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Use of 4D-CBCT to Assess Target and Organ Motion in Esophageal Cancer Patients
Use of 4D-CBCT to Assess Target and Organ Motion in Esophageal Cancer Patients Cindy Tran, HonBSc, MRT(T), Stephanie Sae, MRSc, MRT(T), Dr. Doug Moseley, Dr. Zahra Kassam, Dr. Charles Cho, Kevin Smith and Dr. Jason Wong Stronach Regional Cancer Centre Background: Radiotherapy for esophageal cancer is challenged by intra-fractional organ movement. Daily image guidance is used to assess patient set-up errors and correct for positional offsets of the target and organs at risk. There exists a paucity of published data on four-dimensional cone-beam computed tomography (4D-CBCT) as a method of image guidance for these patients. This study utilized 4D-CBCTs to compare the efficacy of different registration volumes (bone, internal target volume (ITV), carina) for image guidance with focus on whether carina is a useful ITV surrogate. The study also assessed our centre’s current planning target volume (PTV) margins of 0.5 cm around the ITV. Methods: This retrospective study involved 17 esophageal cancer patients treated radically from July 2012-July 2013 using volumetric-modulated arc therapy. Daily CBCTs (402) were reconstructed into 4D Medium Resolution 8-phase 4D-CBCTs using Elekta XVI software and registered to the helical CT simulation scan in voluntary exhale. Two separate dual registration matches were done; the first registered a clipbox around the vertebrae and a mask around the ITV, and the second used carina as the mask. T-test was used to test for significant difference between X,Y,Z-offsets; means and standard deviations were calculated. For each directional shift, the average difference in amplitude (absolute value of maximum inhale plus maximum exhale) between 4DCT and 4D-CBCT was determined. Results: In some comparisons of vertebrae/ITV/carina mean offsets, statistical significance was found (t-test, p¼0.05). However, only comparison of vertebrae and ITV mean offsets revealed clinical significance for the Y-dimension with the magnitude being >0.2 cm. For 14 patients (3 excluded due to unavailable data), average difference in amplitude between 4DCT and 4DCBCT in the X,Y,Z-directions were determined to be 0.12 cm, -0.05 cm, and 0.04 cm, respectively. In 8.4% of the cases, movement of the ITV in the Y-direction was greater than the PTV margin. Discussion and Conclusion: Carina appears to be a better ITV surrogate versus vertebrae for image guidance on 4D-CBCTs in the Y-dimension. In the majority of cases, PTV margins are sufficient for target coverage. Future research on patient-specific indicators for significant ITV movement in the Ydirection is needed.
Dosimetric Adequacy of the Non-delineated Post-operative Cavity in Whole Breast RadiotherapyTtreatment of Women with Early Breast Cancer Hugh Felix Tsui, BSc, Dr. Robert Dinniwell, MD, FRCPC and Grace Lee, MRT(T), BSc, CMD, MhSc(c) Princess Margaret Cancer Center Background: The delineation of the postoperative cavity (POC) is not common practice in tangential whole breast radiotherapy planning. Without a defined POC, the tumour bed may not be incorporated as part of the clinical target volume and risks the failure to deliver the intended therapeutic dose. The aim of this study is to review the location of the POC in relation to the radiotherapy dose distribution and the adequacy of coverage of POC using standard tangential whole breast treatment fields. Methods: Following Research Ethics Board approval, 50 consecutive patients treated in September to October 2004 were identified. The POC for each patient was delineated and a dose evaluation volume (DEV) was created using a modified 1 cm isotropic expansion around the POC. Dosimetric data of the contoured POC, DEV and the original CTV used in the design of the actual treatment plan were abstracted as were the patient’s demographic and treatment data. Statistical analyses were performed and a 0.05 alpha value was considered statistically significant. Results: The median age of the women was 63 (31-86). The mean volume of the POC was 25.48 cc (SD 20.07). For the 50 patients, the locations of
the POCs were: Upper Inner (7); Lower Inner (8); Central (11); Upper Outer (19) and Lower Outer (5). Five (10%) of the patients had POCs partially outside (4) or at the edge (1) of the treatment fields. Twenty (40%) patients had DEVs located at the edge (8) or partially outside (12) of the tangential fields. The %volume of POC covered by 92% of the prescription dose for DEVs within the irradiated volume and DEVs at or outside the field edge were 99.22% (SD 1.11) and 92.00% (SD 15.12), respectively. Discussion and Conclusion: Patients with a POC or DEV that lie at the edge or outside the treatment fields received inadequate dose to the tumour bed. Given the benefits of radiotherapy in improving local control and overall survival in women with early breast cancer, these results demonstrate the need to routinely delineate the POC to best ensure they receive maximal benefit.
Sexual Healthcare in Cancer Patients: Awareness and Role Perceptions of Radiation Therapists Angela Turner, MRT(T) Odette Cancer Centre Introduction/Background: Cancer patients report dissatisfaction with care they receive in relation to changes affecting sexual health, intimacy and relationships. Health care professionals (HCPs) describe barriers in providing support in these areas due to lack of time, training, education and privacy. Radiation therapists (RTs) play a key role in cancer care but there is little evidence of their role in sexual healthcare. This project investigated awareness levels and role perceptions of RTs in sexual health issues related to cancer patients receiving radiation therapy. Methods: A mixed methods approach was used for this investigation. Quantitative data was collected via an online questionnaire developed from the literature. 284 RTs from two large cancer centers were eligible to participate; 84 responded (29%). Two focus groups were conducted with 15 volunteer RTs to validate questionnaire data and further explore the topic. Content analysis was employed to identify themes from the qualitative data. Results: RT respondents acknowledge the complexity of sexual health issues; 85% recognized that sexual health issues can occur across all cancer sites. 92% agreed that sexual health is important for quality of life. Barriers identified to RT provision of sexual healthcare are similar to other HCPs i.e. environment, time, lack of training and education. Conclusions: Barriers to RT involvement in sexual healthcare may be resolved through training and education. Provision of private space for patient education may provide a more conducive environment for sexual healthcare interactions. Involvement of RTs in sexual health care may increase services for cancer patients and improve patient satisfaction in this domain. Evaluation of British Columbia Cancer Agency Radiation Therapists’ Current Level of Knowledge, Comfort with, and Desire for Resources to Discuss Erectile Dysfunction with Prostate Cancer Patients Amanjot Thind, Studenta, Marta Slaats, Studenta and Christina Chan, Studentb a British Columbia Institute of Technology b British Columbia Institute of British Columbia Background: Sexuality has a profound impact on the quality of life of prostate cancer patients, yet erectile dysfunction (ED) is often overlooked as a side effect by healthcare professionals. Mounting evidence shows early rehabilitation of ED patients can improve recovery of sexual function and satisfaction. The strong rapport radiation therapists (RTs) have with patients through daily interactions provides an invaluable opportunity to offer patients resources to make informed decisions regarding aftercare. The aim of this study is to evaluate RTs’ current level of knowledge, comfort with, and desire for resources to discuss ED with patients. Methods: An electronic survey was emailed to British Columbia Cancer Agency RTs (n ¼253). A total of 109 surveys were returned (43% RR). Descriptive statistics and correlation were performed. A literature review on health-care communication, early rehabilitation, and the impacts of ED was completed.
Conference Proceedings from RTi3 2014/Journal of Medical Imaging and Radiation Sciences 45 (2014) 162-188
185
Dosimetric Adequacy of the Non-delineated Post-operative Cavity in Whole Breast RadiotherapyTtreatment of Women with Early Breast Cancer Hugh Felix Tsui, BSc, Dr. Robert Dinniwell, MD, FRCPC and Grace Lee, MRT(T), BSc, CMD, MhSc(c) Princess Margaret Cancer Center Background: The delineation of the postoperative cavity (POC) is not common practice in tangential whole breast radiotherapy planning. Without a defined POC, the tumour bed may not be incorporated as part of the clinical target volume and risks the failure to deliver the intended therapeutic dose. The aim of this study is to review the location of the POC in relation to the radiotherapy dose distribution and the adequacy of coverage of POC using standard tangential whole breast treatment fields. Methods: Following Research Ethics Board approval, 50 consecutive patients treated in September to October 2004 were identified. The POC for each patient was delineated and a dose evaluation volume (DEV) was created using a modified 1 cm isotropic expansion around the POC. Dosimetric data of the contoured POC, DEV and the original CTV used in the design of the actual treatment plan were abstracted as were the patient’s demographic and treatment data. Statistical analyses were performed and a 0.05 alpha value was considered statistically significant. Results: The median age of the women was 63 (31-86). The mean volume of the POC was 25.48 cc (SD 20.07). For the 50 patients, the locations of
the POCs were: Upper Inner (7); Lower Inner (8); Central (11); Upper Outer (19) and Lower Outer (5). Five (10%) of the patients had POCs partially outside (4) or at the edge (1) of the treatment fields. Twenty (40%) patients had DEVs located at the edge (8) or partially outside (12) of the tangential fields. The %volume of POC covered by 92% of the prescription dose for DEVs within the irradiated volume and DEVs at or outside the field edge were 99.22% (SD 1.11) and 92.00% (SD 15.12), respectively. Discussion and Conclusion: Patients with a POC or DEV that lie at the edge or outside the treatment fields received inadequate dose to the tumour bed. Given the benefits of radiotherapy in improving local control and overall survival in women with early breast cancer, these results demonstrate the need to routinely delineate the POC to best ensure they receive maximal benefit.
Sexual Healthcare in Cancer Patients: Awareness and Role Perceptions of Radiation Therapists Angela Turner, MRT(T) Odette Cancer Centre Introduction/Background: Cancer patients report dissatisfaction with care they receive in relation to changes affecting sexual health, intimacy and relationships. Health care professionals (HCPs) describe barriers in providing support in these areas due to lack of time, training, education and privacy. Radiation therapists (RTs) play a key role in cancer care but there is little evidence of their role in sexual healthcare. This project investigated awareness levels and role perceptions of RTs in sexual health issues related to cancer patients receiving radiation therapy. Methods: A mixed methods approach was used for this investigation. Quantitative data was collected via an online questionnaire developed from the literature. 284 RTs from two large cancer centers were eligible to participate; 84 responded (29%). Two focus groups were conducted with 15 volunteer RTs to validate questionnaire data and further explore the topic. Content analysis was employed to identify themes from the qualitative data. Results: RT respondents acknowledge the complexity of sexual health issues; 85% recognized that sexual health issues can occur across all cancer sites. 92% agreed that sexual health is important for quality of life. Barriers identified to RT provision of sexual healthcare are similar to other HCPs i.e. environment, time, lack of training and education. Conclusions: Barriers to RT involvement in sexual healthcare may be resolved through training and education. Provision of private space for patient education may provide a more conducive environment for sexual healthcare interactions. Involvement of RTs in sexual health care may increase services for cancer patients and improve patient satisfaction in this domain. Evaluation of British Columbia Cancer Agency Radiation Therapists’ Current Level of Knowledge, Comfort with, and Desire for Resources to Discuss Erectile Dysfunction with Prostate Cancer Patients Amanjot Thind, Studenta, Marta Slaats, Studenta and Christina Chan, Studentb a British Columbia Institute of Technology b British Columbia Institute of British Columbia Background: Sexuality has a profound impact on the quality of life of prostate cancer patients, yet erectile dysfunction (ED) is often overlooked as a side effect by healthcare professionals. Mounting evidence shows early rehabilitation of ED patients can improve recovery of sexual function and satisfaction. The strong rapport radiation therapists (RTs) have with patients through daily interactions provides an invaluable opportunity to offer patients resources to make informed decisions regarding aftercare. The aim of this study is to evaluate RTs’ current level of knowledge, comfort with, and desire for resources to discuss ED with patients. Methods: An electronic survey was emailed to British Columbia Cancer Agency RTs (n ¼253). A total of 109 surveys were returned (43% RR). Descriptive statistics and correlation were performed. A literature review on health-care communication, early rehabilitation, and the impacts of ED was completed.
Conference Proceedings from RTi3 2014/Journal of Medical Imaging and Radiation Sciences 45 (2014) 162-188
185