Advances in Radiation Oncology最新文献

Purpose

Methods and Materials

Results

Conclusions

Purpose

Methods

Results

Conclusion

Purpose

Methods and Materials

Results

Conclusions

Purpose

This study aimed to compare the outcomes and toxicities between patients treated with image guided radiation therapy (IGRT) using fiducial markers and non-IGRT in intensity modulated radiation therapy (IMRT) for prostate cancer.

Methods and Materials

In total, 518 patients with intermediate- and high-risk prostate cancer received IMRT with 78 Gy in 39 fractions after neoadjuvant androgen deprivation therapy for at least 3 months. Of these patients, 371 were in the non-IGRT group and 147 in the IGRT group, including the IGRT-A group using the same margins as the non-IGRT group and the IGRT-B group using reduced margins. The median follow-up periods for the non-IGRT, IGRT-A, and IGRT-B groups were 99 months, 88 months, and 63 months, respectively.

Results

The 5-year biochemical recurrence-free survival rates in the non-IGRT, IGRT-A, and IGRT-B groups were 88%, 95%, and 98% (non-IGRT vs IGRT-A, P = .396; IGRT-A vs IGRT-B, P = .426), respectively. Those for intermediate- and high-risk patients were 94%, 93%, and 96% (non-IGRT vs IGRT-A, P = .916; IGRT-A vs IGRT-B, P = .646), respectively, and 87%, 96%, and 100% (non-IGRT vs IGRT-A, P = .500; IGRT-A vs IGRT-B, P = .483), respectively. For the non-IGRT and IGRT-A groups, the rates of acute grade ≥ 2 gastrointestinal toxicities and late grade ≥ 2 genitourinary toxicities were 17% and 7% (P = .019), respectively, and 28% and 16% (P = .028), respectively. In the IGRT-A and IGRT-B groups, the rates of acute grade ≥ 2 genitourinary toxicities were 45% and 21% (P = .003), respectively. All V60_Gy = the volume at least received 60Gy and V70_Gy = the volume at least received 70Gy values of the bladder and rectal walls in the IGRT-B group were smaller than those in the IGRT-A group.

Conclusions

IGRT with fiducial markers results in lower acute and late toxicities compared with non-IGRT in IMRT for intermediate- and high-risk prostate cancer. Moreover, the toxicities are further decreased by reducing the margins in the treatment planning under IGRT. These processes do not decrease the biochemical recurrence-free survival rates.

Purpose

Patients with primary sinonasal and cutaneous head and neck (H&N) malignancies often receive meaningful radiation dose to their hippocampi, but this not a classic avoidance structure in radiation planning. We aimed to characterize the feasibility and tradeoffs of hippocampal-sparing radiation therapy (HSRT) for patients with primary sinonasal and cutaneous H&N malignancies.

Methods and Materials

We retrospectively selected patients who were treated definitively for primary sinonasal or cutaneous malignancies of the H&N at an academic medical center. All received (chemo)radiation alone or adjuvantly and substantial radiation dose to 1 or both hippocampi. We created new HSRT plans for each patient with intensity modulated radiation therapy using the original target and organ-at-risk (OAR) volumes. Hippocampi were contoured based on Radiation Therapy Oncology Group guidelines and reviewed by a neuroradiologist. Absolute and relative differences in radiation dose to the hippocampi, planning target volumes (PTVs), and OARs were recorded and compared.

Results

There were 18 sinonasal and 12 cutaneous H&N primary tumors (30 patients in total). Median prescription dose was 6600 cGy (range, 5000-7440 cGy), and 14 of the 30 patients received 120 cGy/fraction twice daily, 13 of the 30 patients received 200 cGy/fraction once daily, whereas others received 180-275 cGy/fraction once daily. The relative decrease in ipsilateral hippocampal D_max and D100% using HSRT was 44% (median, 2009 cGy from 3586 cGy) and 65% (median 434 cGy from 1257 cGy), respectively. There were no statistically significant or clinically meaningful differences in PTV V100%, PTV D1%, or radiation dose to other OARs between HSRT and non-HSRT plans.

Conclusions

HSRT is feasible and results in meaningful dose reduction to the hippocampi without reducing PTV coverage or increasing dose to other OARs. We suggest target hippocampal constraints of D_max < 1600 cGy and D100% < 500 cGy when feasible (without compromising PTV coverage or impacting other critical OARs). The clinical significance of HSRT in patients with primary H&N tumors should be investigated prospectively.

Purpose

Head and neck lymphedema (HNL) following radiation therapy for head and neck cancer (HNC) causes patient morbidity. Predicting individual patients’ risk of HNL after treatment is challenging. We aimed to identify the demographic, disease-related, and treatment-related factors associated with external and internal HNL following treatment of HNC with definitive or adjuvant radiation therapy.

Methods and Materials

Relevant clinical, pathologic, and dosimetric data for 76 consecutive patients who received definitive or adjuvant radiation ± chemotherapy were retrospectively collected from a single institution. Multivariable models predictive of external and internal lymphedema using clinicopathologic variables alone and in combination with dosimetric variables were constructed and optimized using competing risk regression.

Results

After median follow-up of 550 days, the incidence of external and internal HNL at 360 days was 70% and 34%, respectively. When evaluating clinical and treatment-related factors alone, number of lymph nodes removed and advanced adenopathy status were predictive of external lymphedema. With incorporation of dosimetric variables, the optimized model included the percentage volume of the contralateral lymph node level VII receiving 30Gy V30 ≥50%, number of lymph nodes removed, and advanced adenopathy status. For internal lymphedema, our clinicopathologic model identified both adjuvant radiation, as opposed to definitive radiation, and advanced adenopathy status. With inclusion of a dosimetric variable, the optimized model included larynx V45 ≥50% and advanced adenopathy.

Conclusions

HNL following HNC treatment is common. For both external and internal lymphedema, nodal disease burden at diagnosis predicts increased risk. For external lymphedema, increasing extent of lymph node dissection prior to adjuvant therapy increases risk. The contralateral level VII lymph node region is also predictive of external lymphedema when radiation dose to V30 is ≥50%, meriting investigation. For internal lymphedema, we confirm that increasing radiation dose to the larynx is the most significant dosimetric predictor of mucosal edema when larynx V45 is ≥50%.

Purpose

The Audiovisual-Assisted Therapeutic Ambience in Radiotherapy (AVATAR) trial was a prospective multicenter study (NCT03991156) examining the combination of video immersion with radiation therapy and was successfully conducted through the collaboration of pediatric radiation oncology teams at 10 institutions independent of any pre-existing consortium. We sought to analyze and report the methodology of trial conception and development, process map, and cost.

Methods and Materials

The study enrolled patients aged 3 to 10 years preparing to undergo radiation therapy, integrated the combination of AVATAR-based video immersion with radiation therapy at each institution, and offered AVATAR use as an alternative to anesthesia, with rates of anesthesia use and outcomes of serial standardized anxiety and quality-of-life assessments assessed among the 81 children enrolled. A process map was created based on the trial timeline with the following components: study development time (time from conception of the trial to the accrual of the first patient, including design phase, agreement and approval phase, and site preparation phase), and accrual duration time (time from the first to last accrual). Costs and institutional success rates were calculated.

Results

Time from inception of study to last accrual was 3.6 years (1313 days). The study development time was 417 days (31.7%), and accrual duration time was 896 days (68.3%), with the final 50% of accrual occurring in <6 months. Equipment cost was approximately $550 per institution and was covered by funding from the lead study institution. All 10 centers were successful with AVATAR implementation, defined as ≥50% of patients able to avoid anesthesia with the use of AVATAR, including centers with both photon and proton therapy.

Conclusions

This report elaborates on the methodology and timeline of trial conception and development using data from a previously published supportive care study combining video immersion with radiation therapy among 10 cooperating pediatric oncology institutions. It highlights the potential for multicenter collaborations on prospective trials integrating supportive care therapies with radiation therapy.

Purpose

The clinically accepted planning target volume margin for radiation therapy to the paraortic nodal region in cervical cancer patients is 5 mm. However, the comprehensive alignment and variability from the pelvic bone to all lumbar vertebrae are undetermined. This study aims to quantify the residual setup errors between the pelvic bone and lumbar vertebrae and determine the optimal correction strategy for patients with cervical cancer.

Materials and Methods

Fifteen patients underwent pretreatment mega-voltage computed tomography scans (375 total fractions). Residual setup errors and required margins for each lumbar vertebra were calculated based on registrations accounting for pelvic rotation and translation.

Results

The systematic residual errors (1 SD) at L1, L2, L3, L4, and L5 using pelvic bone registration were 6.5, 4.9, 3.1, 1.5, and 0.6 mm in the anterior-posterior (AP) direction, 3.1, 2.3, 1.4, 0.6, and 0.3 mm in the right-left direction, and 2.7, 2.2, 1.7, 1.0, and 0.5 mm in the superior-inferior direction, respectively. The residual setup errors were the largest in the AP direction. Registration based on the pelvic bone required margins in the AP direction of 16.0, 12.1, 7.7, 3.6, and 1.3 mm for L1, L2, L3, L4, and L5, respectively, whereas registration based on L3 required margins of 8.8, 4.8, 4.4, 7.1, and 7.7 mm for L1, L2, L4, L5, and pelvic bone, respectively.

Conclusions

Considerable local setup variability was found in patients with cervical cancer. After reviewing the corrective strategies, we determined that L3-based registration effectively minimized the required margins.

Purpose

Material and Methods

Results

Conclusions