mediation correlated with the percent of pituitary stalk receiving .8 Gy (p = 0.025), more specifically, the middle portion of the pituitary stalk (p = 0.045). There was no statistic correlation with hormone use and the prescribed dose to the pituitary directly (p = 0.86). Also, there were no statistical correlations between hormone medication use and pre-GK ACTH (p = 0.16), cortisol (p = 0.75), GH (p = 0.43), IGF (p = 0.35), prolactin (p = 0.17), and TSH (p = 0.49) levels. Conclusions: Our analysis suggests that the use of post-surgery hormone medication correlated with the percent of pituitary stalk receiving .8 Gy and dose to the middle portion of the stalk, but not the prescribed dose to the pituitary itself. Author Disclosure: M.W. Tee: None. R. Weil: None. J. Valerio-Pascua: None. A. Hamrahian: None. J.H. Suh: None. G. Neyman: None. C.A. Reddy: None. S.T. Chao: None.
2897
Ovarian Radiation Dose During Heterotopic Ossification Radiation Prophylaxis
W. F. Mourad1,2, S. Packianathan2, M. C. Baird2, R. A. Shourbaji3, G. Dieck2, J. Edwards2, P. Mobit2, C. C. Claus2, K. S. Hu1, L. B. Harrison1 1 Beth Israel Medical Center, New York, NY, 2University of Mississippi Medical Center, Jackson, MS, 3Jackson State University, Jackson, MS
Purpose/Objective(s): To evaluate the impact of different photon energies and techniques in the total dose of radiation received by ovaries after radiation prophylaxis RT) of heterotopic ossification (HO) around the hip joint. Materials/Methods: This is a single-institution, retrospective study investigating the dose of radiation to the ovaries during RT for HO prophylaxis. From January (2008 - 2010), 32 patients, all had traumatic acetabular fractures (TAF) underwent surgery followed by RT. Postoperative RT was delivered within 72 hours in a single fraction of 700 cGy, prescribed to the mid-plane, using MV photons. The fields included the soft tissues around the proximal femur and acetabulum without bone shielding. All patients underwent CT simulation and 2 portal images prior to treatment. In all patients, the ipsilateral (IL OV) and contralateral (CL OV) ovaries were contoured separately as a region of interest and dose volume histograms (DVH) generated. Additional planning trials were created for each patient by utilizing a beam split technique medially and by using different photon energies (6 - 18 MV) to investigate the effects of these maneuvers on the delivered dose to the ovaries. Results: 32 female patients, with median age 41 years (range 18 - 85). In reviewing the DVH for all patients, it was noted that the median Mean dose) delivered to the (IL OV) was 59 cGy (range 6 - 262) and the median Max.dose) was 177 cGy (range 7 - 650). (CL OV) median Mean dose) was 6 cGy (range 1 - 11) and median Max.dose) was 10 cGy (range 1 - 21). When a beam split was applied at the medial edge of the field, (27%, 22%) dose reduction in the mean and max.dose, respectively, delivered to the (IL OV) while (9%, 5%) reduction in the mean and maximum dose, respectively, to the (CL OV). When higher energies (10 - 18 MV) were compared to 6 MV, additional 28%, 16 % reduction in mean and max.doses, respectively, of the (IL OV) were achieved. The (CL OV) mean dose was reduced by 18% and the maximum dose was reduced by 12%. Conclusions: A biologically meaningful radiation dose is delivered to the ovaries during RT HO prophylaxis around the hip. This dose could be reduced to the IL Ov by half and the CL Ov by one-quarter by using simple technical adjustments (medial beam split technique and photon energies above 6 MV). All female patients especially those in the childbearing age should be informed and consented with ovarian radiation exposure and possible temporary alteration in ova production and morphology.
Results Both Ovaries DVH
IL OV Mean Dose
IL OV Max Dose
CL OV Mean Dose
CL OV Max Dose
Delivered Median Beam Split Reduction 10 - 18 MV Reduction Total Reduction
59 cGy 27% 28% 65%
177 cGy 22% 16% 38%
6 cGy 9% 18% 27%
10 cGy 5% 12% 17%
Author Disclosure: W.F. Mourad: None. S. Packianathan: None. M.C. Baird: None. R.A. Shourbaji: None. G. Dieck: None. J. Edwards: None. P. Mobit: None. C.C. Claus: None. K.S. Hu: None. L.B. Harrison: None.
2898
Regression of Ipilumimab Induced Hypophysitis Using Low Dose Conformal Radiotherapy
C. D. Marquez, M. Scala, P. Menzel, J. Lee, M. Rounsaville, D. Minor, R. Abendroth CPMC, San Francisco, CA Purpose/Objective(s): Ipilumimab is an anti-CTL-4 receptor antibody shown to improve survival in patients with metastatic melanoma. 1 - 6% of patients treated with ipilumimab develop steroid-refractory autoimmune hypophysitis necessitating lifelong hormone replacement. Here we present our experience using low dose conformal radiotherapy in the management of ipilumimab induced hypophysitis. Materials/Methods: Retrospective analysis of three metastatic melanoma patients with ipilumimab induced lymphocytic hypophysitis treated with low dose conformal radiotherapy. All patients had MRI confirmed hypophysitis and were symptomatic on steroids. MRI features of hypophysitis included diffuse enlargement of the pituitary gland with homogenous enhancement. All patients received 450cGy in three fractions delivered every other day using conformal planning. Radiation fields encompassed the entire MRI pituitary volume plus a 1 cm margin. Patients were immobilized with a thermoplastic mask. Post radiation MRIs and symptom assessments were obtained to evaluate treatment efficacy. MRI pituitary volume was calculated using the elliptic formula (L x H x W x 0.5). Mean pre and post RT pituitary volumes were compared through the use of the t-test.
S640
Volume 81, Number 2, Supplement, 2011
hormone mediation correlated with the percent of pituitary stalk receiving .8 Gy (p = 0.025), more specifically, the middle portion of the pituitary stalk (p = 0.045). There was no statistic correlation with hormone use and the prescribed dose to the pituitary directly (p = 0.86). Also, there were no statistical correlations between hormone medication use and pre-GK ACTH (p = 0.16), cortisol (p = 0.75), GH (p = 0.43), IGF (p = 0.35), prolactin (p = 0.17), and TSH (p = 0.49) levels. Conclusions: Our analysis suggests that the use of post-surgery hormone medication correlated with the percent of pituitary stalk receiving .8 Gy and dose to the middle portion of the stalk, but not the prescribed dose to the pituitary itself. Author Disclosure: M.W. Tee: None. R. Weil: None. J. Valerio-Pascua: None. A. Hamrahian: None. J.H. Suh: None. G. Neyman: None. C.A. Reddy: None. S.T. Chao: None.
2897
Ovarian Radiation Dose During Heterotopic Ossification Radiation Prophylaxis
W. F. Mourad1,2, S. Packianathan2, M. C. Baird2, R. A. Shourbaji3, G. Dieck2, J. Edwards2, P. Mobit2, C. C. Claus2, K. S. Hu1, L. B. Harrison1 1 Beth Israel Medical Center, New York, NY, 2University of Mississippi Medical Center, Jackson, MS, 3Jackson State University, Jackson, MS
Purpose/Objective(s): To evaluate the impact of different photon energies and techniques in the total dose of radiation received by ovaries after radiation prophylaxis RT) of heterotopic ossification (HO) around the hip joint. Materials/Methods: This is a single-institution, retrospective study investigating the dose of radiation to the ovaries during RT for HO prophylaxis. From January (2008 - 2010), 32 patients, all had traumatic acetabular fractures (TAF) underwent surgery followed by RT. Postoperative RT was delivered within 72 hours in a single fraction of 700 cGy, prescribed to the mid-plane, using MV photons. The fields included the soft tissues around the proximal femur and acetabulum without bone shielding. All patients underwent CT simulation and 2 portal images prior to treatment. In all patients, the ipsilateral (IL OV) and contralateral (CL OV) ovaries were contoured separately as a region of interest and dose volume histograms (DVH) generated. Additional planning trials were created for each patient by utilizing a beam split technique medially and by using different photon energies (6 - 18 MV) to investigate the effects of these maneuvers on the delivered dose to the ovaries. Results: 32 female patients, with median age 41 years (range 18 - 85). In reviewing the DVH for all patients, it was noted that the median Mean dose) delivered to the (IL OV) was 59 cGy (range 6 - 262) and the median Max.dose) was 177 cGy (range 7 - 650). (CL OV) median Mean dose) was 6 cGy (range 1 - 11) and median Max.dose) was 10 cGy (range 1 - 21). When a beam split was applied at the medial edge of the field, (27%, 22%) dose reduction in the mean and max.dose, respectively, delivered to the (IL OV) while (9%, 5%) reduction in the mean and maximum dose, respectively, to the (CL OV). When higher energies (10 - 18 MV) were compared to 6 MV, additional 28%, 16 % reduction in mean and max.doses, respectively, of the (IL OV) were achieved. The (CL OV) mean dose was reduced by 18% and the maximum dose was reduced by 12%. Conclusions: A biologically meaningful radiation dose is delivered to the ovaries during RT HO prophylaxis around the hip. This dose could be reduced to the IL Ov by half and the CL Ov by one-quarter by using simple technical adjustments (medial beam split technique and photon energies above 6 MV). All female patients especially those in the childbearing age should be informed and consented with ovarian radiation exposure and possible temporary alteration in ova production and morphology.
Results Both Ovaries DVH
IL OV Mean Dose
IL OV Max Dose
CL OV Mean Dose
CL OV Max Dose
Delivered Median Beam Split Reduction 10 - 18 MV Reduction Total Reduction
59 cGy 27% 28% 65%
177 cGy 22% 16% 38%
6 cGy 9% 18% 27%
10 cGy 5% 12% 17%
Author Disclosure: W.F. Mourad: None. S. Packianathan: None. M.C. Baird: None. R.A. Shourbaji: None. G. Dieck: None. J. Edwards: None. P. Mobit: None. C.C. Claus: None. K.S. Hu: None. L.B. Harrison: None.
2898
Regression of Ipilumimab Induced Hypophysitis Using Low Dose Conformal Radiotherapy
C. D. Marquez, M. Scala, P. Menzel, J. Lee, M. Rounsaville, D. Minor, R. Abendroth CPMC, San Francisco, CA Purpose/Objective(s): Ipilumimab is an anti-CTL-4 receptor antibody shown to improve survival in patients with metastatic melanoma. 1 - 6% of patients treated with ipilumimab develop steroid-refractory autoimmune hypophysitis necessitating lifelong hormone replacement. Here we present our experience using low dose conformal radiotherapy in the management of ipilumimab induced hypophysitis. Materials/Methods: Retrospective analysis of three metastatic melanoma patients with ipilumimab induced lymphocytic hypophysitis treated with low dose conformal radiotherapy. All patients had MRI confirmed hypophysitis and were symptomatic on steroids. MRI features of hypophysitis included diffuse enlargement of the pituitary gland with homogenous enhancement. All patients received 450cGy in three fractions delivered every other day using conformal planning. Radiation fields encompassed the entire MRI pituitary volume plus a 1 cm margin. Patients were immobilized with a thermoplastic mask. Post radiation MRIs and symptom assessments were obtained to evaluate treatment efficacy. MRI pituitary volume was calculated using the elliptic formula (L x H x W x 0.5). Mean pre and post RT pituitary volumes were compared through the use of the t-test.