Inclusion Criteria

Inclusion Criteria

- Histologically proven diagnosis of testicular seminoma

- Histologically confirmed seminomatous germ cell tumor of the testis categorized as
either "classical" or "anaplastic"

- Stage I disease

- Any pT N0 M0 S0-3 (Appendix B) [AJCC, 7th Ed.] (72)

- Stage IIA or IIB disease

- Any pT N1 M0 S0-3 (Appendix B) [AJCC, 7th Ed.] (72)

- Any pT N2 M0 S0-3 (Appendix B) [AJCC, 7th Ed.] (72) (at the discretion of the
principal investigators, bulky stage IIB may be excluded from the study, according to
National Comprehensive Cancer Center Guidelines.

- Pre-orchiectomy alpha-fetoprotein within normal limits

- Appropriate stage for protocol entry, as per protocol section 3.2.1,based upon the
following minimum diagnostic workup: History and physical examination, including a
complete list of current medications

- Chest x-ray (PA and lateral views)

- Abdominal/pelvic CT scan;

- Brain MRI if clinically indicated

- Bone scan if clinically indicated

- For stage I seminoma patients only, definitive surgical intervention within ten weeks
prior to registration

- Patients undergoing scrotal violations (scrotal orchiectomy, transscrotal biopsy,
testicular fine needle aspiration, scrotal exploration) will be eligible

- The patient is a candidate for definitive external beam radiotherapy

- The patient has had no prior radiotherapy to the region of study

- The patient has no inflammatory bowel disease, active collagen vascular or connective
tissue disorders, and no other medical or social contraindications to radiotherapy,
as determined by a participating radiation oncologist

- Patient age: 18 years

- Patient ECOG performance status: 0-1 (Appendix C)

- Patients requiring concurrent noninvestigational medications will be permitted

- Adequate renal function, defined as follows: Serum creatinine <1.4 mg/dl or
creatinine clearance ≥60 ml/min within one month prior to registration

- Informed consent: Patients must have the ability to understand and be willing to sign
the study-specific informed consent indicating their understanding of the
investigational nature and the risks of this study before any of the protocol related
studies are preformed (this does not include routine laboratory testing or imaging
studies required to establish study eligibility)

Exclusion Criteria

- Prior radiotherapy to the region of the study cancer

- Prior radiation therapy for a different cancer or disease process is allowed,
provided there will be no overlap of radiation therapy fields between the
participant's prior and current course of radiation therapy, radiotherapy was
completed more than four weeks from first fraction of proton therapy administered in
this study, and the participant has recovered to Grade ≤1 toxicity related to prior
radiotherapy

- Chemotherapy administered for the diagnosis of seminoma

- Prior chemotherapy for a different cancer is allowed, provided therapy was completed
more than twelve months from first fraction of proton therapy administered in this
study and the participant has recovered to Grade ≤1 toxicity related to agents
previously administered

- Incomplete definitive surgical orchiectomy, including diagnostic biopsy alone

- Pelvic lymph node dissection for the diagnosis of seminoma

- An investigational drug administered for the diagnosis of seminoma given concurrently
or within four weeks of the first fraction of proton therapy administration

- Prior or concurrent second invasive malignancy other than non-melanoma skin cancer,
unless disease free for a minimum of five years

- Known severe, active co-morbidity, defined as follows:Any clinically significant
unrelated systemic illness, medical condition, or other factor, which at the
discretion of the Principal Investigators, would interfere in the safe and timely
completion of study procedures, compromise the patient's ability to tolerate the
protocol therapy, or is likely to interfere with the study procedures or results

- Cognitively impaired patients who cannot provide informed consent