Long-Term Outcomes of De-Intensified Chemoradiotherapy for Human Papillomavirus-Associated Oropharyngeal Squamous Cell Carcinoma

PURPOSE/OBJECTIVE(S)

To report long-term oncologic outcomes among patients with human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC) treated with definitive de-intensified chemoradiotherapy.

MATERIALS/METHODS

Major criteria for de-intensification were (1) AJCC 7th edition T0-T3, N0-N2c, M0 (AJCC 8th edition T0-T3, N0-N2, M0), (2) pathologically confirmed p16 positive, and (3) no or minimal/remote smoking history (non-mutated p53 if ≥30 pack-years). Treatment was 60 Gy intensity-modulated radiotherapy with first-choice concurrent cisplatin 30 mg/m2 once per week (alternative regimens permissible for cisplatin ineligible patients). Patients with T0-T2 N0-1 (AJCC 7th edition) were recommended 60 Gy radiation alone. Systemic therapy received included: cisplatin 30 mg/m2 (n = 122), cetuximab (n = 15), cisplatin 40 mg/m2 (n = 12), carboplatin/paclitaxel (n = 2), and radiation alone (n = 25). Kaplan Meier estimates for overall survival (OS), progression-free survival (PFS), locoregional control (LRC), and freedom from distant metastasis (FFDM) were calculated. Cox regression models were used for comparisons among subgroups.

RESULTS

A total 176 patients received de-intensified treatment (n = 153 prospective protocol, n = 23 off-protocol). Median follow-up was 52.6 months (range 5.3 - 102.0, 90.8% with minimum 2-year follow-up); 56.8% (n = 100) were never smokers and 43.2% (n = 76) former smokers; former smokers had median 9 pack-years smoking history (range 0.25 - 50) with 46% ≥10 pack-years. Outcomes were as follows: 2-year OS 99.4% and 5-year OS 91.8%; 2-year PFS 94.1% and 5-year PFS 84.3%; 2-year LRC 98.3% and 5-year LRC 95.8%; 2-year FFDM 95.8% and 5-year FFDM 93.2%. Median time to progression events were 21.1 months (range, 7.2 - 54.1) with 37.5% (6 of 16) of recurrences occurring after 24 months. Six total locoregional events occurred (five recurrences and one site of persistent disease), within the 60 Gy planning target volume. Twenty-three patients with T0-T2 N0-1 disease received radiation alone with 2-year PFS 92.9% (5-year 83.8%) and 2-year LRC 100% (5-year 95.2%). Outcomes for former smokers with ≥10 pack-years were comparable to patients with less or no smoking history (2-year PFS 94.1% vs 94.1%; 5-year PFS 90.6% vs 82.7%; HR 0.58, p = 0.38). Early results suggest similar oncologic outcomes among those treated off-protocol (median follow-up 25.6 months) with 1 of 23 patients experiencing locoregional recurrence.

CONCLUSION

Dose de-intensification of 60 Gy radiotherapy with weekly cisplatin results in favorable long-term tumor control in patients with HPV-associated OPSCC. De-intensified 60 Gy alone may be efficacious in carefully selected patients with T0-T2 N0-1 (AJCC 7th edition) disease. Inclusion of biologically favorable patients with more extensive former smoking history in de-intensification clinical trials may be warranted.

Challenging the Role of Subtotal Resection Following Proton Radiotherapy for Adenoid Cystic Carcinoma of the Head and Neck

PURPOSE/OBJECTIVE(S)

To report long-term outcomes of patients with adenoid cystic carcinoma (ACC) of the head and neck treated with proton radiotherapy.

MATERIALS/METHODS

On this IRB-approved, single institutional prospective outcomes registry, 56 patients were included with de novo, nonmetastatic adenoid carcinoma of the head and neck treated with primary (n = 9) or adjuvant proton therapy from June 2007 to December 2021. The cohort had 30 women and 26 men with a median age of 57 years (range, 10-81 years). Twenty-nine percent (n = 16) had intracranial extension, 23% (n = 13) had orbital extension, and 55% (n = 31) had clinical cranial nerve involvement at the time of radiotherapy. Thirty patients underwent gross total resection (GTR), 26 had gross disease at the time of treatment undergoing a subtotal resection (STR) (n = 17) or biopsy alone (n = 9). The median dose to the primary site was 72.6 GyRBE (range, 64-74.4 GyRBE) delivered in either once (n = 19) or twice (n = 37) daily treatments. Thirty patients received either elective nodal irradiation (ENI) in a node negative neck or concurrent chemotherapy.

RESULTS

With a median follow-up of 6.2 years (range, 0.9 - 14.7 years), the 5-year local-regional control (LRC), disease free survival (DFS), cause-specific survival (CCS) and overall survival (OS) were 88%, 85%, 89%, and 89%, respectively. Cranial extension (p = 0.003) and gross residual tumor (p = 0.0388) were factors associated with decreased LRC. While LRC for those with a GTR was 96%, those with STR or biopsy alone were 81% and 76%, respectively. T-stage (p = 0.0154), cranial extension (p = 0.0056), extent of resection (p = 0.0355), and gross residual tumor (p = 0.0094) were associated with decreased DFS. T-stage (p = 0.0099), extent of surgery (p = 0.029) and gross residual tumor (p.0071) were associated with decreased CCS. The 5-year cumulative incidence of clinically significant late grade ³3 toxicity was 15% and the crude incidence at most recent follow-up was 23% (n = 13). There was no LRC benefit with ENI (p = 0.94).

CONCLUSION

Proton therapy provides excellent disease control for head and neck ACC with acceptable toxicity. Gross residual disease at the time of treatment and intracranial involvement were significant prognostic features for worse outcomes. STR did not confer benefit over biopsy only at 5-years and may question the role of extensive and morbid operations if GTR is not technically feasible.

Low Tesla MR Imaging for Spine with Hardware

PURPOSE/OBJECTIVE(S)

Acquiring MR images with minimized susceptibility artifacts is essential for spines with medical hardware to delineate clinical target volumes (CTVs) in radiation therapy for chordomas, chondrosarcomas, and other sarcomas. Since it can be more challenging to visualize the primary structures in high-tesla MR images due to metal-induced artifacts, we optimized imaging parameters to acquire high-quality, low-tesla MR images for clinical use.

MATERIALS/METHODS

OptimalMR imaging parameters were investigated under general guidelines for artifact reduction techniques by testing several 3D spin echo and gradient echo sequences in a 0.23-T MR scanner. A customized spine phantom was developed to acquire MR images for bony materials which included, 4-6 industrial titanium screws, an aluminum plate, and a superflab bolus. While the 3D b-FFE sequence was used to acquire MR images with a high signal-to-noise ratio, the other 3D T1-FFE, THRIVE, and DTSE sequences were applied to reduce susceptible artifacts to the medical hardware. The optimized parameters determined in the phantom test were applied to the 15 clinical cases, including patients with residual spinal tumors and fusion hardware. The low-tesla MR imaging technique was also used to scan sarcomas of the extremities and re-irradiation cases of spinal metastases.

RESULTS

The optimized low-tesla MR images in the spine were noticeably useful to guide CTV delineations for patients with medical hardware, especially for residual or recurrent tumors. The imaging technique to minimize susceptibility artifacts enabled a more defined separation of each hardware component from the spinal cord and CTVs. In spine metastasis cases, pre-irradiated target volumes were determined, reflecting property changes in the bone marrow.

CONCLUSION

The MR images acquired using the optimized parameters showed minimal artifacts to scan spine patients with hardware. By using the low-tesla MR images, spinal chordoma and chondrosarcoma patients could be treated to improve tumor control probabilities with minimized complications.

Pediatric Esthesioneuroblastoma Treated with Proton Radiotherapy

PURPOSE/OBJECTIVE(S)

Given its tendency to abut and infiltrate critical skull base anatomy, pediatric esthesioneuroblastoma (EN) presents a local control challenge, particularly given the high dose of radiation historically utilized in adult patients and the sensitivity of developing pediatric normal tissue. The purpose of this study was to report the outcomes of pediatric EN treated with proton radiotherapy.

MATERIALS/METHODS

Using an IRB-approved, single institutional prospective outcomes registry, we analyzed disease control and toxicity in pediatric patients with non-metastatic EN treated with a multimodality approach, including proton radiotherapy, between March 2008 and March 2022. Of the 15 patients, 8 were female, and 7 were male. The median age was 16 years (range, 3-21 years). Patients were Kadish stage B (n = 2), C (n = 8), and D (n = 5) and Hyams low-grade (n = 9), high-grade (n = 5), and not specified (n = 1). Six patients had intracranial involvement, 4 had cranial nerve deficits, and 4 had positive cervical lymph nodes. Prior to radiation, 2 patients had a subtotal resection and 13 had a gross total resection via either endoscopic (n = 8) or craniofacial (n = 7) approaches. Two patients underwent neck dissection (one unilateral and one bilateral). A total of 11 patients received chemotherapy before (n = 5), concurrent (n = 4) with radiation, or both (n = 2). The median total radiation dose delivered to the primary site was 66 Gy/CGE (range, 59.4-72.8 Gy/CGE) for patients with gross disease and 54 Gy/CGE (range, 54-74.4 Gy/CGE) for patients with microscopic disease.

RESULTS

With a median follow-up of 4.8 years (range, 0.1-12.2 years), both the 5-year disease free and overall survival rates were 86%. There were no local or regional recurrences. Two patients with Kadish D, high grade tumors developed vertebral metastases and died with disease. Serious acute toxicity included 2 patients requiring a temporary feeding tube for oral mucositis/dysphagia. Serious late toxicity included symptomatic retinopathy (n = 3), major reconstructive surgery (n = 2), cataracts requiring intervention (n = 2), chronic otitis media (n = 2), chronic keratoconjunctivitis (n = 2), hypothyroidism (n = 2), and in-field basal cell skin cancer (n = 1).

CONCLUSION

A multimodality approach to pediatric EN results in excellent local control. Despite the use of moderate dose proton therapy, serious radiation toxicity was observed and thus select patients may benefit from further dose and target volume reduction. Longer follow-up and comparative data from modern photon series are necessary to fully characterize any relative advantage of proton therapy.

930 SAFETY, TOLERABILITY AND IMMUNOGENICITY OF 15-VALENT PNEUMOCOCCAL CONJUGATE VACCINE + PPV23 12 MONTHS LATER IN HEALTHY ADULTS ≥ 50

Background

Older adults are at increased risk of pneumococcal disease (PD). V114, an investigational 15-valent Pneumococcal Conjugate Vaccine (PCV), contains all serotypes in 13-valent PCV (PCV13) plus serotypes 22F and 33F. This phase 3 trial evaluated the safety, tolerability and immunogenicity of V114 or PCV13 followed 12 months later by PPSV23 in healthy adults aged ≥50 years.

Materials/Method

652 eligible adults were randomised 1:1 to receive V114 or PCV13 followed by PPSV23 12 months later. Solicited and non-solicited adverse events (AEs) were collected after each vaccination. Serotype-specific opsonophagocytic activity (OPA) and immunoglobulin G (IgG) antibodies were measured at Day 1, Day 30, Month 12 and Month 13.

Results

The most common solicited AEs following PCV were injection-site pain, fatigue and myalgia; higher proportions of participants with solicited AEs were observed in the V114 group; however, the differences were not clinically significant, as most AEs were mild and of short duration. The most common solicited AEs following PPSV23 were injection-site pain, injection-site swelling, fatigue and myalgia; these events were comparable across both intervention groups. The proportion of participants with serious AEs were low in both groups and none reported to be vaccine related. No deaths occurred during the study. Serotype-specific OPA geometric mean titres (GMTs) and IgG geometric mean concentrations (GMCs) were comparable between the groups for all 15 serotypes 30 days post-vaccination with PPSV23. OPA GMTs and IgG GMCs were comparable between PCV groups for the 13 shared serotypes and higher in V114 than PCV13 for serotypes 22F and 33F 30 days and 12 months post-vaccination with PCV. V114 elicited an immune response that persisted for at least 12 months.

Conclusion

Sequential administration of V114 and PPSV23 is well tolerated, immunogenic and generally comparable to PCV13 followed by PPSV23 in healthy adults ≥50 years of age.

Outcomes and toxicities in oligometastatic patients treated with stereotactic body radiotherapy for adrenal gland metastases: A multi-institutional retrospective study

•

SBRT to adrenal gland oligometastases achieves a satisfactory local control and OS.

•

A minimum PTV dose BED₁₀ > 46 Gy was associated with an improved OS and LRFS.

•

A prescribed BED₁₀ > 70 Gy was correlated with improved local control.

•

High adrenal metastases volume should not preclude the delivery of SBRT.

Background

Studies reporting SBRT outcomes in oligometastatic patients with adrenal gland metastases (AGM) are limited. Herein, we present a multi-institutional analysis of oligometastatic patients treated with SBRT for AGM.

Material/methods

The Consortium for Oligometastases Research (CORE) is among the largest retrospective series of patients with oligometastases. Among CORE patients, those treated with SBRT for AGM were included. Clinical and dosimetric data were collected. Adrenal metastatic burden (AMB) was defined as the sum of all adrenal GTV if more than one oligometastases is present.

Competing risk analysis was used to estimate actuarial cumulative local recurrence (LR) and widespread progression (WP). Kaplan-Meier method was used to report overall survival (OS), local recurrence-free survival (LRFS), and progression-free survival (PFS). Treatment related toxicities were also reported.

Results

The analysis included 47 patients with 57 adrenal lesions. Median follow-up was 18.2 months. Median LRFS, PFS, and OS were 15.3, 5.3, and 19.1 months, respectively. A minimum PTV dose BED₁₀ > 46 Gy was associated with an improved OS and LRFS. A prescribed BED₁₀ > 70 Gy was an independent predictor of a lower LR probability. AMB>10 cc was an independent predictor of a lower risk for WP. Only one patient developed an acute Grade 3 toxicity consisting of abdominal pain.

Conclusion

SBRT to AGM achieved a satisfactory local control and OS in oligometastatic patients. High minimum PTV dose and BED₁₀ prescription doses were predictive of improved LR and OS, respectively. Prospective studies are needed to determine comprehensive criteria for patients SBRT eligibility and dosimetric planning.

Can CT imaging improve targeting accuracy in clip-based proton therapy of ocular melanoma?

To evaluate the benefit of adding CT imaging to the simulation process of clip-based proton therapy of ocular melanomas. For thirty ocular melanoma cases, the clip position in the eye model was determined based on orthogonal radiographs as well as on a CT image set. The geometrical shift of the clips between the standard simulation process and standard simulation process with addition of CT imaging (CT-guided) was determined. The dosimetric impact was evaluated by developing treatment plans based on both the standard-process model and the CT-guided model. In 40% of the studied cases, the difference in clip position between eye models created with and without CT was less than 0.5 mm. This difference was more than 1 mm in 17% of cases. The dosimetric impact of shifts below 1 mm was low because these shifts did not exceed the planning margins. For the four cases with a shift of more than 1 mm a reduction in target coverage (ΔV99%) of  -3% to  -6% was observed. Changes in macula and optic-disc mean dose of up to 16% and 35% of the prescribed dose were seen when these structures abutted the target. Adding CT imaging to the simulation process is beneficial in select cases where discrepancies between the eye model and ophthalmology measurements occur or where a critical structure is located close to the target and improved localization accuracy is wanted. For the majority of patients, addition of CT imaging does not result in quantifiable changes in dosimetry. Nevertheless, CT imaging is a valuable tool in the quality control of the modeling and treatment-planning process of clip-based eye treatments.

Glutaraldehyde Treated Cat Small Bowel as an Arterial Graft

The materials used up to now for grafting arteries have not proved entirely satisfactory. It was the purpose of the project described here to find a more satisfactory method for replacing arteries. Previous experience has shown that glutaraldehyde-treated grafts are non-viable, avascular, and known to pre serve their general structure. In this study small bowel taken from a cat and treated with glutaraldehyde was used to replace the aorta in dogs.

Ten dogs were used. The G.A. treated graft in a length of 10 cm bypassed the abdominal aorta. The dogs were sacrificed from 20 days up to one year. Repeated angiographies showed the patency of the graft. After sacrificing the dogs, the grafts were examined macroscopically and microscopically. The site of the anastomosis was strong and no aneurysms were seen. The graft is easy to handle and can be tailored to size.

Impact of PCV7/PCV13 introduction on invasive pneumococcal disease (IPD) in young children: Comparison between meningitis and non-meningitis IPD

BACKGROUND

The worldwide introduction of pneumococcal conjugate vaccines (PCV) into National Immunization Programs resulted in rapid and substantial reduction of invasive pneumococcal disease (IPD) rates in children. However, the reduction of meningitis vs. non-meningitis IPD (nm-IPD) was not yet fully elucidated. We compared 7-valent and 13-valent PCV (PCV7 and PCV13) impact on pneumococcal-meningitis vs. nm-IPD in Israeli children <5years.

METHODS

We conducted an ongoing nationwide, prospective, population-based, active surveillance. PCV7 and PCV13 were implemented in Israel in July 2009 and November 2010, respectively. All pneumococcal isolates (blood and/or CSF) from IPD episodes in children <5years from July 2000 through June 2015 were included. Extrapolation for missing serotypes (34.7% of all isolates) was conducted.

RESULTS

4163 IPD cases were identified; 3739nm-IPD (89.8%) and 424 meningitis (10.2%). During the pre-PCV period (2000-2008), children <12months constituted 52.1% and 33.7% of meningitis and nm-IPD, respectively (p<0.001). The respective proportions of non-PCV13 serotypes (non-VT) were 18.2% vs. 10.1%, (p<0.001). Comparing the last study year (2014-2015) to the mean of pre-PCV period, meningitis incidence in children <5years decreased non-significantly by 27%, while nm-IPD decreased significantly by 69%. Dynamic rates of meningitis and nm-IPD caused by PCV13 serotypes were similar, with 93% and 95% overall reductions, respectively. However, non-VT increased in meningitis relatively to nm-IPD, mainly in children <24months. Serotype 12F rose sharply and significantly since 2009-2010 through 2014-2015 (28.6% of all non-VT meningitis in children <24m).

CONCLUSIONS

The overall impact of PCV7/PCV13 in children <5years in Israel was less prominent in meningitis than in nm-IPD. This could be attributed to the younger age of children with meningitis and differences in causative serotypes between the two groups, as the decline of the incidence of meningitis and nm-IPD caused by vaccine-serotypes is similar. Continuous monitoring of meningitis and nm-IPD is warranted.

The impact of a national routine immunisation programme initiated in 1999 on Hepatitis A incidence in Israel, 1993 to 2012

Data on long-term impact of universal national vaccination programmes against hepatitis A are lacking. We aimed at evaluating the impact on hepatitis A incidence of the Israeli toddlers-only universal routine two-dose vaccination programme against hepatitis A initiated in 1999. All hepatitis A episodes reported to the national surveillance system from 1993 to 2012 were analysed in relation to the vaccination programme and coverage. Mean vaccine coverage in Israel between 2003 and 2010 was 92% for the first dose, given at 18 months of age, and 88% for the second dose, given at 24 months. The annual hepatitis A incidence declined from a mean of 50.4 per 100,000 in the period between 1993 and 1998 to a mean of?<1.0, during the period from 2008 to 2012, representing a reduction of?>98%. The decline was evident in all ages and ethnicity groups, including unvaccinated populations. Of the 1,247 cases reported nationwide between 2002 and 2012, the vaccination status could be ascertained in 1,108 (89%). Among them, only 20 (2%) were reported be vaccinated with one dose and three (<1%) received two doses. The sustained results of this long-term impact study suggest that a toddlers-only universal routine two-dose vaccination programme is highly effective and practical. These findings underscore the importance of sustainability in both the surveillance systems and vaccination programmes and will aid to determine vaccination policies.