Lower disease control rates and survival outcomes among Blacks with pharyngeal squamous cell carcinomas compared with Whites: a retrospective analysis at the University of Florida.

Disparate clinical outcomes for pharyngeal squamous cell carcinoma (PSCC) of the oropharynx (OPSCC) and hypopharynx (HPSCC) have been observed in Black compared with White patients. Higher tobacco and alcohol use has been associated with decreased survival in Black patients with PSCC. Higher human papilloma virus (HPV) infection rates, associated with specific subsites of the oropharynx, are linked to improved overall survival (OS). Using an institutional cohort of Black and White patients with PSCC, we performed a retrospective analysis using multiple disease endpoints including local control (LC), local-regional control (LRC), freedom from distant metastases (DMFS), OS, cause-specific survival (CSS), and recorded tobacco and alcohol use. 1419 patients [Black (n = 111) and White (n = 1,308)] treated for PSCC from 1973 to 2013 were evaluated. PSCC 5- and 10-year LC, LRC, and DMFS and CSS rates were lower for Blacks. Notably, Black patients with OPSCC had higher stage cancers, higher percentage of soft palate tumors, and lower percentage of base of tongue cancers, were more likely to receive radiotherapy, and had higher tobacco and alcohol use. OS was significantly lower in Black patients at both anatomic sites, with the greatest difference observed for OPSCC. Multivariate analysis showed race and tobacco independently predicted DMFS, OS, and CSS; however, tobacco use had a greater impact on DMFS (HR 2.5, p = 0.021) than race (HR 1.9, p = 0.027). Overall, we propose that the higher burden of tobacco use along with a lower rate of tumors arising from traditional HPV-related subsites were important contributors to disparate disease outcomes seen in our Black patients.

Management of cutaneous Merkel cell carcinoma.

PURPOSE: To report the outcomes of patients with previously untreated cutaneous Merkel cell carcinoma (MCC) managed with curative intent. MATERIAL AND METHODS: Between December 1984 and August 2015, 59 patients with previously untreated cutaneous MCC were managed with curative intent with surgery and adjuvant radiotherapy (54 patients) or radiotherapy alone (5 patients) at the University of Florida. Primary sites included head and neck (45 patients), extremities (11 patients) and trunk (3 patients). Adjuvant chemotherapy was employed in 14 patients. Patients were staged according to the AJCC staging system: stage I, 25 patients; stage IIA, 7 patients; and, stage III, 27 patients. No patients had distant metastases. Median follow-up for all patients was 3.2 years (range, 0.3-20.9 years). Median follow-up for survivors was 6.7 years (range, 1.6-20.9 years). RESULTS: The 5-year outcomes were as follows: local control, 91%; regional control, 79%; local-regional control, 77%; disease metastasis-free survival, 60%; cause-specific survival, 53%; and overall survival, 39%. The 5-year outcomes for patients with stage I-IIA versus stage-III disease were the following: local-regional control, 90% versus 57% (p = .0115); distant metastasis-free survival, 78% versus 36% (p = .0002); cause-specific survival, 68% versus 35% (p = .0050); and overall survival, 48% versus 27% (p = .0377). Local-regional recurrences occurred in 12 patients; no patients were successfully salvaged. Severe late complications were observed in four patients. CONCLUSIONS: Although radiotherapy alone or combined with surgery results in a relatively high likelihood of local-regional control, the majority of recurrences are distant and approximately half of patients are cured. Patients with regional disease at diagnosis have significantly worse outcomes.

Primary radiotherapy for squamous cell carcinoma of the pyriform sinus.

The objective of this study is to report the long-term outcomes of primary radiotherapy (RT) for patients with T1-T2 squamous cell carcinomas (SCC) of the pyriform sinus. Between November 1964 and March 2008, 135 patients with T1-T2 pyriform sinus SCC were treated with primary RT at the University of Florida. Adjuvant chemotherapy was employed in 21 patients (16 %) and 62 patients (46 %) underwent a planned neck dissection. Median follow-up was 3.5 years (range 0.2-24.7 years); median follow-up on living patients was 8.3 years (range 3.8-24.0 years). The 5-year outcomes were as follows: local control, 85 %; regional control, 81 %; local-regional control, 71 %; distant metastasis-free survival, 76 %; cause-specific survival, 62 %; and overall survival, 38 %. The 5-year local control rate was 88 % for T1 cancers and 84 % for those with T2 SCCs (p = 0.5429). Sixteen patients (12 %) experienced severe late complications. Primary RT results in a high probability of cure with a relatively modest risk of severe late complications for patients with T1-T2 SCCs of the pyriform sinus.

Radiation therapy for nasal vestibule squamous cell carcinoma: a 40-year experience.

We evaluated the treatment of squamous cell carcinoma (SCC) of the nasal vestibule. Eighty-six patients were treated with radiotherapy (RT) and 13 patients received surgery and RT. The mean follow-up was: 9.7 years (range 4 months-35.9 years). The 5- and 10-year outcomes were: local control (LC), 88 and 82 %; local-regional control (LRC), 78 and 73 %; freedom from distant metastases (FFDM), 96 and 96 %; cause-specific survival (CSS), 91 and 86 %; and overall survival, 75 and 51 %. The 5- and 10-year LC rates for patients treated with RT were 94 and 89 % overall. A multivariate analysis was performed. Tumor size predicted LC, LRC, OS, and CSS. Overall stage predicted LRC. RT cures most patients with T1-T2 and favorable T4 SCCs with acceptable toxicity. RT and surgery result in improved likelihood of cure for patients with advanced T4 lesions.

Radiotherapy alone or combined with chemotherapy as definitive treatment for squamous cell carcinoma of the tonsil.

This study is aimed at updating our institution's experience with definitive radiotherapy (RT) for squamous cell carcinoma of the tonsil. We reviewed 531 patients treated between 1983 and 2012 with definitive RT for squamous cell carcinoma of the tonsil. Of these, 179 patients were treated with either induction (n = 19) or concomitant (n = 160) chemotherapy. Planned neck dissection was performed on 217 patients: unilaterally in 199 and bilaterally in 18 patients. Median follow-up was 5.2 years for all patients (range 0.1-31.6 years) and 8.2 years for living patients (range 1.9-31.6 years). The 5-year local control rates by T stage were as follows: T1, 94 %; T2, 87 %; T3 79 %; T4, 70 %; and overall, 83 %. Multivariate analysis revealed that local control was significantly influenced by T stage and neck dissection. The 5-year cause-specific survival rates by overall stage were as follows: I, 94 %; II, 88 %; III, 87 %; IVA, 75 %; IVB, 52 %; and overall, 78 %. Multivariate analysis revealed that cause-specific survival was significantly influenced by T stage, N stage, overall stage, fractionation, neck dissection, sex, and ethnicity. Of 77 patients treated with ipsilateral fields only, contralateral neck failure occurred in 1 %. The rate of severe complications was 12 %. Definitive RT for patients with tonsillar squamous cell carcinoma provides control rates equivalent to other modalities with a comparatively low incidence of late complications. Patients with anterior tonsillar pillar or tonsillar fossa primaries that are well lateralized with no base of tongue or soft palate extension may be treated with ipsilateral fields.

Radiotherapy for benign head and neck paragangliomas: a 45-year experience.

BACKGROUND: Paragangliomas of the head and neck are rare, slow-growing, generally benign tumors of neuroendocrine cells associated with the peripheral nervous system that commonly involve the carotid body, jugular bulb, vagal ganglia, and temporal bone. Treatment options include surgery, radiotherapy (RT), stereotactic radiosurgery (SRS), and observation. This article briefly reviews our 45-year institutional experience treating this neoplasm with RT. METHODS: From January 1968 through March 2011, 131 patients with 156 benign paragangliomas of the temporal bone, carotid body, jugular bulb, or glomus vagale were treated with RT at a median dose of 45 Gy in 25 fractions. The mean and median follow-up times were 11.5 years and 8.7 years, respectively. RESULTS: Five tumors (3.2%) recurred locally after RT, all within 10 years of treatment. The overall local control rates at 5 and 10 years were 99% and 96%, respectively. The cause-specific survival rates at 5 and 10 years were 98% and 97%, respectively. The distant-metastasis free survival rates at 5 and 10 years were 99% and 99%, respectively. The overall survival rates at 5 and 10 years were 91% and 72%, respectively. There were no severe complications. CONCLUSION: RT for benign head and neck paragangliomas is a safe and efficacious treatment associated with minimal morbidity. Surgery is reserved for patients in good health whose risk of associated morbidity is low. SRS may be suitable for patients with skull base tumors <3 cm where RT is logistically unsuitable. Observation is a reasonable option for asymptomatic patients with a limited life expectancy.

Radiotherapy for pleomorphic adenoma.

PURPOSE: The aim of this study was to update our experience in treating pleomorphic adenoma with radiotherapy (RT). MATERIALS AND METHODS: This is a retrospective analysis of 25 patients treated with RT alone (2 patients) or combined with surgery (23 patients), with follow-up ranging from 1.8 to 34.9 years (median, 10.5 years). RESULTS: Local control was achieved in 13 (75%) of 16 patients with subclinical disease and 5 (56%) of 9 patients with gross disease. Overall local control was achieved in 18 (72%) of 25 patients. The 5-, 10-, and 15-year overall local control rates were 76 %, 76%, and 68%, respectively. Ten patients died of the following causes: recurrent disease, 2; malignant transformation, 2; and intercurrent disease, 6. At last follow-up, 14 patients were alive without evidence of disease, and 1 patient was alive with disease. Dental carries and transient facial nerve deficits were the most common complications. No patients developed severe complications subsequent to RT. CONCLUSIONS: In patients at high risk for developing recurrent pleomorphic adenoma after surgery, RT is effective in controlling subclinical disease.

Surgery and adjuvant radiotherapy for cutaneous melanoma considered high-risk for local-regional recurrence.

PURPOSE: To assess the efficacy of postoperative radiotherapy (RT) in the treatment of cutaneous melanoma. MATERIALS: Between August 1981 and December 2009, 82 patients were treated with surgery and postoperative RT for cutaneous melanoma. Patients were thought to be high risk for local-regional recurrence after surgery alone because of the presence of one or more risk factors including recurrence after prior surgery, positive lymph nodes, extracapsular extension, incomplete regional node dissection, microscopically positive margins, gross residual disease, and in-transit metastases. The primary site was located in the head and neck in 64 patients and elsewhere in the remainder. Forty-two patients (47%) were treated with hypofractionated RT and the remainder with conventional fractionation. Median age was 62 years (range, 21 to >89 years). Median follow-up overall and for survivors was 3.0 years (range, 0.1 to 17.4 years) and 6.4 years (1.6 to 17.4 years), respectively. RESULTS: The 5-year outcomes were: in-field local-regional control 82%; local-regional control, 76%; distant metastasis-free survival, 48%; cause-specific survival, 56%; and overall survival, 43%. In-field local-regional control at 5 years was 87% after hypofractionated RT and 78% after conventionally fractionated RT. CONCLUSIONS: Postoperative adjuvant RT likely reduces the risk of local-regional recurrence after surgery for patients with high risk cutaneous melanoma. Hypofractionated RT is as effective as conventional fractionation and is logistically advantageous, particularly for patients with a relatively poor prognosis. The risk of RT complications is low.

Mohs resection and postoperative radiotherapy for head and neck cancers with incidental perineural invasion.

PURPOSE: To update our experience treating cutaneous squamous cell carcinoma (SCC) and basal cell carcinomas (BCC) of the head and neck with incidental perineural invasion (PNI) using Mohs resection followed by radiotherapy (RT). We compare outcomes between head and neck patients with incidental PNI who received Mohs surgery and those who did not. MATERIALS AND METHODS: From 1987 to 2009, 36 patients were treated with Mohs resection followed by postoperative RT; 82 patients were treated with resection other than Mohs followed by postoperative RT. RESULTS: The 5-year overall survival and cause-specific survival rates for patients who received Mohs resection plus RT and those who received a non-Mohs resection plus RT were 53% versus 56% (p=0.809) and 84% versus 68% (p=0.0329), respectively. The 5-year local control rates for Mohs and non-Mohs patients were 86% versus 76% (p=0.0606), respectively. The 5-year local-regional control and freedom from distant metastases rates for the Mohs group were 77% and 92%, respectively. The 5-year overall neck control, neck control with elective neck RT, and neck control without elective RT treatment rates for the Mohs group were 91%, 100%, and 82% (p=0.0763), respectively. The rate of grade 3 or higher complication in the Mohs group was 22%, which included bone exposure (N=3), cataract (N=2), chronic non-healing wound (N=2), wound infection (N=1), fistula (N=1), and/or radiation retinopathy (N=1). CONCLUSIONS: Mohs surgery appears to result in improved local control and cause-specific survival in patients with incidental PNI who receive postoperative RT. Elective nodal RT improves regional control in patients with SCC.

Elective neck management for high-grade salivary gland carcinoma.

PURPOSE: To determine whether patients with clinically node negative (cNo) high grade salivary gland carcinomas benefit from an elective neck dissection prior to postoperative radiotherapy (RT). MATERIAL/METHODS: Between October 1964 and October 2009, 59 previously untreated patients with cNo high-grade salivary gland carcinomas (squamous cell carcinomas were excluded) were treated with curative intent using elective neck dissection (END; n=41), or elective neck irradiation (ENI; n=18) at the University of Florida College of Medicine (Gainesville, FL). All patients underwent resection of the primary cancer followed by postoperative RT. The median follow-up period was 5.2years (range, 0.3-34years). RESULTS: Occult metastases were found in 18 (44%) of the 41 patients in the END group. There were 4 recurrences (10%) in the END group and 0 recurrence in the ENI group. Neck control rates at 5years were: END, 90%; ENI, 100%; and overall, 93% (p=0.1879). Cause-specific survival was 94% in the ENI group, 84% in the END group, and 86% for all patients (p=0.6998). There were 3 reported grade 3 or 4 toxicities. Two patients had a postoperative fistula and one patient had a grade 4 osteoradionecrosis that required a partial mandibulectomy. CONCLUSIONS: Patients with cNo high grade salivary gland carcinomas who are planned to undergo surgery and postoperative RT likely do not benefit from a planned neck dissection.

Proton Beam Radiation Therapy for Oropharyngeal Squamous Cell Carcinoma.

Purpose: To discuss the role of proton beam therapy (PBT) in the treatment of patients with oropharyngeal squamous cell carcinoma (OPSCC). Materials and Methods: A review of the pertinent literature. Results: Proton beam therapy likely results in reduced acute and late toxicity as compared with intensity-modulated radiation therapy (IMRT). The extent of the reduced toxicity, which may be modest, depends on the endpoint and technical factors such as pencil beam versus passive scattered PBT and adaptive replanning. The disease control rates after PBT are likely similar to those after IMRT. Conclusion: Proton beam therapy is an attractive option to treat patients with OPSCC. Whether it becomes widely available depends on access.

The significance of a marginal excision after preoperative radiation therapy for soft tissue sarcoma of the extremity.

BACKGROUND: Marginal excision of soft tissue sarcoma (STS), defined as resection through the tumor pseudocapsule or surrounding reactive tissue, increases the likelihood of local recurrence and necessitates re-excision or postoperative radiation. However, its impact after preoperative radiation therapy (RT) remains unclear. This study therefore investigated the significance of marginal margins in patients treated with preoperative RT for extremity STS, reporting long-term local control and limb preservation endpoints. METHODS: The records of 317 adults at the University of Florida with nonmetastatic extremity STS treated from 1980 to 2008 with preoperative RT as part of a limb conservation strategy were reviewed. The median follow-up was 4.7 years (8.3 years for living patients). The median tumor size was 10 cm (range, 2-36 cm), and 86% were high grade. The median RT dose was 50.4 Gy (range, 12.5-57.6 Gy). Margins were classified as wide/radical (n = 105), marginal (n = 179), contaminated (n = 15), positive (n = 17), or unknown (n = 1). Endpoints were local control (LC), amputation-free survival (AFS), cause-specific survival (CSS), and overall survival (OS). RESULTS: Five-year CSS and OS rates were 62% and 59%, respectively. Five-year LC and AFS was 93% and 89%, respectively. AFS by margin status was 64%, 83%, 97%, and 92% for positive, contaminated, marginal, and wide/radical margins, respectively (P<.005). Marginal excision following preoperative RT resulted in equivalent LC and AFS compared with wide/radical margins. CONCLUSIONS: Marginal resection after preoperative RT does not compromise LC or AFS in extremity STS. This finding may be related to radiosterilization of tumor cells within the reactive zone following preoperative RT.

Cutaneous Merkel cell carcinoma.

PURPOSE: The aim of this study was to describe the treatment outcomes of patients with cutaneous Merkel cell carcinoma managed with curative intent. MATERIALS AND METHODS: Between December 1984 and November 2009, 40 patients with previously untreated Merkel cell carcinoma were managed with curative intent with radiotherapy alone (3 patients) or combined with surgery (37 patients). Adjuvant chemotherapy was administered to 11 patients. Primary sites were the following: head and neck, 32 patients; extremities, 6 patients; and trunk, 2 patients. Patients were staged according to the Yiengpruksawan staging system: stage I, local disease; stage II, regional disease; and stage III, distant metastases. Twenty-four patients had stage I disease, and 16 patients had stage II disease. Median follow-up on all patients was 3.0 years (range, 0.6-15.6 years). Median follow-up on survivors was 4.2 years (range, 2.2-14.2 years). RESULTS: The 5-year outcomes were local control, 92%; regional control, 78%; local-regional control, 79%; distant metastasis-free survival, 57%; cause-specific survival, 45%; and overall survival, 36%. The 5-year outcomes for those with stage I vs stage II disease were the following: local-regional control, 87% and 67% (P = .1607); distant metastasis-free survival, 71% and 37% (P = .0073); cause-specific survival, 58% and 27% (P = .0090); and overall survival, 48% and 18% (P = .0037). Local-regional recurrences were observed in 6 patients; one patient was successfully salvaged. Severe complications were observed in 3 patients. CONCLUSIONS: Radiotherapy alone or combined with surgery results in a high local-regional control rate. The main mode of recurrence is distant. Approximately one half of patients are cured.

Adenoid cystic carcinoma of the head and neck.

PURPOSE: To report our experience using radiotherapy alone or combined with surgery to treat adenoid cystic carcinoma of the head and neck. MATERIALS AND METHODS: Radiotherapy alone or combined with surgery was used to treat 120 previously untreated patients with adenoid cystic carcinoma (ACC) of the head and neck from August 1966 to March 2008. Patients were treated with curative intent. American Joint Committee on Cancer stage distribution was,T0 (n = 1), T1 (n = 26), T2 (n = 25), T3 (n = 14), T4 (n = 54), N0 (n = 113), N1 (n = 2), N2a (n = 1), N2b (n = 2), and N2c (n = 2). Treatment included surgery with postoperative radiotherapy (n = 71), radiotherapy alone (n = 46), and preoperative radiotherapy and surgery (n = 3). Incidental and clinical perineural invasion was found in 41 (34%) and 35 (29%) patients, respectively. Median follow-up was 8.6 and 11.6 years overall and among living patients, respectively. RESULTS: The 10-year overall, cause-specific, and distant metastasis-free survival rates, respectively, were as follows: radiotherapy alone, 37%, 46%, and 76%; surgery and radiotherapy, 57%, 71%, and 62%; and overall, 50%. The 10-year local control rates were as follows: radiotherapy alone, 36%; surgery and radiotherapy, 84%; and overall, 65%. The 10-year neck control rates were as follows: elective nodal irradiation (ENI), 98%; no ENI, 89%; and overall, 95%. CONCLUSIONS: Surgery and adjuvant radiotherapy offer the best chance for cure for patients with resectable adenoid cystic carcinomas of the head and neck. Some patients with advanced, incompletely resectable disease can be cured with radiotherapy alone. ENI should be considered for primary sites located in lymphatic-rich regions.

Skin carcinoma of the head and neck with perineural invasion.

PURPOSE: The aim of the study was to update the experience treating cutaneous squamous cell and basal cell carcinomas of the head and neck with incidental or clinical perineural invasion (PNI) with radiotherapy (RT). MATERIALS AND METHODS: From 1965 to 2007, 216 patients received RT alone or with surgery and/or chemotherapy. RESULTS: The 5-year overall, cause-specific, and disease-free survivals for incidental and clinical PNIs were 55% vs 54%, 73% vs 64%, and 67% vs 51%. The 5-year local control, local-regional control, and freedom from distant metastases for incidental and clinical PNIs were 80% vs 54%, 70% vs 51%, and 90% vs 94%. On univariate and multivariate (P = .0038 and .0047) analyses, clinical PNI was a poor prognostic factor for local control. The rates of grade 3 or higher complication in the incidental and clinical PNI groups were 16% and 36%, respectively. CONCLUSIONS: Radiotherapy plays a critical role in the treatment of this disease. Clinical PNI should be adequately irradiated to include the involved nerves to the skull base.

Definitive radiotherapy for unresectable pediatric and young adult nonrhabdomyosarcoma soft tissue sarcoma.

BACKGROUND: Few published articles describe outcomes following definitive radiation for unresectable pediatric and young adult nonrhabdomyosarcoma soft tissue sarcoma (NRSTS). The purpose of this study is to evaluate the prognostic factors, outcomes, and complications in patients age 30 years or younger with NRSTS treated at the University of Florida from 1973 to 2002. PROCEDURE: Nineteen pediatric and young adult patients with NRSTS were treated with radiotherapy after biopsy. Thirteen patients had high-grade tumors. The median age at radiotherapy was 19.6 years; the median dose was 55.2 Gy. Twelve patients received chemotherapy. Prognostic factors for local recurrence, distant metastases, and survival were analyzed. RESULTS: Median follow-up was 2.6 years. The 5-year local-control rate was 40%. Nine out of 13 local failures occurred in the absence of metastatic disease. All patients with local failures died of their cancer, and 8 patients died without evidence of distant metastases. There was a trend toward improved local control with low/intermediate-grade tumors. Freedom from distant metastases at 5 years was 68%. Fourteen patients died of their disease. The 5-year overall survival was 37%. There was one grade 4 complication based on NCI Common Terminology Criteria for Adverse Events version 3. CONCLUSION: Young patients with unresectable NRSTS have a poor outcome thereby justifying current study efforts focused on treatment intensification. By demonstrating that all patients with local recurrence died of disease and more than half of these deaths occurred in the absence of distant spread, these results suggests that improved means of local control may translate into improvement in survival.

Head and neck squamous cell carcinoma from an unknown primary site.

BACKGROUND: The purpose of this study is to present our experience treating patients with squamous cell carcinoma (SCC) from an unknown head and neck primary site and to determine whether a policy change eliminating the larynx and hypopharynx from the radiotherapy (RT) portals has impacted outcome. METHODS: One hundred seventy-nine patients received definitive RT with or without a neck dissection for SCC from an unknown head and neck primary site. RT was delivered to the ipsilateral neck alone or both sides of the neck and, usually, the potential mucosal primary sites. The median mucosal dose was 5670 cGy. The median neck dose was 6500 cGy. One hundred nine patients (61%) received a planned neck dissection. RESULTS: Mucosal control at 5 years was 92%. The mucosal control rate in patients with RT limited to the nasopharynx and oropharynx was 100%. The 5-year neck-control rates were as follows: N(1), 94%; N(2a), 98%; N(2b), 86%; N(2c), 86%; N(3), 57%; and overall, 81%. The 5-year cause-specific survival rates were as follows: N(1), 94%; N(2a), 88%; N(2b), 82%; N(2c), 71%; N(3), 48%; and overall, 73%. The 5-year overall survival rates were as follows: N(1), 50%; N(2a), 70%; N(2b), 59%; N(2c), 45%; N(3), 34%; and overall, 52%. Eleven patients (7%) developed severe complications. CONCLUSION: RT alone or combined with neck dissection results in a high probability of cure with a low risk of severe complications. Eliminating the larynx and hypopharynx from the RT portals did not compromise outcome and likely reduces treatment toxicity.

Carbon Ion Radiotherapy in the Management of Hepatocellular Carcinoma.

Localized hepatocellular carcinoma (HCC) that is unresectable and non-transplantable can be treated by several liver-directed therapies. External beam radiation therapy (EBRT) is an increasingly accepted and widely utilized treatment modality in this setting. Accelerated charged particles such as proton beam therapy (PBT) and carbon ion radiation therapy (CIRT) offer technological advancements over conventional photon radiotherapy. In this review, we summarize the distinct advantages of CIRT use for HCC treatment, focusing on physical and biological attributes, and outline dosimetric and treatment planning caveats. Based on these considerations, we posit that HCC may be among the best indications for use of CIRT, as it allows for maximizing tumoricidal doses to the target volume while minimizing the dose to the organs at risk.

Primary Mediastinal B Cell Lymphoma in the Positron-Emission Tomography Era Executive Summary of the American Radium Society Appropriate Use Criteria.

PURPOSE: Primary mediastinal B cell lymphoma (PMBCL) is a highly curable subtype of non-Hodgkin lymphoma that is diagnosed predominantly in adolescents and young adults. Consequently, long-term treatment-related morbidity is critical to consider when devising treatment strategies that include different chemoimmunotherapy strategies with or without radiation therapy. Furthermore, adaptive approaches using the end-of-chemotherapy (EOC) positron emission tomography (PET)/computed tomography (CT) scanning may help to determine which patients may benefit from additional therapies. We aimed to develop evidence-based guidelines for treating these patients. METHODS AND MATERIALS: We conducted a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline using the PubMed database. The ARS expert committee, composed of radiation oncologists, hematologists, and pediatric oncologists, developed consensus guidelines using the modified Delphi framework. RESULTS: Nine studies met the full criteria for inclusion based on reporting outcomes on patients with primary mediastinal B cell lymphoma with EOC PET/CT response scored with the 5-point Deauville scale. These studies formed the evidence for these guidelines in managing patients with PMBCL according to the EOC PET response, including after a 5-point Deauville scale of 1 to 3, 4, or 5, and for patients with relapsed and refractory disease. The expert group also developed guidance on radiation simulation, treatment planning, and plan evaluation based on expert opinion. CONCLUSIONS: Various treatment approaches exist in the management of PMBCL, including different chemoimmunotherapy regimens, the use of consolidative radiation therapy, and adaptive approaches based on EOC PET/CT response. These guidelines can be used by practitioners to provide appropriate treatment according to different disease scenarios.